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linux-stable/arch/powerpc/kernel/head_32.h

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powerpc/32: Refactor EXCEPTION entry macros for head_8xx.S and head_32.S EXCEPTION_PROLOG is similar in head_8xx.S and head_32.S This patch creates head_32.h and moves EXCEPTION_PROLOG macro into it. It also converts it from a GCC macro to a GAS macro in order to ease refactorisation with 40x later, since GAS macros allows the use of #ifdef/#else/#endif inside it. And it also has the advantage of not requiring the uggly "; \" at the end of each line. This patch also moves EXCEPTION() and EXC_XFER_XXXX() macros which are also similar while adding START_EXCEPTION() out of EXCEPTION(). Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-30 12:38:50 +00:00
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __HEAD_32_H__
#define __HEAD_32_H__
#include <asm/ptrace.h> /* for STACK_FRAME_REGS_MARKER */
/*
* Exception entry code. This code runs with address translation
* turned off, i.e. using physical addresses.
* We assume sprg3 has the physical address of the current
* task's thread_struct.
*/
powerpc/32: Save trap number on stack in exception prolog Saving the trap number into the stack goes into the exception prolog, as EXC_XFER_xxx will soon disappear. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/2ac7a0c9cde2ec2b23cd79e3a54cfedd816a91ae.1615552867.git.christophe.leroy@csgroup.eu
2021-03-12 12:50:38 +00:00
.macro EXCEPTION_PROLOG trapno name handle_dar_dsisr=0
powerpc/32: prepare for CONFIG_VMAP_STACK To support CONFIG_VMAP_STACK, the kernel has to activate Data MMU Translation for accessing the stack. Before doing that it must save SRR0, SRR1 and also DAR and DSISR when relevant, in order to not loose them in case there is a Data TLB Miss once the translation is reactivated. This patch adds fields in thread struct for saving those registers. It prepares entry_32.S to handle exception entry with Data MMU Translation enabled and alters EXCEPTION_PROLOG macros to save SRR0, SRR1, DAR and DSISR then reenables Data MMU. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/a775a1fea60f190e0f63503463fb775310a2009b.1576916812.git.christophe.leroy@c-s.fr
2019-12-21 08:32:27 +00:00
EXCEPTION_PROLOG_0 handle_dar_dsisr=\handle_dar_dsisr
powerpc/32: Add EXCEPTION_PROLOG_0 in head_32.h This patch creates a macro for the very first part of exception prolog, this will help when implementing CONFIG_VMAP_STACK Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/2249fe62f481121a180e9655ad2b998093f318f3.1576916812.git.christophe.leroy@c-s.fr
2019-12-21 08:32:23 +00:00
EXCEPTION_PROLOG_1
powerpc/32: Save trap number on stack in exception prolog Saving the trap number into the stack goes into the exception prolog, as EXC_XFER_xxx will soon disappear. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/2ac7a0c9cde2ec2b23cd79e3a54cfedd816a91ae.1615552867.git.christophe.leroy@csgroup.eu
2021-03-12 12:50:38 +00:00
EXCEPTION_PROLOG_2 \trapno \name handle_dar_dsisr=\handle_dar_dsisr
powerpc/32: Add EXCEPTION_PROLOG_0 in head_32.h This patch creates a macro for the very first part of exception prolog, this will help when implementing CONFIG_VMAP_STACK Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/2249fe62f481121a180e9655ad2b998093f318f3.1576916812.git.christophe.leroy@c-s.fr
2019-12-21 08:32:23 +00:00
.endm
powerpc/32: prepare for CONFIG_VMAP_STACK To support CONFIG_VMAP_STACK, the kernel has to activate Data MMU Translation for accessing the stack. Before doing that it must save SRR0, SRR1 and also DAR and DSISR when relevant, in order to not loose them in case there is a Data TLB Miss once the translation is reactivated. This patch adds fields in thread struct for saving those registers. It prepares entry_32.S to handle exception entry with Data MMU Translation enabled and alters EXCEPTION_PROLOG macros to save SRR0, SRR1, DAR and DSISR then reenables Data MMU. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/a775a1fea60f190e0f63503463fb775310a2009b.1576916812.git.christophe.leroy@c-s.fr
2019-12-21 08:32:27 +00:00
.macro EXCEPTION_PROLOG_0 handle_dar_dsisr=0
powerpc/32: Refactor EXCEPTION entry macros for head_8xx.S and head_32.S EXCEPTION_PROLOG is similar in head_8xx.S and head_32.S This patch creates head_32.h and moves EXCEPTION_PROLOG macro into it. It also converts it from a GCC macro to a GAS macro in order to ease refactorisation with 40x later, since GAS macros allows the use of #ifdef/#else/#endif inside it. And it also has the advantage of not requiring the uggly "; \" at the end of each line. This patch also moves EXCEPTION() and EXC_XFER_XXXX() macros which are also similar while adding START_EXCEPTION() out of EXCEPTION(). Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-30 12:38:50 +00:00
mtspr SPRN_SPRG_SCRATCH0,r10
mtspr SPRN_SPRG_SCRATCH1,r11
powerpc/32: prepare for CONFIG_VMAP_STACK To support CONFIG_VMAP_STACK, the kernel has to activate Data MMU Translation for accessing the stack. Before doing that it must save SRR0, SRR1 and also DAR and DSISR when relevant, in order to not loose them in case there is a Data TLB Miss once the translation is reactivated. This patch adds fields in thread struct for saving those registers. It prepares entry_32.S to handle exception entry with Data MMU Translation enabled and alters EXCEPTION_PROLOG macros to save SRR0, SRR1, DAR and DSISR then reenables Data MMU. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/a775a1fea60f190e0f63503463fb775310a2009b.1576916812.git.christophe.leroy@c-s.fr
2019-12-21 08:32:27 +00:00
mfspr r10, SPRN_SPRG_THREAD
.if \handle_dar_dsisr
powerpc/40x: Prepare normal exception handler for enabling MMU early Ensure normal exception handler are able to manage stuff with MMU enabled. For that we use CONFIG_VMAP_STACK related code allthough there is no intention to really activate CONFIG_VMAP_STACK on powerpc 40x for the moment. 40x uses SPRN_DEAR instead of SPRN_DAR and SPRN_ESR instead of SPRN_DSISR. Take it into account in common macros. 40x MSR value doesn't fit on 15 bits, use LOAD_REG_IMMEDIATE() in common macros that will be used also with 40x. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/01963af2b83037bca270d7bf1336ffcf35da8282.1615552866.git.christophe.leroy@csgroup.eu
2021-03-12 12:50:16 +00:00
#ifdef CONFIG_40x
mfspr r11, SPRN_DEAR
#else
powerpc/32: prepare for CONFIG_VMAP_STACK To support CONFIG_VMAP_STACK, the kernel has to activate Data MMU Translation for accessing the stack. Before doing that it must save SRR0, SRR1 and also DAR and DSISR when relevant, in order to not loose them in case there is a Data TLB Miss once the translation is reactivated. This patch adds fields in thread struct for saving those registers. It prepares entry_32.S to handle exception entry with Data MMU Translation enabled and alters EXCEPTION_PROLOG macros to save SRR0, SRR1, DAR and DSISR then reenables Data MMU. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/a775a1fea60f190e0f63503463fb775310a2009b.1576916812.git.christophe.leroy@c-s.fr
2019-12-21 08:32:27 +00:00
mfspr r11, SPRN_DAR
powerpc/40x: Prepare normal exception handler for enabling MMU early Ensure normal exception handler are able to manage stuff with MMU enabled. For that we use CONFIG_VMAP_STACK related code allthough there is no intention to really activate CONFIG_VMAP_STACK on powerpc 40x for the moment. 40x uses SPRN_DEAR instead of SPRN_DAR and SPRN_ESR instead of SPRN_DSISR. Take it into account in common macros. 40x MSR value doesn't fit on 15 bits, use LOAD_REG_IMMEDIATE() in common macros that will be used also with 40x. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/01963af2b83037bca270d7bf1336ffcf35da8282.1615552866.git.christophe.leroy@csgroup.eu
2021-03-12 12:50:16 +00:00
#endif
powerpc/32: prepare for CONFIG_VMAP_STACK To support CONFIG_VMAP_STACK, the kernel has to activate Data MMU Translation for accessing the stack. Before doing that it must save SRR0, SRR1 and also DAR and DSISR when relevant, in order to not loose them in case there is a Data TLB Miss once the translation is reactivated. This patch adds fields in thread struct for saving those registers. It prepares entry_32.S to handle exception entry with Data MMU Translation enabled and alters EXCEPTION_PROLOG macros to save SRR0, SRR1, DAR and DSISR then reenables Data MMU. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/a775a1fea60f190e0f63503463fb775310a2009b.1576916812.git.christophe.leroy@c-s.fr
2019-12-21 08:32:27 +00:00
stw r11, DAR(r10)
powerpc/40x: Prepare normal exception handler for enabling MMU early Ensure normal exception handler are able to manage stuff with MMU enabled. For that we use CONFIG_VMAP_STACK related code allthough there is no intention to really activate CONFIG_VMAP_STACK on powerpc 40x for the moment. 40x uses SPRN_DEAR instead of SPRN_DAR and SPRN_ESR instead of SPRN_DSISR. Take it into account in common macros. 40x MSR value doesn't fit on 15 bits, use LOAD_REG_IMMEDIATE() in common macros that will be used also with 40x. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/01963af2b83037bca270d7bf1336ffcf35da8282.1615552866.git.christophe.leroy@csgroup.eu
2021-03-12 12:50:16 +00:00
#ifdef CONFIG_40x
mfspr r11, SPRN_ESR
#else
powerpc/32: prepare for CONFIG_VMAP_STACK To support CONFIG_VMAP_STACK, the kernel has to activate Data MMU Translation for accessing the stack. Before doing that it must save SRR0, SRR1 and also DAR and DSISR when relevant, in order to not loose them in case there is a Data TLB Miss once the translation is reactivated. This patch adds fields in thread struct for saving those registers. It prepares entry_32.S to handle exception entry with Data MMU Translation enabled and alters EXCEPTION_PROLOG macros to save SRR0, SRR1, DAR and DSISR then reenables Data MMU. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/a775a1fea60f190e0f63503463fb775310a2009b.1576916812.git.christophe.leroy@c-s.fr
2019-12-21 08:32:27 +00:00
mfspr r11, SPRN_DSISR
powerpc/40x: Prepare normal exception handler for enabling MMU early Ensure normal exception handler are able to manage stuff with MMU enabled. For that we use CONFIG_VMAP_STACK related code allthough there is no intention to really activate CONFIG_VMAP_STACK on powerpc 40x for the moment. 40x uses SPRN_DEAR instead of SPRN_DAR and SPRN_ESR instead of SPRN_DSISR. Take it into account in common macros. 40x MSR value doesn't fit on 15 bits, use LOAD_REG_IMMEDIATE() in common macros that will be used also with 40x. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/01963af2b83037bca270d7bf1336ffcf35da8282.1615552866.git.christophe.leroy@csgroup.eu
2021-03-12 12:50:16 +00:00
#endif
powerpc/32: prepare for CONFIG_VMAP_STACK To support CONFIG_VMAP_STACK, the kernel has to activate Data MMU Translation for accessing the stack. Before doing that it must save SRR0, SRR1 and also DAR and DSISR when relevant, in order to not loose them in case there is a Data TLB Miss once the translation is reactivated. This patch adds fields in thread struct for saving those registers. It prepares entry_32.S to handle exception entry with Data MMU Translation enabled and alters EXCEPTION_PROLOG macros to save SRR0, SRR1, DAR and DSISR then reenables Data MMU. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/a775a1fea60f190e0f63503463fb775310a2009b.1576916812.git.christophe.leroy@c-s.fr
2019-12-21 08:32:27 +00:00
stw r11, DSISR(r10)
.endif
mfspr r11, SPRN_SRR0
stw r11, SRR0(r10)
powerpc/32: move MSR_PR test into EXCEPTION_PROLOG_0 In order to simplify VMAP stack implementation, move MSR_PR test into EXCEPTION_PROLOG_0. This requires to not modify cr0 between EXCEPTION_PROLOG_0 and EXCEPTION_PROLOG_1. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/5c8b5bba692b92654dbd363a229a1ba91db725bb.1576916812.git.christophe.leroy@c-s.fr
2019-12-21 08:32:25 +00:00
mfspr r11, SPRN_SRR1 /* check whether user or kernel */
powerpc/32: prepare for CONFIG_VMAP_STACK To support CONFIG_VMAP_STACK, the kernel has to activate Data MMU Translation for accessing the stack. Before doing that it must save SRR0, SRR1 and also DAR and DSISR when relevant, in order to not loose them in case there is a Data TLB Miss once the translation is reactivated. This patch adds fields in thread struct for saving those registers. It prepares entry_32.S to handle exception entry with Data MMU Translation enabled and alters EXCEPTION_PROLOG macros to save SRR0, SRR1, DAR and DSISR then reenables Data MMU. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/a775a1fea60f190e0f63503463fb775310a2009b.1576916812.git.christophe.leroy@c-s.fr
2019-12-21 08:32:27 +00:00
stw r11, SRR1(r10)
powerpc/32: Refactor EXCEPTION entry macros for head_8xx.S and head_32.S EXCEPTION_PROLOG is similar in head_8xx.S and head_32.S This patch creates head_32.h and moves EXCEPTION_PROLOG macro into it. It also converts it from a GCC macro to a GAS macro in order to ease refactorisation with 40x later, since GAS macros allows the use of #ifdef/#else/#endif inside it. And it also has the advantage of not requiring the uggly "; \" at the end of each line. This patch also moves EXCEPTION() and EXC_XFER_XXXX() macros which are also similar while adding START_EXCEPTION() out of EXCEPTION(). Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-30 12:38:50 +00:00
mfcr r10
powerpc/32: move MSR_PR test into EXCEPTION_PROLOG_0 In order to simplify VMAP stack implementation, move MSR_PR test into EXCEPTION_PROLOG_0. This requires to not modify cr0 between EXCEPTION_PROLOG_0 and EXCEPTION_PROLOG_1. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/5c8b5bba692b92654dbd363a229a1ba91db725bb.1576916812.git.christophe.leroy@c-s.fr
2019-12-21 08:32:25 +00:00
andi. r11, r11, MSR_PR
powerpc/32: Refactor EXCEPTION entry macros for head_8xx.S and head_32.S EXCEPTION_PROLOG is similar in head_8xx.S and head_32.S This patch creates head_32.h and moves EXCEPTION_PROLOG macro into it. It also converts it from a GCC macro to a GAS macro in order to ease refactorisation with 40x later, since GAS macros allows the use of #ifdef/#else/#endif inside it. And it also has the advantage of not requiring the uggly "; \" at the end of each line. This patch also moves EXCEPTION() and EXC_XFER_XXXX() macros which are also similar while adding START_EXCEPTION() out of EXCEPTION(). Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-30 12:38:50 +00:00
.endm
powerpc/32: Always enable data translation in exception prolog If the code can use a stack in vm area, it can also use a stack in linear space. Simplify code by removing old non VMAP stack code on PPC32. That means the data translation is now re-enabled early in exception prolog in all cases, not only when using VMAP stacks. While we are touching EXCEPTION_PROLOG macros, remove the unused for_rtas parameter in EXCEPTION_PROLOG_1. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/7cd6440c60a7e8f4f035b245c57720f51e225aae.1615552866.git.christophe.leroy@csgroup.eu
2021-03-12 12:50:22 +00:00
.macro EXCEPTION_PROLOG_1
powerpc/32: Use SPRN_SPRG_SCRATCH2 in exception prologs Use SPRN_SPRG_SCRATCH2 as a third scratch register in exception prologs in order to simplify them and avoid data going back and forth from/to CR. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/6f5c8a7faa8cc54acb89c55c20aa579a2f30a4e9.1606285014.git.christophe.leroy@csgroup.eu
2020-11-25 07:10:53 +00:00
mtspr SPRN_SPRG_SCRATCH2,r1
powerpc/32: Fix vmap stack - Properly set r1 before activating MMU We need r1 to be properly set before activating MMU, otherwise any new exception taken while saving registers into the stack in exception prologs will use the user stack, which is wrong and will even lockup or crash when KUAP is selected. Do that by switching the meaning of r11 and r1 until we have saved r1 to the stack: copy r1 into r11 and setup the new stack pointer in r1. To avoid complicating and impacting all generic and specific prolog code (and more), copy back r1 into r11 once r11 is save onto the stack. We could get rid of copying r1 back and forth at the cost of rewriting everything to use r1 instead of r11 all the way when CONFIG_VMAP_STACK is set, but the effort is probably not worth it. Fixes: 028474876f47 ("powerpc/32: prepare for CONFIG_VMAP_STACK") Cc: stable@vger.kernel.org Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/8f85e8752ac5af602db7237ef53d634f4f3d3892.1599486108.git.christophe.leroy@csgroup.eu
2020-09-07 13:42:10 +00:00
subi r1, r1, INT_FRAME_SIZE /* use r1 if kernel */
beq 1f
mfspr r1,SPRN_SPRG_THREAD
lwz r1,TASK_STACK-THREAD(r1)
addi r1, r1, THREAD_SIZE - INT_FRAME_SIZE
powerpc/32: Simplify EXCEPTION_PROLOG_1 macro Make code more readable with a clear CONFIG_VMAP_STACK section and a clear non CONFIG_VMAP_STACK section. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/c0f16cf432d22fc80097264d94649460d3dd761d.1606285014.git.christophe.leroy@csgroup.eu
2020-11-25 07:10:51 +00:00
1:
powerpc/32: Always enable data translation in exception prolog If the code can use a stack in vm area, it can also use a stack in linear space. Simplify code by removing old non VMAP stack code on PPC32. That means the data translation is now re-enabled early in exception prolog in all cases, not only when using VMAP stacks. While we are touching EXCEPTION_PROLOG macros, remove the unused for_rtas parameter in EXCEPTION_PROLOG_1. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/7cd6440c60a7e8f4f035b245c57720f51e225aae.1615552866.git.christophe.leroy@csgroup.eu
2021-03-12 12:50:22 +00:00
#ifdef CONFIG_VMAP_STACK
powerpc/32: Preserve cr1 in exception prolog stack check to fix build error THREAD_ALIGN_SHIFT = THREAD_SHIFT + 1 = PAGE_SHIFT + 1 Maximum PAGE_SHIFT is 18 for 256k pages so THREAD_ALIGN_SHIFT is 19 at the maximum. No need to clobber cr1, it can be preserved when moving r1 into CR when we check stack overflow. This reduces the number of instructions in Machine Check Exception prolog and fixes a build failure reported by the kernel test robot on v5.10 stable when building with RTAS + VMAP_STACK + KVM. That build failure is due to too many instructions in the prolog hence not fitting between 0x200 and 0x300. Allthough the problem doesn't show up in mainline, it is still worth the change. Fixes: 98bf2d3f4970 ("powerpc/32s: Fix RTAS machine check with VMAP stack") Cc: stable@vger.kernel.org Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/5ae4d545e3ac58e133d2599e0deb88843cb494fc.1612768623.git.christophe.leroy@csgroup.eu
2021-02-08 07:17:40 +00:00
mtcrf 0x3f, r1
powerpc/32: Add vmap_stack_overflow label inside the macro For consistency, add in the macro the label used by exception prolog to branch to stack overflow processing. While at it, enclose the macro in #ifdef CONFIG_VMAP_STACK on the 8xx as already done on book3s/32. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/cf80056f5b946572ad98aea9d915dd25b23beda6.1615552867.git.christophe.leroy@csgroup.eu
2021-03-12 12:50:27 +00:00
bt 32 - THREAD_ALIGN_SHIFT, vmap_stack_overflow
powerpc/32: Add early stack overflow detection with VMAP stack. To avoid recursive faults, stack overflow detection has to be performed before writing in the stack in exception prologs. Do it by checking the alignment. If the stack pointer alignment is wrong, it means it is pointing to the following or preceding page. Without VMAP stack, a stack overflow is catastrophic. With VMAP stack, a stack overflow isn't destructive, so don't panic. Kill the task with SIGSEGV instead. A dedicated overflow stack is set up for each CPU. lkdtm: Performing direct entry EXHAUST_STACK lkdtm: Calling function with 512 frame size to depth 32 ... lkdtm: loop 32/32 ... lkdtm: loop 31/32 ... lkdtm: loop 30/32 ... lkdtm: loop 29/32 ... lkdtm: loop 28/32 ... lkdtm: loop 27/32 ... lkdtm: loop 26/32 ... lkdtm: loop 25/32 ... lkdtm: loop 24/32 ... lkdtm: loop 23/32 ... lkdtm: loop 22/32 ... lkdtm: loop 21/32 ... lkdtm: loop 20/32 ... Kernel stack overflow in process test[359], r1=c900c008 Oops: Kernel stack overflow, sig: 6 [#1] BE PAGE_SIZE=4K MMU=Hash PowerMac Modules linked in: CPU: 0 PID: 359 Comm: test Not tainted 5.3.0-rc7+ #2225 NIP: c0622060 LR: c0626710 CTR: 00000000 REGS: c0895f48 TRAP: 0000 Not tainted (5.3.0-rc7+) MSR: 00001032 <ME,IR,DR,RI> CR: 28004224 XER: 00000000 GPR00: c0626ca4 c900c008 c783c000 c07335cc c900c010 c07335cc c900c0f0 c07335cc GPR08: c900c0f0 00000001 00000000 00000000 28008222 00000000 00000000 00000000 GPR16: 00000000 00000000 10010128 10010000 b799c245 10010158 c07335cc 00000025 GPR24: c0690000 c08b91d4 c068f688 00000020 c900c0f0 c068f668 c08b95b4 c08b91d4 NIP [c0622060] format_decode+0x0/0x4d4 LR [c0626710] vsnprintf+0x80/0x5fc Call Trace: [c900c068] [c0626ca4] vscnprintf+0x18/0x48 [c900c078] [c007b944] vprintk_store+0x40/0x214 [c900c0b8] [c007bf50] vprintk_emit+0x90/0x1dc [c900c0e8] [c007c5cc] printk+0x50/0x60 [c900c128] [c03da5b0] recursive_loop+0x44/0x6c [c900c338] [c03da5c4] recursive_loop+0x58/0x6c [c900c548] [c03da5c4] recursive_loop+0x58/0x6c [c900c758] [c03da5c4] recursive_loop+0x58/0x6c [c900c968] [c03da5c4] recursive_loop+0x58/0x6c [c900cb78] [c03da5c4] recursive_loop+0x58/0x6c [c900cd88] [c03da5c4] recursive_loop+0x58/0x6c [c900cf98] [c03da5c4] recursive_loop+0x58/0x6c [c900d1a8] [c03da5c4] recursive_loop+0x58/0x6c [c900d3b8] [c03da5c4] recursive_loop+0x58/0x6c [c900d5c8] [c03da5c4] recursive_loop+0x58/0x6c [c900d7d8] [c03da5c4] recursive_loop+0x58/0x6c [c900d9e8] [c03da5c4] recursive_loop+0x58/0x6c [c900dbf8] [c03da5c4] recursive_loop+0x58/0x6c [c900de08] [c03da67c] lkdtm_EXHAUST_STACK+0x30/0x4c [c900de18] [c03da3e8] direct_entry+0xc8/0x140 [c900de48] [c029fb40] full_proxy_write+0x64/0xcc [c900de68] [c01500f8] __vfs_write+0x30/0x1d0 [c900dee8] [c0152cb8] vfs_write+0xb8/0x1d4 [c900df08] [c0152f7c] ksys_write+0x58/0xe8 [c900df38] [c0014208] ret_from_syscall+0x0/0x34 --- interrupt: c01 at 0xf806664 LR = 0x1000c868 Instruction dump: 4bffff91 80010014 7c832378 7c0803a6 38210010 4e800020 3d20c08a 3ca0c089 8089a0cc 38a58f0c 38600001 4ba2d494 <9421ffe0> 7c0802a6 bfc10018 7c9f2378 Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1b89c121b4070c7ee99e4f22cc178f15a736b07b.1576916812.git.christophe.leroy@c-s.fr
2019-12-21 08:32:29 +00:00
#endif
powerpc/32: Refactor EXCEPTION entry macros for head_8xx.S and head_32.S EXCEPTION_PROLOG is similar in head_8xx.S and head_32.S This patch creates head_32.h and moves EXCEPTION_PROLOG macro into it. It also converts it from a GCC macro to a GAS macro in order to ease refactorisation with 40x later, since GAS macros allows the use of #ifdef/#else/#endif inside it. And it also has the advantage of not requiring the uggly "; \" at the end of each line. This patch also moves EXCEPTION() and EXC_XFER_XXXX() macros which are also similar while adding START_EXCEPTION() out of EXCEPTION(). Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-30 12:38:50 +00:00
.endm
powerpc/32: Save trap number on stack in exception prolog Saving the trap number into the stack goes into the exception prolog, as EXC_XFER_xxx will soon disappear. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/2ac7a0c9cde2ec2b23cd79e3a54cfedd816a91ae.1615552867.git.christophe.leroy@csgroup.eu
2021-03-12 12:50:38 +00:00
.macro EXCEPTION_PROLOG_2 trapno name handle_dar_dsisr=0
powerpc/32: Tag DAR in EXCEPTION_PROLOG_2 for the 8xx 8xx requires to tag the DAR with a magic value in order to fixup DAR on faults generated by 'dcbX', as the 8xx forgets to update the DAR for those faults. Do the tagging as early as possible, that is before enabling MMU. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/853a2e28ca7c5fc85617037030f99fe6070c9536.1615552867.git.christophe.leroy@csgroup.eu
2021-03-12 12:50:23 +00:00
#ifdef CONFIG_PPC_8xx
.if \handle_dar_dsisr
li r11, RPN_PATTERN
mtspr SPRN_DAR, r11 /* Tag DAR, to be used in DTLB Error */
.endif
#endif
powerpc/32: Enable instruction translation at the same time as data translation On 40x and 8xx, kernel text is pinned. On book3s/32, kernel text is mapped by BATs. Enable instruction translation at the same time as data translation, it makes things simpler. In syscall handler, MSR_RI can also be set at the same time because srr0/srr1 are already saved and r1 is set properly. On booke, translation is always on, so at the end all PPC32 have translation on early. Just update msr. Also update comment in power_save_ppc32_restore(). Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/5269c7e5f5d2117358af3a89744d75a116be27b0.1615552867.git.christophe.leroy@csgroup.eu
2021-03-12 12:50:24 +00:00
LOAD_REG_IMMEDIATE(r11, MSR_KERNEL & ~MSR_RI) /* re-enable MMU */
mtspr SPRN_SRR1, r11
lis r11, 1f@h
ori r11, r11, 1f@l
mtspr SPRN_SRR0, r11
powerpc/32: Use SPRN_SPRG_SCRATCH2 in exception prologs Use SPRN_SPRG_SCRATCH2 as a third scratch register in exception prologs in order to simplify them and avoid data going back and forth from/to CR. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/6f5c8a7faa8cc54acb89c55c20aa579a2f30a4e9.1606285014.git.christophe.leroy@csgroup.eu
2020-11-25 07:10:53 +00:00
mfspr r11, SPRN_SPRG_SCRATCH2
powerpc/32: Enable instruction translation at the same time as data translation On 40x and 8xx, kernel text is pinned. On book3s/32, kernel text is mapped by BATs. Enable instruction translation at the same time as data translation, it makes things simpler. In syscall handler, MSR_RI can also be set at the same time because srr0/srr1 are already saved and r1 is set properly. On booke, translation is always on, so at the end all PPC32 have translation on early. Just update msr. Also update comment in power_save_ppc32_restore(). Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/5269c7e5f5d2117358af3a89744d75a116be27b0.1615552867.git.christophe.leroy@csgroup.eu
2021-03-12 12:50:24 +00:00
rfi
powerpc/32: Move exception prolog code into .text once MMU is back on The space in the head section is rather constrained by the fact that exception vectors are spread every 0x100 bytes and sometimes we need to have "out of line" code because it doesn't fit. Now that we are enabling MMU early in the prolog, take that opportunity to jump somewhere else in the .text section where we don't have any space constraint. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/38b31ca4bc782a4985bc7952a675404d7ff27c24.1615552867.git.christophe.leroy@csgroup.eu
2021-03-12 12:50:29 +00:00
.text
powerpc/32: Provide a name to exception prolog continuation in virtual mode Now that the prolog continuation is separated in .text, give it a name and mark it _ASM_NOKPROBE_SYMBOL. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/d96374218815a6627e1e922ab2aba994050fb87a.1615552867.git.christophe.leroy@csgroup.eu
2021-03-12 12:50:30 +00:00
\name\()_virt:
powerpc/32: Enable instruction translation at the same time as data translation On 40x and 8xx, kernel text is pinned. On book3s/32, kernel text is mapped by BATs. Enable instruction translation at the same time as data translation, it makes things simpler. In syscall handler, MSR_RI can also be set at the same time because srr0/srr1 are already saved and r1 is set properly. On booke, translation is always on, so at the end all PPC32 have translation on early. Just update msr. Also update comment in power_save_ppc32_restore(). Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/5269c7e5f5d2117358af3a89744d75a116be27b0.1615552867.git.christophe.leroy@csgroup.eu
2021-03-12 12:50:24 +00:00
1:
powerpc/32: Fix vmap stack - Properly set r1 before activating MMU We need r1 to be properly set before activating MMU, otherwise any new exception taken while saving registers into the stack in exception prologs will use the user stack, which is wrong and will even lockup or crash when KUAP is selected. Do that by switching the meaning of r11 and r1 until we have saved r1 to the stack: copy r1 into r11 and setup the new stack pointer in r1. To avoid complicating and impacting all generic and specific prolog code (and more), copy back r1 into r11 once r11 is save onto the stack. We could get rid of copying r1 back and forth at the cost of rewriting everything to use r1 instead of r11 all the way when CONFIG_VMAP_STACK is set, but the effort is probably not worth it. Fixes: 028474876f47 ("powerpc/32: prepare for CONFIG_VMAP_STACK") Cc: stable@vger.kernel.org Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/8f85e8752ac5af602db7237ef53d634f4f3d3892.1599486108.git.christophe.leroy@csgroup.eu
2020-09-07 13:42:10 +00:00
stw r11,GPR1(r1)
stw r11,0(r1)
mr r11, r1
powerpc/32: Use SPRN_SPRG_SCRATCH2 in exception prologs Use SPRN_SPRG_SCRATCH2 as a third scratch register in exception prologs in order to simplify them and avoid data going back and forth from/to CR. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/6f5c8a7faa8cc54acb89c55c20aa579a2f30a4e9.1606285014.git.christophe.leroy@csgroup.eu
2020-11-25 07:10:53 +00:00
stw r10,_CCR(r11) /* save registers */
powerpc/32: Refactor EXCEPTION entry macros for head_8xx.S and head_32.S EXCEPTION_PROLOG is similar in head_8xx.S and head_32.S This patch creates head_32.h and moves EXCEPTION_PROLOG macro into it. It also converts it from a GCC macro to a GAS macro in order to ease refactorisation with 40x later, since GAS macros allows the use of #ifdef/#else/#endif inside it. And it also has the advantage of not requiring the uggly "; \" at the end of each line. This patch also moves EXCEPTION() and EXC_XFER_XXXX() macros which are also similar while adding START_EXCEPTION() out of EXCEPTION(). Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-30 12:38:50 +00:00
stw r12,GPR12(r11)
stw r9,GPR9(r11)
powerpc/32: Use SPRN_SPRG_SCRATCH2 in exception prologs Use SPRN_SPRG_SCRATCH2 as a third scratch register in exception prologs in order to simplify them and avoid data going back and forth from/to CR. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/6f5c8a7faa8cc54acb89c55c20aa579a2f30a4e9.1606285014.git.christophe.leroy@csgroup.eu
2020-11-25 07:10:53 +00:00
mfspr r10,SPRN_SPRG_SCRATCH0
powerpc/32: Refactor EXCEPTION entry macros for head_8xx.S and head_32.S EXCEPTION_PROLOG is similar in head_8xx.S and head_32.S This patch creates head_32.h and moves EXCEPTION_PROLOG macro into it. It also converts it from a GCC macro to a GAS macro in order to ease refactorisation with 40x later, since GAS macros allows the use of #ifdef/#else/#endif inside it. And it also has the advantage of not requiring the uggly "; \" at the end of each line. This patch also moves EXCEPTION() and EXC_XFER_XXXX() macros which are also similar while adding START_EXCEPTION() out of EXCEPTION(). Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-30 12:38:50 +00:00
mfspr r12,SPRN_SPRG_SCRATCH1
powerpc/32: Use SPRN_SPRG_SCRATCH2 in exception prologs Use SPRN_SPRG_SCRATCH2 as a third scratch register in exception prologs in order to simplify them and avoid data going back and forth from/to CR. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/6f5c8a7faa8cc54acb89c55c20aa579a2f30a4e9.1606285014.git.christophe.leroy@csgroup.eu
2020-11-25 07:10:53 +00:00
stw r10,GPR10(r11)
powerpc/32: Refactor EXCEPTION entry macros for head_8xx.S and head_32.S EXCEPTION_PROLOG is similar in head_8xx.S and head_32.S This patch creates head_32.h and moves EXCEPTION_PROLOG macro into it. It also converts it from a GCC macro to a GAS macro in order to ease refactorisation with 40x later, since GAS macros allows the use of #ifdef/#else/#endif inside it. And it also has the advantage of not requiring the uggly "; \" at the end of each line. This patch also moves EXCEPTION() and EXC_XFER_XXXX() macros which are also similar while adding START_EXCEPTION() out of EXCEPTION(). Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-30 12:38:50 +00:00
stw r12,GPR11(r11)
mflr r10
stw r10,_LINK(r11)
powerpc/32: prepare for CONFIG_VMAP_STACK To support CONFIG_VMAP_STACK, the kernel has to activate Data MMU Translation for accessing the stack. Before doing that it must save SRR0, SRR1 and also DAR and DSISR when relevant, in order to not loose them in case there is a Data TLB Miss once the translation is reactivated. This patch adds fields in thread struct for saving those registers. It prepares entry_32.S to handle exception entry with Data MMU Translation enabled and alters EXCEPTION_PROLOG macros to save SRR0, SRR1, DAR and DSISR then reenables Data MMU. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/a775a1fea60f190e0f63503463fb775310a2009b.1576916812.git.christophe.leroy@c-s.fr
2019-12-21 08:32:27 +00:00
mfspr r12, SPRN_SPRG_THREAD
tovirt(r12, r12)
.if \handle_dar_dsisr
lwz r10, DAR(r12)
stw r10, _DAR(r11)
lwz r10, DSISR(r12)
stw r10, _DSISR(r11)
.endif
lwz r9, SRR1(r12)
lwz r12, SRR0(r12)
powerpc/40x: Refactor exception entry macros by using head_32.h Refactor exception entry macros by using the ones defined in head_32.h Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-30 12:38:56 +00:00
#ifdef CONFIG_40x
rlwinm r9,r9,0,14,12 /* clear MSR_WE (necessary?) */
powerpc/32: Use fast instruction to set MSR RI in exception prolog on 8xx 8xx has registers SPRN_NRI, SPRN_EID and SPRN_EIE for changing MSR EE and RI. Use SPRN_EID in exception prolog to set RI. On an 8xx, it reduces the null_syscall test by 3 cycles. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/65f6bda827c2a2abce71ea7e07543e791163da33.1615552866.git.christophe.leroy@csgroup.eu
2021-03-12 12:50:20 +00:00
#elif defined(CONFIG_PPC_8xx)
mtspr SPRN_EID, r2 /* Set MSR_RI */
powerpc/32: prepare for CONFIG_VMAP_STACK To support CONFIG_VMAP_STACK, the kernel has to activate Data MMU Translation for accessing the stack. Before doing that it must save SRR0, SRR1 and also DAR and DSISR when relevant, in order to not loose them in case there is a Data TLB Miss once the translation is reactivated. This patch adds fields in thread struct for saving those registers. It prepares entry_32.S to handle exception entry with Data MMU Translation enabled and alters EXCEPTION_PROLOG macros to save SRR0, SRR1, DAR and DSISR then reenables Data MMU. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/a775a1fea60f190e0f63503463fb775310a2009b.1576916812.git.christophe.leroy@c-s.fr
2019-12-21 08:32:27 +00:00
#else
powerpc/32: Enable instruction translation at the same time as data translation On 40x and 8xx, kernel text is pinned. On book3s/32, kernel text is mapped by BATs. Enable instruction translation at the same time as data translation, it makes things simpler. In syscall handler, MSR_RI can also be set at the same time because srr0/srr1 are already saved and r1 is set properly. On booke, translation is always on, so at the end all PPC32 have translation on early. Just update msr. Also update comment in power_save_ppc32_restore(). Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/5269c7e5f5d2117358af3a89744d75a116be27b0.1615552867.git.christophe.leroy@csgroup.eu
2021-03-12 12:50:24 +00:00
li r10, MSR_KERNEL /* can take exceptions */
powerpc/32: replace MTMSRD() by mtmsr On PPC32, MTMSRD() is simply defined as mtmsr. Replace MTMSRD(reg) by mtmsr reg in files dedicated to PPC32, this makes the code less obscure. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/22469e78230edea3dbd0c79a555d73124f6c6d93.1576916812.git.christophe.leroy@c-s.fr
2019-12-21 08:32:22 +00:00
mtmsr r10 /* (except for mach check in rtas) */
powerpc/40x: Refactor exception entry macros by using head_32.h Refactor exception entry macros by using the ones defined in head_32.h Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-30 12:38:56 +00:00
#endif
powerpc/32: Refactor saving of volatile registers in exception prologs Exception prologs all do the same at the end: - Save trapno in stack - Mark stack with exception marker - Save r0 - Save r3 to r8 Refactor that into a COMMON_EXCEPTION_PROLOG_END macro. At the same time use r1 instead of r11. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/e1c45d2e895e0693c42d2a6840df1105a148efea.1615552867.git.christophe.leroy@csgroup.eu
2021-03-12 12:50:43 +00:00
COMMON_EXCEPTION_PROLOG_END \trapno
_ASM_NOKPROBE_SYMBOL(\name\()_virt)
.endm
.macro COMMON_EXCEPTION_PROLOG_END trapno
stw r0,GPR0(r1)
powerpc/32: Refactor EXCEPTION entry macros for head_8xx.S and head_32.S EXCEPTION_PROLOG is similar in head_8xx.S and head_32.S This patch creates head_32.h and moves EXCEPTION_PROLOG macro into it. It also converts it from a GCC macro to a GAS macro in order to ease refactorisation with 40x later, since GAS macros allows the use of #ifdef/#else/#endif inside it. And it also has the advantage of not requiring the uggly "; \" at the end of each line. This patch also moves EXCEPTION() and EXC_XFER_XXXX() macros which are also similar while adding START_EXCEPTION() out of EXCEPTION(). Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-30 12:38:50 +00:00
lis r10,STACK_FRAME_REGS_MARKER@ha /* exception frame marker */
addi r10,r10,STACK_FRAME_REGS_MARKER@l
powerpc/32: Refactor saving of volatile registers in exception prologs Exception prologs all do the same at the end: - Save trapno in stack - Mark stack with exception marker - Save r0 - Save r3 to r8 Refactor that into a COMMON_EXCEPTION_PROLOG_END macro. At the same time use r1 instead of r11. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/e1c45d2e895e0693c42d2a6840df1105a148efea.1615552867.git.christophe.leroy@csgroup.eu
2021-03-12 12:50:43 +00:00
stw r10,8(r1)
powerpc/32: Save trap number on stack in exception prolog Saving the trap number into the stack goes into the exception prolog, as EXC_XFER_xxx will soon disappear. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/2ac7a0c9cde2ec2b23cd79e3a54cfedd816a91ae.1615552867.git.christophe.leroy@csgroup.eu
2021-03-12 12:50:38 +00:00
li r10, \trapno
powerpc/32: Refactor saving of volatile registers in exception prologs Exception prologs all do the same at the end: - Save trapno in stack - Mark stack with exception marker - Save r0 - Save r3 to r8 Refactor that into a COMMON_EXCEPTION_PROLOG_END macro. At the same time use r1 instead of r11. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/e1c45d2e895e0693c42d2a6840df1105a148efea.1615552867.git.christophe.leroy@csgroup.eu
2021-03-12 12:50:43 +00:00
stw r10,_TRAP(r1)
SAVE_4GPRS(3, r1)
SAVE_2GPRS(7, r1)
powerpc/32: Save remaining registers in exception prolog Save non volatile registers, XER, CTR, MSR and NIP in exception prolog. Also assign proper value to r2 and r3 there. For now, recalculate thread pointer in prepare_transfer_to_handler. It will disappear once KUAP is ported to C. And remove the comment which is now completely wrong. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/56f0cde9dd0362edf2ddba4d887552013eee7329.1615552867.git.christophe.leroy@csgroup.eu
2021-03-12 12:50:44 +00:00
SAVE_NVGPRS(r1)
stw r2,GPR2(r1)
stw r12,_NIP(r1)
stw r9,_MSR(r1)
mfctr r10
mfspr r2,SPRN_SPRG_THREAD
stw r10,_CTR(r1)
tovirt(r2, r2)
mfspr r10,SPRN_XER
addi r2, r2, -THREAD
stw r10,_XER(r1)
addi r3,r1,STACK_FRAME_OVERHEAD
powerpc/32: Refactor EXCEPTION entry macros for head_8xx.S and head_32.S EXCEPTION_PROLOG is similar in head_8xx.S and head_32.S This patch creates head_32.h and moves EXCEPTION_PROLOG macro into it. It also converts it from a GCC macro to a GAS macro in order to ease refactorisation with 40x later, since GAS macros allows the use of #ifdef/#else/#endif inside it. And it also has the advantage of not requiring the uggly "; \" at the end of each line. This patch also moves EXCEPTION() and EXC_XFER_XXXX() macros which are also similar while adding START_EXCEPTION() out of EXCEPTION(). Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-30 12:38:50 +00:00
.endm
powerpc/32: Add a prepare_transfer_to_handler macro for exception prologs In order to increase flexibility, add a macro that will for now call transfer_to_handler. As transfer_to_handler doesn't do the actual transfer anymore, also name it prepare_transfer_to_handler. The following patches will progressively remove the use of transfer_to_handler label. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/7f757c52518ab1d7b27ad5113b10f860e803f467.1615552867.git.christophe.leroy@csgroup.eu
2021-03-12 12:50:39 +00:00
.macro prepare_transfer_to_handler
powerpc/32: Only use prepare_transfer_to_handler function on book3s/32 and e500 Only book3s/32 and e500 have significative work to do in prepare_transfer_to_handler. Other 32 bit have nothing to do at all. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/b5e29ca0e557c11340415a13fe8b107189d315e1.1615552867.git.christophe.leroy@csgroup.eu
2021-03-12 12:50:46 +00:00
#ifdef CONFIG_PPC_BOOK3S_32
powerpc/32s: Move KUEP locking/unlocking in C This can be done in C, do it. Unrolling the loop gains approx. 15% performance. From now on, prepare_transfer_to_handler() is only for interrupts from kernel. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/4eadd873927e9a73c3d1dfe2f9497353465514cf.1615552867.git.christophe.leroy@csgroup.eu
2021-03-12 12:50:47 +00:00
andi. r12,r9,MSR_PR
bne 777f
powerpc/32: Add a prepare_transfer_to_handler macro for exception prologs In order to increase flexibility, add a macro that will for now call transfer_to_handler. As transfer_to_handler doesn't do the actual transfer anymore, also name it prepare_transfer_to_handler. The following patches will progressively remove the use of transfer_to_handler label. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/7f757c52518ab1d7b27ad5113b10f860e803f467.1615552867.git.christophe.leroy@csgroup.eu
2021-03-12 12:50:39 +00:00
bl prepare_transfer_to_handler
powerpc/32s: Move KUEP locking/unlocking in C This can be done in C, do it. Unrolling the loop gains approx. 15% performance. From now on, prepare_transfer_to_handler() is only for interrupts from kernel. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/4eadd873927e9a73c3d1dfe2f9497353465514cf.1615552867.git.christophe.leroy@csgroup.eu
2021-03-12 12:50:47 +00:00
777:
powerpc/32: Only use prepare_transfer_to_handler function on book3s/32 and e500 Only book3s/32 and e500 have significative work to do in prepare_transfer_to_handler. Other 32 bit have nothing to do at all. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/b5e29ca0e557c11340415a13fe8b107189d315e1.1615552867.git.christophe.leroy@csgroup.eu
2021-03-12 12:50:46 +00:00
#endif
powerpc/32: Add a prepare_transfer_to_handler macro for exception prologs In order to increase flexibility, add a macro that will for now call transfer_to_handler. As transfer_to_handler doesn't do the actual transfer anymore, also name it prepare_transfer_to_handler. The following patches will progressively remove the use of transfer_to_handler label. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/7f757c52518ab1d7b27ad5113b10f860e803f467.1615552867.git.christophe.leroy@csgroup.eu
2021-03-12 12:50:39 +00:00
.endm
powerpc/32: implement fast entry for syscalls on non BOOKE This patch implements a fast entry for syscalls. Syscalls don't have to preserve non volatile registers except LR. This patch then implement a fast entry for syscalls, where volatile registers get clobbered. As this entry is dedicated to syscall it always sets MSR_EE and warns in case MSR_EE was previously off It also assumes that the call is always from user, system calls are unexpected from kernel. The overall series improves null_syscall selftest by 12,5% on an 83xx and by 17% on a 8xx. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-30 12:39:02 +00:00
.macro SYSCALL_ENTRY trapno
powerpc/32: Warn and return ENOSYS on syscalls from kernel Since commit b86fb88855ea ("powerpc/32: implement fast entry for syscalls on non BOOKE") and commit 1a4b739bbb4f ("powerpc/32: implement fast entry for syscalls on BOOKE"), syscalls from kernel are unexpected and can have catastrophic consequences as it will destroy the kernel stack. Test MSR_PR on syscall entry. In case syscall is from kernel, emit a warning and return ENOSYS error. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/8ee3bdbbdfdfc64ca7001e90c43b2aee6f333578.1580470482.git.christophe.leroy@c-s.fr
2020-01-31 11:34:54 +00:00
mfspr r9, SPRN_SRR1
powerpc/32: Interchange r10 and r12 in SYSCALL_ENTRY on non booke To better match booke version of SYSCALL_ENTRY macro, interchange r10 and r12 in the non booke version. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/5ab3a517bc883a2fc905fb2cb5ee9344f37b2cfa.1622818435.git.christophe.leroy@csgroup.eu
2021-06-04 14:54:12 +00:00
mfspr r12, SPRN_SRR0
powerpc/32: Reorder instructions to avoid using CTR in syscall entry Now that we are using rfi instead of mtmsr to reactivate MMU, it is possible to reorder instructions and avoid the need to use CTR for stashing SRR0. null_syscall on 8xx is reduced by 3 cycles (283 => 280 cycles). Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/8fa13a59f73647e058c95fc7e1c7a98f316bd20a.1612796617.git.christophe.leroy@csgroup.eu
2021-02-08 15:10:23 +00:00
LOAD_REG_IMMEDIATE(r11, MSR_KERNEL) /* can take exceptions */
powerpc/32: Interchange r10 and r12 in SYSCALL_ENTRY on non booke To better match booke version of SYSCALL_ENTRY macro, interchange r10 and r12 in the non booke version. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/5ab3a517bc883a2fc905fb2cb5ee9344f37b2cfa.1622818435.git.christophe.leroy@csgroup.eu
2021-06-04 14:54:12 +00:00
lis r10, 1f@h
ori r10, r10, 1f@l
powerpc/32: Reorder instructions to avoid using CTR in syscall entry Now that we are using rfi instead of mtmsr to reactivate MMU, it is possible to reorder instructions and avoid the need to use CTR for stashing SRR0. null_syscall on 8xx is reduced by 3 cycles (283 => 280 cycles). Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/8fa13a59f73647e058c95fc7e1c7a98f316bd20a.1612796617.git.christophe.leroy@csgroup.eu
2021-02-08 15:10:23 +00:00
mtspr SPRN_SRR1, r11
powerpc/32: Interchange r10 and r12 in SYSCALL_ENTRY on non booke To better match booke version of SYSCALL_ENTRY macro, interchange r10 and r12 in the non booke version. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/5ab3a517bc883a2fc905fb2cb5ee9344f37b2cfa.1622818435.git.christophe.leroy@csgroup.eu
2021-06-04 14:54:12 +00:00
mtspr SPRN_SRR0, r10
mfspr r10,SPRN_SPRG_THREAD
powerpc/32: Fix vmap stack - Properly set r1 before activating MMU on syscall too We need r1 to be properly set before activating MMU, otherwise any new exception taken while saving registers into the stack in syscall prologs will use the user stack, which is wrong and will even lockup or crash when KUAP is selected. Do that by switching the meaning of r11 and r1 until we have saved r1 to the stack: copy r1 into r11 and setup the new stack pointer in r1. To avoid complicating and impacting all generic and specific prolog code (and more), copy back r1 into r11 once r11 is save onto the stack. We could get rid of copying r1 back and forth at the cost of rewriting everything to use r1 instead of r11 all the way when CONFIG_VMAP_STACK is set, but the effort is probably not worth it for now. Fixes: da7bb43ab9da ("powerpc/32: Fix vmap stack - Properly set r1 before activating MMU") Cc: stable@vger.kernel.org # v5.10+ Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/a3d819d5c348cee9783a311d5d3f3ba9b48fd219.1608531452.git.christophe.leroy@csgroup.eu
2020-12-21 06:18:03 +00:00
mr r11, r1
powerpc/32: Interchange r10 and r12 in SYSCALL_ENTRY on non booke To better match booke version of SYSCALL_ENTRY macro, interchange r10 and r12 in the non booke version. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/5ab3a517bc883a2fc905fb2cb5ee9344f37b2cfa.1622818435.git.christophe.leroy@csgroup.eu
2021-06-04 14:54:12 +00:00
lwz r1,TASK_STACK-THREAD(r10)
tovirt(r10, r10)
powerpc/32: Fix vmap stack - Properly set r1 before activating MMU on syscall too We need r1 to be properly set before activating MMU, otherwise any new exception taken while saving registers into the stack in syscall prologs will use the user stack, which is wrong and will even lockup or crash when KUAP is selected. Do that by switching the meaning of r11 and r1 until we have saved r1 to the stack: copy r1 into r11 and setup the new stack pointer in r1. To avoid complicating and impacting all generic and specific prolog code (and more), copy back r1 into r11 once r11 is save onto the stack. We could get rid of copying r1 back and forth at the cost of rewriting everything to use r1 instead of r11 all the way when CONFIG_VMAP_STACK is set, but the effort is probably not worth it for now. Fixes: da7bb43ab9da ("powerpc/32: Fix vmap stack - Properly set r1 before activating MMU") Cc: stable@vger.kernel.org # v5.10+ Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/a3d819d5c348cee9783a311d5d3f3ba9b48fd219.1608531452.git.christophe.leroy@csgroup.eu
2020-12-21 06:18:03 +00:00
addi r1, r1, THREAD_SIZE - INT_FRAME_SIZE
powerpc/32: On syscall entry, enable instruction translation at the same time as data On 40x and 8xx, kernel text is pinned. On book3s/32, kernel text is mapped by BATs. Enable instruction translation at the same time as data translation, it makes things simpler. MSR_RI can also be set at the same time because srr0/srr1 are already saved and r1 is set properly. On booke, translation is always on, so at the end all PPC32 have translation on early. This reduces null_syscall benchmark by 13 cycles on 8xx (296 ==> 283 cycles). Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/3fe8891c814103a3549efc1d4e7ffc828bba5993.1612796617.git.christophe.leroy@csgroup.eu
2021-02-08 15:10:22 +00:00
rfi
1:
powerpc/32: Interchange r1 and r11 in SYSCALL_ENTRY on booke To better match non booke version of SYSCALL_ENTRY macro, interchange r1 and r11 in the booke version. While at it, in both versions use r1 instead of r11 to save _NIP and _CCR. All other uses of r11 will go away in next patch, so don't bother changing them for now. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1684c39724a069b0ce1aa82eaee6ec194e354e4e.1622818435.git.christophe.leroy@csgroup.eu
2021-06-04 14:54:13 +00:00
stw r12,_NIP(r1)
powerpc/32: Interchange r10 and r12 in SYSCALL_ENTRY on non booke To better match booke version of SYSCALL_ENTRY macro, interchange r10 and r12 in the non booke version. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/5ab3a517bc883a2fc905fb2cb5ee9344f37b2cfa.1622818435.git.christophe.leroy@csgroup.eu
2021-06-04 14:54:12 +00:00
mfcr r12
rlwinm r12,r12,0,4,2 /* Clear SO bit in CR */
powerpc/32: Interchange r1 and r11 in SYSCALL_ENTRY on booke To better match non booke version of SYSCALL_ENTRY macro, interchange r1 and r11 in the booke version. While at it, in both versions use r1 instead of r11 to save _NIP and _CCR. All other uses of r11 will go away in next patch, so don't bother changing them for now. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1684c39724a069b0ce1aa82eaee6ec194e354e4e.1622818435.git.christophe.leroy@csgroup.eu
2021-06-04 14:54:13 +00:00
stw r12,_CCR(r1)
powerpc/32: On syscall entry, enable instruction translation at the same time as data On 40x and 8xx, kernel text is pinned. On book3s/32, kernel text is mapped by BATs. Enable instruction translation at the same time as data translation, it makes things simpler. MSR_RI can also be set at the same time because srr0/srr1 are already saved and r1 is set properly. On booke, translation is always on, so at the end all PPC32 have translation on early. This reduces null_syscall benchmark by 13 cycles on 8xx (296 ==> 283 cycles). Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/3fe8891c814103a3549efc1d4e7ffc828bba5993.1612796617.git.christophe.leroy@csgroup.eu
2021-02-08 15:10:22 +00:00
b transfer_to_syscall /* jump to handler */
powerpc/32: implement fast entry for syscalls on non BOOKE This patch implements a fast entry for syscalls. Syscalls don't have to preserve non volatile registers except LR. This patch then implement a fast entry for syscalls, where volatile registers get clobbered. As this entry is dedicated to syscall it always sets MSR_EE and warns in case MSR_EE was previously off It also assumes that the call is always from user, system calls are unexpected from kernel. The overall series improves null_syscall selftest by 12,5% on an 83xx and by 17% on a 8xx. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-30 12:39:02 +00:00
.endm
powerpc/32: Refactor EXCEPTION entry macros for head_8xx.S and head_32.S EXCEPTION_PROLOG is similar in head_8xx.S and head_32.S This patch creates head_32.h and moves EXCEPTION_PROLOG macro into it. It also converts it from a GCC macro to a GAS macro in order to ease refactorisation with 40x later, since GAS macros allows the use of #ifdef/#else/#endif inside it. And it also has the advantage of not requiring the uggly "; \" at the end of each line. This patch also moves EXCEPTION() and EXC_XFER_XXXX() macros which are also similar while adding START_EXCEPTION() out of EXCEPTION(). Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-30 12:38:50 +00:00
/*
* Note: code which follows this uses cr0.eq (set if from kernel),
* r11, r12 (SRR0), and r9 (SRR1).
*
* Note2: once we have set r1 we are in a position to take exceptions
* again, and we could thus set MSR:RI at that point.
*/
/*
* Exception vectors.
*/
#ifdef CONFIG_PPC_BOOK3S
#define START_EXCEPTION(n, label) \
powerpc/32: Move exception prolog code into .text once MMU is back on The space in the head section is rather constrained by the fact that exception vectors are spread every 0x100 bytes and sometimes we need to have "out of line" code because it doesn't fit. Now that we are enabling MMU early in the prolog, take that opportunity to jump somewhere else in the .text section where we don't have any space constraint. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/38b31ca4bc782a4985bc7952a675404d7ff27c24.1615552867.git.christophe.leroy@csgroup.eu
2021-03-12 12:50:29 +00:00
__HEAD; \
powerpc/32: Refactor EXCEPTION entry macros for head_8xx.S and head_32.S EXCEPTION_PROLOG is similar in head_8xx.S and head_32.S This patch creates head_32.h and moves EXCEPTION_PROLOG macro into it. It also converts it from a GCC macro to a GAS macro in order to ease refactorisation with 40x later, since GAS macros allows the use of #ifdef/#else/#endif inside it. And it also has the advantage of not requiring the uggly "; \" at the end of each line. This patch also moves EXCEPTION() and EXC_XFER_XXXX() macros which are also similar while adding START_EXCEPTION() out of EXCEPTION(). Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-30 12:38:50 +00:00
. = n; \
DO_KVM n; \
label:
#else
#define START_EXCEPTION(n, label) \
powerpc/32: Move exception prolog code into .text once MMU is back on The space in the head section is rather constrained by the fact that exception vectors are spread every 0x100 bytes and sometimes we need to have "out of line" code because it doesn't fit. Now that we are enabling MMU early in the prolog, take that opportunity to jump somewhere else in the .text section where we don't have any space constraint. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/38b31ca4bc782a4985bc7952a675404d7ff27c24.1615552867.git.christophe.leroy@csgroup.eu
2021-03-12 12:50:29 +00:00
__HEAD; \
powerpc/32: Refactor EXCEPTION entry macros for head_8xx.S and head_32.S EXCEPTION_PROLOG is similar in head_8xx.S and head_32.S This patch creates head_32.h and moves EXCEPTION_PROLOG macro into it. It also converts it from a GCC macro to a GAS macro in order to ease refactorisation with 40x later, since GAS macros allows the use of #ifdef/#else/#endif inside it. And it also has the advantage of not requiring the uggly "; \" at the end of each line. This patch also moves EXCEPTION() and EXC_XFER_XXXX() macros which are also similar while adding START_EXCEPTION() out of EXCEPTION(). Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-30 12:38:50 +00:00
. = n; \
label:
#endif
powerpc/32: Remove the xfer parameter in EXCEPTION() macro The xfer parameter is not used anymore, remove it. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/17c7d68bd18f7d2f1ab24a1a20d9ed33bbcda741.1615552867.git.christophe.leroy@csgroup.eu
2021-03-12 12:50:42 +00:00
#define EXCEPTION(n, label, hdlr) \
powerpc/32: Refactor EXCEPTION entry macros for head_8xx.S and head_32.S EXCEPTION_PROLOG is similar in head_8xx.S and head_32.S This patch creates head_32.h and moves EXCEPTION_PROLOG macro into it. It also converts it from a GCC macro to a GAS macro in order to ease refactorisation with 40x later, since GAS macros allows the use of #ifdef/#else/#endif inside it. And it also has the advantage of not requiring the uggly "; \" at the end of each line. This patch also moves EXCEPTION() and EXC_XFER_XXXX() macros which are also similar while adding START_EXCEPTION() out of EXCEPTION(). Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-30 12:38:50 +00:00
START_EXCEPTION(n, label) \
powerpc/32: Save trap number on stack in exception prolog Saving the trap number into the stack goes into the exception prolog, as EXC_XFER_xxx will soon disappear. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/2ac7a0c9cde2ec2b23cd79e3a54cfedd816a91ae.1615552867.git.christophe.leroy@csgroup.eu
2021-03-12 12:50:38 +00:00
EXCEPTION_PROLOG n label; \
powerpc/32: Dismantle EXC_XFER_STD/LITE/TEMPLATE In order to get more control in exception prolog, dismantle all non standard exception macros, finishing with EXC_XFER_STD and EXC_XFER_LITE and EXC_XFER_TEMPLATE. Also remove transfer_to_handler_full and ret_from_except and ret_from_except_full as they are not used anymore. Last parameter of EXCEPTION() is now ignored, will be removed in a later patch to avoid too much churn. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/ca5795d04a220586b7037dbbbe6951dfa9e768eb.1615552867.git.christophe.leroy@csgroup.eu
2021-03-12 12:50:41 +00:00
prepare_transfer_to_handler; \
bl hdlr; \
b interrupt_return
powerpc/32: Refactor EXCEPTION entry macros for head_8xx.S and head_32.S EXCEPTION_PROLOG is similar in head_8xx.S and head_32.S This patch creates head_32.h and moves EXCEPTION_PROLOG macro into it. It also converts it from a GCC macro to a GAS macro in order to ease refactorisation with 40x later, since GAS macros allows the use of #ifdef/#else/#endif inside it. And it also has the advantage of not requiring the uggly "; \" at the end of each line. This patch also moves EXCEPTION() and EXC_XFER_XXXX() macros which are also similar while adding START_EXCEPTION() out of EXCEPTION(). Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-30 12:38:50 +00:00
powerpc/32: Add early stack overflow detection with VMAP stack. To avoid recursive faults, stack overflow detection has to be performed before writing in the stack in exception prologs. Do it by checking the alignment. If the stack pointer alignment is wrong, it means it is pointing to the following or preceding page. Without VMAP stack, a stack overflow is catastrophic. With VMAP stack, a stack overflow isn't destructive, so don't panic. Kill the task with SIGSEGV instead. A dedicated overflow stack is set up for each CPU. lkdtm: Performing direct entry EXHAUST_STACK lkdtm: Calling function with 512 frame size to depth 32 ... lkdtm: loop 32/32 ... lkdtm: loop 31/32 ... lkdtm: loop 30/32 ... lkdtm: loop 29/32 ... lkdtm: loop 28/32 ... lkdtm: loop 27/32 ... lkdtm: loop 26/32 ... lkdtm: loop 25/32 ... lkdtm: loop 24/32 ... lkdtm: loop 23/32 ... lkdtm: loop 22/32 ... lkdtm: loop 21/32 ... lkdtm: loop 20/32 ... Kernel stack overflow in process test[359], r1=c900c008 Oops: Kernel stack overflow, sig: 6 [#1] BE PAGE_SIZE=4K MMU=Hash PowerMac Modules linked in: CPU: 0 PID: 359 Comm: test Not tainted 5.3.0-rc7+ #2225 NIP: c0622060 LR: c0626710 CTR: 00000000 REGS: c0895f48 TRAP: 0000 Not tainted (5.3.0-rc7+) MSR: 00001032 <ME,IR,DR,RI> CR: 28004224 XER: 00000000 GPR00: c0626ca4 c900c008 c783c000 c07335cc c900c010 c07335cc c900c0f0 c07335cc GPR08: c900c0f0 00000001 00000000 00000000 28008222 00000000 00000000 00000000 GPR16: 00000000 00000000 10010128 10010000 b799c245 10010158 c07335cc 00000025 GPR24: c0690000 c08b91d4 c068f688 00000020 c900c0f0 c068f668 c08b95b4 c08b91d4 NIP [c0622060] format_decode+0x0/0x4d4 LR [c0626710] vsnprintf+0x80/0x5fc Call Trace: [c900c068] [c0626ca4] vscnprintf+0x18/0x48 [c900c078] [c007b944] vprintk_store+0x40/0x214 [c900c0b8] [c007bf50] vprintk_emit+0x90/0x1dc [c900c0e8] [c007c5cc] printk+0x50/0x60 [c900c128] [c03da5b0] recursive_loop+0x44/0x6c [c900c338] [c03da5c4] recursive_loop+0x58/0x6c [c900c548] [c03da5c4] recursive_loop+0x58/0x6c [c900c758] [c03da5c4] recursive_loop+0x58/0x6c [c900c968] [c03da5c4] recursive_loop+0x58/0x6c [c900cb78] [c03da5c4] recursive_loop+0x58/0x6c [c900cd88] [c03da5c4] recursive_loop+0x58/0x6c [c900cf98] [c03da5c4] recursive_loop+0x58/0x6c [c900d1a8] [c03da5c4] recursive_loop+0x58/0x6c [c900d3b8] [c03da5c4] recursive_loop+0x58/0x6c [c900d5c8] [c03da5c4] recursive_loop+0x58/0x6c [c900d7d8] [c03da5c4] recursive_loop+0x58/0x6c [c900d9e8] [c03da5c4] recursive_loop+0x58/0x6c [c900dbf8] [c03da5c4] recursive_loop+0x58/0x6c [c900de08] [c03da67c] lkdtm_EXHAUST_STACK+0x30/0x4c [c900de18] [c03da3e8] direct_entry+0xc8/0x140 [c900de48] [c029fb40] full_proxy_write+0x64/0xcc [c900de68] [c01500f8] __vfs_write+0x30/0x1d0 [c900dee8] [c0152cb8] vfs_write+0xb8/0x1d4 [c900df08] [c0152f7c] ksys_write+0x58/0xe8 [c900df38] [c0014208] ret_from_syscall+0x0/0x34 --- interrupt: c01 at 0xf806664 LR = 0x1000c868 Instruction dump: 4bffff91 80010014 7c832378 7c0803a6 38210010 4e800020 3d20c08a 3ca0c089 8089a0cc 38a58f0c 38600001 4ba2d494 <9421ffe0> 7c0802a6 bfc10018 7c9f2378 Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1b89c121b4070c7ee99e4f22cc178f15a736b07b.1576916812.git.christophe.leroy@c-s.fr
2019-12-21 08:32:29 +00:00
.macro vmap_stack_overflow_exception
powerpc/32: Move exception prolog code into .text once MMU is back on The space in the head section is rather constrained by the fact that exception vectors are spread every 0x100 bytes and sometimes we need to have "out of line" code because it doesn't fit. Now that we are enabling MMU early in the prolog, take that opportunity to jump somewhere else in the .text section where we don't have any space constraint. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/38b31ca4bc782a4985bc7952a675404d7ff27c24.1615552867.git.christophe.leroy@csgroup.eu
2021-03-12 12:50:29 +00:00
__HEAD
powerpc/32: Add vmap_stack_overflow label inside the macro For consistency, add in the macro the label used by exception prolog to branch to stack overflow processing. While at it, enclose the macro in #ifdef CONFIG_VMAP_STACK on the 8xx as already done on book3s/32. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/cf80056f5b946572ad98aea9d915dd25b23beda6.1615552867.git.christophe.leroy@csgroup.eu
2021-03-12 12:50:27 +00:00
vmap_stack_overflow:
powerpc/32: Add early stack overflow detection with VMAP stack. To avoid recursive faults, stack overflow detection has to be performed before writing in the stack in exception prologs. Do it by checking the alignment. If the stack pointer alignment is wrong, it means it is pointing to the following or preceding page. Without VMAP stack, a stack overflow is catastrophic. With VMAP stack, a stack overflow isn't destructive, so don't panic. Kill the task with SIGSEGV instead. A dedicated overflow stack is set up for each CPU. lkdtm: Performing direct entry EXHAUST_STACK lkdtm: Calling function with 512 frame size to depth 32 ... lkdtm: loop 32/32 ... lkdtm: loop 31/32 ... lkdtm: loop 30/32 ... lkdtm: loop 29/32 ... lkdtm: loop 28/32 ... lkdtm: loop 27/32 ... lkdtm: loop 26/32 ... lkdtm: loop 25/32 ... lkdtm: loop 24/32 ... lkdtm: loop 23/32 ... lkdtm: loop 22/32 ... lkdtm: loop 21/32 ... lkdtm: loop 20/32 ... Kernel stack overflow in process test[359], r1=c900c008 Oops: Kernel stack overflow, sig: 6 [#1] BE PAGE_SIZE=4K MMU=Hash PowerMac Modules linked in: CPU: 0 PID: 359 Comm: test Not tainted 5.3.0-rc7+ #2225 NIP: c0622060 LR: c0626710 CTR: 00000000 REGS: c0895f48 TRAP: 0000 Not tainted (5.3.0-rc7+) MSR: 00001032 <ME,IR,DR,RI> CR: 28004224 XER: 00000000 GPR00: c0626ca4 c900c008 c783c000 c07335cc c900c010 c07335cc c900c0f0 c07335cc GPR08: c900c0f0 00000001 00000000 00000000 28008222 00000000 00000000 00000000 GPR16: 00000000 00000000 10010128 10010000 b799c245 10010158 c07335cc 00000025 GPR24: c0690000 c08b91d4 c068f688 00000020 c900c0f0 c068f668 c08b95b4 c08b91d4 NIP [c0622060] format_decode+0x0/0x4d4 LR [c0626710] vsnprintf+0x80/0x5fc Call Trace: [c900c068] [c0626ca4] vscnprintf+0x18/0x48 [c900c078] [c007b944] vprintk_store+0x40/0x214 [c900c0b8] [c007bf50] vprintk_emit+0x90/0x1dc [c900c0e8] [c007c5cc] printk+0x50/0x60 [c900c128] [c03da5b0] recursive_loop+0x44/0x6c [c900c338] [c03da5c4] recursive_loop+0x58/0x6c [c900c548] [c03da5c4] recursive_loop+0x58/0x6c [c900c758] [c03da5c4] recursive_loop+0x58/0x6c [c900c968] [c03da5c4] recursive_loop+0x58/0x6c [c900cb78] [c03da5c4] recursive_loop+0x58/0x6c [c900cd88] [c03da5c4] recursive_loop+0x58/0x6c [c900cf98] [c03da5c4] recursive_loop+0x58/0x6c [c900d1a8] [c03da5c4] recursive_loop+0x58/0x6c [c900d3b8] [c03da5c4] recursive_loop+0x58/0x6c [c900d5c8] [c03da5c4] recursive_loop+0x58/0x6c [c900d7d8] [c03da5c4] recursive_loop+0x58/0x6c [c900d9e8] [c03da5c4] recursive_loop+0x58/0x6c [c900dbf8] [c03da5c4] recursive_loop+0x58/0x6c [c900de08] [c03da67c] lkdtm_EXHAUST_STACK+0x30/0x4c [c900de18] [c03da3e8] direct_entry+0xc8/0x140 [c900de48] [c029fb40] full_proxy_write+0x64/0xcc [c900de68] [c01500f8] __vfs_write+0x30/0x1d0 [c900dee8] [c0152cb8] vfs_write+0xb8/0x1d4 [c900df08] [c0152f7c] ksys_write+0x58/0xe8 [c900df38] [c0014208] ret_from_syscall+0x0/0x34 --- interrupt: c01 at 0xf806664 LR = 0x1000c868 Instruction dump: 4bffff91 80010014 7c832378 7c0803a6 38210010 4e800020 3d20c08a 3ca0c089 8089a0cc 38a58f0c 38600001 4ba2d494 <9421ffe0> 7c0802a6 bfc10018 7c9f2378 Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1b89c121b4070c7ee99e4f22cc178f15a736b07b.1576916812.git.christophe.leroy@c-s.fr
2019-12-21 08:32:29 +00:00
#ifdef CONFIG_SMP
powerpc/32: Fix vmap stack - Properly set r1 before activating MMU We need r1 to be properly set before activating MMU, otherwise any new exception taken while saving registers into the stack in exception prologs will use the user stack, which is wrong and will even lockup or crash when KUAP is selected. Do that by switching the meaning of r11 and r1 until we have saved r1 to the stack: copy r1 into r11 and setup the new stack pointer in r1. To avoid complicating and impacting all generic and specific prolog code (and more), copy back r1 into r11 once r11 is save onto the stack. We could get rid of copying r1 back and forth at the cost of rewriting everything to use r1 instead of r11 all the way when CONFIG_VMAP_STACK is set, but the effort is probably not worth it. Fixes: 028474876f47 ("powerpc/32: prepare for CONFIG_VMAP_STACK") Cc: stable@vger.kernel.org Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/8f85e8752ac5af602db7237ef53d634f4f3d3892.1599486108.git.christophe.leroy@csgroup.eu
2020-09-07 13:42:10 +00:00
mfspr r1, SPRN_SPRG_THREAD
lwz r1, TASK_CPU - THREAD(r1)
slwi r1, r1, 3
powerpc/32: Fix hardlockup on vmap stack overflow Since the commit c118c7303ad5 ("powerpc/32: Fix vmap stack - Do not activate MMU before reading task struct") a vmap stack overflow results in a hard lockup. This is because emergency_ctx is still addressed with its virtual address allthough data MMU is not active anymore at that time. Fix it by using a physical address instead. Fixes: c118c7303ad5 ("powerpc/32: Fix vmap stack - Do not activate MMU before reading task struct") Cc: stable@vger.kernel.org # v5.10+ Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/ce30364fb7ccda489272af4a1612b6aa147e1d23.1637227521.git.christophe.leroy@csgroup.eu
2021-11-18 09:39:53 +00:00
addis r1, r1, emergency_ctx-PAGE_OFFSET@ha
powerpc/32: Add early stack overflow detection with VMAP stack. To avoid recursive faults, stack overflow detection has to be performed before writing in the stack in exception prologs. Do it by checking the alignment. If the stack pointer alignment is wrong, it means it is pointing to the following or preceding page. Without VMAP stack, a stack overflow is catastrophic. With VMAP stack, a stack overflow isn't destructive, so don't panic. Kill the task with SIGSEGV instead. A dedicated overflow stack is set up for each CPU. lkdtm: Performing direct entry EXHAUST_STACK lkdtm: Calling function with 512 frame size to depth 32 ... lkdtm: loop 32/32 ... lkdtm: loop 31/32 ... lkdtm: loop 30/32 ... lkdtm: loop 29/32 ... lkdtm: loop 28/32 ... lkdtm: loop 27/32 ... lkdtm: loop 26/32 ... lkdtm: loop 25/32 ... lkdtm: loop 24/32 ... lkdtm: loop 23/32 ... lkdtm: loop 22/32 ... lkdtm: loop 21/32 ... lkdtm: loop 20/32 ... Kernel stack overflow in process test[359], r1=c900c008 Oops: Kernel stack overflow, sig: 6 [#1] BE PAGE_SIZE=4K MMU=Hash PowerMac Modules linked in: CPU: 0 PID: 359 Comm: test Not tainted 5.3.0-rc7+ #2225 NIP: c0622060 LR: c0626710 CTR: 00000000 REGS: c0895f48 TRAP: 0000 Not tainted (5.3.0-rc7+) MSR: 00001032 <ME,IR,DR,RI> CR: 28004224 XER: 00000000 GPR00: c0626ca4 c900c008 c783c000 c07335cc c900c010 c07335cc c900c0f0 c07335cc GPR08: c900c0f0 00000001 00000000 00000000 28008222 00000000 00000000 00000000 GPR16: 00000000 00000000 10010128 10010000 b799c245 10010158 c07335cc 00000025 GPR24: c0690000 c08b91d4 c068f688 00000020 c900c0f0 c068f668 c08b95b4 c08b91d4 NIP [c0622060] format_decode+0x0/0x4d4 LR [c0626710] vsnprintf+0x80/0x5fc Call Trace: [c900c068] [c0626ca4] vscnprintf+0x18/0x48 [c900c078] [c007b944] vprintk_store+0x40/0x214 [c900c0b8] [c007bf50] vprintk_emit+0x90/0x1dc [c900c0e8] [c007c5cc] printk+0x50/0x60 [c900c128] [c03da5b0] recursive_loop+0x44/0x6c [c900c338] [c03da5c4] recursive_loop+0x58/0x6c [c900c548] [c03da5c4] recursive_loop+0x58/0x6c [c900c758] [c03da5c4] recursive_loop+0x58/0x6c [c900c968] [c03da5c4] recursive_loop+0x58/0x6c [c900cb78] [c03da5c4] recursive_loop+0x58/0x6c [c900cd88] [c03da5c4] recursive_loop+0x58/0x6c [c900cf98] [c03da5c4] recursive_loop+0x58/0x6c [c900d1a8] [c03da5c4] recursive_loop+0x58/0x6c [c900d3b8] [c03da5c4] recursive_loop+0x58/0x6c [c900d5c8] [c03da5c4] recursive_loop+0x58/0x6c [c900d7d8] [c03da5c4] recursive_loop+0x58/0x6c [c900d9e8] [c03da5c4] recursive_loop+0x58/0x6c [c900dbf8] [c03da5c4] recursive_loop+0x58/0x6c [c900de08] [c03da67c] lkdtm_EXHAUST_STACK+0x30/0x4c [c900de18] [c03da3e8] direct_entry+0xc8/0x140 [c900de48] [c029fb40] full_proxy_write+0x64/0xcc [c900de68] [c01500f8] __vfs_write+0x30/0x1d0 [c900dee8] [c0152cb8] vfs_write+0xb8/0x1d4 [c900df08] [c0152f7c] ksys_write+0x58/0xe8 [c900df38] [c0014208] ret_from_syscall+0x0/0x34 --- interrupt: c01 at 0xf806664 LR = 0x1000c868 Instruction dump: 4bffff91 80010014 7c832378 7c0803a6 38210010 4e800020 3d20c08a 3ca0c089 8089a0cc 38a58f0c 38600001 4ba2d494 <9421ffe0> 7c0802a6 bfc10018 7c9f2378 Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1b89c121b4070c7ee99e4f22cc178f15a736b07b.1576916812.git.christophe.leroy@c-s.fr
2019-12-21 08:32:29 +00:00
#else
powerpc/32: Fix hardlockup on vmap stack overflow Since the commit c118c7303ad5 ("powerpc/32: Fix vmap stack - Do not activate MMU before reading task struct") a vmap stack overflow results in a hard lockup. This is because emergency_ctx is still addressed with its virtual address allthough data MMU is not active anymore at that time. Fix it by using a physical address instead. Fixes: c118c7303ad5 ("powerpc/32: Fix vmap stack - Do not activate MMU before reading task struct") Cc: stable@vger.kernel.org # v5.10+ Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/ce30364fb7ccda489272af4a1612b6aa147e1d23.1637227521.git.christophe.leroy@csgroup.eu
2021-11-18 09:39:53 +00:00
lis r1, emergency_ctx-PAGE_OFFSET@ha
powerpc/32: Add early stack overflow detection with VMAP stack. To avoid recursive faults, stack overflow detection has to be performed before writing in the stack in exception prologs. Do it by checking the alignment. If the stack pointer alignment is wrong, it means it is pointing to the following or preceding page. Without VMAP stack, a stack overflow is catastrophic. With VMAP stack, a stack overflow isn't destructive, so don't panic. Kill the task with SIGSEGV instead. A dedicated overflow stack is set up for each CPU. lkdtm: Performing direct entry EXHAUST_STACK lkdtm: Calling function with 512 frame size to depth 32 ... lkdtm: loop 32/32 ... lkdtm: loop 31/32 ... lkdtm: loop 30/32 ... lkdtm: loop 29/32 ... lkdtm: loop 28/32 ... lkdtm: loop 27/32 ... lkdtm: loop 26/32 ... lkdtm: loop 25/32 ... lkdtm: loop 24/32 ... lkdtm: loop 23/32 ... lkdtm: loop 22/32 ... lkdtm: loop 21/32 ... lkdtm: loop 20/32 ... Kernel stack overflow in process test[359], r1=c900c008 Oops: Kernel stack overflow, sig: 6 [#1] BE PAGE_SIZE=4K MMU=Hash PowerMac Modules linked in: CPU: 0 PID: 359 Comm: test Not tainted 5.3.0-rc7+ #2225 NIP: c0622060 LR: c0626710 CTR: 00000000 REGS: c0895f48 TRAP: 0000 Not tainted (5.3.0-rc7+) MSR: 00001032 <ME,IR,DR,RI> CR: 28004224 XER: 00000000 GPR00: c0626ca4 c900c008 c783c000 c07335cc c900c010 c07335cc c900c0f0 c07335cc GPR08: c900c0f0 00000001 00000000 00000000 28008222 00000000 00000000 00000000 GPR16: 00000000 00000000 10010128 10010000 b799c245 10010158 c07335cc 00000025 GPR24: c0690000 c08b91d4 c068f688 00000020 c900c0f0 c068f668 c08b95b4 c08b91d4 NIP [c0622060] format_decode+0x0/0x4d4 LR [c0626710] vsnprintf+0x80/0x5fc Call Trace: [c900c068] [c0626ca4] vscnprintf+0x18/0x48 [c900c078] [c007b944] vprintk_store+0x40/0x214 [c900c0b8] [c007bf50] vprintk_emit+0x90/0x1dc [c900c0e8] [c007c5cc] printk+0x50/0x60 [c900c128] [c03da5b0] recursive_loop+0x44/0x6c [c900c338] [c03da5c4] recursive_loop+0x58/0x6c [c900c548] [c03da5c4] recursive_loop+0x58/0x6c [c900c758] [c03da5c4] recursive_loop+0x58/0x6c [c900c968] [c03da5c4] recursive_loop+0x58/0x6c [c900cb78] [c03da5c4] recursive_loop+0x58/0x6c [c900cd88] [c03da5c4] recursive_loop+0x58/0x6c [c900cf98] [c03da5c4] recursive_loop+0x58/0x6c [c900d1a8] [c03da5c4] recursive_loop+0x58/0x6c [c900d3b8] [c03da5c4] recursive_loop+0x58/0x6c [c900d5c8] [c03da5c4] recursive_loop+0x58/0x6c [c900d7d8] [c03da5c4] recursive_loop+0x58/0x6c [c900d9e8] [c03da5c4] recursive_loop+0x58/0x6c [c900dbf8] [c03da5c4] recursive_loop+0x58/0x6c [c900de08] [c03da67c] lkdtm_EXHAUST_STACK+0x30/0x4c [c900de18] [c03da3e8] direct_entry+0xc8/0x140 [c900de48] [c029fb40] full_proxy_write+0x64/0xcc [c900de68] [c01500f8] __vfs_write+0x30/0x1d0 [c900dee8] [c0152cb8] vfs_write+0xb8/0x1d4 [c900df08] [c0152f7c] ksys_write+0x58/0xe8 [c900df38] [c0014208] ret_from_syscall+0x0/0x34 --- interrupt: c01 at 0xf806664 LR = 0x1000c868 Instruction dump: 4bffff91 80010014 7c832378 7c0803a6 38210010 4e800020 3d20c08a 3ca0c089 8089a0cc 38a58f0c 38600001 4ba2d494 <9421ffe0> 7c0802a6 bfc10018 7c9f2378 Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1b89c121b4070c7ee99e4f22cc178f15a736b07b.1576916812.git.christophe.leroy@c-s.fr
2019-12-21 08:32:29 +00:00
#endif
powerpc/32: Fix hardlockup on vmap stack overflow Since the commit c118c7303ad5 ("powerpc/32: Fix vmap stack - Do not activate MMU before reading task struct") a vmap stack overflow results in a hard lockup. This is because emergency_ctx is still addressed with its virtual address allthough data MMU is not active anymore at that time. Fix it by using a physical address instead. Fixes: c118c7303ad5 ("powerpc/32: Fix vmap stack - Do not activate MMU before reading task struct") Cc: stable@vger.kernel.org # v5.10+ Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/ce30364fb7ccda489272af4a1612b6aa147e1d23.1637227521.git.christophe.leroy@csgroup.eu
2021-11-18 09:39:53 +00:00
lwz r1, emergency_ctx-PAGE_OFFSET@l(r1)
powerpc/32: Statically initialise first emergency context The check of the emergency context initialisation in vmap_stack_overflow is buggy for the SMP case, as it compares r1 with 0 while in the SMP case r1 is offseted by the CPU id. Instead of fixing it, just perform static initialisation of the first emergency context. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/4a67ba422be75713286dca0c86ee0d3df2eb6dfa.1615552867.git.christophe.leroy@csgroup.eu
2021-03-12 12:50:25 +00:00
addi r1, r1, THREAD_SIZE - INT_FRAME_SIZE
powerpc/32: Save trap number on stack in exception prolog Saving the trap number into the stack goes into the exception prolog, as EXC_XFER_xxx will soon disappear. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/2ac7a0c9cde2ec2b23cd79e3a54cfedd816a91ae.1615552867.git.christophe.leroy@csgroup.eu
2021-03-12 12:50:38 +00:00
EXCEPTION_PROLOG_2 0 vmap_stack_overflow
powerpc/32: Dismantle EXC_XFER_STD/LITE/TEMPLATE In order to get more control in exception prolog, dismantle all non standard exception macros, finishing with EXC_XFER_STD and EXC_XFER_LITE and EXC_XFER_TEMPLATE. Also remove transfer_to_handler_full and ret_from_except and ret_from_except_full as they are not used anymore. Last parameter of EXCEPTION() is now ignored, will be removed in a later patch to avoid too much churn. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/ca5795d04a220586b7037dbbbe6951dfa9e768eb.1615552867.git.christophe.leroy@csgroup.eu
2021-03-12 12:50:41 +00:00
prepare_transfer_to_handler
bl stack_overflow_exception
b interrupt_return
powerpc/32: Add early stack overflow detection with VMAP stack. To avoid recursive faults, stack overflow detection has to be performed before writing in the stack in exception prologs. Do it by checking the alignment. If the stack pointer alignment is wrong, it means it is pointing to the following or preceding page. Without VMAP stack, a stack overflow is catastrophic. With VMAP stack, a stack overflow isn't destructive, so don't panic. Kill the task with SIGSEGV instead. A dedicated overflow stack is set up for each CPU. lkdtm: Performing direct entry EXHAUST_STACK lkdtm: Calling function with 512 frame size to depth 32 ... lkdtm: loop 32/32 ... lkdtm: loop 31/32 ... lkdtm: loop 30/32 ... lkdtm: loop 29/32 ... lkdtm: loop 28/32 ... lkdtm: loop 27/32 ... lkdtm: loop 26/32 ... lkdtm: loop 25/32 ... lkdtm: loop 24/32 ... lkdtm: loop 23/32 ... lkdtm: loop 22/32 ... lkdtm: loop 21/32 ... lkdtm: loop 20/32 ... Kernel stack overflow in process test[359], r1=c900c008 Oops: Kernel stack overflow, sig: 6 [#1] BE PAGE_SIZE=4K MMU=Hash PowerMac Modules linked in: CPU: 0 PID: 359 Comm: test Not tainted 5.3.0-rc7+ #2225 NIP: c0622060 LR: c0626710 CTR: 00000000 REGS: c0895f48 TRAP: 0000 Not tainted (5.3.0-rc7+) MSR: 00001032 <ME,IR,DR,RI> CR: 28004224 XER: 00000000 GPR00: c0626ca4 c900c008 c783c000 c07335cc c900c010 c07335cc c900c0f0 c07335cc GPR08: c900c0f0 00000001 00000000 00000000 28008222 00000000 00000000 00000000 GPR16: 00000000 00000000 10010128 10010000 b799c245 10010158 c07335cc 00000025 GPR24: c0690000 c08b91d4 c068f688 00000020 c900c0f0 c068f668 c08b95b4 c08b91d4 NIP [c0622060] format_decode+0x0/0x4d4 LR [c0626710] vsnprintf+0x80/0x5fc Call Trace: [c900c068] [c0626ca4] vscnprintf+0x18/0x48 [c900c078] [c007b944] vprintk_store+0x40/0x214 [c900c0b8] [c007bf50] vprintk_emit+0x90/0x1dc [c900c0e8] [c007c5cc] printk+0x50/0x60 [c900c128] [c03da5b0] recursive_loop+0x44/0x6c [c900c338] [c03da5c4] recursive_loop+0x58/0x6c [c900c548] [c03da5c4] recursive_loop+0x58/0x6c [c900c758] [c03da5c4] recursive_loop+0x58/0x6c [c900c968] [c03da5c4] recursive_loop+0x58/0x6c [c900cb78] [c03da5c4] recursive_loop+0x58/0x6c [c900cd88] [c03da5c4] recursive_loop+0x58/0x6c [c900cf98] [c03da5c4] recursive_loop+0x58/0x6c [c900d1a8] [c03da5c4] recursive_loop+0x58/0x6c [c900d3b8] [c03da5c4] recursive_loop+0x58/0x6c [c900d5c8] [c03da5c4] recursive_loop+0x58/0x6c [c900d7d8] [c03da5c4] recursive_loop+0x58/0x6c [c900d9e8] [c03da5c4] recursive_loop+0x58/0x6c [c900dbf8] [c03da5c4] recursive_loop+0x58/0x6c [c900de08] [c03da67c] lkdtm_EXHAUST_STACK+0x30/0x4c [c900de18] [c03da3e8] direct_entry+0xc8/0x140 [c900de48] [c029fb40] full_proxy_write+0x64/0xcc [c900de68] [c01500f8] __vfs_write+0x30/0x1d0 [c900dee8] [c0152cb8] vfs_write+0xb8/0x1d4 [c900df08] [c0152f7c] ksys_write+0x58/0xe8 [c900df38] [c0014208] ret_from_syscall+0x0/0x34 --- interrupt: c01 at 0xf806664 LR = 0x1000c868 Instruction dump: 4bffff91 80010014 7c832378 7c0803a6 38210010 4e800020 3d20c08a 3ca0c089 8089a0cc 38a58f0c 38600001 4ba2d494 <9421ffe0> 7c0802a6 bfc10018 7c9f2378 Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1b89c121b4070c7ee99e4f22cc178f15a736b07b.1576916812.git.christophe.leroy@c-s.fr
2019-12-21 08:32:29 +00:00
.endm
powerpc/32: Refactor EXCEPTION entry macros for head_8xx.S and head_32.S EXCEPTION_PROLOG is similar in head_8xx.S and head_32.S This patch creates head_32.h and moves EXCEPTION_PROLOG macro into it. It also converts it from a GCC macro to a GAS macro in order to ease refactorisation with 40x later, since GAS macros allows the use of #ifdef/#else/#endif inside it. And it also has the advantage of not requiring the uggly "; \" at the end of each line. This patch also moves EXCEPTION() and EXC_XFER_XXXX() macros which are also similar while adding START_EXCEPTION() out of EXCEPTION(). Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-30 12:38:50 +00:00
#endif /* __HEAD_32_H__ */
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