Commit graph

25754 commits

Author SHA1 Message Date
Michael Ellerman
33a4aa08d5 powerpc/fsl: Fix mfpmr build errors with newer binutils
[ Upstream commit 5f491356b7 ]

Binutils 2.38 complains about the use of mfpmr when building
ppc6xx_defconfig:

    CC      arch/powerpc/kernel/pmc.o
  {standard input}: Assembler messages:
  {standard input}:45: Error: unrecognized opcode: `mfpmr'
  {standard input}:56: Error: unrecognized opcode: `mtpmr'

This is because by default the kernel is built with -mcpu=powerpc, and
the mt/mfpmr instructions are not defined.

It can be avoided by enabling CONFIG_E300C3_CPU, but just adding that to
the defconfig will leave open the possibility of randconfig failures.

So add machine directives around the mt/mfpmr instructions to tell
binutils how to assemble them.

Cc: stable@vger.kernel.org
Reported-by: Jan-Benedict Glaw <jbglaw@lug-owl.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240229122521.762431-3-mpe@ellerman.id.au
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-04-03 15:19:29 +02:00
Michael Ellerman
605ddb3a6e powerpc/smp: Increase nr_cpu_ids to include the boot CPU
[ Upstream commit 777f81f0a9 ]

If nr_cpu_ids is too low to include the boot CPU adjust nr_cpu_ids
upward. Otherwise the kernel will BUG when trying to allocate a paca
for the boot CPU and fail to boot.

Cc: stable@vger.kernel.org
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231229120107.2281153-2-mpe@ellerman.id.au
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-04-03 15:19:26 +02:00
Michael Ellerman
334fb14389 powerpc/smp: Adjust nr_cpu_ids to cover all threads of a core
[ Upstream commit 5580e96dad ]

If nr_cpu_ids is too low to include at least all the threads of a single
core adjust nr_cpu_ids upwards. This avoids triggering odd bugs in code
that assumes all threads of a core are available.

Cc: stable@vger.kernel.org
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231229120107.2281153-1-mpe@ellerman.id.au
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-04-03 15:19:26 +02:00
Michael Ellerman
c2c32faae8 powerpc/embedded6xx: Fix no previous prototype for avr_uart_send() etc.
[ Upstream commit 20933531be ]

Move the prototypes into mpc10x.h which is included by all the relevant
C files, fixes:

  arch/powerpc/platforms/embedded6xx/ls_uart.c:59:6: error: no previous prototype for 'avr_uart_configure'
  arch/powerpc/platforms/embedded6xx/ls_uart.c:82:6: error: no previous prototype for 'avr_uart_send'

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240305123410.3306253-1-mpe@ellerman.id.au
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-03-26 18:20:52 -04:00
Kajol Jain
48feaf23f3 powerpc/hv-gpci: Fix the H_GET_PERF_COUNTER_INFO hcall return value checks
[ Upstream commit ad86d7ee43 ]

Running event hv_gpci/dispatch_timebase_by_processor_processor_time_in_timebase_cycles,phys_processor_idx=0/
in one of the system throws below error:

 ---Logs---
 # perf list | grep hv_gpci/dispatch_timebase_by_processor_processor_time_in_timebase_cycles
  hv_gpci/dispatch_timebase_by_processor_processor_time_in_timebase_cycles,phys_processor_idx=?/[Kernel PMU event]

 # perf stat -v -e hv_gpci/dispatch_timebase_by_processor_processor_time_in_timebase_cycles,phys_processor_idx=0/ sleep 2
Using CPUID 00800200
Control descriptor is not initialized
Warning:
hv_gpci/dispatch_timebase_by_processor_processor_time_in_timebase_cycles,phys_processor_idx=0/ event is not supported by the kernel.
failed to read counter hv_gpci/dispatch_timebase_by_processor_processor_time_in_timebase_cycles,phys_processor_idx=0/

 Performance counter stats for 'system wide':

   <not supported>      hv_gpci/dispatch_timebase_by_processor_processor_time_in_timebase_cycles,phys_processor_idx=0/

       2.000700771 seconds time elapsed

The above error is because of the hcall failure as required
permission "Enable Performance Information Collection" is not set.
Based on current code, single_gpci_request function did not check the
error type incase hcall fails and by default returns EINVAL. But we can
have other reasons for hcall failures like H_AUTHORITY/H_PARAMETER with
detail_rc as GEN_BUF_TOO_SMALL, for which we need to act accordingly.

Fix this issue by adding new checks in the single_gpci_request and
h_gpci_event_init functions.

Result after fix patch changes:

 # perf stat -e hv_gpci/dispatch_timebase_by_processor_processor_time_in_timebase_cycles,phys_processor_idx=0/ sleep 2
Error:
No permission to enable hv_gpci/dispatch_timebase_by_processor_processor_time_in_timebase_cycles,phys_processor_idx=0/ event.

Fixes: 220a0c609a ("powerpc/perf: Add support for the hv gpci (get performance counter info) interface")
Reported-by: Akanksha J N <akanksha@linux.ibm.com>
Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240229122847.101162-1-kjain@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-03-26 18:20:52 -04:00
Qiheng Lin
a3f22feb22 powerpc/pseries: Fix potential memleak in papr_get_attr()
[ Upstream commit cda9c0d556 ]

`buf` is allocated in papr_get_attr(), and krealloc() of `buf`
could fail. We need to free the original `buf` in the case of failure.

Fixes: 3c14b73454 ("powerpc/pseries: Interface to represent PAPR firmware attributes")
Signed-off-by: Qiheng Lin <linqiheng@huawei.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20221208133449.16284-1-linqiheng@huawei.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-03-26 18:20:52 -04:00
Christophe Leroy
b494caad9c powerpc: Force inlining of arch_vmap_p{u/m}d_supported()
[ Upstream commit c5aebb53b3 ]

arch_vmap_pud_supported() and arch_vmap_pmd_supported() are
expected to constant-fold to false when RADIX is not enabled.

Force inlining in order to avoid following failure which
leads to unexpected call of non-existing pud_set_huge() and
pmd_set_huge() on powerpc 8xx.

In function 'pud_huge_tests',
    inlined from 'debug_vm_pgtable' at mm/debug_vm_pgtable.c:1399:2:
./arch/powerpc/include/asm/vmalloc.h:9:33: warning: inlining failed in call to 'arch_vmap_pud_supported.isra': call is unlikely and code size would grow [-Winline]
    9 | #define arch_vmap_pud_supported arch_vmap_pud_supported
      |                                 ^~~~~~~~~~~~~~~~~~~~~~~
./arch/powerpc/include/asm/vmalloc.h:10:20: note: in expansion of macro 'arch_vmap_pud_supported'
   10 | static inline bool arch_vmap_pud_supported(pgprot_t prot)
      |                    ^~~~~~~~~~~~~~~~~~~~~~~
./arch/powerpc/include/asm/vmalloc.h:9:33: note: called from here
    9 | #define arch_vmap_pud_supported arch_vmap_pud_supported
mm/debug_vm_pgtable.c:458:14: note: in expansion of macro 'arch_vmap_pud_supported'
  458 |         if (!arch_vmap_pud_supported(args->page_prot) ||
      |              ^~~~~~~~~~~~~~~~~~~~~~~

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202402131836.OU1TDuoi-lkp@intel.com/
Fixes: 8309c9d717 ("powerpc: inline huge vmap supported functions")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/bbd84ad52bf377e8d3b5865a906f2dc5d99964ba.1707832677.git.christophe.leroy@csgroup.eu
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-03-26 18:20:48 -04:00
Gaurav Batra
7eb95e0af5 powerpc/pseries/iommu: IOMMU table is not initialized for kdump over SR-IOV
[ Upstream commit 09a3c1e461 ]

When kdump kernel tries to copy dump data over SR-IOV, LPAR panics due
to NULL pointer exception:

  Kernel attempted to read user page (0) - exploit attempt? (uid: 0)
  BUG: Kernel NULL pointer dereference on read at 0x00000000
  Faulting instruction address: 0xc000000020847ad4
  Oops: Kernel access of bad area, sig: 11 [#1]
  LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA pSeries
  Modules linked in: mlx5_core(+) vmx_crypto pseries_wdt papr_scm libnvdimm mlxfw tls psample sunrpc fuse overlay squashfs loop
  CPU: 12 PID: 315 Comm: systemd-udevd Not tainted 6.4.0-Test102+ #12
  Hardware name: IBM,9080-HEX POWER10 (raw) 0x800200 0xf000006 of:IBM,FW1060.00 (NH1060_008) hv:phyp pSeries
  NIP:  c000000020847ad4 LR: c00000002083b2dc CTR: 00000000006cd18c
  REGS: c000000029162ca0 TRAP: 0300   Not tainted  (6.4.0-Test102+)
  MSR:  800000000280b033 <SF,VEC,VSX,EE,FP,ME,IR,DR,RI,LE>  CR: 48288244  XER: 00000008
  CFAR: c00000002083b2d8 DAR: 0000000000000000 DSISR: 40000000 IRQMASK: 1
  ...
  NIP _find_next_zero_bit+0x24/0x110
  LR  bitmap_find_next_zero_area_off+0x5c/0xe0
  Call Trace:
    dev_printk_emit+0x38/0x48 (unreliable)
    iommu_area_alloc+0xc4/0x180
    iommu_range_alloc+0x1e8/0x580
    iommu_alloc+0x60/0x130
    iommu_alloc_coherent+0x158/0x2b0
    dma_iommu_alloc_coherent+0x3c/0x50
    dma_alloc_attrs+0x170/0x1f0
    mlx5_cmd_init+0xc0/0x760 [mlx5_core]
    mlx5_function_setup+0xf0/0x510 [mlx5_core]
    mlx5_init_one+0x84/0x210 [mlx5_core]
    probe_one+0x118/0x2c0 [mlx5_core]
    local_pci_probe+0x68/0x110
    pci_call_probe+0x68/0x200
    pci_device_probe+0xbc/0x1a0
    really_probe+0x104/0x540
    __driver_probe_device+0xb4/0x230
    driver_probe_device+0x54/0x130
    __driver_attach+0x158/0x2b0
    bus_for_each_dev+0xa8/0x130
    driver_attach+0x34/0x50
    bus_add_driver+0x16c/0x300
    driver_register+0xa4/0x1b0
    __pci_register_driver+0x68/0x80
    mlx5_init+0xb8/0x100 [mlx5_core]
    do_one_initcall+0x60/0x300
    do_init_module+0x7c/0x2b0

At the time of LPAR dump, before kexec hands over control to kdump
kernel, DDWs (Dynamic DMA Windows) are scanned and added to the FDT.
For the SR-IOV case, default DMA window "ibm,dma-window" is removed from
the FDT and DDW added, for the device.

Now, kexec hands over control to the kdump kernel.

When the kdump kernel initializes, PCI busses are scanned and IOMMU
group/tables created, in pci_dma_bus_setup_pSeriesLP(). For the SR-IOV
case, there is no "ibm,dma-window". The original commit: b1fc44eaa9,
fixes the path where memory is pre-mapped (direct mapped) to the DDW.
When TCEs are direct mapped, there is no need to initialize IOMMU
tables.

iommu_table_setparms_lpar() only considers "ibm,dma-window" property
when initiallizing IOMMU table. In the scenario where TCEs are
dynamically allocated for SR-IOV, newly created IOMMU table is not
initialized. Later, when the device driver tries to enter TCEs for the
SR-IOV device, NULL pointer execption is thrown from iommu_area_alloc().

The fix is to initialize the IOMMU table with DDW property stored in the
FDT. There are 2 points to remember:

	1. For the dedicated adapter, kdump kernel would encounter both
	   default and DDW in FDT. In this case, DDW property is used to
	   initialize the IOMMU table.

	2. A DDW could be direct or dynamic mapped. kdump kernel would
	   initialize IOMMU table and mark the existing DDW as
	   "dynamic". This works fine since, at the time of table
	   initialization, iommu_table_clear() makes some space in the
	   DDW, for some predefined number of TCEs which are needed for
	   kdump to succeed.

Fixes: b1fc44eaa9 ("pseries/iommu/ddw: Fix kdump to work in absence of ibm,dma-window")
Signed-off-by: Gaurav Batra <gbatra@linux.vnet.ibm.com>
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240125203017.61014-1-gbatra@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-03-06 14:45:19 +00:00
Shrikanth Hegde
c194adaa8a powerpc/pseries: fix accuracy of stolen time
commit cbecc9fcbb upstream.

powerVM hypervisor updates the VPA fields with stolen time data.
It currently reports enqueue_dispatch_tb and ready_enqueue_tb for
this purpose. In linux these two fields are used to report the stolen time.

The VPA fields are updated at the TB frequency. On powerPC its mostly
set at 512Mhz. Hence this needs a conversion to ns when reporting it
back as rest of the kernel timings are in ns. This conversion is already
handled in tb_to_ns function. So use that function to report accurate
stolen time.

Observed this issue and used an Capped Shared Processor LPAR(SPLPAR) to
simplify the experiments. In all these cases, 100% VP Load is run using
stress-ng workload. Values of stolen time is in percentages as reported
by mpstat. With the patch values are close to expected.

		6.8.rc1		+Patch
12EC/12VP	   0.0		   0.0
12EC/24VP	  25.7		  50.2
12EC/36VP	  37.3		  69.2
12EC/48VP	  38.5		  78.3

Fixes: 0e8a631328 ("powerpc/pseries: Implement CONFIG_PARAVIRT_TIME_ACCOUNTING")
Cc: stable@vger.kernel.org # v6.1+
Signed-off-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240213052635.231597-1-sshegde@linux.ibm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-02-23 09:12:43 +01:00
David Engraf
42422f8f8c powerpc/cputable: Add missing PPC_FEATURE_BOOKE on PPC64 Book-E
commit eb6d871f4b upstream.

Commit e320a76db4 ("powerpc/cputable: Split cpu_specs[] out of
cputable.h") moved the cpu_specs to separate header files. Previously
PPC_FEATURE_BOOKE was enabled by CONFIG_PPC_BOOK3E_64. The definition in
cpu_specs_e500mc.h for PPC64 no longer enables PPC_FEATURE_BOOKE.

This breaks user space reading the ELF hwcaps and expect
PPC_FEATURE_BOOKE. Debugging an application with gdb is no longer
working on e5500/e6500 because the 64-bit detection relies on
PPC_FEATURE_BOOKE for Book-E.

Fixes: e320a76db4 ("powerpc/cputable: Split cpu_specs[] out of cputable.h")
Cc: stable@vger.kernel.org # v6.1+
Signed-off-by: David Engraf <david.engraf@sysgo.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240207092758.1058893-1-david.engraf@sysgo.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-02-23 09:12:43 +01:00
Naveen N Rao
76d3ad7d02 powerpc/64: Set task pt_regs->link to the LR value on scv entry
commit aad98efd0b upstream.

Nysal reported that userspace backtraces are missing in offcputime bcc
tool. As an example:
    $ sudo ./bcc/tools/offcputime.py -uU
    Tracing off-CPU time (us) of user threads by user stack... Hit Ctrl-C to end.

    ^C
	write
	-                python (9107)
	    8

	write
	-                sudo (9105)
	    9

	mmap
	-                python (9107)
	    16

	clock_nanosleep
	-                multipathd (697)
	    3001604

The offcputime bcc tool attaches a bpf program to a kprobe on
finish_task_switch(), which is usually hit on a syscall from userspace.
With the switch to system call vectored, we started setting
pt_regs->link to zero. This is because system call vectored behaves like
a function call with LR pointing to the system call return address, and
with no modification to SRR0/SRR1. The LR value does indicate our next
instruction, so it is being saved as pt_regs->nip, and pt_regs->link is
being set to zero. This is not a problem by itself, but BPF uses perf
callchain infrastructure for capturing stack traces, and that stores LR
as the second entry in the stack trace. perf has code to cope with the
second entry being zero, and skips over it. However, generic userspace
unwinders assume that a zero entry indicates end of the stack trace,
resulting in a truncated userspace stack trace.

Rather than fixing all userspace unwinders to ignore/skip past the
second entry, store the real LR value in pt_regs->link so that there
continues to be a valid, though duplicate entry in the stack trace.

With this change:
    $ sudo ./bcc/tools/offcputime.py -uU
    Tracing off-CPU time (us) of user threads by user stack... Hit Ctrl-C to end.

    ^C
	write
	write
	[unknown]
	[unknown]
	[unknown]
	[unknown]
	[unknown]
	PyObject_VectorcallMethod
	[unknown]
	[unknown]
	PyObject_CallOneArg
	PyFile_WriteObject
	PyFile_WriteString
	[unknown]
	[unknown]
	PyObject_Vectorcall
	_PyEval_EvalFrameDefault
	PyEval_EvalCode
	[unknown]
	[unknown]
	[unknown]
	_PyRun_SimpleFileObject
	_PyRun_AnyFileObject
	Py_RunMain
	[unknown]
	Py_BytesMain
	[unknown]
	__libc_start_main
	-                python (1293)
	    7

	write
	write
	[unknown]
	sudo_ev_loop_v1
	sudo_ev_dispatch_v1
	[unknown]
	[unknown]
	[unknown]
	[unknown]
	__libc_start_main
	-                sudo (1291)
	    7

	syscall
	syscall
	bpf_open_perf_buffer_opts
	[unknown]
	[unknown]
	[unknown]
	[unknown]
	_PyObject_MakeTpCall
	PyObject_Vectorcall
	_PyEval_EvalFrameDefault
	PyEval_EvalCode
	[unknown]
	[unknown]
	[unknown]
	_PyRun_SimpleFileObject
	_PyRun_AnyFileObject
	Py_RunMain
	[unknown]
	Py_BytesMain
	[unknown]
	__libc_start_main
	-                python (1293)
	    11

	clock_nanosleep
	clock_nanosleep
	nanosleep
	sleep
	[unknown]
	[unknown]
	__clone
	-                multipathd (698)
	    3001661

Fixes: 7fa95f9ada ("powerpc/64s: system call support for scv/rfscv instructions")
Cc: stable@vger.kernel.org
Reported-by: "Nysal Jan K.A" <nysal@linux.ibm.com>
Signed-off-by: Naveen N Rao <naveen@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240202154316.395276-1-naveen@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-02-23 09:12:42 +01:00
Michael Ellerman
4297217bcf powerpc/kasan: Limit KASAN thread size increase to 32KB
[ Upstream commit f1acb10950 ]

KASAN is seen to increase stack usage, to the point that it was reported
to lead to stack overflow on some 32-bit machines (see link).

To avoid overflows the stack size was doubled for KASAN builds in
commit 3e8635fb2e ("powerpc/kasan: Force thread size increase with
KASAN").

However with a 32KB stack size to begin with, the doubling leads to a
64KB stack, which causes build errors:
  arch/powerpc/kernel/switch.S:249: Error: operand out of range (0x000000000000fe50 is not between 0xffffffffffff8000 and 0x0000000000007fff)

Although the asm could be reworked, in practice a 32KB stack seems
sufficient even for KASAN builds - the additional usage seems to be in
the 2-3KB range for a 64-bit KASAN build.

So only increase the stack for KASAN if the stack size is < 32KB.

Fixes: 18f14afe28 ("powerpc/64s: Increase default stack size to 32KB")
Reported-by: Spoorthy <spoorthy@linux.ibm.com>
Reported-by: Benjamin Gray <bgray@linux.ibm.com>
Reviewed-by: Benjamin Gray <bgray@linux.ibm.com>
Link: https://lore.kernel.org/linuxppc-dev/bug-207129-206035@https.bugzilla.kernel.org%2F/
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240212064244.3924505-1-mpe@ellerman.id.au
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-02-23 09:12:35 +01:00
Jiangfeng Xiao
0c09912dd8 powerpc/kasan: Fix addr error caused by page alignment
[ Upstream commit 4a7aee9620 ]

In kasan_init_region, when k_start is not page aligned, at the begin of
for loop, k_cur = k_start & PAGE_MASK is less than k_start, and then
`va = block + k_cur - k_start` is less than block, the addr va is invalid,
because the memory address space from va to block is not alloced by
memblock_alloc, which will not be reserved by memblock_reserve later, it
will be used by other places.

As a result, memory overwriting occurs.

for example:
int __init __weak kasan_init_region(void *start, size_t size)
{
[...]
	/* if say block(dcd97000) k_start(feef7400) k_end(feeff3fe) */
	block = memblock_alloc(k_end - k_start, PAGE_SIZE);
	[...]
	for (k_cur = k_start & PAGE_MASK; k_cur < k_end; k_cur += PAGE_SIZE) {
		/* at the begin of for loop
		 * block(dcd97000) va(dcd96c00) k_cur(feef7000) k_start(feef7400)
		 * va(dcd96c00) is less than block(dcd97000), va is invalid
		 */
		void *va = block + k_cur - k_start;
		[...]
	}
[...]
}

Therefore, page alignment is performed on k_start before
memblock_alloc() to ensure the validity of the VA address.

Fixes: 663c0c9496 ("powerpc/kasan: Fix shadow area set up for modules.")
Signed-off-by: Jiangfeng Xiao <xiaojiangfeng@huawei.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/1705974359-43790-1-git-send-email-xiaojiangfeng@huawei.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-02-23 09:12:35 +01:00
Linus Torvalds
f70efe54b9 work around gcc bugs with 'asm goto' with outputs
commit 68fb3ca0e4 upstream.

We've had issues with gcc and 'asm goto' before, and we created a
'asm_volatile_goto()' macro for that in the past: see commits
3f0116c323 ("compiler/gcc4: Add quirk for 'asm goto' miscompilation
bug") and a9f180345f ("compiler/gcc4: Make quirk for
asm_volatile_goto() unconditional").

Then, much later, we ended up removing the workaround in commit
43c249ea0b ("compiler-gcc.h: remove ancient workaround for gcc PR
58670") because we no longer supported building the kernel with the
affected gcc versions, but we left the macro uses around.

Now, Sean Christopherson reports a new version of a very similar
problem, which is fixed by re-applying that ancient workaround.  But the
problem in question is limited to only the 'asm goto with outputs'
cases, so instead of re-introducing the old workaround as-is, let's
rename and limit the workaround to just that much less common case.

It looks like there are at least two separate issues that all hit in
this area:

 (a) some versions of gcc don't mark the asm goto as 'volatile' when it
     has outputs:

        https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98619
        https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110420

     which is easy to work around by just adding the 'volatile' by hand.

 (b) Internal compiler errors:

        https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110422

     which are worked around by adding the extra empty 'asm' as a
     barrier, as in the original workaround.

but the problem Sean sees may be a third thing since it involves bad
code generation (not an ICE) even with the manually added 'volatile'.

The same old workaround works for this case, even if this feels a
bit like voodoo programming and may only be hiding the issue.

Reported-and-tested-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/all/20240208220604.140859-1-seanjc@google.com/
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Uros Bizjak <ubizjak@gmail.com>
Cc: Jakub Jelinek <jakub@redhat.com>
Cc: Andrew Pinski <quic_apinski@quicinc.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-02-23 09:12:28 +01:00
Arnd Bergmann
d6c8d8ab76 arch: consolidate arch_irq_work_raise prototypes
[ Upstream commit 64bac5ea17 ]

The prototype was hidden in an #ifdef on x86, which causes a warning:

kernel/irq_work.c:72:13: error: no previous prototype for 'arch_irq_work_raise' [-Werror=missing-prototypes]

Some architectures have a working prototype, while others don't.
Fix this by providing it in only one place that is always visible.

Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
Acked-by: Guo Ren <guoren@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-02-05 20:12:49 +00:00
Naveen N Rao
abd26515d4 powerpc/lib: Validate size for vector operations
[ Upstream commit 8f9abaa6d7 ]

Some of the fp/vmx code in sstep.c assume a certain maximum size for the
instructions being emulated. The size of those operations however is
determined separately in analyse_instr().

Add a check to validate the assumption on the maximum size of the
operations, so as to prevent any unintended kernel stack corruption.

Signed-off-by: Naveen N Rao <naveen@kernel.org>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Build-tested-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231123071705.397625-1-naveen@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-02-05 20:12:47 +00:00
Stephen Rothwell
0be5614f26 powerpc: pmd_move_must_withdraw() is only needed for CONFIG_TRANSPARENT_HUGEPAGE
[ Upstream commit 0d555b57ee ]

The linux-next build of powerpc64 allnoconfig fails with:

  arch/powerpc/mm/book3s64/pgtable.c:557:5: error: no previous prototype for 'pmd_move_must_withdraw'
    557 | int pmd_move_must_withdraw(struct spinlock *new_pmd_ptl,
        |     ^~~~~~~~~~~~~~~~~~~~~~

Caused by commit:

  c6345dfa6e3e ("Makefile.extrawarn: turn on missing-prototypes globally")

Fix it by moving the function definition under
CONFIG_TRANSPARENT_HUGEPAGE like the prototype. The function is only
called when CONFIG_TRANSPARENT_HUGEPAGE=y.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
[mpe: Flesh out change log from linux-next patch]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231127132809.45c2b398@canb.auug.org.au
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-02-05 20:12:47 +00:00
Michael Ellerman
a6fd14db75 powerpc/64s: Fix CONFIG_NUMA=n build due to create_section_mapping()
[ Upstream commit ede66cd224 ]

With CONFIG_NUMA=n the build fails with:

  arch/powerpc/mm/book3s64/pgtable.c:275:15: error: no previous prototype for ‘create_section_mapping’ [-Werror=missing-prototypes]
  275 | int __meminit create_section_mapping(unsigned long start, unsigned long end,
      |               ^~~~~~~~~~~~~~~~~~~~~~

That happens because the prototype for create_section_mapping() is in
asm/mmzone.h, but asm/mmzone.h is only included by linux/mmzone.h
when CONFIG_NUMA=y.

In fact the prototype is only needed by arch/powerpc/mm code, so move
the prototype into arch/powerpc/mm/mmu_decl.h, which also fixes the
build error.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231129131919.2528517-5-mpe@ellerman.id.au
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-02-05 20:12:46 +00:00
Michael Ellerman
cf3256c431 powerpc/mm: Fix build failures due to arch_reserved_kernel_pages()
[ Upstream commit d8c3f243d4 ]

With NUMA=n and FA_DUMP=y or PRESERVE_FA_DUMP=y the build fails with:

  arch/powerpc/kernel/fadump.c:1739:22: error: no previous prototype for ‘arch_reserved_kernel_pages’ [-Werror=missing-prototypes]
  1739 | unsigned long __init arch_reserved_kernel_pages(void)
       |                      ^~~~~~~~~~~~~~~~~~~~~~~~~~

The prototype for arch_reserved_kernel_pages() is in include/linux/mm.h,
but it's guarded by __HAVE_ARCH_RESERVED_KERNEL_PAGES. The powerpc
headers define __HAVE_ARCH_RESERVED_KERNEL_PAGES in asm/mmzone.h, which
is not included into the generic headers when NUMA=n.

Move the definition of __HAVE_ARCH_RESERVED_KERNEL_PAGES into asm/mmu.h
which is included regardless of NUMA=n.

Additionally the ifdef around __HAVE_ARCH_RESERVED_KERNEL_PAGES needs to
also check for CONFIG_PRESERVE_FA_DUMP.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231130114433.3053544-1-mpe@ellerman.id.au
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-02-05 20:12:46 +00:00
Michael Ellerman
7ad4b2a6b2 powerpc: Fix build error due to is_valid_bugaddr()
[ Upstream commit f8d3555355 ]

With CONFIG_GENERIC_BUG=n the build fails with:

  arch/powerpc/kernel/traps.c:1442:5: error: no previous prototype for ‘is_valid_bugaddr’ [-Werror=missing-prototypes]
  1442 | int is_valid_bugaddr(unsigned long addr)
       |     ^~~~~~~~~~~~~~~~

The prototype is only defined, and the function is only needed, when
CONFIG_GENERIC_BUG=y, so move the implementation under that.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231130114433.3053544-2-mpe@ellerman.id.au
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-02-05 20:12:46 +00:00
Kunwu Chan
d482d61025 powerpc/mm: Fix null-pointer dereference in pgtable_cache_add
[ Upstream commit f46c8a7526 ]

kasprintf() returns a pointer to dynamically allocated memory
which can be NULL upon failure. Ensure the allocation was successful
by checking the pointer validity.

Suggested-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Kunwu Chan <chentao@kylinos.cn>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231204023223.2447523-1-chentao@kylinos.cn
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-02-05 20:12:46 +00:00
Sasha Levin
f9a4c401bf Revert "powerpc/64s: Increase default stack size to 32KB"
This reverts commit 9ccf64e763 which is
upstream commit 18f14afe28.

Breaks the build:

arch/powerpc/kvm/book3s_hv_rmhandlers.S:2689: Error: operand out of range (0x0000000000008310 is not between 0xffffffffffff8001 and 0x0000000000008000)
make[3]: *** [scripts/Makefile.build:382: arch/powerpc/kvm/book3s_hv_rmhandlers.o] Error 1

Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-01-31 16:17:10 -08:00
Michael Ellerman
9ccf64e763 powerpc/64s: Increase default stack size to 32KB
commit 18f14afe28 upstream.

There are reports of kernels crashing due to stack overflow while
running OpenShift (Kubernetes). The primary contributor to the stack
usage seems to be openvswitch, which is used by OVN-Kubernetes (based on
OVN (Open Virtual Network)), but NFS also contributes in some stack
traces.

There may be some opportunities to reduce stack usage in the openvswitch
code, but doing so potentially require tradeoffs vs performance, and
also requires testing across architectures.

Looking at stack usage across the kernel (using -fstack-usage), shows
that ppc64le stack frames are on average 50-100% larger than the
equivalent function built for x86-64. Which is not surprising given the
minimum stack frame size is 32 bytes on ppc64le vs 16 bytes on x86-64.

So increase the default stack size to 32KB for the modern 64-bit Book3S
platforms, ie. pseries (virtualised) and powernv (bare metal). That
leaves the older systems like G5s, and the AmigaOne (pasemi) with a 16KB
stack which should be sufficient on those machines.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Aneesh Kumar K.V (IBM) <aneesh.kumar@kernel.org>
Link: https://msgid.link/20231215124449.317597-1-mpe@ellerman.id.au
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-25 15:27:39 -08:00
Kunwu Chan
a2da3f9b1a powerpc/imc-pmu: Add a null pointer check in update_events_in_group()
[ Upstream commit 0a233867a3 ]

kasprintf() returns a pointer to dynamically allocated memory
which can be NULL upon failure.

Fixes: 885dcd709b ("powerpc/perf: Add nest IMC PMU support")
Signed-off-by: Kunwu Chan <chentao@kylinos.cn>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231126093719.1440305-1-chentao@kylinos.cn
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-01-25 15:27:19 -08:00
Kunwu Chan
f152a6bfd1 powerpc/powernv: Add a null pointer check in opal_powercap_init()
[ Upstream commit e123015c0b ]

kasprintf() returns a pointer to dynamically allocated memory
which can be NULL upon failure.

Fixes: b9ef7b4b86 ("powerpc: Convert to using %pOFn instead of device_node.name")
Signed-off-by: Kunwu Chan <chentao@kylinos.cn>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231126095739.1501990-1-chentao@kylinos.cn
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-01-25 15:27:19 -08:00
Kunwu Chan
9a523e1da6 powerpc/powernv: Add a null pointer check in opal_event_init()
[ Upstream commit 8649829a1d ]

kasprintf() returns a pointer to dynamically allocated memory
which can be NULL upon failure.

Fixes: 2717a33d60 ("powerpc/opal-irqchip: Use interrupt names if present")
Signed-off-by: Kunwu Chan <chentao@kylinos.cn>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231127030755.1546750-1-chentao@kylinos.cn
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-01-25 15:27:19 -08:00
Kunwu Chan
ed8d023cfa powerpc/powernv: Add a null pointer check to scom_debug_init_one()
[ Upstream commit 9a260f2dd8 ]

kasprintf() returns a pointer to dynamically allocated memory
which can be NULL upon failure.
Add a null pointer check, and release 'ent' to avoid memory leaks.

Fixes: bfd2f0d49a ("powerpc/powernv: Get rid of old scom_controller abstraction")
Signed-off-by: Kunwu Chan <chentao@kylinos.cn>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231208085937.107210-1-chentao@kylinos.cn
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-01-25 15:27:19 -08:00
Nathan Lynch
026fd977dc powerpc/pseries/memhp: Fix access beyond end of drmem array
[ Upstream commit bd68ffce69 ]

dlpar_memory_remove_by_index() may access beyond the bounds of the
drmem lmb array when the LMB lookup fails to match an entry with the
given DRC index. When the search fails, the cursor is left pointing to
&drmem_info->lmbs[drmem_info->n_lmbs], which is one element past the
last valid entry in the array. The debug message at the end of the
function then dereferences this pointer:

        pr_debug("Failed to hot-remove memory at %llx\n",
                 lmb->base_addr);

This was found by inspection and confirmed with KASAN:

  pseries-hotplug-mem: Attempting to hot-remove LMB, drc index 1234
  ==================================================================
  BUG: KASAN: slab-out-of-bounds in dlpar_memory+0x298/0x1658
  Read of size 8 at addr c000000364e97fd0 by task bash/949

  dump_stack_lvl+0xa4/0xfc (unreliable)
  print_report+0x214/0x63c
  kasan_report+0x140/0x2e0
  __asan_load8+0xa8/0xe0
  dlpar_memory+0x298/0x1658
  handle_dlpar_errorlog+0x130/0x1d0
  dlpar_store+0x18c/0x3e0
  kobj_attr_store+0x68/0xa0
  sysfs_kf_write+0xc4/0x110
  kernfs_fop_write_iter+0x26c/0x390
  vfs_write+0x2d4/0x4e0
  ksys_write+0xac/0x1a0
  system_call_exception+0x268/0x530
  system_call_vectored_common+0x15c/0x2ec

  Allocated by task 1:
   kasan_save_stack+0x48/0x80
   kasan_set_track+0x34/0x50
   kasan_save_alloc_info+0x34/0x50
   __kasan_kmalloc+0xd0/0x120
   __kmalloc+0x8c/0x320
   kmalloc_array.constprop.0+0x48/0x5c
   drmem_init+0x2a0/0x41c
   do_one_initcall+0xe0/0x5c0
   kernel_init_freeable+0x4ec/0x5a0
   kernel_init+0x30/0x1e0
   ret_from_kernel_user_thread+0x14/0x1c

  The buggy address belongs to the object at c000000364e80000
   which belongs to the cache kmalloc-128k of size 131072
  The buggy address is located 0 bytes to the right of
   allocated 98256-byte region [c000000364e80000, c000000364e97fd0)

  ==================================================================
  pseries-hotplug-mem: Failed to hot-remove memory at 0

Log failed lookups with a separate message and dereference the
cursor only when it points to a valid entry.

Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Fixes: 51925fb3c5 ("powerpc/pseries: Implement memory hotplug remove in the kernel")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231114-pseries-memhp-fixes-v1-1-fb8f2bb7c557@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-01-25 15:27:19 -08:00
Randy Dunlap
63df75d383 powerpc/44x: select I2C for CURRITUCK
[ Upstream commit 4a74197b65 ]

Fix build errors when CURRITUCK=y and I2C is not builtin (=m or is
not set). Fixes these build errors:

powerpc-linux-ld: arch/powerpc/platforms/44x/ppc476.o: in function `avr_halt_system':
ppc476.c:(.text+0x58): undefined reference to `i2c_smbus_write_byte_data'
powerpc-linux-ld: arch/powerpc/platforms/44x/ppc476.o: in function `ppc47x_device_probe':
ppc476.c:(.init.text+0x18): undefined reference to `i2c_register_driver'

Fixes: 2a2c74b2ef ("IBM Akebono: Add the Akebono platform")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: kernel test robot <lkp@intel.com>
Closes: lore.kernel.org/r/202312010820.cmdwF5X9-lkp@intel.com
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231201055159.8371-1-rdunlap@infradead.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-01-25 15:27:19 -08:00
Masahiro Yamada
2fc51c4b7d powerpc: add crtsavres.o to always-y instead of extra-y
[ Upstream commit 1b1e380026 ]

crtsavres.o is linked to modules. However, as explained in commit
d0e628cd81 ("kbuild: doc: clarify the difference between extra-y
and always-y"), 'make modules' does not build extra-y.

For example, the following command fails:

  $ make ARCH=powerpc LLVM=1 KBUILD_MODPOST_WARN=1 mrproper ps3_defconfig modules
    [snip]
    LD [M]  arch/powerpc/platforms/cell/spufs/spufs.ko
  ld.lld: error: cannot open arch/powerpc/lib/crtsavres.o: No such file or directory
  make[3]: *** [scripts/Makefile.modfinal:56: arch/powerpc/platforms/cell/spufs/spufs.ko] Error 1
  make[2]: *** [Makefile:1844: modules] Error 2
  make[1]: *** [/home/masahiro/workspace/linux-kbuild/Makefile:350: __build_one_by_one] Error 2
  make: *** [Makefile:234: __sub-make] Error 2

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Fixes: baa25b571a ("powerpc/64: Do not link crtsavres.o in vmlinux")
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231120232332.4100288-1-masahiroy@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-01-25 15:27:19 -08:00
Masahiro Yamada
16b88e68b8 powerpc: remove checks for binutils older than 2.25
[ Upstream commit 54a11654de ]

Commit e441273947 ("Documentation: raise minimum supported version of
binutils to 2.25") allows us to remove the checks for old binutils.

There is no more user for ld-ifversion. Remove it as well.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230119082250.151485-1-masahiroy@kernel.org
Stable-dep-of: 1b1e380026 ("powerpc: add crtsavres.o to always-y instead of extra-y")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-01-25 15:27:18 -08:00
Naveen N Rao
1c077acf24 powerpc/ftrace: Fix stack teardown in ftrace_no_trace
[ Upstream commit 4b3338aaa7 ]

Commit 41a506ef71 ("powerpc/ftrace: Create a dummy stackframe to fix
stack unwind") added use of a new stack frame on ftrace entry to fix
stack unwind. However, the commit missed updating the offset used while
tearing down the ftrace stack when ftrace is disabled. Fix the same.

In addition, the commit missed saving the correct stack pointer in
pt_regs. Update the same.

Fixes: 41a506ef71 ("powerpc/ftrace: Create a dummy stackframe to fix stack unwind")
Cc: stable@vger.kernel.org # v6.5+
Signed-off-by: Naveen N Rao <naveen@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231130065947.2188860-1-naveen@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-12-20 17:00:14 +01:00
Timothy Pearson
c23b9eaca8 powerpc: Don't clobber f0/vs0 during fp|altivec register save
commit 5e1d824f9a upstream.

During floating point and vector save to thread data f0/vs0 are
clobbered by the FPSCR/VSCR store routine. This has been obvserved to
lead to userspace register corruption and application data corruption
with io-uring.

Fix it by restoring f0/vs0 after FPSCR/VSCR store has completed for
all the FP, altivec, VMX register save paths.

Tested under QEMU in kvm mode, running on a Talos II workstation with
dual POWER9 DD2.2 CPUs.

Additional detail (mpe):

Typically save_fpu() is called from __giveup_fpu() which saves the FP
regs and also *turns off FP* in the tasks MSR, meaning the kernel will
reload the FP regs from the thread struct before letting the task use FP
again. So in that case save_fpu() is free to clobber f0 because the FP
regs no longer hold live values for the task.

There is another case though, which is the path via:
  sys_clone()
    ...
    copy_process()
      dup_task_struct()
        arch_dup_task_struct()
          flush_all_to_thread()
            save_all()

That path saves the FP regs but leaves them live. That's meant as an
optimisation for a process that's using FP/VSX and then calls fork(),
leaving the regs live means the parent process doesn't have to take a
fault after the fork to get its FP regs back. The optimisation was added
in commit 8792468da5 ("powerpc: Add the ability to save FPU without
giving it up").

That path does clobber f0, but f0 is volatile across function calls,
and typically programs reach copy_process() from userspace via a syscall
wrapper function. So in normal usage f0 being clobbered across a
syscall doesn't cause visible data corruption.

But there is now a new path, because io-uring can call copy_process()
via create_io_thread() from the signal handling path. That's OK if the
signal is handled as part of syscall return, but it's not OK if the
signal is handled due to some other interrupt.

That path is:

interrupt_return_srr_user()
  interrupt_exit_user_prepare()
    interrupt_exit_user_prepare_main()
      do_notify_resume()
        get_signal()
          task_work_run()
            create_worker_cb()
              create_io_worker()
                copy_process()
                  dup_task_struct()
                    arch_dup_task_struct()
                      flush_all_to_thread()
                        save_all()
                          if (tsk->thread.regs->msr & MSR_FP)
                            save_fpu()
                            # f0 is clobbered and potentially live in userspace

Note the above discussion applies equally to save_altivec().

Fixes: 8792468da5 ("powerpc: Add the ability to save FPU without giving it up")
Cc: stable@vger.kernel.org # v4.6+
Closes: https://lore.kernel.org/all/480932026.45576726.1699374859845.JavaMail.zimbra@raptorengineeringinc.com/
Closes: https://lore.kernel.org/linuxppc-dev/480221078.47953493.1700206777956.JavaMail.zimbra@raptorengineeringinc.com/
Tested-by: Timothy Pearson <tpearson@raptorengineering.com>
Tested-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Timothy Pearson <tpearson@raptorengineering.com>
[mpe: Reword change log to describe exact path of corruption & other minor tweaks]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/1921539696.48534988.1700407082933.JavaMail.zimbra@raptorengineeringinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-12-08 08:51:15 +01:00
Nicholas Piggin
e6bc42fae6 KVM: PPC: Book3S HV: Fix KVM_RUN clobbering FP/VEC user registers
commit dc158d23b3 upstream.

Before running a guest, the host process (e.g., QEMU) FP/VEC registers
are saved if they were being used, similarly to when the kernel uses FP
registers. The guest values are then loaded into regs, and the host
process registers will be restored lazily when it uses FP/VEC.

KVM HV has a bug here: the host process registers do get saved, but the
user MSR bits remain enabled, which indicates the registers are valid
for the process. After they are clobbered by running the guest, this
valid indication causes the host process to take on the FP/VEC register
values of the guest.

Fixes: 34e119c96b ("KVM: PPC: Book3S HV P9: Reduce mtmsrd instructions required to save host SPRs")
Cc: stable@vger.kernel.org # v5.17+
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231122025811.2973-1-npiggin@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-12-08 08:51:15 +01:00
Michael Ellerman
6460508dce powerpc/powernv: Fix fortify source warnings in opal-prd.c
commit feea65a338 upstream.

As reported by Mahesh & Aneesh, opal_prd_msg_notifier() triggers a
FORTIFY_SOURCE warning:

  memcpy: detected field-spanning write (size 32) of single field "&item->msg" at arch/powerpc/platforms/powernv/opal-prd.c:355 (size 4)
  WARNING: CPU: 9 PID: 660 at arch/powerpc/platforms/powernv/opal-prd.c:355 opal_prd_msg_notifier+0x174/0x188 [opal_prd]
  NIP opal_prd_msg_notifier+0x174/0x188 [opal_prd]
  LR  opal_prd_msg_notifier+0x170/0x188 [opal_prd]
  Call Trace:
    opal_prd_msg_notifier+0x170/0x188 [opal_prd] (unreliable)
    notifier_call_chain+0xc0/0x1b0
    atomic_notifier_call_chain+0x2c/0x40
    opal_message_notify+0xf4/0x2c0

This happens because the copy is targeting item->msg, which is only 4
bytes in size, even though the enclosing item was allocated with extra
space following the msg.

To fix the warning define struct opal_prd_msg with a union of the header
and a flex array, and have the memcpy target the flex array.

Reported-by: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Reported-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Tested-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Reviewed-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230821142820.497107-1-mpe@ellerman.id.au
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-11-28 17:07:23 +00:00
Nicholas Piggin
bee4f891fe powerpc/perf: Fix disabling BHRB and instruction sampling
commit ea142e590a upstream.

When the PMU is disabled, MMCRA is not updated to disable BHRB and
instruction sampling. This can lead to those features remaining enabled,
which can slow down a real or emulated CPU.

Fixes: 1cade527f6 ("powerpc/perf: BHRB control to disable BHRB logic when not used")
Cc: stable@vger.kernel.org # v5.9+
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231018153423.298373-1-npiggin@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-11-28 17:07:07 +00:00
Wang Yufen
abdd1f47ef powerpc/pseries: fix potential memory leak in init_cpu_associativity()
[ Upstream commit 95f1a128cd ]

If the vcpu_associativity alloc memory successfully but the
pcpu_associativity fails to alloc memory, the vcpu_associativity
memory leaks.

Fixes: d62c8deeb6 ("powerpc/pseries: Provide vcpu dispatch statistics")
Signed-off-by: Wang Yufen <wangyufen@huawei.com>
Reviewed-by: "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/1671003983-10794-1-git-send-email-wangyufen@huawei.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-11-20 11:52:12 +01:00
Sebastian Andrzej Siewior
257517c00b powerpc/imc-pmu: Use the correct spinlock initializer.
[ Upstream commit 007240d59c ]

The macro __SPIN_LOCK_INITIALIZER() is implementation specific. Users
that desire to initialize a spinlock in a struct must use
__SPIN_LOCK_UNLOCKED().

Use __SPIN_LOCK_UNLOCKED() for the spinlock_t in imc_global_refc.

Fixes: 76d588dddc ("powerpc/imc-pmu: Fix use of mutex in IRQs disabled section")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230309134831.Nz12nqsU@linutronix.de
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-11-20 11:52:12 +01:00
Haren Myneni
8409ee076d powerpc/vas: Limit open window failure messages in log bufffer
[ Upstream commit 73b25505ce ]

The VAS open window call prints error message and returns -EBUSY
after the migration suspend event initiated and until the resume
event completed on the destination system. It can cause the log
buffer filled with these error messages if the user space issues
continuous open window calls.  Similar case even for DLPAR CPU
remove event when no credits are available until the credits are
freed or with the other DLPAR CPU add event.

So changes in the patch to use pr_err_ratelimited() instead of
pr_err() to display open window failure and not-available credits
error messages.

Use pr_fmt() and make the corresponding changes to have the
consistencein prefix all pr_*() messages (vas-api.c).

Fixes: 37e6764895 ("powerpc/pseries/vas: Add VAS migration handler")
Signed-off-by: Haren Myneni <haren@linux.ibm.com>
[mpe: Use "vas-api" as the prefix to match the file name.]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231019215033.1335251-1-haren@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-11-20 11:52:12 +01:00
Benjamin Gray
0f8dabe79a powerpc/xive: Fix endian conversion size
[ Upstream commit ff7a60ab1e ]

Sparse reports a size mismatch in the endian swap. The Opal
implementation[1] passes the value as a __be64, and the receiving
variable out_qsize is a u64, so the use of be32_to_cpu() appears to be
an error.

[1]: https://github.com/open-power/skiboot/blob/80e2b1dc73/hw/xive.c#L3854

Fixes: 88ec6b93c8 ("powerpc/xive: add OPAL extensions for the XIVE native exploitation support")
Signed-off-by: Benjamin Gray <bgray@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231011053711.93427-2-bgray@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-11-20 11:52:12 +01:00
Christophe Leroy
b4bc030af7 powerpc/40x: Remove stale PTE_ATOMIC_UPDATES macro
[ Upstream commit cc8ee288f4 ]

40x TLB handlers were reworked by commit 2c74e2586b ("powerpc/40x:
Rework 40x PTE access and TLB miss") to not require PTE_ATOMIC_UPDATES
anymore.

Then commit 4e1df545e2 ("powerpc/pgtable: Drop PTE_ATOMIC_UPDATES")
removed all code related to PTE_ATOMIC_UPDATES.

Remove left over PTE_ATOMIC_UPDATES macro.

Fixes: 2c74e2586b ("powerpc/40x: Rework 40x PTE access and TLB miss")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/f061db5857fcd748f84a6707aad01754686ce97e.1695659959.git.christophe.leroy@csgroup.eu
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-11-20 11:52:12 +01:00
Christophe Leroy
9d4f7441cd powerpc: Only define __parse_fpscr() when required
[ Upstream commit c7e0d9bb91 ]

Clang 17 reports:

arch/powerpc/kernel/traps.c:1167:19: error: unused function '__parse_fpscr' [-Werror,-Wunused-function]

__parse_fpscr() is called from two sites. First call is guarded
by #ifdef CONFIG_PPC_FPU_REGS

Second call is guarded by CONFIG_MATH_EMULATION which selects
CONFIG_PPC_FPU_REGS.

So only define __parse_fpscr() when CONFIG_PPC_FPU_REGS is defined.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202309210327.WkqSd5Bq-lkp@intel.com/
Fixes: b6254ced4d ("powerpc/signal: Don't manage floating point regs when no FPU")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/5de2998c57f3983563b27b39228ea9a7229d4110.1695385984.git.christophe.leroy@csgroup.eu
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-11-20 11:52:12 +01:00
Michael Ellerman
ed0ba37e7b powerpc/mm: Fix boot crash with FLATMEM
[ Upstream commit daa9ada209 ]

Erhard reported that his G5 was crashing with v6.6-rc kernels:

  mpic: Setting up HT PICs workarounds for U3/U4
  BUG: Unable to handle kernel data access at 0xfeffbb62ffec65fe
  Faulting instruction address: 0xc00000000005dc40
  Oops: Kernel access of bad area, sig: 11 [#1]
  BE PAGE_SIZE=4K MMU=Hash SMP NR_CPUS=2 PowerMac
  Modules linked in:
  CPU: 0 PID: 0 Comm: swapper/0 Tainted: G                T  6.6.0-rc3-PMacGS #1
  Hardware name: PowerMac11,2 PPC970MP 0x440101 PowerMac
  NIP:  c00000000005dc40 LR: c000000000066660 CTR: c000000000007730
  REGS: c0000000022bf510 TRAP: 0380   Tainted: G                T (6.6.0-rc3-PMacGS)
  MSR:  9000000000001032 <SF,HV,ME,IR,DR,RI>  CR: 44004242  XER: 00000000
  IRQMASK: 3
  GPR00: 0000000000000000 c0000000022bf7b0 c0000000010c0b00 00000000000001ac
  GPR04: 0000000003c80000 0000000000000300 c0000000f20001ae 0000000000000300
  GPR08: 0000000000000006 feffbb62ffec65ff 0000000000000001 0000000000000000
  GPR12: 9000000000001032 c000000002362000 c000000000f76b80 000000000349ecd8
  GPR16: 0000000002367ba8 0000000002367f08 0000000000000006 0000000000000000
  GPR20: 00000000000001ac c000000000f6f920 c0000000022cd985 000000000000000c
  GPR24: 0000000000000300 00000003b0a3691d c0003e008030000e 0000000000000000
  GPR28: c00000000000000c c0000000f20001ee feffbb62ffec65fe 00000000000001ac
  NIP hash_page_do_lazy_icache+0x50/0x100
  LR  __hash_page_4K+0x420/0x590
  Call Trace:
    hash_page_mm+0x364/0x6f0
    do_hash_fault+0x114/0x2b0
    data_access_common_virt+0x198/0x1f0
  --- interrupt: 300 at mpic_init+0x4bc/0x10c4
  NIP:  c000000002020a5c LR: c000000002020a04 CTR: 0000000000000000
  REGS: c0000000022bf9f0 TRAP: 0300   Tainted: G                T (6.6.0-rc3-PMacGS)
  MSR:  9000000000001032 <SF,HV,ME,IR,DR,RI>  CR: 24004248  XER: 00000000
  DAR: c0003e008030000e DSISR: 40000000 IRQMASK: 1
  ...
  NIP mpic_init+0x4bc/0x10c4
  LR  mpic_init+0x464/0x10c4
  --- interrupt: 300
    pmac_setup_one_mpic+0x258/0x2dc
    pmac_pic_init+0x28c/0x3d8
    init_IRQ+0x90/0x140
    start_kernel+0x57c/0x78c
    start_here_common+0x1c/0x20

A bisect pointed to the breakage beginning with commit 9fee28baa6 ("powerpc:
implement the new page table range API").

Analysis of the oops pointed to a struct page with a corrupted
compound_head being loaded via page_folio() -> _compound_head() in
hash_page_do_lazy_icache().

The access by the mpic code is to an MMIO address, so the expectation
is that the struct page for that address would be initialised by
init_unavailable_range(), as pointed out by Aneesh.

Instrumentation showed that was not the case, which eventually lead to
the realisation that pfn_valid() was returning false for that address,
causing the struct page to not be initialised.

Because the system is using FLATMEM, the version of pfn_valid() in
memory_model.h is used:

static inline int pfn_valid(unsigned long pfn)
{
	...
	return pfn >= pfn_offset && (pfn - pfn_offset) < max_mapnr;
}

Which relies on max_mapnr being initialised. Early in boot max_mapnr is
zero meaning no PFNs are valid.

max_mapnr is initialised in mem_init() called via:

  start_kernel()
    mm_core_init()  # init/main.c:928
      mem_init()

But that is too late for the usage in init_unavailable_range() called via:

  start_kernel()
    setup_arch()    # init/main.c:893
      paging_init()
        free_area_init()
          init_unavailable_range()

Although max_mapnr is currently set in mem_init(), the value is actually
already available much earlier, as soon as mem_topology_setup() has
completed, which is also before paging_init() is called. So move the
initialisation there, which causes paging_init() to correctly initialise
the struct page and fixes the bug.

This bug seems to have been lurking for years, but went unnoticed
because the pre-folio code was inspecting the uninitialised page->flags
but not dereferencing it.

Thanks to Erhard and Aneesh for help debugging.

Reported-by: Erhard Furtner <erhard_f@mailbox.org>
Closes: https://lore.kernel.org/all/20230929132750.3cd98452@yea/
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231023112500.1550208-1-mpe@ellerman.id.au
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-11-08 14:11:02 +01:00
Christophe Leroy
c64c237275 powerpc/85xx: Fix math emulation exception
[ Upstream commit 8e8a12ecbc ]

Booting mpc85xx_defconfig kernel on QEMU leads to:

Bad trap at PC: fe9bab0, SR: 2d000, vector=800
awk[82]: unhandled trap (5) at 0 nip fe9bab0 lr fe9e01c code 5 in libc-2.27.so[fe5a000+17a000]
awk[82]: code: 3aa00000 3a800010 4bffe03c 9421fff0 7ca62b78 38a00000 93c10008 83c10008
awk[82]: code: 38210010 4bffdec8 9421ffc0 7c0802a6 <fc00048e> d8010008 4815190d 93810030
Trace/breakpoint trap
WARNING: no useful console

This is because allthough CONFIG_MATH_EMULATION is selected,
Exception 800 calls unknown_exception().

Call emulation_assist_interrupt() instead.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/066caa6d9480365da9b8ed83692d7101e10ac5f8.1695657339.git.christophe.leroy@csgroup.eu
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-11-08 14:10:58 +01:00
Christophe Leroy
54357fcafa powerpc/64e: Fix wrong test in __ptep_test_and_clear_young()
[ Upstream commit 5ea0bbaa32 ]

Commit 45201c8794 ("powerpc/nohash: Remove hash related code from
nohash headers.") replaced:

  if ((pte_val(*ptep) & (_PAGE_ACCESSED | _PAGE_HASHPTE)) == 0)
	return 0;

By:

  if (pte_young(*ptep))
	return 0;

But it should be:

  if (!pte_young(*ptep))
	return 0;

Fix it.

Fixes: 45201c8794 ("powerpc/nohash: Remove hash related code from nohash headers.")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/8bb7f06494e21adada724ede47a4c3d97e879d40.1695659959.git.christophe.leroy@csgroup.eu
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-10-19 23:08:58 +02:00
Christophe Leroy
0afcc9d4a1 powerpc/8xx: Fix pte_access_permitted() for PAGE_NONE
[ Upstream commit 5d9cea8a55 ]

On 8xx, PAGE_NONE is handled by setting _PAGE_NA instead of clearing
_PAGE_USER.

But then pte_user() returns 1 also for PAGE_NONE.

As _PAGE_NA prevent reads, add a specific version of pte_read()
that returns 0 when _PAGE_NA is set instead of always returning 1.

Fixes: 351750331f ("powerpc/mm: Introduce _PAGE_NA")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/57bcfbe578e43123f9ed73e040229b80f1ad56ec.1695659959.git.christophe.leroy@csgroup.eu
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-10-19 23:08:58 +02:00
Michael Ellerman
8ac2689502 powerpc/47x: Fix 47x syscall return crash
commit f0eee815ba upstream.

Eddie reported that newer kernels were crashing during boot on his 476
FSP2 system:

  kernel tried to execute user page (b7ee2000) - exploit attempt? (uid: 0)
  BUG: Unable to handle kernel instruction fetch
  Faulting instruction address: 0xb7ee2000
  Oops: Kernel access of bad area, sig: 11 [#1]
  BE PAGE_SIZE=4K FSP-2
  Modules linked in:
  CPU: 0 PID: 61 Comm: mount Not tainted 6.1.55-d23900f.ppcnf-fsp2 #1
  Hardware name: ibm,fsp2 476fpe 0x7ff520c0 FSP-2
  NIP:  b7ee2000 LR: 8c008000 CTR: 00000000
  REGS: bffebd83 TRAP: 0400   Not tainted (6.1.55-d23900f.ppcnf-fs p2)
  MSR:  00000030 <IR,DR>  CR: 00001000  XER: 20000000
  GPR00: c00110ac bffebe63 bffebe7e bffebe88 8c008000 00001000 00000d12 b7ee2000
  GPR08: 00000033 00000000 00000000 c139df10 48224824 1016c314 10160000 00000000
  GPR16: 10160000 10160000 00000008 00000000 10160000 00000000 10160000 1017f5b0
  GPR24: 1017fa50 1017f4f0 1017fa50 1017f740 1017f630 00000000 00000000 1017f4f0
  NIP [b7ee2000] 0xb7ee2000
  LR [8c008000] 0x8c008000
  Call Trace:
  Instruction dump:
  XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX
  XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX
  ---[ end trace 0000000000000000 ]---

The problem is in ret_from_syscall where the check for
icache_44x_need_flush is done. When the flush is needed the code jumps
out-of-line to do the flush, and then intends to jump back to continue
the syscall return.

However the branch back to label 1b doesn't return to the correct
location, instead branching back just prior to the return to userspace,
causing bogus register values to be used by the rfi.

The breakage was introduced by commit 6f76a01173
("powerpc/syscall: implement system call entry/exit logic in C for PPC32") which
inadvertently removed the "1" label and reused it elsewhere.

Fix it by adding named local labels in the correct locations. Note that
the return label needs to be outside the ifdef so that CONFIG_PPC_47x=n
compiles.

Fixes: 6f76a01173 ("powerpc/syscall: implement system call entry/exit logic in C for PPC32")
Cc: stable@vger.kernel.org # v5.12+
Reported-by: Eddie James <eajames@linux.ibm.com>
Tested-by: Eddie James <eajames@linux.ibm.com>
Link: https://lore.kernel.org/linuxppc-dev/fdaadc46-7476-9237-e104-1d2168526e72@linux.ibm.com/
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Link: https://msgid.link/20231010114750.847794-1-mpe@ellerman.id.au
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-10-19 23:08:56 +02:00
Benjamin Gray
c93aa8cfae powerpc/watchpoints: Annotate atomic context in more places
[ Upstream commit 27646b2e02 ]

It can be easy to miss that the notifier mechanism invokes the callbacks
in an atomic context, so add some comments to that effect on the two
handlers we register here.

Signed-off-by: Benjamin Gray <bgray@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230829063457.54157-4-bgray@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-10-06 14:56:57 +02:00
Benjamin Gray
3632e9fd82 powerpc/watchpoint: Disable pagefaults when getting user instruction
[ Upstream commit 3241f260eb ]

This is called in an atomic context, so is not allowed to sleep if a
user page needs to be faulted in and has nowhere it can be deferred to.
The pagefault_disabled() function is documented as preventing user
access methods from sleeping.

In practice the page will be mapped in nearly always because we are
reading the instruction that just triggered the watchpoint trap.

Signed-off-by: Benjamin Gray <bgray@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230829063457.54157-3-bgray@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-10-06 14:56:57 +02:00
Benjamin Gray
16722418cb powerpc/watchpoints: Disable preemption in thread_change_pc()
[ Upstream commit cc879ab3ce ]

thread_change_pc() uses CPU local data, so must be protected from
swapping CPUs while it is reading the breakpoint struct.

The error is more noticeable after 1e60f3564b ("powerpc/watchpoints:
Track perf single step directly on the breakpoint"), which added an
unconditional __this_cpu_read() call in thread_change_pc(). However the
existing __this_cpu_read() that runs if a breakpoint does need to be
re-inserted has the same issue.

Signed-off-by: Benjamin Gray <bgray@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230829063457.54157-2-bgray@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-10-06 14:56:57 +02:00