arm64: enable context tracking

Make calls to ct_user_enter when the kernel is exited
and ct_user_exit when the kernel is entered (in el0_da,
el0_ia, el0_svc, el0_irq and all of the "error" paths).

These macros expand to function calls which will only work
properly if el0_sync and related code has been rearranged
(in a previous patch of this series).

The calls to ct_user_exit are made after hw debugging has been
enabled (enable_dbg_and_irq).

The call to ct_user_enter is made at the beginning of the
kernel_exit macro.

This patch is based on earlier work by Kevin Hilman.
Save/restore optimizations were also done by Kevin.

Acked-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Kevin Hilman <khilman@linaro.org>
Tested-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Larry Bassel <larry.bassel@linaro.org>
Signed-off-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
This commit is contained in:
Larry Bassel 2014-05-30 12:34:15 -07:00 committed by Catalin Marinas
parent 6ab6463aeb
commit 6c81fe7925
3 changed files with 41 additions and 1 deletions

View File

@ -63,6 +63,7 @@ config ARM64
select RTC_LIB
select SPARSE_IRQ
select SYSCTL_EXCEPTION_TRACE
select HAVE_CONTEXT_TRACKING
help
ARM 64-bit (AArch64) Linux support.

View File

@ -103,6 +103,7 @@ static inline struct thread_info *current_thread_info(void)
#define TIF_NEED_RESCHED 1
#define TIF_NOTIFY_RESUME 2 /* callback before returning to user */
#define TIF_FOREIGN_FPSTATE 3 /* CPU's FP state is not current's */
#define TIF_NOHZ 7
#define TIF_SYSCALL_TRACE 8
#define TIF_SYSCALL_AUDIT 9
#define TIF_SYSCALL_TRACEPOINT 10
@ -118,6 +119,7 @@ static inline struct thread_info *current_thread_info(void)
#define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED)
#define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME)
#define _TIF_FOREIGN_FPSTATE (1 << TIF_FOREIGN_FPSTATE)
#define _TIF_NOHZ (1 << TIF_NOHZ)
#define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE)
#define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT)
#define _TIF_SYSCALL_TRACEPOINT (1 << TIF_SYSCALL_TRACEPOINT)
@ -128,7 +130,8 @@ static inline struct thread_info *current_thread_info(void)
_TIF_NOTIFY_RESUME | _TIF_FOREIGN_FPSTATE)
#define _TIF_SYSCALL_WORK (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | \
_TIF_SYSCALL_TRACEPOINT | _TIF_SECCOMP)
_TIF_SYSCALL_TRACEPOINT | _TIF_SECCOMP | \
_TIF_NOHZ)
#endif /* __KERNEL__ */
#endif /* __ASM_THREAD_INFO_H */

View File

@ -29,6 +29,32 @@
#include <asm/unistd.h>
#include <asm/unistd32.h>
/*
* Context tracking subsystem. Used to instrument transitions
* between user and kernel mode.
*/
.macro ct_user_exit, syscall = 0
#ifdef CONFIG_CONTEXT_TRACKING
bl context_tracking_user_exit
.if \syscall == 1
/*
* Save/restore needed during syscalls. Restore syscall arguments from
* the values already saved on stack during kernel_entry.
*/
ldp x0, x1, [sp]
ldp x2, x3, [sp, #S_X2]
ldp x4, x5, [sp, #S_X4]
ldp x6, x7, [sp, #S_X6]
.endif
#endif
.endm
.macro ct_user_enter
#ifdef CONFIG_CONTEXT_TRACKING
bl context_tracking_user_enter
#endif
.endm
/*
* Bad Abort numbers
*-----------------
@ -91,6 +117,7 @@
.macro kernel_exit, el, ret = 0
ldp x21, x22, [sp, #S_PC] // load ELR, SPSR
.if \el == 0
ct_user_enter
ldr x23, [sp, #S_SP] // load return stack pointer
.endif
.if \ret
@ -426,6 +453,7 @@ el0_da:
mrs x26, far_el1
// enable interrupts before calling the main handler
enable_dbg_and_irq
ct_user_exit
bic x0, x26, #(0xff << 56)
mov x1, x25
mov x2, sp
@ -438,6 +466,7 @@ el0_ia:
mrs x26, far_el1
// enable interrupts before calling the main handler
enable_dbg_and_irq
ct_user_exit
mov x0, x26
orr x1, x25, #1 << 24 // use reserved ISS bit for instruction aborts
mov x2, sp
@ -448,6 +477,7 @@ el0_fpsimd_acc:
* Floating Point or Advanced SIMD access
*/
enable_dbg
ct_user_exit
mov x0, x25
mov x1, sp
adr lr, ret_to_user
@ -457,6 +487,7 @@ el0_fpsimd_exc:
* Floating Point or Advanced SIMD exception
*/
enable_dbg
ct_user_exit
mov x0, x25
mov x1, sp
adr lr, ret_to_user
@ -479,6 +510,7 @@ el0_undef:
*/
// enable interrupts before calling the main handler
enable_dbg_and_irq
ct_user_exit
mov x0, sp
adr lr, ret_to_user
b do_undefinstr
@ -492,9 +524,11 @@ el0_dbg:
mov x2, sp
bl do_debug_exception
enable_dbg
ct_user_exit
b ret_to_user
el0_inv:
enable_dbg
ct_user_exit
mov x0, sp
mov x1, #BAD_SYNC
mrs x2, esr_el1
@ -511,6 +545,7 @@ el0_irq_naked:
bl trace_hardirqs_off
#endif
ct_user_exit
irq_handler
#ifdef CONFIG_TRACE_IRQFLAGS
@ -615,6 +650,7 @@ el0_svc:
el0_svc_naked: // compat entry point
stp x0, scno, [sp, #S_ORIG_X0] // save the original x0 and syscall number
enable_dbg_and_irq
ct_user_exit 1
ldr x16, [tsk, #TI_FLAGS] // check for syscall hooks
tst x16, #_TIF_SYSCALL_WORK