From d99f5abc00687df8b32e3afaee52eac399fef69e Mon Sep 17 00:00:00 2001 From: Larry Bassel Date: Wed, 15 Oct 2014 16:09:39 -0700 Subject: arm64: enable context tracking Backport of the following patch to 3.14 LSK: commit 6c81fe7925cc4c42de49e17be21eb86d1173c3a7 Author: Larry Bassel Date: Fri May 30 12:34:15 2014 -0700 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 Reviewed-by: Kevin Hilman Tested-by: Kevin Hilman Signed-off-by: Larry Bassel Signed-off-by: Kevin Hilman Signed-off-by: Will Deacon Signed-off-by: Catalin Marinas Signed-off-by: Larry Bassel --- arch/arm64/Kconfig | 1 + arch/arm64/include/asm/thread_info.h | 5 ++++- arch/arm64/kernel/entry.S | 38 +++++++++++++++++++++++++++++++++++- 3 files changed, 42 insertions(+), 2 deletions(-) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 43564fce31a8..372eb823e92f 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -64,6 +64,7 @@ config ARM64 select RTC_LIB select SPARSE_IRQ select SYSCTL_EXCEPTION_TRACE + select HAVE_CONTEXT_TRACKING help ARM 64-bit (AArch64) Linux support. diff --git a/arch/arm64/include/asm/thread_info.h b/arch/arm64/include/asm/thread_info.h index 0a8b2a97a32e..cebe0ff4c80e 100644 --- a/arch/arm64/include/asm/thread_info.h +++ b/arch/arm64/include/asm/thread_info.h @@ -103,6 +103,7 @@ static inline struct thread_info *current_thread_info(void) #define TIF_SIGPENDING 0 #define TIF_NEED_RESCHED 1 #define TIF_NOTIFY_RESUME 2 /* callback before returning to user */ +#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_SIGPENDING (1 << TIF_SIGPENDING) #define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED) #define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME) +#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) #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 */ diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index c779ef357e43..e59b7b3500fc 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -29,6 +29,32 @@ #include #include +/* + * 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 *----------------- @@ -88,6 +114,7 @@ .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 @@ -424,6 +451,7 @@ el0_da: enable_dbg // enable interrupts before calling the main handler enable_irq + ct_user_exit bic x0, x26, #(0xff << 56) mov x1, x25 mov x2, sp @@ -439,6 +467,7 @@ el0_ia: enable_dbg // enable interrupts before calling the main handler enable_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 */ + ct_user_exit mov x0, x25 mov x1, sp adr lr, ret_from_exception @@ -456,6 +486,7 @@ el0_fpsimd_exc: /* * Floating Point or Advanced SIMD exception */ + ct_user_exit mov x0, x25 mov x1, sp adr lr, ret_from_exception @@ -479,9 +510,10 @@ el0_undef: /* * Undefined instruction */ - mov x0, sp // enable interrupts before calling the main handler + ct_user_exit enable_irq + mov x0, sp adr lr, ret_from_exception b do_undefinstr el0_dbg: @@ -489,12 +521,14 @@ el0_dbg: * Debug exception handling */ tbnz x24, #0, el0_inv // EL0 only + ct_user_exit mrs x0, far_el1 disable_step x1 mov x1, x25 mov x2, sp b do_debug_exception el0_inv: + ct_user_exit mov x0, sp mov x1, #BAD_SYNC mrs x2, esr_el1 @@ -513,6 +547,7 @@ el0_irq_naked: bl trace_hardirqs_off #endif + ct_user_exit irq_handler get_thread_info tsk @@ -635,6 +670,7 @@ el0_svc_naked: // compat entry point isb enable_dbg enable_irq + ct_user_exit 1 get_thread_info tsk ldr x16, [tsk, #TI_FLAGS] // check for syscall hooks -- cgit v1.2.3