From 6c81fe7925cc4c42de49e17be21eb86d1173c3a7 Mon Sep 17 00:00:00 2001 From: Larry Bassel Date: Fri, 30 May 2014 12:34:15 -0700 Subject: [PATCH] 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 --- arch/arm64/Kconfig | 1 + arch/arm64/include/asm/thread_info.h | 5 +++- arch/arm64/kernel/entry.S | 36 ++++++++++++++++++++++++++++ 3 files changed, 41 insertions(+), 1 deletion(-) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index f865436096b6..1cb806529393 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -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. diff --git a/arch/arm64/include/asm/thread_info.h b/arch/arm64/include/asm/thread_info.h index e40b6d06d515..45108d802f5e 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_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 */ diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index d7230bf68ad1..93ac58dbf07c 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 *----------------- @@ -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 -- 2.20.1