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Message-Id: <1400786855-32656-3-git-send-email-larry.bassel@linaro.org> Date: Thu, 22 May 2014 12:27:35 -0700 From: Larry Bassel <larry.bassel@...aro.org> To: catalin.marinas@....com, will.deacon@....com Cc: linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org, linaro-kernel@...ts.linaro.org, khilman@...aro.org, Larry Bassel <larry.bassel@...aro.org> Subject: [PATCH v4 2/2] 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. Signed-off-by: Kevin Hilman <khilman@...aro.org> Signed-off-by: Larry Bassel <larry.bassel@...aro.org> --- arch/arm64/Kconfig | 1 + arch/arm64/include/asm/thread_info.h | 1 + arch/arm64/kernel/entry.S | 48 ++++++++++++++++++++++++++++++++++++ 3 files changed, 50 insertions(+) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index e759af5..ef18ae5 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -55,6 +55,7 @@ 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 720e70b..301ea6a 100644 --- a/arch/arm64/include/asm/thread_info.h +++ b/arch/arm64/include/asm/thread_info.h @@ -108,6 +108,7 @@ static inline struct thread_info *current_thread_info(void) #define TIF_SINGLESTEP 21 #define TIF_32BIT 22 /* 32bit process */ #define TIF_SWITCH_MM 23 /* deferred switch_mm */ +#define TIF_NOHZ 24 #define _TIF_SIGPENDING (1 << TIF_SIGPENDING) #define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED) diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index 20b336e..520da4c 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -30,6 +30,44 @@ #include <asm/unistd32.h> /* + * Context tracking subsystem. Used to instrument transitions + * between user and kernel mode. + */ + .macro ct_user_exit, restore = 0 +#ifdef CONFIG_CONTEXT_TRACKING + bl context_tracking_user_exit + .if \restore == 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, save = 0 +#ifdef CONFIG_CONTEXT_TRACKING + .if \save == 1 + /* + * Save/restore only needed on syscall fastpath, which uses + * x0-x2. + */ + push x2, x3 + push x0, x1 + .endif + bl context_tracking_user_enter + .if \save == 1 + pop x0, x1 + pop x2, x3 + .endif +#endif + .endm + +/* * Bad Abort numbers *----------------- */ @@ -91,6 +129,7 @@ .macro kernel_exit, el, ret = 0 ldp x21, x22, [sp, #S_PC] // load ELR, SPSR .if \el == 0 + ct_user_enter \ret ldr x23, [sp, #S_SP] // load return stack pointer .endif .if \ret @@ -318,6 +357,7 @@ el1_irq: bl trace_hardirqs_off #endif + ct_user_exit irq_handler #ifdef CONFIG_PREEMPT @@ -427,6 +467,7 @@ el0_da: mrs x26, far_el1 // enable interrupts before calling the main handler enable_dbg_and_irq + ct_user_exit mov x0, x26 bic x0, x0, #(0xff << 56) mov x1, x25 @@ -440,6 +481,7 @@ 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 @@ -450,6 +492,7 @@ 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 @@ -459,6 +502,7 @@ 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 @@ -481,6 +525,7 @@ 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 @@ -495,10 +540,12 @@ el0_dbg: mov x2, sp bl do_debug_exception enable_dbg + ct_user_exit mov x0, x26 b ret_to_user el0_inv: enable_dbg + ct_user_exit mov x0, sp mov x1, #BAD_SYNC mrs x2, esr_el1 @@ -619,6 +666,7 @@ 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 tracing tbnz x16, #TIF_SYSCALL_TRACE, __sys_trace // are we tracing syscalls? -- 1.8.3.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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