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authorLarry Bassel <larry.bassel@linaro.org>2014-05-30 21:34:15 +0200
committerCatalin Marinas <catalin.marinas@arm.com>2014-07-10 11:10:21 +0200
commit6c81fe7925cc4c42de49e17be21eb86d1173c3a7 (patch)
tree386156dd2370309268d9455d09782dc0638428a0 /arch/arm64/kernel/entry.S
parentarm64: adjust el0_sync so that a function can be called (diff)
downloadlinux-6c81fe7925cc4c42de49e17be21eb86d1173c3a7.tar.xz
linux-6c81fe7925cc4c42de49e17be21eb86d1173c3a7.zip
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>
Diffstat (limited to 'arch/arm64/kernel/entry.S')
-rw-r--r--arch/arm64/kernel/entry.S36
1 files changed, 36 insertions, 0 deletions
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
@@ -30,6 +30,32 @@
#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