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).
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).
In order to avoid saving registers, the slow syscall path
is forced (as x86 does).
The calls to ct_user_exit are made after hw debugging has been
enabled (enable_dbg).
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.
Signed-off-by: Kevin Hilman <khil...@linaro.org>
Signed-off-by: Larry Bassel <larry.bas...@linaro.org>
---
arch/arm64/Kconfig | 1 +
arch/arm64/include/asm/thread_info.h | 1 +
arch/arm64/kernel/entry.S | 22 ++++++++++++++++++++++
3 files changed, 24 insertions(+)
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index e6e4d37..152d92b 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 d920d7f..5fe447c 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -30,6 +30,22 @@
#include <asm/unistd32.h>
/*
+ * Context tracking subsystem. Used to instrument transitions
+ * between user and kernel mode.
+ */
+ .macro ct_user_exit
+#ifdef CONFIG_CONTEXT_TRACKING
+ bl context_tracking_user_exit
+#endif
+ .endm
+
+ .macro ct_user_enter
+#ifdef CONFIG_CONTEXT_TRACKING
+ bl context_tracking_user_enter
+#endif
+ .endm
+
+/*
* Bad Abort numbers
*-----------------
*/
@@ -88,6 +104,7 @@
.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
@@ -427,6 +444,7 @@ el0_da:
enable_dbg
// enable interrupts before calling the main handler
enable_irq
+ ct_user_exit
mov x0, x26
bic x0, x0, #(0xff << 56)
mov x1, x25
@@ -443,6 +461,7 @@ 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
@@ -511,6 +530,7 @@ el0_irq_naked:
bl trace_hardirqs_off
#endif
+ ct_user_exit
irq_handler
get_thread_info tsk
@@ -633,10 +653,12 @@ el0_svc_naked: //
compat entry point
isb
enable_dbg
enable_irq
+ ct_user_exit
get_thread_info tsk
ldr x16, [tsk, #TI_FLAGS] // check for syscall tracing
tbnz x16, #TIF_SYSCALL_TRACE, __sys_trace // are we tracing syscalls?
+ tbnz x16, #TIF_NOHZ, __sys_trace
adr lr, ret_fast_syscall // return address
cmp scno, sc_nr // check upper syscall limit
b.hs ni_sys
--
1.8.3.2
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