Larry Bassel larry.bassel@linaro.org writes:
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@linaro.org Signed-off-by: Larry Bassel larry.bassel@linaro.org
arch/arm64/Kconfig | 1 + arch/arm64/include/asm/thread_info.h | 4 ++++ arch/arm64/kernel/entry.S | 39 +++++++++++++++++++++++++++++++++++- 3 files changed, 43 insertions(+), 1 deletion(-)
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..8363f34 100644 --- a/arch/arm64/include/asm/thread_info.h +++ b/arch/arm64/include/asm/thread_info.h @@ -100,6 +100,7 @@ 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
FWIW, in earlier versions this was bit 24, but we had to move it into the first 2 bytes..
#define TIF_SYSCALL_TRACE 8 #define TIF_POLLING_NRFLAG 16 #define TIF_MEMDIE 18 /* is terminating due to OOM killer */ @@ -113,9 +114,12 @@ 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_32BIT (1 << TIF_32BIT) +#define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE) +#define _TIF_NOHZ (1 << TIF_NOHZ) #define _TIF_WORK_MASK (_TIF_NEED_RESCHED | _TIF_SIGPENDING | \ _TIF_NOTIFY_RESUME) +#define _TIF_SYSCALL_WORK (_TIF_SYSCALL_TRACE | _TIF_NOHZ)
...so that when this is used...
[...]
@@ -616,9 +651,11 @@ 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?
- and x16, x16, #_TIF_SYSCALL_WORK // are we tracing syscalls?
- cbnz x16, __sys_trace
...here, it doesn't get something like this:
entry.S:697: Error: immediate out of range at operand 3 -- `and x16,x16,#((1<<8)|(1<<24))'
Kevin