Refactor syscall_trace_enter() and syscall_trace_exit() to move thread
flag reading to the caller. This aligns arm64's syscall trace enter/exit
function signature with generic entry framework.
[Changes]
1. Function signature changes:
- syscall_trace_enter(regs) → syscall_trace_enter(regs, flags)
- syscall_trace_exit(regs) → syscall_trace_exit(regs, flags)
2. Move flags reading to caller:
- Previously: read_thread_flags() called inside each function.
- Now: caller (like el0_svc_common) passes flags as parameter.
3. Update syscall.c:
- el0_svc_common() now passes flags to tracing functions and
re-fetches flags before exit to handle potential TIF updates.
[Why this matters]
- Aligns arm64 with the generic entry interface.
- Makes future migration to generic entry framework.
No functional changes intended.
Cc: Will Deacon <[email protected]>
Cc: Catalin Marinas <[email protected]>
Reviewed-by: Kevin Brodsky <[email protected]>
Signed-off-by: Jinjie Ruan <[email protected]>
---
arch/arm64/include/asm/syscall.h | 4 ++--
arch/arm64/kernel/ptrace.c | 7 ++-----
arch/arm64/kernel/syscall.c | 5 +++--
3 files changed, 7 insertions(+), 9 deletions(-)
diff --git a/arch/arm64/include/asm/syscall.h b/arch/arm64/include/asm/syscall.h
index 5e4c7fc44f73..30b203ef156b 100644
--- a/arch/arm64/include/asm/syscall.h
+++ b/arch/arm64/include/asm/syscall.h
@@ -120,7 +120,7 @@ static inline int syscall_get_arch(struct task_struct *task)
return AUDIT_ARCH_AARCH64;
}
-int syscall_trace_enter(struct pt_regs *regs);
-void syscall_trace_exit(struct pt_regs *regs);
+int syscall_trace_enter(struct pt_regs *regs, unsigned long flags);
+void syscall_trace_exit(struct pt_regs *regs, unsigned long flags);
#endif /* __ASM_SYSCALL_H */
diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c
index ba5eab23fd90..e4d524ccbc7b 100644
--- a/arch/arm64/kernel/ptrace.c
+++ b/arch/arm64/kernel/ptrace.c
@@ -2408,9 +2408,8 @@ static void report_syscall_exit(struct pt_regs *regs)
}
}
-int syscall_trace_enter(struct pt_regs *regs)
+int syscall_trace_enter(struct pt_regs *regs, unsigned long flags)
{
- unsigned long flags = read_thread_flags();
int ret;
if (flags & (_TIF_SYSCALL_EMU | _TIF_SYSCALL_TRACE)) {
@@ -2432,10 +2431,8 @@ int syscall_trace_enter(struct pt_regs *regs)
return regs->syscallno;
}
-void syscall_trace_exit(struct pt_regs *regs)
+void syscall_trace_exit(struct pt_regs *regs, unsigned long flags)
{
- unsigned long flags = read_thread_flags();
-
audit_syscall_exit(regs);
if (flags & _TIF_SYSCALL_TRACEPOINT)
diff --git a/arch/arm64/kernel/syscall.c b/arch/arm64/kernel/syscall.c
index c062badd1a56..e8fd0d60ab09 100644
--- a/arch/arm64/kernel/syscall.c
+++ b/arch/arm64/kernel/syscall.c
@@ -124,7 +124,7 @@ static void el0_svc_common(struct pt_regs *regs, int scno,
int sc_nr,
*/
if (scno == NO_SYSCALL)
syscall_set_return_value(current, regs, -ENOSYS, 0);
- scno = syscall_trace_enter(regs);
+ scno = syscall_trace_enter(regs, flags);
if (scno == NO_SYSCALL)
goto trace_exit;
}
@@ -143,7 +143,8 @@ static void el0_svc_common(struct pt_regs *regs, int scno,
int sc_nr,
}
trace_exit:
- syscall_trace_exit(regs);
+ flags = read_thread_flags();
+ syscall_trace_exit(regs, flags);
}
void do_el0_svc(struct pt_regs *regs)
--
2.34.1
