xtensa: use actual syscall number in do_syscall_trace_leave

Syscall may alter pt_regs structure passed to it, resulting in a
mismatch between syscall entry end syscall exit entries in the ftrace.
Temporary restore syscall field of the pt_regs for the duration of
do_syscall_trace_leave.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

diff --git a/arch/xtensa/kernel/entry.S b/arch/xtensa/kernel/entry.S
index e50f512..e54af8b 100644 (file)
--- a/arch/xtensa/kernel/entry.S
+++ b/arch/xtensa/kernel/entry.S
@@ -1860,6 +1860,8 @@ ENTRY(system_call)
        l32i    a7, a2, PT_SYSCALL
 
 1:
+       s32i    a7, a1, 4
+
        /* syscall = sys_call_table[syscall_nr] */
 
        movi    a4, sys_call_table
@@ -1893,8 +1895,12 @@ ENTRY(system_call)
        retw
 
 1:
+       l32i    a4, a1, 4
+       l32i    a3, a2, PT_SYSCALL
+       s32i    a4, a2, PT_SYSCALL
        mov     a6, a2
        call4   do_syscall_trace_leave
+       s32i    a3, a2, PT_SYSCALL
        retw
 
 ENDPROC(system_call)