On Mon, Oct 08, 2012 at 04:18:06PM -0400, David Miller wrote:
>
> There is an attempt to fix a bad interaction between syscall tracing
> and force_successful_syscall() from Al Viro, but it needs to be redone
> as it introduced regressions and thus had to be reverted for now.
>
> Al is working on an updated version.
See below. Just in case: Linus, please DO NOT APPLY unless it goes through
sparc tree - this is modulo approval by davem.
sparc64: fix ptrace interaction with force_successful_syscall_return()
we want syscall_trace_leave() called on exit from any syscall;
skipping its call in case we'd done force_successful_syscall_return()
is broken...
Signed-off-by: Al Viro <v...@zeniv.linux.org.uk>
diff --git a/arch/sparc/kernel/syscalls.S b/arch/sparc/kernel/syscalls.S
index 1d7e274..7f5f65d 100644
--- a/arch/sparc/kernel/syscalls.S
+++ b/arch/sparc/kernel/syscalls.S
@@ -212,24 +212,20 @@ linux_sparc_syscall:
3: stx %o0, [%sp + PTREGS_OFF + PT_V9_I0]
ret_sys_call:
ldx [%sp + PTREGS_OFF + PT_V9_TSTATE], %g3
- ldx [%sp + PTREGS_OFF + PT_V9_TNPC], %l1 ! pc = npc
sra %o0, 0, %o0
mov %ulo(TSTATE_XCARRY | TSTATE_ICARRY), %g2
sllx %g2, 32, %g2
- /* Check if force_successful_syscall_return()
- * was invoked.
- */
- ldub [%g6 + TI_SYS_NOERROR], %l2
- brnz,a,pn %l2, 80f
- stb %g0, [%g6 + TI_SYS_NOERROR]
-
cmp %o0, -ERESTART_RESTARTBLOCK
bgeu,pn %xcc, 1f
- andcc %l0,
(_TIF_SYSCALL_TRACE|_TIF_SECCOMP|_TIF_SYSCALL_AUDIT|_TIF_SYSCALL_TRACEPOINT),
%l6
-80:
+ andcc %l0,
(_TIF_SYSCALL_TRACE|_TIF_SECCOMP|_TIF_SYSCALL_AUDIT|_TIF_SYSCALL_TRACEPOINT),
%g0
+ ldx [%sp + PTREGS_OFF + PT_V9_TNPC], %l1 ! pc = npc
+
+2:
+ stb %g0, [%g6 + TI_SYS_NOERROR]
/* System call success, clear Carry condition code. */
andn %g3, %g2, %g3
+3:
stx %g3, [%sp + PTREGS_OFF + PT_V9_TSTATE]
bne,pn %icc, linux_syscall_trace2
add %l1, 0x4, %l2 ! npc = npc+4
@@ -238,20 +234,20 @@ ret_sys_call:
stx %l2, [%sp + PTREGS_OFF + PT_V9_TNPC]
1:
+ /* Check if force_successful_syscall_return()
+ * was invoked.
+ */
+ ldub [%g6 + TI_SYS_NOERROR], %l2
+ brnz,pn %l2, 2b
+ ldx [%sp + PTREGS_OFF + PT_V9_TNPC], %l1 ! pc = npc
/* System call failure, set Carry condition code.
* Also, get abs(errno) to return to the process.
*/
- andcc %l0,
(_TIF_SYSCALL_TRACE|_TIF_SECCOMP|_TIF_SYSCALL_AUDIT|_TIF_SYSCALL_TRACEPOINT),
%l6
sub %g0, %o0, %o0
- or %g3, %g2, %g3
stx %o0, [%sp + PTREGS_OFF + PT_V9_I0]
- stx %g3, [%sp + PTREGS_OFF + PT_V9_TSTATE]
- bne,pn %icc, linux_syscall_trace2
- add %l1, 0x4, %l2 ! npc = npc+4
- stx %l1, [%sp + PTREGS_OFF + PT_V9_TPC]
+ ba,pt %xcc, 3b
+ or %g3, %g2, %g3
- b,pt %xcc, rtrap
- stx %l2, [%sp + PTREGS_OFF + PT_V9_TNPC]
linux_syscall_trace2:
call syscall_trace_leave
add %sp, PTREGS_OFF, %o0
--
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