[PATCH 168/241] sparc64: fix ptrace interaction with force_successful_syscall_return()

From: Herton Ronaldo Krzesinski
Date: Thu Dec 13 2012 - 09:31:34 EST


3.5.7.2 -stable review patch. If anyone has any objections, please let me know.

------------------

From: Al Viro <viro@xxxxxxxxxxxxxxxxxx>

commit 55c2770e413e96871147b9406a9c41fe9bc5209c upstream.

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 <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski@xxxxxxxxxxxxx>
---
arch/sparc/kernel/syscalls.S | 32 ++++++++++++++------------------
1 file changed, 14 insertions(+), 18 deletions(-)

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
--
1.7.9.5

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