diff options
| author | Stuart Menefy <stuart.menefy@st.com> | 2006-11-24 07:01:36 +0300 |
|---|---|---|
| committer | Paul Mundt <lethal@linux-sh.org> | 2006-12-06 04:45:38 +0300 |
| commit | e0969e0c9b609fdfe217e34f3e046179ffe88eb6 (patch) | |
| tree | e0769039173233ea75d4e9ed87bbcfec690dc446 /arch | |
| parent | c9f0b1c1410e9e637b819c5050fc8c1f1971e178 (diff) | |
| download | linux-e0969e0c9b609fdfe217e34f3e046179ffe88eb6.tar.xz | |
sh: Fix syscall tracing ordering.
The implementation of system call tracing in the kernel has a
couple of ordering problems:
- the validity of the system call number is checked before
calling out to system call tracing code, and should be
done after
- the system call number used when tracing is the one the
system call was invoked with, while the system call tracing
code can legitimatly change the call number (for example
strace permutes fork into clone)
This patch fixes both of these problems, and also reoders the
code slightly to make the direct path through the code the
common case.
Signed-off-by: Stuart Menefy <stuart.menefy@st.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/sh/kernel/entry-common.S | 45 |
1 files changed, 22 insertions, 23 deletions
diff --git a/arch/sh/kernel/entry-common.S b/arch/sh/kernel/entry-common.S index 5bc7fa91d095..8f96d21fcb1c 100644 --- a/arch/sh/kernel/entry-common.S +++ b/arch/sh/kernel/entry-common.S @@ -256,8 +256,7 @@ syscall_trace_entry: mov.l @(OFF_R6,r15), r6 mov.l @(OFF_R7,r15), r7 ! arg3 mov.l @(OFF_R3,r15), r3 ! syscall_nr - ! Arrange for do_syscall_trace to be called - ! again as the system call returns. + ! mov.l 2f, r10 ! Number of syscalls cmp/hs r10, r3 bf syscall_call @@ -273,6 +272,18 @@ __restore_all: .align 2 1: .long restore_all + .align 2 +not_syscall_tra: + bra debug_trap + nop + + .align 2 +syscall_badsys: ! Bad syscall number + mov #-ENOSYS, r0 + bra resume_userspace + mov.l r0, @(OFF_R0,r15) ! Return value + + /* * Syscall interface: * @@ -316,39 +327,27 @@ ENTRY(system_call) ! Is the trap argument >= 0x20? (TRA will be >= 0x80) mov #0x7f, r9 cmp/hi r9, r8 - bt/s 0f + bt/s not_syscall_tra mov #OFF_TRA, r9 add r15, r9 - ! mov.l r8, @r9 ! set TRA value to tra sti - ! Call the system call handler through the table. - ! First check for bad syscall number - mov r3, r9 - mov.l 2f, r8 ! Number of syscalls - cmp/hs r8, r9 - get_current_thread_info r8, r10 - bf good_system_call -syscall_badsys: ! Bad syscall number - mov #-ENOSYS, r0 - bra resume_userspace - mov.l r0, @(OFF_R0,r15) ! Return value ! -0: - bra debug_trap - nop - ! -good_system_call: ! Good syscall number + get_current_thread_info r8, r10 mov.l @(TI_FLAGS,r8), r8 mov #_TIF_SYSCALL_TRACE, r10 tst r10, r8 bf syscall_trace_entry ! + mov.l 2f, r8 ! Number of syscalls + cmp/hs r8, r3 + bt syscall_badsys + ! syscall_call: - shll2 r9 ! x4 + shll2 r3 ! x4 mov.l 3f, r8 ! Load the address of sys_call_table - add r8, r9 - mov.l @r9, r8 + add r8, r3 + mov.l @r3, r8 jsr @r8 ! jump to specific syscall handler nop mov.l @(OFF_R0,r15), r12 ! save r0 |