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authorMarkos Chandras <markos.chandras@imgtec.com>2015-09-25 09:17:42 +0200
committerRalf Baechle <ralf@linux-mips.org>2015-10-04 12:10:56 +0200
commitd218af78492a36a4ae607c08fedfb59258440314 (patch)
treefb9a1d1c08161c39c6f8b8db04b0cc116959718b /arch/mips/kernel/scall64-o32.S
parentMIPS: Octeon: Fix kernel panic on startup from memory corruption (diff)
downloadlinux-d218af78492a36a4ae607c08fedfb59258440314.tar.xz
linux-d218af78492a36a4ae607c08fedfb59258440314.zip
MIPS: scall: Always run the seccomp syscall filters
The MIPS syscall handler code used to return -ENOSYS on invalid syscalls. Whilst this is expected, it caused problems for seccomp filters because the said filters never had the change to run since the code returned -ENOSYS before triggering them. This caused problems on the chromium testsuite for filters looking for invalid syscalls. This has now changed and the seccomp filters are always run even if the syscall is invalid. We return -ENOSYS once we return from the seccomp filters. Moreover, similar codepaths have been merged in the process which simplifies somewhat the overall syscall code. Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/11236/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to '')
-rw-r--r--arch/mips/kernel/scall64-o32.S19
1 files changed, 5 insertions, 14 deletions
diff --git a/arch/mips/kernel/scall64-o32.S b/arch/mips/kernel/scall64-o32.S
index 6622980d82ea..6369cfd390c6 100644
--- a/arch/mips/kernel/scall64-o32.S
+++ b/arch/mips/kernel/scall64-o32.S
@@ -87,6 +87,7 @@ loads_done:
and t0, t1, t0
bnez t0, trace_a_syscall
+syscall_common:
jalr t2 # Do The Real Thing (TM)
li t0, -EMAXERRNO - 1 # error?
@@ -130,9 +131,9 @@ trace_a_syscall:
1: jal syscall_trace_enter
- bltz v0, 2f # seccomp failed? Skip syscall
+ bltz v0, 1f # seccomp failed? Skip syscall
- move t0, s0
+ move t2, s0
RESTORE_STATIC
ld a0, PT_R4(sp) # Restore argument registers
ld a1, PT_R5(sp)
@@ -142,19 +143,9 @@ trace_a_syscall:
ld a5, PT_R9(sp)
ld a6, PT_R10(sp)
ld a7, PT_R11(sp) # For indirect syscalls
- jalr t0
+ j syscall_common
- li t0, -EMAXERRNO - 1 # error?
- sltu t0, t0, v0
- sd t0, PT_R7(sp) # set error flag
- beqz t0, 1f
-
- ld t1, PT_R2(sp) # syscall number
- dnegu v0 # error
- sd t1, PT_R0(sp) # save it for syscall restarting
-1: sd v0, PT_R2(sp) # result
-
-2: j syscall_exit
+1: j syscall_exit
/* ------------------------------------------------------------------------ */