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authorAl Viro <viro@ftp.linux.org.uk>2010-09-28 19:50:37 +0200
committerRalf Baechle <ralf@linux-mips.org>2010-10-18 17:59:02 +0200
commit8f5a00eb422ed86e77bb8f67e08b9fe6d30f679a (patch)
tree6b625361c9581fb71fd2d005b5de54804d4f9798 /arch/mips/kernel/scall32-o32.S
parentMIPS: secure_computing, syscall audit: syscall number should in r2, not r0. (diff)
downloadlinux-8f5a00eb422ed86e77bb8f67e08b9fe6d30f679a.tar.xz
linux-8f5a00eb422ed86e77bb8f67e08b9fe6d30f679a.zip
MIPS: Sanitize restart logics
Put the original syscall number into ->regs[0] when we leave syscall with error. Use it in restart logics. Everything else will have it 0 since we pass through SAVE_SOME on all the ways in. Note that in places like bad_stack and inllegal_syscall we leave it 0 - it's not restartable. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Cc: linux-kernel@vger.kernel.org Cc: linux-arch@vger.kernel.org Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/1698/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch/mips/kernel/scall32-o32.S')
-rw-r--r--arch/mips/kernel/scall32-o32.S9
1 files changed, 4 insertions, 5 deletions
diff --git a/arch/mips/kernel/scall32-o32.S b/arch/mips/kernel/scall32-o32.S
index 17202bbe843f..73a061e85531 100644
--- a/arch/mips/kernel/scall32-o32.S
+++ b/arch/mips/kernel/scall32-o32.S
@@ -63,9 +63,9 @@ stack_done:
sw t0, PT_R7(sp) # set error flag
beqz t0, 1f
+ lw t1, PT_R2(sp) # syscall number
negu v0 # error
- sw v0, PT_R0(sp) # set flag for syscall
- # restarting
+ sw t1, PT_R0(sp) # save it for syscall restarting
1: sw v0, PT_R2(sp) # result
o32_syscall_exit:
@@ -104,9 +104,9 @@ syscall_trace_entry:
sw t0, PT_R7(sp) # set error flag
beqz t0, 1f
+ lw t1, PT_R2(sp) # syscall number
negu v0 # error
- sw v0, PT_R0(sp) # set flag for syscall
- # restarting
+ sw t1, PT_R0(sp) # save it for syscall restarting
1: sw v0, PT_R2(sp) # result
j syscall_exit
@@ -170,7 +170,6 @@ stackargs:
*/
bad_stack:
negu v0 # error
- sw v0, PT_R0(sp)
sw v0, PT_R2(sp)
li t0, 1 # set error flag
sw t0, PT_R7(sp)