[ARM] 3262/4: allow ptraced syscalls to be overriden

Patch from Nicolas Pitre

This is needed by strace to properly handle the tracing of some system
calls. It could be useful for other applications as well.

Based on an earlier patch from Daniel Jacobowitz.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Daniel Jacobowitz <dan@debian.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Nicolas Pitre
2006-01-14 19:30:04 +00:00
committed by Russell King
parent 6c90c87201
commit 3f471126ee
3 changed files with 18 additions and 3 deletions

View File

@@ -214,11 +214,13 @@ ENTRY(vector_swi)
* context switches, and waiting for our parent to respond.
*/
__sys_trace:
mov r2, scno
add r1, sp, #S_OFF
mov r0, #0 @ trace entry [IP = 0]
bl syscall_trace
adr lr, __sys_trace_return @ return address
mov scno, r0 @ syscall number (possibly new)
add r1, sp, #S_R0 + S_OFF @ pointer to regs
cmp scno, #NR_syscalls @ check upper syscall limit
ldmccia r1, {r0 - r3} @ have to reload r0 - r3
@@ -227,6 +229,7 @@ __sys_trace:
__sys_trace_return:
str r0, [sp, #S_R0 + S_OFF]! @ save returned r0
mov r2, scno
mov r1, sp
mov r0, #1 @ trace exit [IP = 1]
bl syscall_trace