Techwizz/kernel-fxtec-pro1x
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

ARM: 7474/1: get rid of TIF_SYSCALL_RESTARTSYS

Browse source 
just let do_work_pending() return 1 on normal local restarts and
-1 on those that had been caused by ERESTART_RESTARTBLOCK (and 0
is still "all done, sod off to userland now").  And let the asm
glue flip scno to restart_syscall(2) one if it got negative from
us...

[will: resolved conflicts with audit fixes]

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Al Viro 2012-07-19 17:48:50 +01:00 committed by Russell King
parent 81783786d5
commit 6628521784
4 changed files with 10 additions and 20 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

5
arch/arm/include/asm/thread_info.h
View file

@ -148,7 +148,6 @@ extern int vfp_restore_user_hwstate(struct user_vfp __user *,
#define TIF_NOTIFY_RESUME 2 /* callback before returning to user */
#define TIF_SYSCALL_TRACE 8
#define TIF_SYSCALL_AUDIT 9
#define TIF_SYSCALL_RESTARTSYS 10
#define TIF_POLLING_NRFLAG 16
#define TIF_USING_IWMMXT 17
#define TIF_MEMDIE 18 /* is terminating due to OOM killer */
@ -164,11 +163,9 @@ extern int vfp_restore_user_hwstate(struct user_vfp __user *,
#define _TIF_POLLING_NRFLAG (1 << TIF_POLLING_NRFLAG)
#define _TIF_USING_IWMMXT (1 << TIF_USING_IWMMXT)
#define _TIF_SECCOMP (1 << TIF_SECCOMP)
#define _TIF_SYSCALL_RESTARTSYS (1 << TIF_SYSCALL_RESTARTSYS)
/* Checks for any syscall work in entry-common.S */
#define _TIF_SYSCALL_WORK (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | \
_TIF_SYSCALL_RESTARTSYS)
#define _TIF_SYSCALL_WORK (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT)
/*
* Change these and you break ASM code in entry-common.S

3
arch/arm/kernel/entry-common.S
View file

@ -54,8 +54,9 @@ work_pending:
mov r0, sp @ 'regs'
mov r2, why @ 'syscall'
bl do_work_pending
tst r0, #1
cmp r0, #0
beq no_work_pending
movlt scno, #(__NR_restart_syscall - __NR_SYSCALL_BASE)
ldmia sp, {r0 - r6} @ have to reload r0 - r6
b local_restart @ ... and off we go

7
arch/arm/kernel/ptrace.c
View file

@ -941,12 +941,7 @@ static int ptrace_syscall_trace(struct pt_regs *regs, int scno,
asmlinkage int syscall_trace_enter(struct pt_regs *regs, int scno)
{
int ret;
if (test_and_clear_thread_flag(TIF_SYSCALL_RESTARTSYS))
scno = __NR_restart_syscall - __NR_SYSCALL_BASE;
ret = ptrace_syscall_trace(regs, scno, PTRACE_SYSCALL_ENTER);
int ret = ptrace_syscall_trace(regs, scno, PTRACE_SYSCALL_ENTER);
audit_syscall_entry(AUDIT_ARCH_ARM, scno, regs->ARM_r0, regs->ARM_r1,
regs->ARM_r2, regs->ARM_r3);
return ret;

15
arch/arm/kernel/signal.c
View file

@ -591,7 +591,7 @@ static int do_signal(struct pt_regs *regs, int syscall)
*/
switch (retval) {
case -ERESTART_RESTARTBLOCK:
restart++;
restart -= 2;
case -ERESTARTNOHAND:
case -ERESTARTSYS:
case -ERESTARTNOINTR:
@ -629,13 +629,9 @@ static int do_signal(struct pt_regs *regs, int syscall)
return 0;
}
if (unlikely(restart)) {
if (restart > 1)
set_thread_flag(TIF_SYSCALL_RESTARTSYS);
regs->ARM_pc = continue_addr;
}
restore_saved_sigmask();
if (unlikely(restart))
regs->ARM_pc = continue_addr;
return restart;
}
@ -650,13 +646,14 @@ do_work_pending(struct pt_regs *regs, unsigned int thread_flags, int syscall)
return 0;
local_irq_enable();
if (thread_flags & _TIF_SIGPENDING) {
if (unlikely(do_signal(regs, syscall))) {
int restart = do_signal(regs, syscall);
if (unlikely(restart)) {
/*
* Restart without handlers.
* Deal with it without leaving
* the kernel space.
*/
return 1;
return restart;
}
syscall = 0;
} else {