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[PATCH] syscall entry/exit revamp 

This cleanup patch speeds up the null syscall path on ppc64 by about 3%,
and brings the ppc32 and ppc64 code slightly closer together.

The ppc64 code was checking current_thread_info()->flags twice in the
syscall exit path; once for TIF_SYSCALL_T_OR_A before disabling
interrupts, and then again for TIF_SIGPENDING|TIF_NEED_RESCHED etc after
disabling interrupts. Now we do the same as ppc32 -- check the flags
only once in the fast path, and re-enable interrupts if necessary in the
ptrace case.

The patch abolishes the 'syscall_noerror' member of struct thread_info
and replaces it with a TIF_NOERROR bit in the flags, which is handled in
the slow path. This shortens the syscall entry code, which no longer
needs to clear syscall_noerror.

The patch adds a TIF_SAVE_NVGPRS flag which causes the syscall exit slow
path to save the non-volatile GPRs into a signal frame. This removes the
need for the assembly wrappers around sys_sigsuspend(),
sys_rt_sigsuspend(), et al which existed solely to save those registers
in advance. It also means I don't have to add new wrappers for ppoll()
and pselect(), which is what I was supposed to be doing when I got
distracted into this...

Finally, it unifies the ppc64 and ppc32 methods of handling syscall exit
directly into a signal handler (as required by sigsuspend et al) by
introducing a TIF_RESTOREALL flag which causes _all_ the registers to be
reloaded from the pt_regs by taking the ret_from_exception path, instead
of the normal syscall exit path which stomps on the callee-saved GPRs.

It appears to pass an LTP test run on ppc64, and passes basic testing on
ppc32 too. Brief tests of ptrace functionality with strace and gdb also
appear OK. I wouldn't send it to Linus for 2.6.15 just yet though :)

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This commit is contained in:
David Woodhouse 2005-11-15 18:52:18 +00:00 committed by Paul Mackerras
parent 1cd8e50620
commit 401d1f029b
8 changed files with 271 additions and 224 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
arch/powerpc/kernel/asm-offsets.c
View File

@ -92,9 +92,9 @@ int main(void)
DEFINE(TI_FLAGS, offsetof(struct thread_info, flags));
DEFINE(TI_PREEMPT, offsetof(struct thread_info, preempt_count));
DEFINE(TI_SC_NOERR, offsetof(struct thread_info, syscall_noerror));
#ifdef CONFIG_PPC32
DEFINE(TI_SIGFRAME, offsetof(struct thread_info, nvgprs_frame));
DEFINE(TI_TASK, offsetof(struct thread_info, task));
#ifdef CONFIG_PPC32
DEFINE(TI_EXECDOMAIN, offsetof(struct thread_info, exec_domain));
DEFINE(TI_CPU, offsetof(struct thread_info, cpu));
#endif /* CONFIG_PPC32 */

167
arch/powerpc/kernel/entry_32.S
View File

@ -200,8 +200,6 @@ _GLOBAL(DoSyscall)
bl do_show_syscall
#endif /* SHOW_SYSCALLS */
rlwinm r10,r1,0,0,(31-THREAD_SHIFT) /* current_thread_info() */
li r11,0
stb r11,TI_SC_NOERR(r10)
lwz r11,TI_FLAGS(r10)
andi. r11,r11,_TIF_SYSCALL_T_OR_A
bne- syscall_dotrace
@ -222,25 +220,21 @@ ret_from_syscall:
bl do_show_syscall_exit
#endif
mr r6,r3
li r11,-_LAST_ERRNO
cmplw 0,r3,r11
rlwinm r12,r1,0,0,(31-THREAD_SHIFT) /* current_thread_info() */
blt+ 30f
lbz r11,TI_SC_NOERR(r12)
cmpwi r11,0
bne 30f
neg r3,r3
lwz r10,_CCR(r1) /* Set SO bit in CR */
oris r10,r10,0x1000
stw r10,_CCR(r1)
/* disable interrupts so current_thread_info()->flags can't change */
30: LOAD_MSR_KERNEL(r10,MSR_KERNEL) /* doesn't include MSR_EE */
LOAD_MSR_KERNEL(r10,MSR_KERNEL) /* doesn't include MSR_EE */
SYNC
MTMSRD(r10)
lwz r9,TI_FLAGS(r12)
andi. r0,r9,(_TIF_SYSCALL_T_OR_A|_TIF_SIGPENDING|_TIF_NEED_RESCHED)
li r8,-_LAST_ERRNO
andi. r0,r9,(_TIF_SYSCALL_T_OR_A|_TIF_SIGPENDING|_TIF_NEED_RESCHED|_TIF_RESTOREALL)
bne- syscall_exit_work
cmplw 0,r3,r8
blt+ syscall_exit_cont
lwz r11,_CCR(r1) /* Load CR */
neg r3,r3
oris r11,r11,0x1000 /* Set SO bit in CR */
stw r11,_CCR(r1)
syscall_exit_cont:
#if defined(CONFIG_4xx) || defined(CONFIG_BOOKE)
/* If the process has its own DBCR0 value, load it up. The single
@ -292,46 +286,113 @@ syscall_dotrace:
b syscall_dotrace_cont
syscall_exit_work:
stw r6,RESULT(r1) /* Save result */
andi. r0,r9,_TIF_RESTOREALL
bne- 2f
cmplw 0,r3,r8
blt+ 1f
andi. r0,r9,_TIF_NOERROR
bne- 1f
lwz r11,_CCR(r1) /* Load CR */
neg r3,r3
oris r11,r11,0x1000 /* Set SO bit in CR */
stw r11,_CCR(r1)
1: stw r6,RESULT(r1) /* Save result */
stw r3,GPR3(r1) /* Update return value */
andi. r0,r9,_TIF_SYSCALL_T_OR_A
beq 5f
ori r10,r10,MSR_EE
SYNC
MTMSRD(r10) /* re-enable interrupts */
2: andi. r0,r9,(_TIF_PERSYSCALL_MASK)
beq 4f
/* Clear per-syscall TIF flags if any are set, but _leave_
_TIF_SAVE_NVGPRS set in r9 since we haven't dealt with that
yet. */
li r11,_TIF_PERSYSCALL_MASK
addi r12,r12,TI_FLAGS
3: lwarx r8,0,r12
andc r8,r8,r11
#ifdef CONFIG_IBM405_ERR77
dcbt 0,r12
#endif
stwcx. r8,0,r12
bne- 3b
subi r12,r12,TI_FLAGS
4: /* Anything which requires enabling interrupts? */
andi. r0,r9,(_TIF_SYSCALL_T_OR_A|_TIF_SINGLESTEP|_TIF_SAVE_NVGPRS)
beq 7f
/* Save NVGPRS if they're not saved already */
lwz r4,_TRAP(r1)
andi. r4,r4,1
beq 4f
beq 5f
SAVE_NVGPRS(r1)
li r4,0xc00
stw r4,_TRAP(r1)
4:
/* Re-enable interrupts */
5: ori r10,r10,MSR_EE
SYNC
MTMSRD(r10)
andi. r0,r9,_TIF_SAVE_NVGPRS
bne save_user_nvgprs
save_user_nvgprs_cont:
andi. r0,r9,(_TIF_SYSCALL_T_OR_A|_TIF_SINGLESTEP)
beq 7f
addi r3,r1,STACK_FRAME_OVERHEAD
bl do_syscall_trace_leave
REST_NVGPRS(r1)
2:
lwz r3,GPR3(r1)
6: lwz r3,GPR3(r1)
LOAD_MSR_KERNEL(r10,MSR_KERNEL) /* doesn't include MSR_EE */
SYNC
MTMSRD(r10) /* disable interrupts again */
rlwinm r12,r1,0,0,(31-THREAD_SHIFT) /* current_thread_info() */
lwz r9,TI_FLAGS(r12)
5:
7:
andi. r0,r9,_TIF_NEED_RESCHED
bne 1f
bne 8f
lwz r5,_MSR(r1)
andi. r5,r5,MSR_PR
beq syscall_exit_cont
beq ret_from_except
andi. r0,r9,_TIF_SIGPENDING
beq syscall_exit_cont
beq ret_from_except
b do_user_signal
1:
8:
ori r10,r10,MSR_EE
SYNC
MTMSRD(r10) /* re-enable interrupts */
bl schedule
b 2b
b 6b
save_user_nvgprs:
ld r8,TI_SIGFRAME(r12)
.macro savewords start, end
1: stw \start,4*(\start)(r8)
.section __ex_table,"a"
.align 2
.long 1b,save_user_nvgprs_fault
.previous
.if \end - \start
savewords "(\start+1)",\end
.endif
.endm
savewords 14,31
b save_user_nvgprs_cont
save_user_nvgprs_fault:
li r3,11 /* SIGSEGV */
ld r4,TI_TASK(r12)
bl force_sigsegv
rlwinm r12,r1,0,0,(31-THREAD_SHIFT) /* current_thread_info() */
ld r9,TI_FLAGS(r12)
b save_user_nvgprs_cont
#ifdef SHOW_SYSCALLS
do_show_syscall:
#ifdef SHOW_SYSCALLS_TASK
@ -401,28 +462,10 @@ show_syscalls_task:
#endif /* SHOW_SYSCALLS */
/*
* The sigsuspend and rt_sigsuspend system calls can call do_signal
* and thus put the process into the stopped state where we might
* want to examine its user state with ptrace. Therefore we need
* to save all the nonvolatile registers (r13 - r31) before calling
* the C code.
* The fork/clone functions need to copy the full register set into
* the child process. Therefore we need to save all the nonvolatile
* registers (r13 - r31) before calling the C code.
*/
.globl ppc_sigsuspend
ppc_sigsuspend:
SAVE_NVGPRS(r1)
lwz r0,_TRAP(r1)
rlwinm r0,r0,0,0,30 /* clear LSB to indicate full */
stw r0,_TRAP(r1) /* register set saved */
b sys_sigsuspend
.globl ppc_rt_sigsuspend
ppc_rt_sigsuspend:
SAVE_NVGPRS(r1)
lwz r0,_TRAP(r1)
rlwinm r0,r0,0,0,30
stw r0,_TRAP(r1)
b sys_rt_sigsuspend
.globl ppc_fork
ppc_fork:
SAVE_NVGPRS(r1)
@ -447,14 +490,6 @@ ppc_clone:
stw r0,_TRAP(r1) /* register set saved */
b sys_clone
.globl ppc_swapcontext
ppc_swapcontext:
SAVE_NVGPRS(r1)
lwz r0,_TRAP(r1)
rlwinm r0,r0,0,0,30 /* clear LSB to indicate full */
stw r0,_TRAP(r1) /* register set saved */
b sys_swapcontext
/*
* Top-level page fault handling.
* This is in assembler because if do_page_fault tells us that
@ -626,16 +661,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_601)
.long ret_from_except
#endif
.globl sigreturn_exit
sigreturn_exit:
subi r1,r3,STACK_FRAME_OVERHEAD
rlwinm r12,r1,0,0,(31-THREAD_SHIFT) /* current_thread_info() */
lwz r9,TI_FLAGS(r12)
andi. r0,r9,_TIF_SYSCALL_T_OR_A
beq+ ret_from_except_full
bl do_syscall_trace_leave
/* fall through */
.globl ret_from_except_full
ret_from_except_full:
REST_NVGPRS(r1)
@ -658,7 +683,7 @@ user_exc_return: /* r10 contains MSR_KERNEL here */
/* Check current_thread_info()->flags */
rlwinm r9,r1,0,0,(31-THREAD_SHIFT)
lwz r9,TI_FLAGS(r9)
andi. r0,r9,(_TIF_SIGPENDING|_TIF_NEED_RESCHED)
andi. r0,r9,(_TIF_SIGPENDING|_TIF_NEED_RESCHED|_TIF_RESTOREALL)
bne do_work
restore_user:

218
arch/powerpc/kernel/entry_64.S
View File

@ -113,9 +113,7 @@ system_call_common:
addi r9,r1,STACK_FRAME_OVERHEAD
#endif
clrrdi r11,r1,THREAD_SHIFT
li r12,0
ld r10,TI_FLAGS(r11)
stb r12,TI_SC_NOERR(r11)
andi. r11,r10,_TIF_SYSCALL_T_OR_A
bne- syscall_dotrace
syscall_dotrace_cont:
@ -144,24 +142,12 @@ system_call: /* label this so stack traces look sane */
bctrl /* Call handler */
syscall_exit:
#ifdef SHOW_SYSCALLS
std r3,GPR3(r1)
bl .do_show_syscall_exit
ld r3,GPR3(r1)
#endif
std r3,RESULT(r1)
ld r5,_CCR(r1)
li r10,-_LAST_ERRNO
cmpld r3,r10
#ifdef SHOW_SYSCALLS
bl .do_show_syscall_exit
ld r3,RESULT(r1)
#endif
clrrdi r12,r1,THREAD_SHIFT
bge- syscall_error
syscall_error_cont:
/* check for syscall tracing or audit */
ld r9,TI_FLAGS(r12)
andi. r0,r9,(_TIF_SYSCALL_T_OR_A|_TIF_SINGLESTEP)
bne- syscall_exit_trace
syscall_exit_trace_cont:
/* disable interrupts so current_thread_info()->flags can't change,
and so that we don't get interrupted after loading SRR0/1. */
@ -173,8 +159,13 @@ syscall_exit_trace_cont:
rotldi r10,r10,16
mtmsrd r10,1
ld r9,TI_FLAGS(r12)
andi. r0,r9,(_TIF_SYSCALL_T_OR_A|_TIF_SIGPENDING|_TIF_NEED_RESCHED)
li r11,-_LAST_ERRNO
andi. r0,r9,(_TIF_SYSCALL_T_OR_A|_TIF_SINGLESTEP|_TIF_SIGPENDING|_TIF_NEED_RESCHED|_TIF_RESTOREALL|_TIF_SAVE_NVGPRS|_TIF_NOERROR)
bne- syscall_exit_work
cmpld r3,r11
ld r5,_CCR(r1)
bge- syscall_error
syscall_error_cont:
ld r7,_NIP(r1)
stdcx. r0,0,r1 /* to clear the reservation */
andi. r6,r8,MSR_PR
@ -193,21 +184,12 @@ syscall_exit_trace_cont:
rfid
b . /* prevent speculative execution */
syscall_enosys:
li r3,-ENOSYS
std r3,RESULT(r1)
clrrdi r12,r1,THREAD_SHIFT
ld r5,_CCR(r1)
syscall_error:
lbz r11,TI_SC_NOERR(r12)
cmpwi 0,r11,0
bne- syscall_error_cont
neg r3,r3
syscall_error:
oris r5,r5,0x1000 /* Set SO bit in CR */
neg r3,r3
std r5,_CCR(r1)
b syscall_error_cont
/* Traced system call support */
syscall_dotrace:
bl .save_nvgprs
@ -225,21 +207,69 @@ syscall_dotrace:
ld r10,TI_FLAGS(r10)
b syscall_dotrace_cont
syscall_exit_trace:
std r3,GPR3(r1)
bl .save_nvgprs
syscall_enosys:
li r3,-ENOSYS
b syscall_exit
syscall_exit_work:
/* If TIF_RESTOREALL is set, don't scribble on either r3 or ccr.
If TIF_NOERROR is set, just save r3 as it is. */
andi. r0,r9,_TIF_RESTOREALL
bne- 2f
cmpld r3,r11 /* r10 is -LAST_ERRNO */
blt+ 1f
andi. r0,r9,_TIF_NOERROR
bne- 1f
ld r5,_CCR(r1)
neg r3,r3
oris r5,r5,0x1000 /* Set SO bit in CR */
std r5,_CCR(r1)
1: std r3,GPR3(r1)
2: andi. r0,r9,(_TIF_PERSYSCALL_MASK)
beq 4f
/* Clear per-syscall TIF flags if any are set, but _leave_
_TIF_SAVE_NVGPRS set in r9 since we haven't dealt with that
yet. */
li r11,_TIF_PERSYSCALL_MASK
addi r12,r12,TI_FLAGS
3: ldarx r10,0,r12
andc r10,r10,r11
stdcx. r10,0,r12
bne- 3b
subi r12,r12,TI_FLAGS
4: bl save_nvgprs
/* Anything else left to do? */
andi. r0,r9,(_TIF_SYSCALL_T_OR_A|_TIF_SINGLESTEP|_TIF_SAVE_NVGPRS)
beq .ret_from_except_lite
/* Re-enable interrupts */
mfmsr r10
ori r10,r10,MSR_EE
mtmsrd r10,1
andi. r0,r9,_TIF_SAVE_NVGPRS
bne save_user_nvgprs
/* If tracing, re-enable interrupts and do it */
save_user_nvgprs_cont:
andi. r0,r9,(_TIF_SYSCALL_T_OR_A|_TIF_SINGLESTEP)
beq 5f
addi r3,r1,STACK_FRAME_OVERHEAD
bl .do_syscall_trace_leave
REST_NVGPRS(r1)
ld r3,GPR3(r1)
ld r5,_CCR(r1)
clrrdi r12,r1,THREAD_SHIFT
b syscall_exit_trace_cont
/* Stuff to do on exit from a system call. */
syscall_exit_work:
std r3,GPR3(r1)
std r5,_CCR(r1)
/* Disable interrupts again and handle other work if any */
5: mfmsr r10
rldicl r10,r10,48,1
rotldi r10,r10,16
mtmsrd r10,1
b .ret_from_except_lite
/* Save non-volatile GPRs, if not already saved. */
@ -252,6 +282,52 @@ _GLOBAL(save_nvgprs)
std r0,_TRAP(r1)
blr
save_user_nvgprs:
ld r10,TI_SIGFRAME(r12)
andi. r0,r9,_TIF_32BIT
beq- save_user_nvgprs_64
/* 32-bit save to userspace */
.macro savewords start, end
1: stw \start,4*(\start)(r10)
.section __ex_table,"a"
.align 3
.llong 1b,save_user_nvgprs_fault
.previous
.if \end - \start
savewords "(\start+1)",\end
.endif
.endm
savewords 14,31
b save_user_nvgprs_cont
save_user_nvgprs_64:
/* 64-bit save to userspace */
.macro savelongs start, end
1: std \start,8*(\start)(r10)
.section __ex_table,"a"
.align 3
.llong 1b,save_user_nvgprs_fault
.previous
.if \end - \start
savelongs "(\start+1)",\end
.endif
.endm
savelongs 14,31
b save_user_nvgprs_cont
save_user_nvgprs_fault:
li r3,11 /* SIGSEGV */
ld r4,TI_TASK(r12)
bl .force_sigsegv
clrrdi r12,r1,THREAD_SHIFT
ld r9,TI_FLAGS(r12)
b save_user_nvgprs_cont
/*
* The sigsuspend and rt_sigsuspend system calls can call do_signal
* and thus put the process into the stopped state where we might
@ -260,35 +336,6 @@ _GLOBAL(save_nvgprs)
* the C code. Similarly, fork, vfork and clone need the full
* register state on the stack so that it can be copied to the child.
*/
_GLOBAL(ppc32_sigsuspend)
bl .save_nvgprs
bl .compat_sys_sigsuspend
b 70f
_GLOBAL(ppc64_rt_sigsuspend)
bl .save_nvgprs
bl .sys_rt_sigsuspend
b 70f
_GLOBAL(ppc32_rt_sigsuspend)
bl .save_nvgprs
bl .compat_sys_rt_sigsuspend
70: cmpdi 0,r3,0
/* If it returned an error, we need to return via syscall_exit to set
the SO bit in cr0 and potentially stop for ptrace. */
bne syscall_exit
/* If sigsuspend() returns zero, we are going into a signal handler. We
may need to call audit_syscall_exit() to mark the exit from sigsuspend() */
#ifdef CONFIG_AUDITSYSCALL
ld r3,PACACURRENT(r13)
ld r4,AUDITCONTEXT(r3)
cmpdi 0,r4,0
beq .ret_from_except /* No audit_context: Leave immediately. */
li r4, 2 /* AUDITSC_FAILURE */
li r5,-4 /* It's always -EINTR */
bl .audit_syscall_exit
#endif
b .ret_from_except
_GLOBAL(ppc_fork)
bl .save_nvgprs
@ -305,37 +352,6 @@ _GLOBAL(ppc_clone)
bl .sys_clone
b syscall_exit
_GLOBAL(ppc32_swapcontext)
bl .save_nvgprs
bl .compat_sys_swapcontext
b 80f
_GLOBAL(ppc64_swapcontext)
bl .save_nvgprs
bl .sys_swapcontext
b 80f
_GLOBAL(ppc32_sigreturn)
bl .compat_sys_sigreturn
b 80f
_GLOBAL(ppc32_rt_sigreturn)
bl .compat_sys_rt_sigreturn
b 80f
_GLOBAL(ppc64_rt_sigreturn)
bl .sys_rt_sigreturn
80: cmpdi 0,r3,0
blt syscall_exit
clrrdi r4,r1,THREAD_SHIFT
ld r4,TI_FLAGS(r4)
andi. r4,r4,(_TIF_SYSCALL_T_OR_A|_TIF_SINGLESTEP)
beq+ 81f
addi r3,r1,STACK_FRAME_OVERHEAD
bl .do_syscall_trace_leave
81: b .ret_from_except
_GLOBAL(ret_from_fork)
bl .schedule_tail
REST_NVGPRS(r1)

59
arch/powerpc/kernel/signal_32.c
View File

@ -76,7 +76,6 @@
* registers from *regs. This is what we need
* to do when a signal has been delivered.
*/
#define sigreturn_exit(regs) return 0
#define GP_REGS_SIZE min(sizeof(elf_gregset_t32), sizeof(struct pt_regs32))
#undef __SIGNAL_FRAMESIZE
@ -156,9 +155,17 @@ static inline int save_general_regs(struct pt_regs *regs,
elf_greg_t64 *gregs = (elf_greg_t64 *)regs;
int i;
for (i = 0; i <= PT_RESULT; i ++)
if (!FULL_REGS(regs)) {
set_thread_flag(TIF_SAVE_NVGPRS);
current_thread_info()->nvgprs_frame = frame->mc_gregs;
}
for (i = 0; i <= PT_RESULT; i ++) {
if (i == 14 && !FULL_REGS(regs))
i = 32;
if (__put_user((unsigned int)gregs[i], &frame->mc_gregs[i]))
return -EFAULT;
}
return 0;
}
@ -179,8 +186,6 @@ static inline int restore_general_regs(struct pt_regs *regs,
#else /* CONFIG_PPC64 */
extern void sigreturn_exit(struct pt_regs *);
#define GP_REGS_SIZE min(sizeof(elf_gregset_t), sizeof(struct pt_regs))
static inline int put_sigset_t(sigset_t __user *uset, sigset_t *set)
@ -256,8 +261,10 @@ long sys_sigsuspend(old_sigset_t mask, int p2, int p3, int p4, int p6, int p7,
while (1) {
current->state = TASK_INTERRUPTIBLE;
schedule();
if (do_signal(&saveset, regs))
sigreturn_exit(regs);
if (do_signal(&saveset, regs)) {
set_thread_flag(TIF_RESTOREALL);
return 0;
}
}
}
@ -292,8 +299,10 @@ long sys_rt_sigsuspend(
while (1) {
current->state = TASK_INTERRUPTIBLE;
schedule();
if (do_signal(&saveset, regs))
sigreturn_exit(regs);
if (do_signal(&saveset, regs)) {
set_thread_flag(TIF_RESTOREALL);
return 0;
}
}
}
@ -391,9 +400,6 @@ struct rt_sigframe {
static int save_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
int sigret)
{
#ifdef CONFIG_PPC32
CHECK_FULL_REGS(regs);
#endif
/* Make sure floating point registers are stored in regs */
flush_fp_to_thread(current);
@ -828,12 +834,6 @@ static int handle_rt_signal(unsigned long sig, struct k_sigaction *ka,
regs->gpr[6] = (unsigned long) rt_sf;
regs->nip = (unsigned long) ka->sa.sa_handler;
regs->trap = 0;
#ifdef CONFIG_PPC64
regs->result = 0;
if (test_thread_flag(TIF_SINGLESTEP))
ptrace_notify(SIGTRAP);
#endif
return 1;
badframe:
@ -911,8 +911,8 @@ long sys_swapcontext(struct ucontext __user *old_ctx,
*/
if (do_setcontext(new_ctx, regs, 0))
do_exit(SIGSEGV);
sigreturn_exit(regs);
/* doesn't actually return back to here */
set_thread_flag(TIF_RESTOREALL);
return 0;
}
@ -945,12 +945,11 @@ long sys_rt_sigreturn(int r3, int r4, int r5, int r6, int r7, int r8,
* nobody does any...
*/
compat_sys_sigaltstack((u32)(u64)&rt_sf->uc.uc_stack, 0, 0, 0, 0, 0, regs);
return (int)regs->result;
#else
do_sigaltstack(&rt_sf->uc.uc_stack, NULL, regs->gpr[1]);
sigreturn_exit(regs); /* doesn't return here */
return 0;
#endif
set_thread_flag(TIF_RESTOREALL);
return 0;
bad:
force_sig(SIGSEGV, current);
@ -1041,9 +1040,7 @@ int sys_debug_setcontext(struct ucontext __user *ctx,
*/
do_sigaltstack(&ctx->uc_stack, NULL, regs->gpr[1]);
sigreturn_exit(regs);
/* doesn't actually return back to here */
set_thread_flag(TIF_RESTOREALL);
out:
return 0;
}
@ -1107,12 +1104,6 @@ static int handle_signal(unsigned long sig, struct k_sigaction *ka,
regs->gpr[4] = (unsigned long) sc;
regs->nip = (unsigned long) ka->sa.sa_handler;
regs->trap = 0;
#ifdef CONFIG_PPC64
regs->result = 0;
if (test_thread_flag(TIF_SINGLESTEP))
ptrace_notify(SIGTRAP);
#endif
return 1;
@ -1160,12 +1151,8 @@ long sys_sigreturn(int r3, int r4, int r5, int r6, int r7, int r8,
|| restore_user_regs(regs, sr, 1))
goto badframe;
#ifdef CONFIG_PPC64
return (int)regs->result;
#else
sigreturn_exit(regs); /* doesn't return */
set_thread_flag(TIF_RESTOREALL);
return 0;
#endif
badframe:
force_sig(SIGSEGV, current);

23
arch/powerpc/kernel/signal_64.c
View File

@ -96,8 +96,10 @@ long sys_rt_sigsuspend(sigset_t __user *unewset, size_t sigsetsize, int p3, int
while (1) {
current->state = TASK_INTERRUPTIBLE;
schedule();
if (do_signal(&saveset, regs))
if (do_signal(&saveset, regs)) {
set_thread_flag(TIF_RESTOREALL);
return 0;
}
}
}
@ -152,6 +154,14 @@ static long setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
err |= __put_user(0, &sc->v_regs);
#endif /* CONFIG_ALTIVEC */
err |= __put_user(&sc->gp_regs, &sc->regs);
if (!FULL_REGS(regs)) {
/* Zero out the unsaved GPRs to avoid information
leak, and set TIF_SAVE_NVGPRS to ensure that the
registers do actually get saved later. */
memset(&regs->gpr[14], 0, 18 * sizeof(unsigned long));
set_thread_flag(TIF_SAVE_NVGPRS);
current_thread_info()->nvgprs_frame = &sc->gp_regs;
}
err |= __copy_to_user(&sc->gp_regs, regs, GP_REGS_SIZE);
err |= __copy_to_user(&sc->fp_regs, &current->thread.fpr, FP_REGS_SIZE);
err |= __put_user(signr, &sc->signal);
@ -340,6 +350,7 @@ int sys_swapcontext(struct ucontext __user *old_ctx,
do_exit(SIGSEGV);
/* This returns like rt_sigreturn */
set_thread_flag(TIF_RESTOREALL);
return 0;
}
@ -372,7 +383,8 @@ int sys_rt_sigreturn(unsigned long r3, unsigned long r4, unsigned long r5,
*/
do_sigaltstack(&uc->uc_stack, NULL, regs->gpr[1]);
return regs->result;
set_thread_flag(TIF_RESTOREALL);
return 0;
badframe:
#if DEBUG_SIG
@ -454,9 +466,6 @@ static int setup_rt_frame(int signr, struct k_sigaction *ka, siginfo_t *info,
if (err)
goto badframe;
if (test_thread_flag(TIF_SINGLESTEP))
ptrace_notify(SIGTRAP);
return 1;
badframe:
@ -502,6 +511,8 @@ static inline void syscall_restart(struct pt_regs *regs, struct k_sigaction *ka)
* we only get here if there is a handler, we dont restart.
*/
regs->result = -EINTR;
regs->gpr[3] = EINTR;
regs->ccr |= 0x10000000;
break;
case -ERESTARTSYS:
/* ERESTARTSYS means to restart the syscall if there is no
@ -509,6 +520,8 @@ static inline void syscall_restart(struct pt_regs *regs, struct k_sigaction *ka)
*/
if (!(ka->sa.sa_flags & SA_RESTART)) {
regs->result = -EINTR;
regs->gpr[3] = EINTR;
regs->ccr |= 0x10000000;
break;
}
/* fallthrough */

10
arch/powerpc/kernel/systbl.S
View File

@ -113,7 +113,7 @@ SYSCALL(sgetmask)
COMPAT_SYS(ssetmask)
SYSCALL(setreuid)
SYSCALL(setregid)
SYSX(sys_ni_syscall,ppc32_sigsuspend,ppc_sigsuspend)
SYS32ONLY(sigsuspend)
COMPAT_SYS(sigpending)
COMPAT_SYS(sethostname)
COMPAT_SYS(setrlimit)
@ -160,7 +160,7 @@ SYSCALL(swapoff)
COMPAT_SYS(sysinfo)
COMPAT_SYS(ipc)
SYSCALL(fsync)
SYSX(sys_ni_syscall,ppc32_sigreturn,sys_sigreturn)
SYS32ONLY(sigreturn)
PPC_SYS(clone)
COMPAT_SYS(setdomainname)
PPC_SYS(newuname)
@ -213,13 +213,13 @@ COMPAT_SYS(nfsservctl)
SYSCALL(setresgid)
SYSCALL(getresgid)
COMPAT_SYS(prctl)
SYSX(ppc64_rt_sigreturn,ppc32_rt_sigreturn,sys_rt_sigreturn)
COMPAT_SYS(rt_sigreturn)
COMPAT_SYS(rt_sigaction)
COMPAT_SYS(rt_sigprocmask)
COMPAT_SYS(rt_sigpending)
COMPAT_SYS(rt_sigtimedwait)
COMPAT_SYS(rt_sigqueueinfo)
SYSX(ppc64_rt_sigsuspend,ppc32_rt_sigsuspend,ppc_rt_sigsuspend)
COMPAT_SYS(rt_sigsuspend)
COMPAT_SYS(pread64)
COMPAT_SYS(pwrite64)
SYSCALL(chown)
@ -290,7 +290,7 @@ COMPAT_SYS(clock_settime)
COMPAT_SYS(clock_gettime)
COMPAT_SYS(clock_getres)
COMPAT_SYS(clock_nanosleep)
SYSX(ppc64_swapcontext,ppc32_swapcontext,ppc_swapcontext)
COMPAT_SYS(swapcontext)
COMPAT_SYS(tgkill)
COMPAT_SYS(utimes)
COMPAT_SYS(statfs64)

2
include/asm-powerpc/ptrace.h
View File

@ -87,7 +87,7 @@ extern unsigned long profile_pc(struct pt_regs *regs);
#define force_successful_syscall_return() \
do { \
current_thread_info()->syscall_noerror = 1; \
set_thread_flag(TIF_NOERROR); \
} while(0)
/*

12
include/asm-powerpc/thread_info.h
View File

@ -37,8 +37,7 @@ struct thread_info {
int preempt_count; /* 0 => preemptable,
<0 => BUG */
struct restart_block restart_block;
/* set by force_successful_syscall_return */
unsigned char syscall_noerror;
void *nvgprs_frame;
/* low level flags - has atomic operations done on it */
unsigned long flags ____cacheline_aligned_in_smp;
};
@ -123,6 +122,9 @@ static inline struct thread_info *current_thread_info(void)
#define TIF_SINGLESTEP 9 /* singlestepping active */
#define TIF_MEMDIE 10
#define TIF_SECCOMP 11 /* secure computing */
#define TIF_RESTOREALL 12 /* Restore all regs (implies NOERROR) */
#define TIF_SAVE_NVGPRS 13 /* Save r14-r31 in signal frame */
#define TIF_NOERROR 14 /* Force successful syscall return */
/* as above, but as bit values */
#define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE)
@ -136,10 +138,14 @@ static inline struct thread_info *current_thread_info(void)
#define _TIF_SYSCALL_AUDIT (1<<TIF_SYSCALL_AUDIT)
#define _TIF_SINGLESTEP (1<<TIF_SINGLESTEP)
#define _TIF_SECCOMP (1<<TIF_SECCOMP)
#define _TIF_RESTOREALL (1<<TIF_RESTOREALL)
#define _TIF_SAVE_NVGPRS (1<<TIF_SAVE_NVGPRS)
#define _TIF_NOERROR (1<<TIF_NOERROR)
#define _TIF_SYSCALL_T_OR_A (_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SECCOMP)
#define _TIF_USER_WORK_MASK (_TIF_NOTIFY_RESUME | _TIF_SIGPENDING | \
_TIF_NEED_RESCHED)
_TIF_NEED_RESCHED | _TIF_RESTOREALL)
#define _TIF_PERSYSCALL_MASK (_TIF_RESTOREALL|_TIF_NOERROR|_TIF_SAVE_NVGPRS)
#endif /* __KERNEL__ */