diff options
| -rw-r--r-- | arch/tile/include/asm/signal.h | 2 | ||||
| -rw-r--r-- | arch/tile/kernel/compat_signal.c | 6 | ||||
| -rw-r--r-- | arch/tile/kernel/intvec_32.S | 24 | ||||
| -rw-r--r-- | arch/tile/kernel/signal.c | 10 |
4 files changed, 29 insertions, 13 deletions
diff --git a/arch/tile/include/asm/signal.h b/arch/tile/include/asm/signal.h index c1ee1d61d44c..81d92a45cd4b 100644 --- a/arch/tile/include/asm/signal.h +++ b/arch/tile/include/asm/signal.h @@ -25,7 +25,7 @@ #if defined(__KERNEL__) && !defined(__ASSEMBLY__) struct pt_regs; -int restore_sigcontext(struct pt_regs *, struct sigcontext __user *, long *); +int restore_sigcontext(struct pt_regs *, struct sigcontext __user *); int setup_sigcontext(struct sigcontext __user *, struct pt_regs *); void do_signal(struct pt_regs *regs); #endif diff --git a/arch/tile/kernel/compat_signal.c b/arch/tile/kernel/compat_signal.c index 543d6a33aa26..dbb0dfc7bece 100644 --- a/arch/tile/kernel/compat_signal.c +++ b/arch/tile/kernel/compat_signal.c @@ -290,12 +290,12 @@ long compat_sys_sigaltstack(const struct compat_sigaltstack __user *uss_ptr, return ret; } +/* The assembly shim for this function arranges to ignore the return value. */ long compat_sys_rt_sigreturn(struct pt_regs *regs) { struct compat_rt_sigframe __user *frame = (struct compat_rt_sigframe __user *) compat_ptr(regs->sp); sigset_t set; - long r0; if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) goto badframe; @@ -308,13 +308,13 @@ long compat_sys_rt_sigreturn(struct pt_regs *regs) recalc_sigpending(); spin_unlock_irq(¤t->sighand->siglock); - if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &r0)) + if (restore_sigcontext(regs, &frame->uc.uc_mcontext)) goto badframe; if (compat_sys_sigaltstack(&frame->uc.uc_stack, NULL, regs) != 0) goto badframe; - return r0; + return 0; badframe: force_sig(SIGSEGV, current); diff --git a/arch/tile/kernel/intvec_32.S b/arch/tile/kernel/intvec_32.S index f5821626247f..5eed4a02bf62 100644 --- a/arch/tile/kernel/intvec_32.S +++ b/arch/tile/kernel/intvec_32.S @@ -1342,8 +1342,8 @@ handle_syscall: lw r20, r20 /* Jump to syscall handler. */ - jalr r20; .Lhandle_syscall_link: - FEEDBACK_REENTER(handle_syscall) + jalr r20 +.Lhandle_syscall_link: /* value of "lr" after "jalr r20" above */ /* * Write our r0 onto the stack so it gets restored instead @@ -1352,6 +1352,9 @@ handle_syscall: PTREGS_PTR(r29, PTREGS_OFFSET_REG(0)) sw r29, r0 +.Lsyscall_sigreturn_skip: + FEEDBACK_REENTER(handle_syscall) + /* Do syscall trace again, if requested. */ lw r30, r31 andi r30, r30, _TIF_SYSCALL_TRACE @@ -1536,9 +1539,24 @@ STD_ENTRY_LOCAL(bad_intr) }; \ STD_ENDPROC(_##x) +/* + * Special-case sigreturn to not write r0 to the stack on return. + * This is technically more efficient, but it also avoids difficulties + * in the 64-bit OS when handling 32-bit compat code, since we must not + * sign-extend r0 for the sigreturn return-value case. + */ +#define PTREGS_SYSCALL_SIGRETURN(x, reg) \ + STD_ENTRY(_##x); \ + addli lr, lr, .Lsyscall_sigreturn_skip - .Lhandle_syscall_link; \ + { \ + PTREGS_PTR(reg, PTREGS_OFFSET_BASE); \ + j x \ + }; \ + STD_ENDPROC(_##x) + PTREGS_SYSCALL(sys_execve, r3) PTREGS_SYSCALL(sys_sigaltstack, r2) -PTREGS_SYSCALL(sys_rt_sigreturn, r0) +PTREGS_SYSCALL_SIGRETURN(sys_rt_sigreturn, r0) PTREGS_SYSCALL(sys_cmpxchg_badaddr, r1) /* Save additional callee-saves to pt_regs, put address in r4 and jump. */ diff --git a/arch/tile/kernel/signal.c b/arch/tile/kernel/signal.c index 757407e36696..1260321155f1 100644 --- a/arch/tile/kernel/signal.c +++ b/arch/tile/kernel/signal.c @@ -52,7 +52,7 @@ SYSCALL_DEFINE3(sigaltstack, const stack_t __user *, uss, */ int restore_sigcontext(struct pt_regs *regs, - struct sigcontext __user *sc, long *pr0) + struct sigcontext __user *sc) { int err = 0; int i; @@ -75,17 +75,15 @@ int restore_sigcontext(struct pt_regs *regs, regs->faultnum = INT_SWINT_1_SIGRETURN; - err |= __get_user(*pr0, &sc->gregs[0]); return err; } -/* sigreturn() returns long since it restores r0 in the interrupted code. */ +/* The assembly shim for this function arranges to ignore the return value. */ SYSCALL_DEFINE1(rt_sigreturn, struct pt_regs *, regs) { struct rt_sigframe __user *frame = (struct rt_sigframe __user *)(regs->sp); sigset_t set; - long r0; if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) goto badframe; @@ -98,13 +96,13 @@ SYSCALL_DEFINE1(rt_sigreturn, struct pt_regs *, regs) recalc_sigpending(); spin_unlock_irq(¤t->sighand->siglock); - if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &r0)) + if (restore_sigcontext(regs, &frame->uc.uc_mcontext)) goto badframe; if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->sp) == -EFAULT) goto badframe; - return r0; + return 0; badframe: force_sig(SIGSEGV, current); |