diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2010-12-18 10:28:54 -0800 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-12-18 10:28:54 -0800 |
commit | 0a59228168d3722b71f8e3dbc623316fb4be78f4 (patch) | |
tree | 90533da9ccb9cc79b05cfc1198c67365d251df4d | |
parent | 2ba16c4f456eb63f54b1d8b065377d41a1cd6a14 (diff) | |
parent | 81711cee933599fa114abb0d258d8bbabef8adfb (diff) | |
download | linux-0a59228168d3722b71f8e3dbc623316fb4be78f4.tar.bz2 |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile
* git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile:
arch/tile: handle rt_sigreturn() more cleanly
arch/tile: handle CLONE_SETTLS in copy_thread(), not user space
-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/process.c | 8 | ||||
-rw-r--r-- | arch/tile/kernel/signal.c | 10 |
5 files changed, 37 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/process.c b/arch/tile/kernel/process.c index 8430f45daea6..e90eb53173b0 100644 --- a/arch/tile/kernel/process.c +++ b/arch/tile/kernel/process.c @@ -212,6 +212,13 @@ int copy_thread(unsigned long clone_flags, unsigned long sp, childregs->sp = sp; /* override with new user stack pointer */ /* + * If CLONE_SETTLS is set, set "tp" in the new task to "r4", + * which is passed in as arg #5 to sys_clone(). + */ + if (clone_flags & CLONE_SETTLS) + childregs->tp = regs->regs[4]; + + /* * Copy the callee-saved registers from the passed pt_regs struct * into the context-switch callee-saved registers area. * This way when we start the interrupt-return sequence, the @@ -539,6 +546,7 @@ struct task_struct *__sched _switch_to(struct task_struct *prev, return __switch_to(prev, next, next_current_ksp0(next)); } +/* Note there is an implicit fifth argument if (clone_flags & CLONE_SETTLS). */ SYSCALL_DEFINE5(clone, unsigned long, clone_flags, unsigned long, newsp, void __user *, parent_tidptr, void __user *, child_tidptr, struct pt_regs *, regs) 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); |