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authorLinus Torvalds <torvalds@linux-foundation.org>2012-10-13 10:05:52 +0900
committerLinus Torvalds <torvalds@linux-foundation.org>2012-10-13 10:05:52 +0900
commit4e21fc138bfd7fe625ff5dc81541399aaf9d429b (patch)
tree43bedf14d2eee7711b8241dcfd6bd7b8737d9bd5 /arch/alpha
parent8418263e3547ed3816475e4c55a77004f0426ee6 (diff)
parent5522be6a4624a5f505555569e4d9cee946630686 (diff)
downloadblackbird-op-linux-4e21fc138bfd7fe625ff5dc81541399aaf9d429b.tar.gz
blackbird-op-linux-4e21fc138bfd7fe625ff5dc81541399aaf9d429b.zip
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal
Pull third pile of kernel_execve() patches from Al Viro: "The last bits of infrastructure for kernel_thread() et.al., with alpha/arm/x86 use of those. Plus sanitizing the asm glue and do_notify_resume() on alpha, fixing the "disabled irq while running task_work stuff" breakage there. At that point the rest of kernel_thread/kernel_execve/sys_execve work can be done independently for different architectures. The only pending bits that do depend on having all architectures converted are restrictred to fs/* and kernel/* - that'll obviously have to wait for the next cycle. I thought we'd have to wait for all of them done before we start eliminating the longjump-style insanity in kernel_execve(), but it turned out there's a very simple way to do that without flagday-style changes." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: alpha: switch to saner kernel_execve() semantics arm: switch to saner kernel_execve() semantics x86, um: convert to saner kernel_execve() semantics infrastructure for saner ret_from_kernel_thread semantics make sure that kernel_thread() callbacks call do_exit() themselves make sure that we always have a return path from kernel_execve() ppc: eeh_event should just use kthread_run() don't bother with kernel_thread/kernel_execve for launching linuxrc alpha: get rid of switch_stack argument of do_work_pending() alpha: don't bother passing switch_stack separately from regs alpha: take SIGPENDING/NOTIFY_RESUME loop into signal.c alpha: simplify TIF_NEED_RESCHED handling
Diffstat (limited to 'arch/alpha')
-rw-r--r--arch/alpha/Kconfig1
-rw-r--r--arch/alpha/include/asm/unistd.h1
-rw-r--r--arch/alpha/kernel/entry.S87
-rw-r--r--arch/alpha/kernel/signal.c48
4 files changed, 57 insertions, 80 deletions
diff --git a/arch/alpha/Kconfig b/arch/alpha/Kconfig
index 7da91246e279..7a08cfb80ee8 100644
--- a/arch/alpha/Kconfig
+++ b/arch/alpha/Kconfig
@@ -21,6 +21,7 @@ config ALPHA
select GENERIC_STRNCPY_FROM_USER
select GENERIC_STRNLEN_USER
select GENERIC_KERNEL_THREAD
+ select GENERIC_KERNEL_EXECVE
help
The Alpha is a 64-bit general-purpose processor designed and
marketed by the Digital Equipment Corporation of blessed memory,
diff --git a/arch/alpha/include/asm/unistd.h b/arch/alpha/include/asm/unistd.h
index 3cb6c1188984..7826e227e4d0 100644
--- a/arch/alpha/include/asm/unistd.h
+++ b/arch/alpha/include/asm/unistd.h
@@ -482,7 +482,6 @@
#define __ARCH_WANT_SYS_SIGPENDING
#define __ARCH_WANT_SYS_RT_SIGSUSPEND
#define __ARCH_WANT_SYS_EXECVE
-#define __ARCH_WANT_KERNEL_EXECVE
/* "Conditional" syscalls. What we want is
diff --git a/arch/alpha/kernel/entry.S b/arch/alpha/kernel/entry.S
index 2a359c9ee3cd..a7607832dd4f 100644
--- a/arch/alpha/kernel/entry.S
+++ b/arch/alpha/kernel/entry.S
@@ -311,7 +311,7 @@ entSys:
.align 4
ret_from_sys_call:
- cmovne $26, 0, $19 /* $19 = 0 => non-restartable */
+ cmovne $26, 0, $18 /* $18 = 0 => non-restartable */
ldq $0, SP_OFF($sp)
and $0, 8, $0
beq $0, ret_to_kernel
@@ -320,8 +320,8 @@ ret_to_user:
sampling and the rti. */
lda $16, 7
call_pal PAL_swpipl
- ldl $5, TI_FLAGS($8)
- and $5, _TIF_WORK_MASK, $2
+ ldl $17, TI_FLAGS($8)
+ and $17, _TIF_WORK_MASK, $2
bne $2, work_pending
restore_all:
RESTORE_ALL
@@ -341,10 +341,10 @@ $syscall_error:
* frame to indicate that a negative return value wasn't an
* error number..
*/
- ldq $19, 0($sp) /* old syscall nr (zero if success) */
- beq $19, $ret_success
+ ldq $18, 0($sp) /* old syscall nr (zero if success) */
+ beq $18, $ret_success
- ldq $20, 72($sp) /* .. and this a3 */
+ ldq $19, 72($sp) /* .. and this a3 */
subq $31, $0, $0 /* with error in v0 */
addq $31, 1, $1 /* set a3 for errno return */
stq $0, 0($sp)
@@ -362,51 +362,35 @@ $ret_success:
* Do all cleanup when returning from all interrupts and system calls.
*
* Arguments:
- * $5: TI_FLAGS.
* $8: current.
- * $19: The old syscall number, or zero if this is not a return
+ * $17: TI_FLAGS.
+ * $18: The old syscall number, or zero if this is not a return
* from a syscall that errored and is possibly restartable.
- * $20: The old a3 value
+ * $19: The old a3 value
*/
.align 4
.ent work_pending
work_pending:
- and $5, _TIF_NEED_RESCHED, $2
- beq $2, $work_notifysig
+ and $17, _TIF_NOTIFY_RESUME | _TIF_SIGPENDING, $2
+ bne $2, $work_notifysig
$work_resched:
- subq $sp, 16, $sp
- stq $19, 0($sp) /* save syscall nr */
- stq $20, 8($sp) /* and error indication (a3) */
+ /*
+ * We can get here only if we returned from syscall without SIGPENDING
+ * or got through work_notifysig already. Either case means no syscall
+ * restarts for us, so let $18 and $19 burn.
+ */
jsr $26, schedule
- ldq $19, 0($sp)
- ldq $20, 8($sp)
- addq $sp, 16, $sp
- /* Make sure need_resched and sigpending don't change between
- sampling and the rti. */
- lda $16, 7
- call_pal PAL_swpipl
- ldl $5, TI_FLAGS($8)
- and $5, _TIF_WORK_MASK, $2
- beq $2, restore_all
- and $5, _TIF_NEED_RESCHED, $2
- bne $2, $work_resched
+ mov 0, $18
+ br ret_to_user
$work_notifysig:
mov $sp, $16
bsr $1, do_switch_stack
- mov $sp, $17
- mov $5, $18
- mov $19, $9 /* save old syscall number */
- mov $20, $10 /* save old a3 */
- and $5, _TIF_SIGPENDING, $2
- cmovne $2, 0, $9 /* we don't want double syscall restarts */
- jsr $26, do_notify_resume
- mov $9, $19
- mov $10, $20
+ jsr $26, do_work_pending
bsr $1, undo_switch_stack
- br ret_to_user
+ br restore_all
.end work_pending
/*
@@ -454,9 +438,9 @@ $strace_success:
.align 3
$strace_error:
- ldq $19, 0($sp) /* old syscall nr (zero if success) */
- beq $19, $strace_success
- ldq $20, 72($sp) /* .. and this a3 */
+ ldq $18, 0($sp) /* old syscall nr (zero if success) */
+ beq $18, $strace_success
+ ldq $19, 72($sp) /* .. and this a3 */
subq $31, $0, $0 /* with error in v0 */
addq $31, 1, $1 /* set a3 for errno return */
@@ -464,11 +448,11 @@ $strace_error:
stq $1, 72($sp) /* a3 for return */
bsr $1, do_switch_stack
- mov $19, $9 /* save old syscall number */
- mov $20, $10 /* save old a3 */
+ mov $18, $9 /* save old syscall number */
+ mov $19, $10 /* save old a3 */
jsr $26, syscall_trace_leave
- mov $9, $19
- mov $10, $20
+ mov $9, $18
+ mov $10, $19
bsr $1, undo_switch_stack
mov $31, $26 /* tell "ret_from_sys_call" we can restart */
@@ -619,24 +603,9 @@ ret_from_kernel_thread:
mov $9, $27
mov $10, $16
jsr $26, ($9)
- ldgp $gp, 0($26)
- mov $0, $16
- mov $31, $26
- jmp $31, sys_exit
-.end ret_from_kernel_thread
-
- .globl ret_from_kernel_execve
- .align 4
- .ent ret_from_kernel_execve
-ret_from_kernel_execve:
- mov $16, $sp
- /* Avoid the HAE being gratuitously wrong, to avoid restoring it. */
- ldq $2, alpha_mv+HAE_CACHE
- stq $2, 152($sp) /* HAE */
mov $31, $19 /* to disable syscall restarts */
br $31, ret_to_user
-
-.end ret_from_kernel_execve
+.end ret_from_kernel_thread
/*
diff --git a/arch/alpha/kernel/signal.c b/arch/alpha/kernel/signal.c
index a8c97d42ec8e..32575f85507d 100644
--- a/arch/alpha/kernel/signal.c
+++ b/arch/alpha/kernel/signal.c
@@ -298,8 +298,9 @@ get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size)
static long
setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
- struct switch_stack *sw, unsigned long mask, unsigned long sp)
+ unsigned long mask, unsigned long sp)
{
+ struct switch_stack *sw = (struct switch_stack *)regs - 1;
long i, err = 0;
err |= __put_user(on_sig_stack((unsigned long)sc), &sc->sc_onstack);
@@ -354,7 +355,7 @@ setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
static int
setup_frame(int sig, struct k_sigaction *ka, sigset_t *set,
- struct pt_regs *regs, struct switch_stack * sw)
+ struct pt_regs *regs)
{
unsigned long oldsp, r26, err = 0;
struct sigframe __user *frame;
@@ -364,7 +365,7 @@ setup_frame(int sig, struct k_sigaction *ka, sigset_t *set,
if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
return -EFAULT;
- err |= setup_sigcontext(&frame->sc, regs, sw, set->sig[0], oldsp);
+ err |= setup_sigcontext(&frame->sc, regs, set->sig[0], oldsp);
if (err)
return -EFAULT;
@@ -401,7 +402,7 @@ setup_frame(int sig, struct k_sigaction *ka, sigset_t *set,
static int
setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
- sigset_t *set, struct pt_regs *regs, struct switch_stack * sw)
+ sigset_t *set, struct pt_regs *regs)
{
unsigned long oldsp, r26, err = 0;
struct rt_sigframe __user *frame;
@@ -420,7 +421,7 @@ setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
err |= __put_user(sas_ss_flags(oldsp), &frame->uc.uc_stack.ss_flags);
err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
- err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, sw,
+ err |= setup_sigcontext(&frame->uc.uc_mcontext, regs,
set->sig[0], oldsp);
err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
if (err)
@@ -464,15 +465,15 @@ setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
*/
static inline void
handle_signal(int sig, struct k_sigaction *ka, siginfo_t *info,
- struct pt_regs * regs, struct switch_stack *sw)
+ struct pt_regs * regs)
{
sigset_t *oldset = sigmask_to_save();
int ret;
if (ka->sa.sa_flags & SA_SIGINFO)
- ret = setup_rt_frame(sig, ka, info, oldset, regs, sw);
+ ret = setup_rt_frame(sig, ka, info, oldset, regs);
else
- ret = setup_frame(sig, ka, oldset, regs, sw);
+ ret = setup_frame(sig, ka, oldset, regs);
if (ret) {
force_sigsegv(sig, current);
@@ -519,8 +520,7 @@ syscall_restart(unsigned long r0, unsigned long r19,
* all (if we get here from anything but a syscall return, it will be 0)
*/
static void
-do_signal(struct pt_regs * regs, struct switch_stack * sw,
- unsigned long r0, unsigned long r19)
+do_signal(struct pt_regs *regs, unsigned long r0, unsigned long r19)
{
siginfo_t info;
int signr;
@@ -537,7 +537,7 @@ do_signal(struct pt_regs * regs, struct switch_stack * sw,
/* Whee! Actually deliver the signal. */
if (r0)
syscall_restart(r0, r19, regs, &ka);
- handle_signal(signr, &ka, &info, regs, sw);
+ handle_signal(signr, &ka, &info, regs);
if (single_stepping)
ptrace_set_bpt(current); /* re-set bpt */
return;
@@ -568,15 +568,23 @@ do_signal(struct pt_regs * regs, struct switch_stack * sw,
}
void
-do_notify_resume(struct pt_regs *regs, struct switch_stack *sw,
- unsigned long thread_info_flags,
+do_work_pending(struct pt_regs *regs, unsigned long thread_flags,
unsigned long r0, unsigned long r19)
{
- if (thread_info_flags & _TIF_SIGPENDING)
- do_signal(regs, sw, r0, r19);
-
- if (thread_info_flags & _TIF_NOTIFY_RESUME) {
- clear_thread_flag(TIF_NOTIFY_RESUME);
- tracehook_notify_resume(regs);
- }
+ do {
+ if (thread_flags & _TIF_NEED_RESCHED) {
+ schedule();
+ } else {
+ local_irq_enable();
+ if (thread_flags & _TIF_SIGPENDING) {
+ do_signal(regs, r0, r19);
+ r0 = 0;
+ } else {
+ clear_thread_flag(TIF_NOTIFY_RESUME);
+ tracehook_notify_resume(regs);
+ }
+ }
+ local_irq_disable();
+ thread_flags = current_thread_info()->flags;
+ } while (thread_flags & _TIF_WORK_MASK);
}
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