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Subject[PATCH 07/21] staging: lustre: improve API and implementation of blocking signals.
According to comment for set_current_blocked() in
kernel/signal.c, changing ->blocked directly is wrong.
sigprocmask() should be called instead.

So change cfs_block_sigsinv() and cfs_restore_sigs()
to use sigprocmask().
For consistency, change them to pass the sigset_t by reference
rather than by value.

Also fix cfs_block_sigsinv() so that it correctly blocks
signals above 32 on a 32bit host.

Signed-off-by: NeilBrown <neilb@suse.com>
---
.../staging/lustre/include/linux/libcfs/libcfs.h | 4 ++-
.../staging/lustre/lnet/libcfs/linux/linux-prim.c | 24 ++++++--------------
drivers/staging/lustre/lustre/include/lustre_lib.h | 18 ++++++++-------
drivers/staging/lustre/lustre/llite/llite_mmap.c | 8 +++----
4 files changed, 22 insertions(+), 32 deletions(-)

diff --git a/drivers/staging/lustre/include/linux/libcfs/libcfs.h b/drivers/staging/lustre/include/linux/libcfs/libcfs.h
index 7f06b0118154..9dff050810c4 100644
--- a/drivers/staging/lustre/include/linux/libcfs/libcfs.h
+++ b/drivers/staging/lustre/include/linux/libcfs/libcfs.h
@@ -67,8 +67,8 @@
/*
* Defined by platform
*/
-sigset_t cfs_block_sigsinv(unsigned long sigs);
-void cfs_restore_sigs(sigset_t sigset);
+void cfs_block_sigsinv(unsigned long sigs, sigset_t *sigset);
+void cfs_restore_sigs(sigset_t *sigset);

struct libcfs_ioctl_handler {
struct list_head item;
diff --git a/drivers/staging/lustre/lnet/libcfs/linux/linux-prim.c b/drivers/staging/lustre/lnet/libcfs/linux/linux-prim.c
index 6b73b9845e3f..0766659ddf70 100644
--- a/drivers/staging/lustre/lnet/libcfs/linux/linux-prim.c
+++ b/drivers/staging/lustre/lnet/libcfs/linux/linux-prim.c
@@ -44,29 +44,19 @@
#endif

/* Block all signals except for the @sigs */
-sigset_t cfs_block_sigsinv(unsigned long sigs)
+void cfs_block_sigsinv(unsigned long sigs, sigset_t *old)
{
- unsigned long flags;
- sigset_t old;
+ sigset_t new;

- spin_lock_irqsave(&current->sighand->siglock, flags);
- old = current->blocked;
- sigaddsetmask(&current->blocked, ~sigs);
- recalc_sigpending();
- spin_unlock_irqrestore(&current->sighand->siglock, flags);
-
- return old;
+ siginitsetinv(&new, sigs);
+ sigorsets(&new, &current->blocked, &new);
+ sigprocmask(SIG_BLOCK, &new, old);
}
EXPORT_SYMBOL(cfs_block_sigsinv);

void
-cfs_restore_sigs(sigset_t old)
+cfs_restore_sigs(sigset_t *old)
{
- unsigned long flags;
-
- spin_lock_irqsave(&current->sighand->siglock, flags);
- current->blocked = old;
- recalc_sigpending();
- spin_unlock_irqrestore(&current->sighand->siglock, flags);
+ sigprocmask(SIG_SETMASK, old, NULL);
}
EXPORT_SYMBOL(cfs_restore_sigs);
diff --git a/drivers/staging/lustre/lustre/include/lustre_lib.h b/drivers/staging/lustre/lustre/include/lustre_lib.h
index 1efd86f18c1f..0053eafc1c10 100644
--- a/drivers/staging/lustre/lustre/include/lustre_lib.h
+++ b/drivers/staging/lustre/lustre/include/lustre_lib.h
@@ -94,31 +94,31 @@ static inline int l_fatal_signal_pending(struct task_struct *p)
*/
#define l_wait_event_abortable(wq, condition) \
({ \
- sigset_t __blocked; \
+ sigset_t __old_blocked; \
int __ret = 0; \
- __blocked = cfs_block_sigsinv(LUSTRE_FATAL_SIGS); \
+ cfs_block_sigsinv(LUSTRE_FATAL_SIGS, &__old_blocked); \
__ret = wait_event_interruptible(wq, condition); \
- cfs_restore_sigs(__blocked); \
+ cfs_restore_sigs(&__old_blocked); \
__ret; \
})

#define l_wait_event_abortable_timeout(wq, condition, timeout) \
({ \
- sigset_t __blocked; \
+ sigset_t __old_blocked; \
int __ret = 0; \
- __blocked = cfs_block_sigsinv(LUSTRE_FATAL_SIGS); \
+ cfs_block_sigsinv(LUSTRE_FATAL_SIGS, &__old_blocked); \
__ret = wait_event_interruptible_timeout(wq, condition, timeout);\
- cfs_restore_sigs(__blocked); \
+ cfs_restore_sigs(&__old_blocked); \
__ret; \
})

#define l_wait_event_abortable_exclusive(wq, condition) \
({ \
- sigset_t __blocked; \
+ sigset_t __old_blocked; \
int __ret = 0; \
- __blocked = cfs_block_sigsinv(LUSTRE_FATAL_SIGS); \
+ cfs_block_sigsinv(LUSTRE_FATAL_SIGS, &__old_blocked); \
__ret = wait_event_interruptible_exclusive(wq, condition); \
- cfs_restore_sigs(__blocked); \
+ cfs_restore_sigs(&__old_blocked); \
__ret; \
})
#endif /* _LUSTRE_LIB_H */
diff --git a/drivers/staging/lustre/lustre/llite/llite_mmap.c b/drivers/staging/lustre/lustre/llite/llite_mmap.c
index c0533bd6f352..214b07554e62 100644
--- a/drivers/staging/lustre/lustre/llite/llite_mmap.c
+++ b/drivers/staging/lustre/lustre/llite/llite_mmap.c
@@ -177,14 +177,14 @@ static int ll_page_mkwrite0(struct vm_area_struct *vma, struct page *vmpage,
vio->u.fault.ft_vma = vma;
vio->u.fault.ft_vmpage = vmpage;

- set = cfs_block_sigsinv(sigmask(SIGKILL) | sigmask(SIGTERM));
+ cfs_block_sigsinv(sigmask(SIGKILL) | sigmask(SIGTERM), &set);

inode = vvp_object_inode(io->ci_obj);
lli = ll_i2info(inode);

result = cl_io_loop(env, io);

- cfs_restore_sigs(set);
+ cfs_restore_sigs(&set);

if (result == 0) {
struct inode *inode = file_inode(vma->vm_file);
@@ -334,7 +334,7 @@ static int ll_fault(struct vm_fault *vmf)
* so that it can be killed by admin but not cause segfault by
* other signals.
*/
- set = cfs_block_sigsinv(sigmask(SIGKILL) | sigmask(SIGTERM));
+ cfs_block_sigsinv(sigmask(SIGKILL) | sigmask(SIGTERM), &set);

restart:
result = ll_fault0(vmf->vma, vmf);
@@ -360,7 +360,7 @@ static int ll_fault(struct vm_fault *vmf)

result = VM_FAULT_LOCKED;
}
- cfs_restore_sigs(set);
+ cfs_restore_sigs(&set);
return result;
}


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