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mm: introduce fault_signal_pending() 

For most architectures, we've got a quick path to detect fatal signal
after a handle_mm_fault().  Introduce a helper for that quick path.

It cleans the current codes a bit so we don't need to duplicate the same
check across archs.  More importantly, this will be an unified place that
we handle the signal immediately right after an interrupted page fault, so
it'll be much easier for us if we want to change the behavior of handling
signals later on for all the archs.

Note that currently only part of the archs are using this new helper,
because some archs have their own way to handle signals.  In the follow up
patches, we'll try to apply this helper to all the rest of archs.

Another note is that the "regs" parameter in the new helper is not used
yet.  It'll be used very soon.  Now we kept it in this patch only to avoid
touching all the archs again in the follow up patches.

[peterx@redhat.com: fix sparse warnings]
  Link: http://lkml.kernel.org/r/20200311145921.GD479302@xz-x1
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Brian Geffon <bgeffon@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Bobby Powers <bobbypowers@gmail.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Denis Plotnikov <dplotnikov@virtuozzo.com>
Cc: "Dr . David Alan Gilbert" <dgilbert@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: "Kirill A . Shutemov" <kirill@shutemov.name>
Cc: Martin Cracauer <cracauer@cons.org>
Cc: Marty McFadden <mcfadden8@llnl.gov>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Maya Gokhale <gokhale2@llnl.gov>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Link: http://lkml.kernel.org/r/20200220155353.8676-4-peterx@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Peter Xu 2020-04-01 21:08:06 -07:00 committed by Linus Torvalds
parent ad415db817
commit 4ef873226c
18 changed files with 32 additions and 18 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
arch/alpha/mm/fault.c
View File

@ -150,7 +150,7 @@ do_page_fault(unsigned long address, unsigned long mmcsr,
the fault. */
fault = handle_mm_fault(vma, address, flags);
if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current))
if (fault_signal_pending(fault, regs))
return;
if (unlikely(fault & VM_FAULT_ERROR)) {

2
arch/arm/mm/fault.c
View File

@ -295,7 +295,7 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
* signal first. We do not need to release the mmap_sem because
* it would already be released in __lock_page_or_retry in
* mm/filemap.c. */
if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current)) {
if (fault_signal_pending(fault, regs)) {
if (!user_mode(regs))
goto no_context;
return 0;

2
arch/hexagon/mm/vm_fault.c
View File

@ -91,7 +91,7 @@ void do_page_fault(unsigned long address, long cause, struct pt_regs *regs)
fault = handle_mm_fault(vma, address, flags);
if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current))
if (fault_signal_pending(fault, regs))
return;
/* The most common case -- we are done. */

2
arch/ia64/mm/fault.c
View File

@ -141,7 +141,7 @@ ia64_do_page_fault (unsigned long address, unsigned long isr, struct pt_regs *re
*/
fault = handle_mm_fault(vma, address, flags);
if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current))
if (fault_signal_pending(fault, regs))
return;
if (unlikely(fault & VM_FAULT_ERROR)) {

2
arch/m68k/mm/fault.c
View File

@ -138,7 +138,7 @@ int do_page_fault(struct pt_regs *regs, unsigned long address,
fault = handle_mm_fault(vma, address, flags);
pr_debug("handle_mm_fault returns %x\n", fault);
if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current))
if (fault_signal_pending(fault, regs))
return 0;
if (unlikely(fault & VM_FAULT_ERROR)) {

2
arch/microblaze/mm/fault.c
View File

@ -217,7 +217,7 @@ void do_page_fault(struct pt_regs *regs, unsigned long address,
*/
fault = handle_mm_fault(vma, address, flags);
if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current))
if (fault_signal_pending(fault, regs))
return;
if (unlikely(fault & VM_FAULT_ERROR)) {

2
arch/mips/mm/fault.c
View File

@ -154,7 +154,7 @@ static void __kprobes __do_page_fault(struct pt_regs *regs, unsigned long write,
*/
fault = handle_mm_fault(vma, address, flags);
if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current))
if (fault_signal_pending(fault, regs))
return;
perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);

2
arch/nds32/mm/fault.c
View File

@ -214,7 +214,7 @@ void do_page_fault(unsigned long entry, unsigned long addr,
* signal first. We do not need to release the mmap_sem because it
* would already be released in __lock_page_or_retry in mm/filemap.c.
*/
if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current)) {
if (fault_signal_pending(fault, regs)) {
if (!user_mode(regs))
goto no_context;
return;

2
arch/nios2/mm/fault.c
View File

@ -133,7 +133,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long cause,
*/
fault = handle_mm_fault(vma, address, flags);
if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current))
if (fault_signal_pending(fault, regs))
return;
if (unlikely(fault & VM_FAULT_ERROR)) {

2
arch/openrisc/mm/fault.c
View File

@ -161,7 +161,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long address,
fault = handle_mm_fault(vma, address, flags);
if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current))
if (fault_signal_pending(fault, regs))
return;
if (unlikely(fault & VM_FAULT_ERROR)) {

2
arch/parisc/mm/fault.c
View File

@ -304,7 +304,7 @@ void do_page_fault(struct pt_regs *regs, unsigned long code,
fault = handle_mm_fault(vma, address, flags);
if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current))
if (fault_signal_pending(fault, regs))
return;
if (unlikely(fault & VM_FAULT_ERROR)) {

2
arch/riscv/mm/fault.c
View File

@ -117,7 +117,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs)
* signal first. We do not need to release the mmap_sem because it
* would already be released in __lock_page_or_retry in mm/filemap.c.
*/
if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(tsk))
if (fault_signal_pending(fault, regs))
return;
if (unlikely(fault & VM_FAULT_ERROR)) {

3
arch/s390/mm/fault.c
View File

@ -480,8 +480,7 @@ static inline vm_fault_t do_exception(struct pt_regs *regs, int access)
* the fault.
*/
fault = handle_mm_fault(vma, address, flags);
/* No reason to continue if interrupted by SIGKILL. */
if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current)) {
if (fault_signal_pending(fault, regs)) {
fault = VM_FAULT_SIGNAL;
if (flags & FAULT_FLAG_RETRY_NOWAIT)
goto out_up;

2
arch/sparc/mm/fault_32.c
View File

@ -237,7 +237,7 @@ asmlinkage void do_sparc_fault(struct pt_regs *regs, int text_fault, int write,
*/
fault = handle_mm_fault(vma, address, flags);
if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current))
if (fault_signal_pending(fault, regs))
return;
if (unlikely(fault & VM_FAULT_ERROR)) {

2
arch/sparc/mm/fault_64.c
View File

@ -425,7 +425,7 @@ asmlinkage void __kprobes do_sparc64_fault(struct pt_regs *regs)
fault = handle_mm_fault(vma, address, flags);
if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current))
if (fault_signal_pending(fault, regs))
goto exit_exception;
if (unlikely(fault & VM_FAULT_ERROR)) {

2
arch/unicore32/mm/fault.c
View File

@ -250,7 +250,7 @@ static int do_pf(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
* signal first. We do not need to release the mmap_sem because
* it would already be released in __lock_page_or_retry in
* mm/filemap.c. */
if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current))
if (fault_signal_pending(fault, regs))
return 0;
if (!(fault & VM_FAULT_ERROR) && (flags & FAULT_FLAG_ALLOW_RETRY)) {

2
arch/xtensa/mm/fault.c
View File

@ -110,7 +110,7 @@ void do_page_fault(struct pt_regs *regs)
*/
fault = handle_mm_fault(vma, address, flags);
if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current))
if (fault_signal_pending(fault, regs))
return;
if (unlikely(fault & VM_FAULT_ERROR)) {

15
include/linux/sched/signal.h
View File

@ -10,6 +10,8 @@
#include <linux/cred.h>
#include <linux/refcount.h>
#include <linux/posix-timers.h>
#include <linux/mm_types.h>
#include <asm/ptrace.h>
/*
* Types defining task->signal and task->sighand and APIs using them:
@ -369,6 +371,19 @@ static inline int signal_pending_state(long state, struct task_struct *p)
return (state & TASK_INTERRUPTIBLE) || __fatal_signal_pending(p);
}
/*
* This should only be used in fault handlers to decide whether we
* should stop the current fault routine to handle the signals
* instead, especially with the case where we've got interrupted with
* a VM_FAULT_RETRY.
*/
static inline bool fault_signal_pending(vm_fault_t fault_flags,
struct pt_regs *regs)
{
return unlikely((fault_flags & VM_FAULT_RETRY) &&
fatal_signal_pending(current));
}
/*
* Reevaluate whether the task has signals pending delivery.
* Wake the task if so.