[Devel] [PATCH RHEL8 COMMIT] mm: introduce fault_signal_pending()
Konstantin Khorenko
khorenko at virtuozzo.com
Mon Apr 20 10:34:09 MSK 2020
The commit is pushed to "branch-rh8-4.18.0-80.1.2.vz8.3.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh8-4.18.0-80.1.2.vz8.3.6
------>
commit b62af0647395b62c7810a0db36f9736c633b86d1
Author: Peter Xu <peterx at redhat.com>
Date: Mon Apr 20 10:34:09 2020 +0300
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 at redhat.com: fix sparse warnings]
Link: http://lkml.kernel.org/r/20200311145921.GD479302@xz-x1
Signed-off-by: Peter Xu <peterx at redhat.com>
Signed-off-by: Andrew Morton <akpm at linux-foundation.org>
Tested-by: Brian Geffon <bgeffon at google.com>
Cc: Andrea Arcangeli <aarcange at redhat.com>
Cc: Bobby Powers <bobbypowers at gmail.com>
Cc: David Hildenbrand <david at redhat.com>
Cc: Denis Plotnikov <dplotnikov at virtuozzo.com>
Cc: "Dr . David Alan Gilbert" <dgilbert at redhat.com>
Cc: Hugh Dickins <hughd at google.com>
Cc: Jerome Glisse <jglisse at redhat.com>
Cc: Johannes Weiner <hannes at cmpxchg.org>
Cc: "Kirill A . Shutemov" <kirill at shutemov.name>
Cc: Martin Cracauer <cracauer at cons.org>
Cc: Marty McFadden <mcfadden8 at llnl.gov>
Cc: Matthew Wilcox <willy at infradead.org>
Cc: Maya Gokhale <gokhale2 at llnl.gov>
Cc: Mel Gorman <mgorman at suse.de>
Cc: Mike Kravetz <mike.kravetz at oracle.com>
Cc: Mike Rapoport <rppt at linux.vnet.ibm.com>
Cc: Pavel Emelyanov <xemul at openvz.org>
Link: http://lkml.kernel.org/r/20200220155353.8676-4-peterx@redhat.com
Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>
https://jira.sw.ru/browse/PSBM-102938
(cherry picked from commit 4ef873226ceb9c7bf11a922caddc5698a24bcfaf)
Signed-off-by: Andrey Ryabinin <aryabinin at virtuozzo.com>
---
arch/alpha/mm/fault.c | 2 +-
arch/arm/mm/fault.c | 2 +-
arch/hexagon/mm/vm_fault.c | 2 +-
arch/ia64/mm/fault.c | 2 +-
arch/m68k/mm/fault.c | 2 +-
arch/microblaze/mm/fault.c | 2 +-
arch/mips/mm/fault.c | 2 +-
arch/nds32/mm/fault.c | 2 +-
arch/nios2/mm/fault.c | 2 +-
arch/openrisc/mm/fault.c | 2 +-
arch/parisc/mm/fault.c | 2 +-
arch/riscv/mm/fault.c | 2 +-
arch/s390/mm/fault.c | 3 +--
arch/sparc/mm/fault_32.c | 2 +-
arch/sparc/mm/fault_64.c | 2 +-
arch/unicore32/mm/fault.c | 2 +-
arch/xtensa/mm/fault.c | 2 +-
include/linux/sched/signal.h | 16 ++++++++++++++++
18 files changed, 33 insertions(+), 18 deletions(-)
diff --git a/arch/alpha/mm/fault.c b/arch/alpha/mm/fault.c
index de2bd217adad..5c14c05c2e77 100644
--- a/arch/alpha/mm/fault.c
+++ b/arch/alpha/mm/fault.c
@@ -149,7 +149,7 @@ 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)) {
diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c
index 84becc911ee3..9d2e2a65da0a 100644
--- a/arch/arm/mm/fault.c
+++ b/arch/arm/mm/fault.c
@@ -319,7 +319,7 @@ 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;
diff --git a/arch/hexagon/mm/vm_fault.c b/arch/hexagon/mm/vm_fault.c
index 933bbcef5363..d81106a0177f 100644
--- a/arch/hexagon/mm/vm_fault.c
+++ b/arch/hexagon/mm/vm_fault.c
@@ -104,7 +104,7 @@ 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. */
diff --git a/arch/ia64/mm/fault.c b/arch/ia64/mm/fault.c
index 817fa120645f..12cdc9b6e27a 100644
--- a/arch/ia64/mm/fault.c
+++ b/arch/ia64/mm/fault.c
@@ -163,7 +163,7 @@ 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)) {
diff --git a/arch/m68k/mm/fault.c b/arch/m68k/mm/fault.c
index f2ff3779875a..6717643670c0 100644
--- a/arch/m68k/mm/fault.c
+++ b/arch/m68k/mm/fault.c
@@ -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 %d\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)) {
diff --git a/arch/microblaze/mm/fault.c b/arch/microblaze/mm/fault.c
index af607447c683..fde3e64687ad 100644
--- a/arch/microblaze/mm/fault.c
+++ b/arch/microblaze/mm/fault.c
@@ -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)) {
diff --git a/arch/mips/mm/fault.c b/arch/mips/mm/fault.c
index 5f71f2b903b7..72f3b936307d 100644
--- a/arch/mips/mm/fault.c
+++ b/arch/mips/mm/fault.c
@@ -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);
diff --git a/arch/nds32/mm/fault.c b/arch/nds32/mm/fault.c
index 9bdb7c3ecbb6..07c2debc0c79 100644
--- a/arch/nds32/mm/fault.c
+++ b/arch/nds32/mm/fault.c
@@ -211,7 +211,7 @@ 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;
diff --git a/arch/nios2/mm/fault.c b/arch/nios2/mm/fault.c
index b804dd06ea1c..0ff63af6134d 100644
--- a/arch/nios2/mm/fault.c
+++ b/arch/nios2/mm/fault.c
@@ -134,7 +134,7 @@ 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)) {
diff --git a/arch/openrisc/mm/fault.c b/arch/openrisc/mm/fault.c
index 9f011d16cc46..06bea244c186 100644
--- a/arch/openrisc/mm/fault.c
+++ b/arch/openrisc/mm/fault.c
@@ -165,7 +165,7 @@ 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)) {
diff --git a/arch/parisc/mm/fault.c b/arch/parisc/mm/fault.c
index a80117980fc2..b7744c313913 100644
--- a/arch/parisc/mm/fault.c
+++ b/arch/parisc/mm/fault.c
@@ -303,7 +303,7 @@ 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)) {
diff --git a/arch/riscv/mm/fault.c b/arch/riscv/mm/fault.c
index 148c98ca9b45..06c1d0b3150b 100644
--- a/arch/riscv/mm/fault.c
+++ b/arch/riscv/mm/fault.c
@@ -126,7 +126,7 @@ 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)) {
diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c
index 4cc3f06b0ab3..7a295776228d 100644
--- a/arch/s390/mm/fault.c
+++ b/arch/s390/mm/fault.c
@@ -499,8 +499,7 @@ static inline int 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;
diff --git a/arch/sparc/mm/fault_32.c b/arch/sparc/mm/fault_32.c
index 9f75b6444bf1..f3eeba49fb43 100644
--- a/arch/sparc/mm/fault_32.c
+++ b/arch/sparc/mm/fault_32.c
@@ -236,7 +236,7 @@ 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)) {
diff --git a/arch/sparc/mm/fault_64.c b/arch/sparc/mm/fault_64.c
index 63166fcf9e25..0c8bd693de39 100644
--- a/arch/sparc/mm/fault_64.c
+++ b/arch/sparc/mm/fault_64.c
@@ -434,7 +434,7 @@ 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)) {
diff --git a/arch/unicore32/mm/fault.c b/arch/unicore32/mm/fault.c
index 381473412937..d4d2821ab672 100644
--- a/arch/unicore32/mm/fault.c
+++ b/arch/unicore32/mm/fault.c
@@ -258,7 +258,7 @@ 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)) {
diff --git a/arch/xtensa/mm/fault.c b/arch/xtensa/mm/fault.c
index c111a833205a..1aacb749a09c 100644
--- a/arch/xtensa/mm/fault.c
+++ b/arch/xtensa/mm/fault.c
@@ -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)) {
diff --git a/include/linux/sched/signal.h b/include/linux/sched/signal.h
index c68241b2dde8..e00c838ef52a 100644
--- a/include/linux/sched/signal.h
+++ b/include/linux/sched/signal.h
@@ -9,6 +9,9 @@
#include <linux/sched/task.h>
#include <linux/cred.h>
#include <linux/rh_kabi.h>
+#include <linux/mm.h>
+#include <linux/mm_types.h>
+#include <asm/ptrace.h>
/*
* Types defining task->signal and task->sighand and APIs using them:
@@ -369,6 +372,19 @@ 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.
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