From a050ba1e7422f2cc60ff8bfde3f96d34d00cb585 Mon Sep 17 00:00:00 2001
From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Sat, 24 Jun 2023 10:55:38 -0700
Subject: [PATCH] mm/fault: convert remaining simple cases to
lock_mm_and_find_vma()
This does the simple pattern conversion of alpha, arc, csky, hexagon,
loongarch, nios2, sh, sparc32, and xtensa to the lock_mm_and_find_vma()
helper. They all have the regular fault handling pattern without odd
special cases.
The remaining architectures all have something that keeps us from a
straightforward conversion: ia64 and parisc have stacks that can grow
both up as well as down (and ia64 has special address region checks).
And m68k, microblaze, openrisc, sparc64, and um end up having extra
rules about only expanding the stack down a limited amount below the
user space stack pointer. That is something that x86 used to do too
(long long ago), and it probably could just be skipped, but it still
makes the conversion less than trivial.
Note that this conversion was done manually and with the exception of
alpha without any build testing, because I have a fairly limited cross-
building environment. The cases are all simple, and I went through the
changes several times, but...
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
arch/alpha/Kconfig | 1 +
arch/alpha/mm/fault.c | 13 +++----------
arch/arc/Kconfig | 1 +
arch/arc/mm/fault.c | 11 +++--------
arch/csky/Kconfig | 1 +
arch/csky/mm/fault.c | 22 +++++-----------------
arch/hexagon/Kconfig | 1 +
arch/hexagon/mm/vm_fault.c | 18 ++++--------------
arch/loongarch/Kconfig | 1 +
arch/loongarch/mm/fault.c | 16 ++++++----------
arch/nios2/Kconfig | 1 +
arch/nios2/mm/fault.c | 17 ++---------------
arch/sh/Kconfig | 1 +
arch/sh/mm/fault.c | 17 ++---------------
arch/sparc/Kconfig | 1 +
arch/sparc/mm/fault_32.c | 32 ++++++++------------------------
arch/xtensa/Kconfig | 1 +
arch/xtensa/mm/fault.c | 14 +++-----------
18 files changed, 45 insertions(+), 124 deletions(-)
diff --git a/arch/alpha/Kconfig b/arch/alpha/Kconfig
index a5c2b1aa46b02..d6968d090d49a 100644
--- a/arch/alpha/Kconfig
+++ b/arch/alpha/Kconfig
@@ -30,6 +30,7 @@ config ALPHA
select HAS_IOPORT
select HAVE_ARCH_AUDITSYSCALL
select HAVE_MOD_ARCH_SPECIFIC
+ select LOCK_MM_AND_FIND_VMA
select MODULES_USE_ELF_RELA
select ODD_RT_SIGACTION
select OLD_SIGSUSPEND
diff --git a/arch/alpha/mm/fault.c b/arch/alpha/mm/fault.c
index 7b01ae4f3bc6c..8c9850437e674 100644
--- a/arch/alpha/mm/fault.c
+++ b/arch/alpha/mm/fault.c
@@ -119,20 +119,12 @@ do_page_fault(unsigned long address, unsigned long mmcsr,
flags |= FAULT_FLAG_USER;
perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
retry:
- mmap_read_lock(mm);
- vma = find_vma(mm, address);
+ vma = lock_mm_and_find_vma(mm, address, regs);
if (!vma)
- goto bad_area;
- if (vma->vm_start <= address)
- goto good_area;
- if (!(vma->vm_flags & VM_GROWSDOWN))
- goto bad_area;
- if (expand_stack(vma, address))
- goto bad_area;
+ goto bad_area_nosemaphore;
/* Ok, we have a good vm_area for this memory access, so
we can handle it. */
- good_area:
si_code = SEGV_ACCERR;
if (cause < 0) {
if (!(vma->vm_flags & VM_EXEC))
@@ -192,6 +184,7 @@ do_page_fault(unsigned long address, unsigned long mmcsr,
bad_area:
mmap_read_unlock(mm);
+ bad_area_nosemaphore:
if (user_mode(regs))
goto do_sigsegv;
diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
index ab6d701365bb0..96cf8720bb939 100644
--- a/arch/arc/Kconfig
+++ b/arch/arc/Kconfig
@@ -41,6 +41,7 @@ config ARC
select HAVE_PERF_EVENTS
select HAVE_SYSCALL_TRACEPOINTS
select IRQ_DOMAIN
+ select LOCK_MM_AND_FIND_VMA
select MODULES_USE_ELF_RELA
select OF
select OF_EARLY_FLATTREE
diff --git a/arch/arc/mm/fault.c b/arch/arc/mm/fault.c
index 5ca59a482632a..f59e722d147f9 100644
--- a/arch/arc/mm/fault.c
+++ b/arch/arc/mm/fault.c
@@ -113,15 +113,9 @@ void do_page_fault(unsigned long address, struct pt_regs *regs)
perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
retry:
- mmap_read_lock(mm);
-
- vma = find_vma(mm, address);
+ vma = lock_mm_and_find_vma(mm, address, regs);
if (!vma)
- goto bad_area;
- if (unlikely(address < vma->vm_start)) {
- if (!(vma->vm_flags & VM_GROWSDOWN) || expand_stack(vma, address))
- goto bad_area;
- }
+ goto bad_area_nosemaphore;
/*
* vm_area is good, now check permissions for this memory access
@@ -161,6 +155,7 @@ void do_page_fault(unsigned long address, struct pt_regs *regs)
bad_area:
mmap_read_unlock(mm);
+bad_area_nosemaphore:
/*
* Major/minor page fault accounting
* (in case of retry we only land here once)
diff --git a/arch/csky/Kconfig b/arch/csky/Kconfig
index 4df1f8c9d170b..03e9f66661570 100644
--- a/arch/csky/Kconfig
+++ b/arch/csky/Kconfig
@@ -96,6 +96,7 @@ config CSKY
select HAVE_REGS_AND_STACK_ACCESS_API
select HAVE_STACKPROTECTOR
select HAVE_SYSCALL_TRACEPOINTS
+ select LOCK_MM_AND_FIND_VMA
select MAY_HAVE_SPARSE_IRQ
select MODULES_USE_ELF_RELA if MODULES
select OF
diff --git a/arch/csky/mm/fault.c b/arch/csky/mm/fault.c
index e15f736cca4b4..ae9781b7d92ea 100644
--- a/arch/csky/mm/fault.c
+++ b/arch/csky/mm/fault.c
@@ -97,13 +97,12 @@ static inline void mm_fault_error(struct pt_regs *regs, unsigned long addr, vm_f
BUG();
}
-static inline void bad_area(struct pt_regs *regs, struct mm_struct *mm, int code, unsigned long addr)
+static inline void bad_area_nosemaphore(struct pt_regs *regs, struct mm_struct *mm, int code, unsigned long addr)
{
/*
* Something tried to access memory that isn't in our memory map.
* Fix it, but check if it's kernel or user first.
*/
- mmap_read_unlock(mm);
/* User mode accesses just cause a SIGSEGV */
if (user_mode(regs)) {
do_trap(regs, SIGSEGV, code, addr);
@@ -238,20 +237,9 @@ asmlinkage void do_page_fault(struct pt_regs *regs)
if (is_write(regs))
flags |= FAULT_FLAG_WRITE;
retry:
- mmap_read_lock(mm);
- vma = find_vma(mm, addr);
+ vma = lock_mm_and_find_vma(mm, address, regs);
if (unlikely(!vma)) {
- bad_area(regs, mm, code, addr);
- return;
- }
- if (likely(vma->vm_start <= addr))
- goto good_area;
- if (unlikely(!(vma->vm_flags & VM_GROWSDOWN))) {
- bad_area(regs, mm, code, addr);
- return;
- }
- if (unlikely(expand_stack(vma, addr))) {
- bad_area(regs, mm, code, addr);
+ bad_area_nosemaphore(regs, mm, code, addr);
return;
}
@@ -259,11 +247,11 @@ asmlinkage void do_page_fault(struct pt_regs *regs)
* Ok, we have a good vm_area for this memory access, so
* we can handle it.
*/
-good_area:
code = SEGV_ACCERR;
if (unlikely(access_error(regs, vma))) {
- bad_area(regs, mm, code, addr);
+ mmap_read_unlock(mm);
+ bad_area_nosemaphore(regs, mm, code, addr);
return;
}
diff --git a/arch/hexagon/Kconfig b/arch/hexagon/Kconfig
index 54eadf2651786..6726f4941015f 100644
--- a/arch/hexagon/Kconfig
+++ b/arch/hexagon/Kconfig
@@ -28,6 +28,7 @@ config HEXAGON
select GENERIC_SMP_IDLE_THREAD
select STACKTRACE_SUPPORT
select GENERIC_CLOCKEVENTS_BROADCAST
+ select LOCK_MM_AND_FIND_VMA
select MODULES_USE_ELF_RELA
select GENERIC_CPU_DEVICES
select ARCH_WANT_LD_ORPHAN_WARN
diff --git a/arch/hexagon/mm/vm_fault.c b/arch/hexagon/mm/vm_fault.c
index 4b578d02fd01a..7295ea3f8cc8d 100644
--- a/arch/hexagon/mm/vm_fault.c
+++ b/arch/hexagon/mm/vm_fault.c
@@ -57,21 +57,10 @@ void do_page_fault(unsigned long address, long cause, struct pt_regs *regs)
perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
retry:
- mmap_read_lock(mm);
- vma = find_vma(mm, address);
- if (!vma)
- goto bad_area;
+ vma = lock_mm_and_find_vma(mm, address, regs);
+ if (unlikely(!vma))
+ goto bad_area_nosemaphore;
- if (vma->vm_start <= address)
- goto good_area;
-
- if (!(vma->vm_flags & VM_GROWSDOWN))
- goto bad_area;
-
- if (expand_stack(vma, address))
- goto bad_area;
-
-good_area:
/* Address space is OK. Now check access rights. */
si_code = SEGV_ACCERR;
@@ -143,6 +132,7 @@ void do_page_fault(unsigned long address, long cause, struct pt_regs *regs)
bad_area:
mmap_read_unlock(mm);
+bad_area_nosemaphore:
if (user_mode(regs)) {
force_sig_fault(SIGSEGV, si_code, (void __user *)address);
return;
diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig
index d38b066fc931b..73519e13bbb39 100644
--- a/arch/loongarch/Kconfig
+++ b/arch/loongarch/Kconfig
@@ -130,6 +130,7 @@ config LOONGARCH
select HAVE_VIRT_CPU_ACCOUNTING_GEN if !SMP
select IRQ_FORCED_THREADING
select IRQ_LOONGARCH_CPU
+ select LOCK_MM_AND_FIND_VMA
select MMU_GATHER_MERGE_VMAS if MMU
select MODULES_USE_ELF_RELA if MODULES
select NEED_PER_CPU_EMBED_FIRST_CHUNK
diff --git a/arch/loongarch/mm/fault.c b/arch/loongarch/mm/fault.c
index 449087bd589d3..da5b6d518cdb1 100644
--- a/arch/loongarch/mm/fault.c
+++ b/arch/loongarch/mm/fault.c
@@ -169,22 +169,18 @@ static void __kprobes __do_page_fault(struct pt_regs *regs,
perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
retry:
- mmap_read_lock(mm);
- vma = find_vma(mm, address);
- if (!vma)
- goto bad_area;
- if (vma->vm_start <= address)
- goto good_area;
- if (!(vma->vm_flags & VM_GROWSDOWN))
- goto bad_area;
- if (!expand_stack(vma, address))
- goto good_area;
+ vma = lock_mm_and_find_vma(mm, address, regs);
+ if (unlikely(!vma))
+ goto bad_area_nosemaphore;
+ goto good_area;
+
/*
* Something tried to access memory that isn't in our memory map..
* Fix it, but check if it's kernel or user first..
*/
bad_area:
mmap_read_unlock(mm);
+bad_area_nosemaphore:
do_sigsegv(regs, write, address, si_code);
return;
diff --git a/arch/nios2/Kconfig b/arch/nios2/Kconfig
index e5936417d3cd3..d54464021a618 100644
--- a/arch/nios2/Kconfig
+++ b/arch/nios2/Kconfig
@@ -16,6 +16,7 @@ config NIOS2
select HAVE_ARCH_TRACEHOOK
select HAVE_ARCH_KGDB
select IRQ_DOMAIN
+ select LOCK_MM_AND_FIND_VMA
select MODULES_USE_ELF_RELA
select OF
select OF_EARLY_FLATTREE
diff --git a/arch/nios2/mm/fault.c b/arch/nios2/mm/fault.c
index ca64eccea5511..e3fa9c15181df 100644
--- a/arch/nios2/mm/fault.c
+++ b/arch/nios2/mm/fault.c
@@ -86,27 +86,14 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long cause,
perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
- if (!mmap_read_trylock(mm)) {
- if (!user_mode(regs) && !search_exception_tables(regs->ea))
- goto bad_area_nosemaphore;
retry:
- mmap_read_lock(mm);
- }
-
- vma = find_vma(mm, address);
+ vma = lock_mm_and_find_vma(mm, address, regs);
if (!vma)
- goto bad_area;
- if (vma->vm_start <= address)
- goto good_area;
- if (!(vma->vm_flags & VM_GROWSDOWN))
- goto bad_area;
- if (expand_stack(vma, address))
- goto bad_area;
+ goto bad_area_nosemaphore;
/*
* Ok, we have a good vm_area for this memory access, so
* we can handle it..
*/
-good_area:
code = SEGV_ACCERR;
switch (cause) {
diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
index 9652d367fc377..393023d092450 100644
--- a/arch/sh/Kconfig
+++ b/arch/sh/Kconfig
@@ -59,6 +59,7 @@ config SUPERH
select HAVE_STACKPROTECTOR
select HAVE_SYSCALL_TRACEPOINTS
select IRQ_FORCED_THREADING
+ select LOCK_MM_AND_FIND_VMA
select MODULES_USE_ELF_RELA
select NEED_SG_DMA_LENGTH
select NO_DMA if !MMU && !DMA_COHERENT
diff --git a/arch/sh/mm/fault.c b/arch/sh/mm/fault.c
index acd2f5e50bfcd..06e6b49529245 100644
--- a/arch/sh/mm/fault.c
+++ b/arch/sh/mm/fault.c
@@ -439,21 +439,9 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs *regs,
}
retry:
- mmap_read_lock(mm);
-
- vma = find_vma(mm, address);
+ vma = lock_mm_and_find_vma(mm, address, regs);
if (unlikely(!vma)) {
- bad_area(regs, error_code, address);
- return;
- }
- if (likely(vma->vm_start <= address))
- goto good_area;
- if (unlikely(!(vma->vm_flags & VM_GROWSDOWN))) {
- bad_area(regs, error_code, address);
- return;
- }
- if (unlikely(expand_stack(vma, address))) {
- bad_area(regs, error_code, address);
+ bad_area_nosemaphore(regs, error_code, address);
return;
}
@@ -461,7 +449,6 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs *regs,
* Ok, we have a good vm_area for this memory access, so
* we can handle it..
*/
-good_area:
if (unlikely(access_error(error_code, vma))) {
bad_area_access_error(regs, error_code, address);
return;
diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index 8535e19062f65..8c196990558b2 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -57,6 +57,7 @@ config SPARC32
select DMA_DIRECT_REMAP
select GENERIC_ATOMIC64
select HAVE_UID16
+ select LOCK_MM_AND_FIND_VMA
select OLD_SIGACTION
select ZONE_DMA
diff --git a/arch/sparc/mm/fault_32.c b/arch/sparc/mm/fault_32.c
index 179295b14664a..a3ccc0267bc20 100644
--- a/arch/sparc/mm/fault_32.c
+++ b/arch/sparc/mm/fault_32.c
@@ -143,28 +143,19 @@ asmlinkage void do_sparc_fault(struct pt_regs *regs, int text_fault, int write,
if (pagefault_disabled() || !mm)
goto no_context;
+ if (!from_user && address >= PAGE_OFFSET)
+ goto no_context;
+
perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
retry:
- mmap_read_lock(mm);
-
- if (!from_user && address >= PAGE_OFFSET)
- goto bad_area;
-
- vma = find_vma(mm, address);
+ vma = lock_mm_and_find_vma(mm, address, regs);
if (!vma)
- goto bad_area;
- if (vma->vm_start <= address)
- goto good_area;
- if (!(vma->vm_flags & VM_GROWSDOWN))
- goto bad_area;
- if (expand_stack(vma, address))
- goto bad_area;
+ goto bad_area_nosemaphore;
/*
* Ok, we have a good vm_area for this memory access, so
* we can handle it..
*/
-good_area:
code = SEGV_ACCERR;
if (write) {
if (!(vma->vm_flags & VM_WRITE))
@@ -321,17 +312,9 @@ static void force_user_fault(unsigned long address, int write)
code = SEGV_MAPERR;
- mmap_read_lock(mm);
- vma = find_vma(mm, address);
+ vma = lock_mm_and_find_vma(mm, address, regs);
if (!vma)
- goto bad_area;
- if (vma->vm_start <= address)
- goto good_area;
- if (!(vma->vm_flags & VM_GROWSDOWN))
- goto bad_area;
- if (expand_stack(vma, address))
- goto bad_area;
-good_area:
+ goto bad_area_nosemaphore;
code = SEGV_ACCERR;
if (write) {
if (!(vma->vm_flags & VM_WRITE))
@@ -350,6 +333,7 @@ static void force_user_fault(unsigned long address, int write)
return;
bad_area:
mmap_read_unlock(mm);
+bad_area_nosemaphore:
__do_fault_siginfo(code, SIGSEGV, tsk->thread.kregs, address);
return;
diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
index 3c6e5471f025b..2d0d6440b9796 100644
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig
@@ -49,6 +49,7 @@ config XTENSA
select HAVE_SYSCALL_TRACEPOINTS
select HAVE_VIRT_CPU_ACCOUNTING_GEN
select IRQ_DOMAIN
+ select LOCK_MM_AND_FIND_VMA
select MODULES_USE_ELF_RELA
select PERF_USE_VMALLOC
select TRACE_IRQFLAGS_SUPPORT
diff --git a/arch/xtensa/mm/fault.c b/arch/xtensa/mm/fault.c
index faf7cf35a0ee3..d1eb8d6c5b826 100644
--- a/arch/xtensa/mm/fault.c
+++ b/arch/xtensa/mm/fault.c
@@ -130,23 +130,14 @@ void do_page_fault(struct pt_regs *regs)
perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
retry:
- mmap_read_lock(mm);
- vma = find_vma(mm, address);
-
+ vma = lock_mm_and_find_vma(mm, address, regs);
if (!vma)
- goto bad_area;
- if (vma->vm_start <= address)
- goto good_area;
- if (!(vma->vm_flags & VM_GROWSDOWN))
- goto bad_area;
- if (expand_stack(vma, address))
- goto bad_area;
+ goto bad_area_nosemaphore;
/* Ok, we have a good vm_area for this memory access, so
* we can handle it..
*/
-good_area:
code = SEGV_ACCERR;
if (is_write) {
@@ -205,6 +196,7 @@ void do_page_fault(struct pt_regs *regs)
*/
bad_area:
mmap_read_unlock(mm);
+bad_area_nosemaphore:
if (user_mode(regs)) {
force_sig_fault(SIGSEGV, code, (void *) address);
return;
--
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