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>

18 files changed, 45 insertions, 124 deletions

diff --git a/arch/alpha/Kconfig b/arch/alpha/Kconfig
index a5c2b1aa46b0..d6968d090d49 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 7b01ae4f3bc6..8c9850437e67 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 @@ retry:
  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 ab6d701365bb..96cf8720bb93 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 5ca59a482632..f59e722d147f 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 @@ retry:
 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 4df1f8c9d170..03e9f6666157 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 e15f736cca4b..ae9781b7d92e 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 @@ retry:
 	 * 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 54eadf265178..6726f4941015 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 4b578d02fd01..7295ea3f8cc8 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 @@ good_area:
 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 d38b066fc931..73519e13bbb3 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 449087bd589d..da5b6d518cdb 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 e5936417d3cd..d54464021a61 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 ca64eccea551..e3fa9c15181d 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 9652d367fc37..393023d09245 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 acd2f5e50bfc..06e6b4952924 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 @@ retry:
 	 * 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 8535e19062f6..8c196990558b 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 179295b14664..a3ccc0267bc2 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 @@ good_area:
 	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 3c6e5471f025..2d0d6440b979 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 faf7cf35a0ee..d1eb8d6c5b82 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 @@ good_area:
 	 */
 bad_area:
 	mmap_read_unlock(mm);
+bad_area_nosemaphore:
 	if (user_mode(regs)) {
 		force_sig_fault(SIGSEGV, code, (void *) address);
 		return;