mm/fault: convert remaining simple cases to lock_mm_and_find_vma()

commit a050ba1e7422f2cc60ff8bfde3f96d34d00cb585 upstream.

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>
Signed-off-by: Samuel Mendoza-Jonas <samjonas@amazon.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2 files changed, 4 insertions, 11 deletions

diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
index bcb0c5d2abc2..6d3c9257aa13 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 8c781b05c0bd..d89b193c779f 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)) {
 		current->thread.bad_vaddr = address;
 		current->thread.error_code = is_write;