From 7267ef7b0b77f4ed23b7b3c87d8eca7bd9c2d007 Mon Sep 17 00:00:00 2001
From: Ben Hutchings <ben@decadent.org.uk>
Date: Thu, 22 Jun 2023 20:18:18 +0200
Subject: [PATCH] riscv/mm: Convert to using lock_mm_and_find_vma()
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
arch/riscv/Kconfig | 1 +
arch/riscv/mm/fault.c | 31 +++++++++++++------------------
2 files changed, 14 insertions(+), 18 deletions(-)
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 5966ad97c30c3..a11b1c038c6d1 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -126,6 +126,7 @@ config RISCV
select IRQ_DOMAIN
select IRQ_FORCED_THREADING
select KASAN_VMALLOC if KASAN
+ select LOCK_MM_AND_FIND_VMA
select MODULES_USE_ELF_RELA if MODULES
select MODULE_SECTIONS if MODULES
select OF
diff --git a/arch/riscv/mm/fault.c b/arch/riscv/mm/fault.c
index 8685f85a7474e..35a84ec69a9fd 100644
--- a/arch/riscv/mm/fault.c
+++ b/arch/riscv/mm/fault.c
@@ -84,13 +84,13 @@ 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, 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);
@@ -100,6 +100,15 @@ static inline void bad_area(struct pt_regs *regs, struct mm_struct *mm, int code
no_context(regs, addr);
}
+static inline void
+bad_area(struct pt_regs *regs, struct mm_struct *mm, int code,
+ unsigned long addr)
+{
+ mmap_read_unlock(mm);
+
+ bad_area_nosemaphore(regs, code, addr);
+}
+
static inline void vmalloc_fault(struct pt_regs *regs, int code, unsigned long addr)
{
pgd_t *pgd, *pgd_k;
@@ -287,23 +296,10 @@ void handle_page_fault(struct pt_regs *regs)
else if (cause == EXC_INST_PAGE_FAULT)
flags |= FAULT_FLAG_INSTRUCTION;
retry:
- mmap_read_lock(mm);
- vma = find_vma(mm, addr);
+ vma = lock_mm_and_find_vma(mm, addr, regs);
if (unlikely(!vma)) {
tsk->thread.bad_cause = cause;
- bad_area(regs, mm, code, addr);
- return;
- }
- if (likely(vma->vm_start <= addr))
- goto good_area;
- if (unlikely(!(vma->vm_flags & VM_GROWSDOWN))) {
- tsk->thread.bad_cause = cause;
- bad_area(regs, mm, code, addr);
- return;
- }
- if (unlikely(expand_stack(vma, addr))) {
- tsk->thread.bad_cause = cause;
- bad_area(regs, mm, code, addr);
+ bad_area_nosemaphore(regs, code, addr);
return;
}
@@ -311,7 +307,6 @@ void handle_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(cause, vma))) {
--
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