[PATCH 55/64] arch/riscv: use mm locking wrappers

From: Davidlohr Bueso
Date: Sun Feb 04 2018 - 20:31:42 EST


From: Davidlohr Bueso <dave@xxxxxxxxxxxx>

This becomes quite straightforward with the mmrange in place.

Signed-off-by: Davidlohr Bueso <dbueso@xxxxxxx>
---
arch/riscv/kernel/vdso.c | 5 +++--
arch/riscv/mm/fault.c | 10 +++++-----
2 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/arch/riscv/kernel/vdso.c b/arch/riscv/kernel/vdso.c
index 582cb153eb24..4bbb6e0425df 100644
--- a/arch/riscv/kernel/vdso.c
+++ b/arch/riscv/kernel/vdso.c
@@ -69,10 +69,11 @@ int arch_setup_additional_pages(struct linux_binprm *bprm,
struct mm_struct *mm = current->mm;
unsigned long vdso_base, vdso_len;
int ret;
+ DEFINE_RANGE_LOCK_FULL(mmrange);

vdso_len = (vdso_pages + 1) << PAGE_SHIFT;

- down_write(&mm->mmap_sem);
+ mm_write_lock(mm, &mmrange);
vdso_base = get_unmapped_area(NULL, 0, vdso_len, 0, 0);
if (IS_ERR_VALUE(vdso_base)) {
ret = vdso_base;
@@ -94,7 +95,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm,
mm->context.vdso = NULL;

end:
- up_write(&mm->mmap_sem);
+ mm_write_unlock(mm, &mmrange);
return ret;
}

diff --git a/arch/riscv/mm/fault.c b/arch/riscv/mm/fault.c
index 75d15e73ba39..6f78080e987c 100644
--- a/arch/riscv/mm/fault.c
+++ b/arch/riscv/mm/fault.c
@@ -79,7 +79,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs)
perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, addr);

retry:
- down_read(&mm->mmap_sem);
+ mm_read_lock(mm, &mmrange);
vma = find_vma(mm, addr);
if (unlikely(!vma))
goto bad_area;
@@ -170,7 +170,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs)
}
}

- up_read(&mm->mmap_sem);
+ mm_read_unlock(mm, &mmrange);
return;

/*
@@ -178,7 +178,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs)
* Fix it, but check if it's kernel or user first.
*/
bad_area:
- up_read(&mm->mmap_sem);
+ mm_read_unlock(mm, &mmrange);
/* User mode accesses just cause a SIGSEGV */
if (user_mode(regs)) {
do_trap(regs, SIGSEGV, code, addr, tsk);
@@ -206,14 +206,14 @@ asmlinkage void do_page_fault(struct pt_regs *regs)
* (which will retry the fault, or kill us if we got oom-killed).
*/
out_of_memory:
- up_read(&mm->mmap_sem);
+ mm_read_unlock(mm, &mmrange);
if (!user_mode(regs))
goto no_context;
pagefault_out_of_memory();
return;

do_sigbus:
- up_read(&mm->mmap_sem);
+ mm_read_unlock(mm, &mmrange);
/* Kernel mode? Handle exceptions or die */
if (!user_mode(regs))
goto no_context;
--
2.13.6