From: Atish Patra atish.patra@wdc.com
commit 0e2c09011d4de4161f615ff860a605a9186cf62a upstream.
As per walk_page_range documentation, mmap lock should be acquired by the caller before invoking walk_page_range. mmap_assert_locked gets triggered without that. The details can be found here.
http://lists.infradead.org/pipermail/linux-riscv/2020-June/010335.html
Fixes: 395a21ff859c(riscv: add ARCH_HAS_SET_DIRECT_MAP support) Signed-off-by: Atish Patra atish.patra@wdc.com Reviewed-by: Michel Lespinasse walken@google.com Reviewed-by: Zong Li zong.li@sifive.com Signed-off-by: Palmer Dabbelt palmerdabbelt@google.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/riscv/mm/pageattr.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-)
--- a/arch/riscv/mm/pageattr.c +++ b/arch/riscv/mm/pageattr.c @@ -151,6 +151,7 @@ int set_memory_nx(unsigned long addr, in
int set_direct_map_invalid_noflush(struct page *page) { + int ret; unsigned long start = (unsigned long)page_address(page); unsigned long end = start + PAGE_SIZE; struct pageattr_masks masks = { @@ -158,11 +159,16 @@ int set_direct_map_invalid_noflush(struc .clear_mask = __pgprot(_PAGE_PRESENT) };
- return walk_page_range(&init_mm, start, end, &pageattr_ops, &masks); + mmap_read_lock(&init_mm); + ret = walk_page_range(&init_mm, start, end, &pageattr_ops, &masks); + mmap_read_unlock(&init_mm); + + return ret; }
int set_direct_map_default_noflush(struct page *page) { + int ret; unsigned long start = (unsigned long)page_address(page); unsigned long end = start + PAGE_SIZE; struct pageattr_masks masks = { @@ -170,7 +176,11 @@ int set_direct_map_default_noflush(struc .clear_mask = __pgprot(0) };
- return walk_page_range(&init_mm, start, end, &pageattr_ops, &masks); + mmap_read_lock(&init_mm); + ret = walk_page_range(&init_mm, start, end, &pageattr_ops, &masks); + mmap_read_unlock(&init_mm); + + return ret; }
void __kernel_map_pages(struct page *page, int numpages, int enable)