On 30/05/2025 04:55, Dev Jain wrote:
On 27/05/25 1:56 pm, Dev Jain wrote:
Commit 9c006972c3fe removes the pxd_present() checks because the caller
nit: "Commit 9c006972c3fe" should have actually been:
Commit 9c006972c3fe ("arm64: mmu: drop pXd_present() checks from pXd_free_pYd_table()")
checks pxd_present(). But, in case of vmap_try_huge_pud(), the caller only checks pud_present(); pud_free_pmd_page() recurses on each pmd through pmd_free_pte_page(), wherein the pmd may be none. Thus it is possible to hit a warning in the latter, since pmd_none => !pmd_table(). Thus, add a pmd_present() check in pud_free_pmd_page().
This problem was found by code inspection.
Fixes: 9c006972c3fe (arm64: mmu: drop pXd_present() checks from pXd_free_pYd_table())
I missed double quotes around the fixes commit message. Can Will or Catalin fix that, or shall I resend.
For future, I have the following in my ~/.gitconfig
""" [pretty] fixes = Fixes: %h ("%s") commit = Commit %h ("%s") """
Then I can do:
$ git show --pretty=fixes <SHA> | head -n 1
or
$ git show --pretty=commit <SHA> | head -n 1
to get the correct format. Note that "Fixes:" is a tag and should all be on a single line. "Commit" is just a way to refer to other commits in prose and can be broken across lines at the usual character limit.
Perhaps there is an even easier way to do it, but this works for me.
Thanks, Ryan
Cc: stable@vger.kernel.org Reported-by: Ryan Roberts ryan.roberts@arm.com Acked-by: David Hildenbrand david@redhat.com Signed-off-by: Dev Jain dev.jain@arm.com
This patch is based on 6.15-rc6.
v2->v3: - Use pmdp_get()
v1->v2: - Enforce check in caller
arch/arm64/mm/mmu.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index ea6695d53fb9..5a9bf291c649 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -1286,7 +1286,8 @@ int pud_free_pmd_page(pud_t *pudp, unsigned long addr) next = addr; end = addr + PUD_SIZE; do { - pmd_free_pte_page(pmdp, next); + if (pmd_present(pmdp_get(pmdp))) + pmd_free_pte_page(pmdp, next); } while (pmdp++, next += PMD_SIZE, next != end); pud_clear(pudp);