From 792b429db7e0217faf7bce9fe46e7708135cf83c Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Wed, 4 Jun 2025 16:05:44 +0200 Subject: mm/gup: remove (VM_)BUG_ONs Especially once we hit one of the assertions in sanity_check_pinned_pages(), observing follow-up assertions failing in other code can give good clues about what went wrong, so use VM_WARN_ON_ONCE instead. While at it, let's just convert all VM_BUG_ON to VM_WARN_ON_ONCE as well. Add one comment for the pfn_valid() check. We have to introduce VM_WARN_ON_ONCE_VMA() to make that fly. Drop the BUG_ON after mmap_read_lock_killable(), if that ever returns something > 0 we're in bigger trouble. Convert the other BUG_ON's into VM_WARN_ON_ONCE as well, they are in a similar domain "should never happen", but more reasonable to check for during early testing. [david@redhat.com: use the _FOLIO variant where possible, per Lorenzo] Link: https://lkml.kernel.org/r/844bd929-a551-48e3-a12e-285cd65ba580@redhat.com Link: https://lkml.kernel.org/r/20250604140544.688711-1-david@redhat.com Signed-off-by: David Hildenbrand Acked-by: Vlastimil Babka Reviewed-by: Suren Baghdasaryan Reviewed-by: Lorenzo Stoakes Acked-by: SeongJae Park Reviewed-by: Liam R. Howlett Acked-by: Michal Hocko Reviewed-by: John Hubbard Cc: Mike Rapoport Cc: Jason Gunthorpe Cc: Peter Xu Signed-off-by: Andrew Morton --- include/linux/mmdebug.h | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'include/linux/mmdebug.h') diff --git a/include/linux/mmdebug.h b/include/linux/mmdebug.h index a0a3894900ed..14a45979cccc 100644 --- a/include/linux/mmdebug.h +++ b/include/linux/mmdebug.h @@ -89,6 +89,17 @@ void vma_iter_dump_tree(const struct vma_iterator *vmi); } \ unlikely(__ret_warn_once); \ }) +#define VM_WARN_ON_ONCE_VMA(cond, vma) ({ \ + static bool __section(".data..once") __warned; \ + int __ret_warn_once = !!(cond); \ + \ + if (unlikely(__ret_warn_once && !__warned)) { \ + dump_vma(vma); \ + __warned = true; \ + WARN_ON(1); \ + } \ + unlikely(__ret_warn_once); \ +}) #define VM_WARN_ON_VMG(cond, vmg) ({ \ int __ret_warn = !!(cond); \ \ @@ -115,6 +126,7 @@ void vma_iter_dump_tree(const struct vma_iterator *vmi); #define VM_WARN_ON_FOLIO(cond, folio) BUILD_BUG_ON_INVALID(cond) #define VM_WARN_ON_ONCE_FOLIO(cond, folio) BUILD_BUG_ON_INVALID(cond) #define VM_WARN_ON_ONCE_MM(cond, mm) BUILD_BUG_ON_INVALID(cond) +#define VM_WARN_ON_ONCE_VMA(cond, vma) BUILD_BUG_ON_INVALID(cond) #define VM_WARN_ON_VMG(cond, vmg) BUILD_BUG_ON_INVALID(cond) #define VM_WARN_ONCE(cond, format...) BUILD_BUG_ON_INVALID(cond) #define VM_WARN(cond, format...) BUILD_BUG_ON_INVALID(cond) -- cgit v1.2.3