| Message ID | 20220127220126.zRE0qPjlu%akpm@linux-foundation.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [alternative-merged] mm-utilc-make-kvfree-safe-for-calling-while-holding-spinlocks.patch removed from -mm tree | expand |
--- a/mm/util.c~mm-utilc-make-kvfree-safe-for-calling-while-holding-spinlocks +++ a/mm/util.c @@ -603,12 +603,12 @@ EXPORT_SYMBOL(kvmalloc_node); * It is slightly more efficient to use kfree() or vfree() if you are certain * that you know which one to use. * - * Context: Either preemptible task context or not-NMI interrupt. + * Context: Any context except NMI interrupt. */ void kvfree(const void *addr) { if (is_vmalloc_addr(addr)) - vfree(addr); + vfree_atomic(addr); else kfree(addr); }
The patch titled Subject: mm/util.c: make kvfree() safe for calling while holding spinlocks has been removed from the -mm tree. Its filename was mm-utilc-make-kvfree-safe-for-calling-while-holding-spinlocks.patch This patch was dropped because an alternative patch was merged ------------------------------------------------------ From: Manfred Spraul <manfred@colorfullife.com> Subject: mm/util.c: make kvfree() safe for calling while holding spinlocks One codepath in find_alloc_undo() calls kvfree() while holding a spinlock. Since vfree() can sleep this is a bug. Previously, the code path used kfree(), and kfree() is safe to be called while holding a spinlock. Minghao proposed to fix this by updating find_alloc_undo(). Alternate proposal to fix this: Instead of changing find_alloc_undo(), change kvfree() so that the same rules as for kfree() apply: Having different rules for kfree() and kvfree() just asks for bugs. Disadvantage: Releasing vmalloc'ed memory will be delayed a bit. Link: https://lkml.kernel.org/r/20211222194828.15320-1-manfred@colorfullife.com Link: https://lore.kernel.org/all/20211222081026.484058-1-chi.minghao@zte.com.cn/ Fixes: fc37a3b8b438 ("[PATCH] ipc sem: use kvmalloc for sem_undo allocation") Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Reported-by: Zeal Robot <zealci@zte.com.cn> Reported-by: Minghao Chi <chi.minghao@zte.com.cn> Cc: Vasily Averin <vvs@virtuozzo.com> Cc: CGEL ZTE <cgel.zte@gmail.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Davidlohr Bueso <dbueso@suse.de> Cc: Bhaskar Chowdhury <unixbhaskar@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Uladzislau Rezki <urezki@gmail.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: <1vier1@web.de> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> --- mm/util.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)