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authorHoward McLauchlan <hmclauchlan@fb.com>2018-04-05 16:23:57 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2018-04-05 21:36:26 -0700
commit4f6923fbb352d126659cabe34806cff75c7b5ea0 (patch)
treef88b75ada9b91b9f78344f7c719ba38b0e1c439d /include/linux/fault-inject.h
parent14298d3663e44705d3f9106343ac8298a5fdff99 (diff)
mm: make should_failslab always available for fault injection
should_failslab() is a convenient function to hook into for directed error injection into kmalloc(). However, it is only available if a config flag is set. The following BCC script, for example, fails kmalloc() calls after a btrfs umount: from bcc import BPF prog = r""" BPF_HASH(flag); #include <linux/mm.h> int kprobe__btrfs_close_devices(void *ctx) { u64 key = 1; flag.update(&key, &key); return 0; } int kprobe__should_failslab(struct pt_regs *ctx) { u64 key = 1; u64 *res; res = flag.lookup(&key); if (res != 0) { bpf_override_return(ctx, -ENOMEM); } return 0; } """ b = BPF(text=prog) while 1: b.kprobe_poll() This patch refactors the should_failslab implementation so that the function is always available for error injection, independent of flags. This change would be similar in nature to commit f5490d3ec921 ("block: Add should_fail_bio() for bpf error injection"). Link: http://lkml.kernel.org/r/20180222020320.6944-1-hmclauchlan@fb.com Signed-off-by: Howard McLauchlan <hmclauchlan@fb.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Akinobu Mita <akinobu.mita@gmail.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Josef Bacik <jbacik@fb.com> Cc: Johannes Weiner <jweiner@fb.com> Cc: Alexei Starovoitov <ast@fb.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/fault-inject.h')
-rw-r--r--include/linux/fault-inject.h5
1 files changed, 3 insertions, 2 deletions
diff --git a/include/linux/fault-inject.h b/include/linux/fault-inject.h
index c3c95d18bf43..7e6c77740413 100644
--- a/include/linux/fault-inject.h
+++ b/include/linux/fault-inject.h
@@ -64,10 +64,11 @@ static inline struct dentry *fault_create_debugfs_attr(const char *name,
struct kmem_cache;
+int should_failslab(struct kmem_cache *s, gfp_t gfpflags);
#ifdef CONFIG_FAILSLAB
-extern bool should_failslab(struct kmem_cache *s, gfp_t gfpflags);
+extern bool __should_failslab(struct kmem_cache *s, gfp_t gfpflags);
#else
-static inline bool should_failslab(struct kmem_cache *s, gfp_t gfpflags)
+static inline bool __should_failslab(struct kmem_cache *s, gfp_t gfpflags)
{
return false;
}