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| author | Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> | 2014-06-17 11:04:42 +0000 |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2014-07-01 07:13:34 -0400 |
| commit | 5c27c775d5e698d5b754d213747e9fb85290e3b8 (patch) | |
| tree | 5bb984d47fddd7d04541ce0c1dda0e68457610d3 | |
| parent | d8fae2f64433cbe7f0389f965081348272b61ff9 (diff) | |
| download | linux-5c27c775d5e698d5b754d213747e9fb85290e3b8.tar.gz linux-5c27c775d5e698d5b754d213747e9fb85290e3b8.tar.bz2 linux-5c27c775d5e698d5b754d213747e9fb85290e3b8.zip | |
ftrace: Simplify ftrace_hash_disable/enable path in ftrace_hash_move
Simplify ftrace_hash_disable/enable path in ftrace_hash_move
for hardening the process if the memory allocation failed.
Link: http://lkml.kernel.org/p/20140617110442.15167.81076.stgit@kbuild-fedora.novalocal
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| -rw-r--r-- | kernel/trace/ftrace.c | 33 |
1 files changed, 11 insertions, 22 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 3ded796e10e0..8323082dbc21 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -1306,25 +1306,15 @@ ftrace_hash_move(struct ftrace_ops *ops, int enable, struct ftrace_hash *new_hash; int size = src->count; int bits = 0; - int ret; int i; /* - * Remove the current set, update the hash and add - * them back. - */ - ftrace_hash_rec_disable(ops, enable); - - /* * If the new source is empty, just free dst and assign it * the empty_hash. */ if (!src->count) { - free_ftrace_hash_rcu(*dst); - rcu_assign_pointer(*dst, EMPTY_HASH); - /* still need to update the function records */ - ret = 0; - goto out; + new_hash = EMPTY_HASH; + goto update; } /* @@ -1337,10 +1327,9 @@ ftrace_hash_move(struct ftrace_ops *ops, int enable, if (bits > FTRACE_HASH_MAX_BITS) bits = FTRACE_HASH_MAX_BITS; - ret = -ENOMEM; new_hash = alloc_ftrace_hash(bits); if (!new_hash) - goto out; + return -ENOMEM; size = 1 << src->size_bits; for (i = 0; i < size; i++) { @@ -1351,20 +1340,20 @@ ftrace_hash_move(struct ftrace_ops *ops, int enable, } } +update: + /* + * Remove the current set, update the hash and add + * them back. + */ + ftrace_hash_rec_disable(ops, enable); + old_hash = *dst; rcu_assign_pointer(*dst, new_hash); free_ftrace_hash_rcu(old_hash); - ret = 0; - out: - /* - * Enable regardless of ret: - * On success, we enable the new hash. - * On failure, we re-enable the original hash. - */ ftrace_hash_rec_enable(ops, enable); - return ret; + return 0; } /* |