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author | Steven Rostedt <srostedt@redhat.com> | 2011-04-21 23:16:46 -0400 |
---|---|---|
committer | Steven Rostedt <rostedt@goodmis.org> | 2011-04-29 22:53:01 -0400 |
commit | 45a4a2372b364107cabea79f255b333236626416 (patch) | |
tree | dfe3e1c3b55451fedc8896aaa8359677d583a0e5 | |
parent | 3499e461147636bf55c41128d83b679ac6ab2d86 (diff) | |
download | kernel_samsung_smdk4412-45a4a2372b364107cabea79f255b333236626416.zip kernel_samsung_smdk4412-45a4a2372b364107cabea79f255b333236626416.tar.gz kernel_samsung_smdk4412-45a4a2372b364107cabea79f255b333236626416.tar.bz2 |
ftrace: Remove FTRACE_FL_FAILED flag
Since we disable all function tracer processing if we detect
that a modification of a instruction had failed, we do not need
to track that the record has failed. No more ftrace processing
is allowed, and the FTRACE_FL_FAILED flag is pointless.
Removing this flag simplifies some of the code, but some ftrace_disabled
checks needed to be added or move around a little.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
-rw-r--r-- | include/linux/ftrace.h | 9 | ||||
-rw-r--r-- | kernel/trace/ftrace.c | 76 |
2 files changed, 51 insertions, 34 deletions
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index ca29e03..2a195ff 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -147,11 +147,10 @@ extern int ftrace_text_reserved(void *start, void *end); enum { FTRACE_FL_FREE = (1 << 0), - FTRACE_FL_FAILED = (1 << 1), - FTRACE_FL_FILTER = (1 << 2), - FTRACE_FL_ENABLED = (1 << 3), - FTRACE_FL_NOTRACE = (1 << 4), - FTRACE_FL_CONVERTED = (1 << 5), + FTRACE_FL_FILTER = (1 << 1), + FTRACE_FL_ENABLED = (1 << 2), + FTRACE_FL_NOTRACE = (1 << 3), + FTRACE_FL_CONVERTED = (1 << 4), }; struct dyn_ftrace { diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 97b30f8..eb19fae 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -1083,19 +1083,20 @@ static void ftrace_replace_code(int enable) struct ftrace_page *pg; int failed; + if (unlikely(ftrace_disabled)) + return; + do_for_each_ftrace_rec(pg, rec) { /* * Skip over free records, records that have * failed and not converted. */ if (rec->flags & FTRACE_FL_FREE || - rec->flags & FTRACE_FL_FAILED || !(rec->flags & FTRACE_FL_CONVERTED)) continue; failed = __ftrace_replace_code(rec, enable); if (failed) { - rec->flags |= FTRACE_FL_FAILED; ftrace_bug(failed, rec->ip); /* Stop processing */ return; @@ -1111,10 +1112,12 @@ ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec) ip = rec->ip; + if (unlikely(ftrace_disabled)) + return 0; + ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR); if (ret) { ftrace_bug(ret, ip); - rec->flags |= FTRACE_FL_FAILED; return 0; } return 1; @@ -1466,6 +1469,9 @@ t_next(struct seq_file *m, void *v, loff_t *pos) struct ftrace_iterator *iter = m->private; struct dyn_ftrace *rec = NULL; + if (unlikely(ftrace_disabled)) + return NULL; + if (iter->flags & FTRACE_ITER_HASH) return t_hash_next(m, pos); @@ -1518,6 +1524,10 @@ static void *t_start(struct seq_file *m, loff_t *pos) loff_t l; mutex_lock(&ftrace_lock); + + if (unlikely(ftrace_disabled)) + return NULL; + /* * If an lseek was done, then reset and start from beginning. */ @@ -1636,8 +1646,6 @@ static void ftrace_filter_reset(int enable) if (enable) ftrace_filtered = 0; do_for_each_ftrace_rec(pg, rec) { - if (rec->flags & FTRACE_FL_FAILED) - continue; rec->flags &= ~type; } while_for_each_ftrace_rec(); mutex_unlock(&ftrace_lock); @@ -1767,9 +1775,6 @@ static int ftrace_match_records(char *buff, int len, int enable) mutex_lock(&ftrace_lock); do_for_each_ftrace_rec(pg, rec) { - if (rec->flags & FTRACE_FL_FAILED) - continue; - if (ftrace_match_record(rec, search, search_len, type)) { if (not) rec->flags &= ~flag; @@ -1837,10 +1842,11 @@ static int ftrace_match_module_records(char *buff, char *mod, int enable) } mutex_lock(&ftrace_lock); - do_for_each_ftrace_rec(pg, rec) { - if (rec->flags & FTRACE_FL_FAILED) - continue; + if (unlikely(ftrace_disabled)) + goto out_unlock; + + do_for_each_ftrace_rec(pg, rec) { if (ftrace_match_module_record(rec, mod, search, search_len, type)) { @@ -1854,6 +1860,7 @@ static int ftrace_match_module_records(char *buff, char *mod, int enable) ftrace_filtered = 1; } while_for_each_ftrace_rec(); + out_unlock: mutex_unlock(&ftrace_lock); return found; @@ -2008,10 +2015,11 @@ register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, return -EINVAL; mutex_lock(&ftrace_lock); - do_for_each_ftrace_rec(pg, rec) { - if (rec->flags & FTRACE_FL_FAILED) - continue; + if (unlikely(ftrace_disabled)) + goto out_unlock; + + do_for_each_ftrace_rec(pg, rec) { if (!ftrace_match_record(rec, search, len, type)) continue; @@ -2218,6 +2226,10 @@ ftrace_regex_write(struct file *file, const char __user *ubuf, mutex_lock(&ftrace_regex_lock); + ret = -ENODEV; + if (unlikely(ftrace_disabled)) + goto out_unlock; + if (file->f_mode & FMODE_READ) { struct seq_file *m = file->private_data; iter = m->private; @@ -2545,9 +2557,6 @@ ftrace_set_func(unsigned long *array, int *idx, char *buffer) bool exists; int i; - if (ftrace_disabled) - return -ENODEV; - /* decode regex */ type = filter_parse_regex(buffer, strlen(buffer), &search, ¬); if (!not && *idx >= FTRACE_GRAPH_MAX_FUNCS) @@ -2556,9 +2565,15 @@ ftrace_set_func(unsigned long *array, int *idx, char *buffer) search_len = strlen(search); mutex_lock(&ftrace_lock); + + if (unlikely(ftrace_disabled)) { + mutex_unlock(&ftrace_lock); + return -ENODEV; + } + do_for_each_ftrace_rec(pg, rec) { - if (rec->flags & (FTRACE_FL_FAILED | FTRACE_FL_FREE)) + if (rec->flags & FTRACE_FL_FREE) continue; if (ftrace_match_record(rec, search, search_len, type)) { @@ -2700,10 +2715,11 @@ void ftrace_release_mod(struct module *mod) struct dyn_ftrace *rec; struct ftrace_page *pg; + mutex_lock(&ftrace_lock); + if (ftrace_disabled) - return; + goto out_unlock; - mutex_lock(&ftrace_lock); do_for_each_ftrace_rec(pg, rec) { if (within_module_core(rec->ip, mod)) { /* @@ -2714,6 +2730,7 @@ void ftrace_release_mod(struct module *mod) ftrace_free_rec(rec); } } while_for_each_ftrace_rec(); + out_unlock: mutex_unlock(&ftrace_lock); } @@ -3108,16 +3125,17 @@ void ftrace_kill(void) */ int register_ftrace_function(struct ftrace_ops *ops) { - int ret; - - if (unlikely(ftrace_disabled)) - return -1; + int ret = -1; mutex_lock(&ftrace_lock); + if (unlikely(ftrace_disabled)) + goto out_unlock; + ret = __register_ftrace_function(ops); ftrace_startup(0); + out_unlock: mutex_unlock(&ftrace_lock); return ret; } @@ -3145,14 +3163,14 @@ ftrace_enable_sysctl(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { - int ret; - - if (unlikely(ftrace_disabled)) - return -ENODEV; + int ret = -ENODEV; mutex_lock(&ftrace_lock); - ret = proc_dointvec(table, write, buffer, lenp, ppos); + if (unlikely(ftrace_disabled)) + goto out; + + ret = proc_dointvec(table, write, buffer, lenp, ppos); if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled)) goto out; |