From c521efd1700a8c0f7ce26f011f5eaecca17fabfa Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Mon, 7 Dec 2009 09:06:24 -0500 Subject: [PATCH 1/6] tracing: Add pipe_close interface An ftrace plugin can add a pipe_open interface when the user opens trace_pipe. But if the plugin allocates something within the pipe_open it can not free it because there exists no pipe_close. The hook to the trace file open has a corresponding close. The closing of the trace_pipe file should also have a corresponding close. Signed-off-by: Steven Rostedt --- kernel/trace/trace.c | 4 ++++ kernel/trace/trace.h | 2 ++ 2 files changed, 6 insertions(+) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 874f2893cff..f804b407d43 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -2898,6 +2898,10 @@ static int tracing_release_pipe(struct inode *inode, struct file *file) else cpumask_clear_cpu(iter->cpu_file, tracing_reader_cpumask); + + if (iter->trace->pipe_open) + iter->trace->pipe_close(iter); + mutex_unlock(&trace_types_lock); free_cpumask_var(iter->started); diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 1d7f4830a80..7fa33cab696 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -272,6 +272,7 @@ struct tracer_flags { * @pipe_open: called when the trace_pipe file is opened * @wait_pipe: override how the user waits for traces on trace_pipe * @close: called when the trace file is released + * @pipe_close: called when the trace_pipe file is released * @read: override the default read callback on trace_pipe * @splice_read: override the default splice_read callback on trace_pipe * @selftest: selftest to run on boot (see trace_selftest.c) @@ -290,6 +291,7 @@ struct tracer { void (*pipe_open)(struct trace_iterator *iter); void (*wait_pipe)(struct trace_iterator *iter); void (*close)(struct trace_iterator *iter); + void (*pipe_close)(struct trace_iterator *iter); ssize_t (*read)(struct trace_iterator *iter, struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos); From 29bf4a5e3fed3dde3eb629a0cb1762c1e9217458 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 9 Dec 2009 12:37:43 -0500 Subject: [PATCH 2/6] tracing: Only call pipe_close if pipe_close is defined This fixes a cut and paste error that had pipe_close get called if pipe_open was defined (not pipe_close). Reported-by: Kosaki Motohiro LKML-Reference: <20091209153204.F4CD.A69D9226@jp.fujitsu.com> Signed-off-by: Steven Rostedt --- kernel/trace/trace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index f804b407d43..dc937e1baa9 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -2899,7 +2899,7 @@ static int tracing_release_pipe(struct inode *inode, struct file *file) cpumask_clear_cpu(iter->cpu_file, tracing_reader_cpumask); - if (iter->trace->pipe_open) + if (iter->trace->pipe_close) iter->trace->pipe_close(iter); mutex_unlock(&trace_types_lock); From a63ce5b306855bccdacba95c03bfc293316c8ae3 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Mon, 7 Dec 2009 09:11:39 -0500 Subject: [PATCH 3/6] tracing: Buffer the output of seq_file in case of filled buffer If the seq_read fills the buffer it will call s_start again on the next itertation with the same position. This causes a problem with the function_graph tracer because it consumes the iteration in order to determine leaf functions. What happens is that the iterator stores the entry, and the function graph plugin will look at the next entry. If that next entry is a return of the same function and task, then the function is a leaf and the function_graph plugin calls ring_buffer_read which moves the ring buffer iterator forward (the trace iterator still points to the function start entry). The copying of the trace_seq to the seq_file buffer will fail if the seq_file buffer is full. The seq_read will not show this entry. The next read by userspace will cause seq_read to again call s_start which will reuse the trace iterator entry (the function start entry). But the function return entry was already consumed. The function graph plugin will think that this entry is a nested function and not a leaf. To solve this, the trace code now checks the return status of the seq_printf (trace_print_seq). If the writing to the seq_file buffer fails, we set a flag in the iterator (leftover) and we do not reset the trace_seq buffer. On the next call to s_start, we check the leftover flag, and if it is set, we just reuse the trace_seq buffer and do not call into the plugin print functions. Before this patch: 2) | fput() { 2) | __fput() { 2) 0.550 us | inotify_inode_queue_event(); 2) | __fsnotify_parent() { 2) 0.540 us | inotify_dentry_parent_queue_event(); After the patch: 2) | fput() { 2) | __fput() { 2) 0.550 us | inotify_inode_queue_event(); 2) 0.548 us | __fsnotify_parent(); 2) 0.540 us | inotify_dentry_parent_queue_event(); [ Updated the patch to fix a missing return 0 from the trace_print_seq() stub when CONFIG_TRACING is disabled. Reported-by: Ingo Molnar ] Reported-by: Jiri Olsa Cc: Frederic Weisbecker Signed-off-by: Steven Rostedt --- include/linux/ftrace_event.h | 1 + include/linux/trace_seq.h | 5 +++-- kernel/trace/trace.c | 35 ++++++++++++++++++++++++++++++++--- kernel/trace/trace_output.c | 14 +++++++++++--- 4 files changed, 47 insertions(+), 8 deletions(-) diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h index 47bbdf9c38d..38f8d655383 100644 --- a/include/linux/ftrace_event.h +++ b/include/linux/ftrace_event.h @@ -57,6 +57,7 @@ struct trace_iterator { /* The below is zeroed out in pipe_read */ struct trace_seq seq; struct trace_entry *ent; + int leftover; int cpu; u64 ts; diff --git a/include/linux/trace_seq.h b/include/linux/trace_seq.h index 09077f6ed12..fad6857bc0f 100644 --- a/include/linux/trace_seq.h +++ b/include/linux/trace_seq.h @@ -33,7 +33,7 @@ extern int trace_seq_vprintf(struct trace_seq *s, const char *fmt, va_list args) __attribute__ ((format (printf, 2, 0))); extern int trace_seq_bprintf(struct trace_seq *s, const char *fmt, const u32 *binary); -extern void trace_print_seq(struct seq_file *m, struct trace_seq *s); +extern int trace_print_seq(struct seq_file *m, struct trace_seq *s); extern ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf, size_t cnt); extern int trace_seq_puts(struct trace_seq *s, const char *str); @@ -55,8 +55,9 @@ trace_seq_bprintf(struct trace_seq *s, const char *fmt, const u32 *binary) return 0; } -static inline void trace_print_seq(struct seq_file *m, struct trace_seq *s) +static inline int trace_print_seq(struct seq_file *m, struct trace_seq *s) { + return 0; } static inline ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf, size_t cnt) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index dc937e1baa9..484114d7074 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1516,6 +1516,8 @@ static void *s_next(struct seq_file *m, void *v, loff_t *pos) int i = (int)*pos; void *ent; + WARN_ON_ONCE(iter->leftover); + (*pos)++; /* can't go backwards */ @@ -1614,8 +1616,16 @@ static void *s_start(struct seq_file *m, loff_t *pos) ; } else { - l = *pos - 1; - p = s_next(m, p, &l); + /* + * If we overflowed the seq_file before, then we want + * to just reuse the trace_seq buffer again. + */ + if (iter->leftover) + p = iter; + else { + l = *pos - 1; + p = s_next(m, p, &l); + } } trace_event_read_lock(); @@ -1923,6 +1933,7 @@ static enum print_line_t print_trace_line(struct trace_iterator *iter) static int s_show(struct seq_file *m, void *v) { struct trace_iterator *iter = v; + int ret; if (iter->ent == NULL) { if (iter->tr) { @@ -1942,9 +1953,27 @@ static int s_show(struct seq_file *m, void *v) if (!(trace_flags & TRACE_ITER_VERBOSE)) print_func_help_header(m); } + } else if (iter->leftover) { + /* + * If we filled the seq_file buffer earlier, we + * want to just show it now. + */ + ret = trace_print_seq(m, &iter->seq); + + /* ret should this time be zero, but you never know */ + iter->leftover = ret; + } else { print_trace_line(iter); - trace_print_seq(m, &iter->seq); + ret = trace_print_seq(m, &iter->seq); + /* + * If we overflow the seq_file buffer, then it will + * ask us for this data again at start up. + * Use that instead. + * ret is 0 if seq_file write succeeded. + * -1 otherwise. + */ + iter->leftover = ret; } return 0; diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c index b6c12c6a1bc..e5cf90fef34 100644 --- a/kernel/trace/trace_output.c +++ b/kernel/trace/trace_output.c @@ -23,13 +23,21 @@ static struct hlist_head event_hash[EVENT_HASHSIZE] __read_mostly; static int next_event_type = __TRACE_LAST_TYPE + 1; -void trace_print_seq(struct seq_file *m, struct trace_seq *s) +int trace_print_seq(struct seq_file *m, struct trace_seq *s) { int len = s->len >= PAGE_SIZE ? PAGE_SIZE - 1 : s->len; + int ret; - seq_write(m, s->buffer, len); + ret = seq_write(m, s->buffer, len); - trace_seq_init(s); + /* + * Only reset this buffer if we successfully wrote to the + * seq_file buffer. + */ + if (!ret) + trace_seq_init(s); + + return ret; } enum print_line_t trace_print_bprintk_msg_only(struct trace_iterator *iter) From d184b31c0e403580aafb3f8955ecc185a3d04801 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Wed, 25 Nov 2009 16:10:14 +0100 Subject: [PATCH 4/6] tracing: Add full state to trace_seq The trace_seq buffer might fill up, and right now one needs to check the return value of each printf into the buffer to check for that. Instead, have the buffer keep track of whether it is full or not, and reject more input if it is full or would have overflowed with an input that wasn't added. Cc: Lai Jiangshan Signed-off-by: Johannes Berg Signed-off-by: Steven Rostedt --- include/linux/trace_seq.h | 2 ++ kernel/trace/trace_output.c | 61 ++++++++++++++++++++++++++++++------- 2 files changed, 52 insertions(+), 11 deletions(-) diff --git a/include/linux/trace_seq.h b/include/linux/trace_seq.h index fad6857bc0f..5cf397ceb72 100644 --- a/include/linux/trace_seq.h +++ b/include/linux/trace_seq.h @@ -14,6 +14,7 @@ struct trace_seq { unsigned char buffer[PAGE_SIZE]; unsigned int len; unsigned int readpos; + int full; }; static inline void @@ -21,6 +22,7 @@ trace_seq_init(struct trace_seq *s) { s->len = 0; s->readpos = 0; + s->full = 0; } /* diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c index e5cf90fef34..8e46b3323cd 100644 --- a/kernel/trace/trace_output.c +++ b/kernel/trace/trace_output.c @@ -93,7 +93,7 @@ trace_seq_printf(struct trace_seq *s, const char *fmt, ...) va_list ap; int ret; - if (!len) + if (s->full || !len) return 0; va_start(ap, fmt); @@ -101,8 +101,10 @@ trace_seq_printf(struct trace_seq *s, const char *fmt, ...) va_end(ap); /* If we can't write it all, don't bother writing anything */ - if (ret >= len) + if (ret >= len) { + s->full = 1; return 0; + } s->len += ret; @@ -127,14 +129,16 @@ trace_seq_vprintf(struct trace_seq *s, const char *fmt, va_list args) int len = (PAGE_SIZE - 1) - s->len; int ret; - if (!len) + if (s->full || !len) return 0; ret = vsnprintf(s->buffer + s->len, len, fmt, args); /* If we can't write it all, don't bother writing anything */ - if (ret >= len) + if (ret >= len) { + s->full = 1; return 0; + } s->len += ret; @@ -147,14 +151,16 @@ int trace_seq_bprintf(struct trace_seq *s, const char *fmt, const u32 *binary) int len = (PAGE_SIZE - 1) - s->len; int ret; - if (!len) + if (s->full || !len) return 0; ret = bstr_printf(s->buffer + s->len, len, fmt, binary); /* If we can't write it all, don't bother writing anything */ - if (ret >= len) + if (ret >= len) { + s->full = 1; return 0; + } s->len += ret; @@ -175,9 +181,14 @@ int trace_seq_puts(struct trace_seq *s, const char *str) { int len = strlen(str); - if (len > ((PAGE_SIZE - 1) - s->len)) + if (s->full) return 0; + if (len > ((PAGE_SIZE - 1) - s->len)) { + s->full = 1; + return 0; + } + memcpy(s->buffer + s->len, str, len); s->len += len; @@ -186,9 +197,14 @@ int trace_seq_puts(struct trace_seq *s, const char *str) int trace_seq_putc(struct trace_seq *s, unsigned char c) { - if (s->len >= (PAGE_SIZE - 1)) + if (s->full) return 0; + if (s->len >= (PAGE_SIZE - 1)) { + s->full = 1; + return 0; + } + s->buffer[s->len++] = c; return 1; @@ -196,9 +212,14 @@ int trace_seq_putc(struct trace_seq *s, unsigned char c) int trace_seq_putmem(struct trace_seq *s, const void *mem, size_t len) { - if (len > ((PAGE_SIZE - 1) - s->len)) + if (s->full) return 0; + if (len > ((PAGE_SIZE - 1) - s->len)) { + s->full = 1; + return 0; + } + memcpy(s->buffer + s->len, mem, len); s->len += len; @@ -211,6 +232,9 @@ int trace_seq_putmem_hex(struct trace_seq *s, const void *mem, size_t len) const unsigned char *data = mem; int i, j; + if (s->full) + return 0; + #ifdef __BIG_ENDIAN for (i = 0, j = 0; i < len; i++) { #else @@ -228,8 +252,13 @@ void *trace_seq_reserve(struct trace_seq *s, size_t len) { void *ret; - if (len > ((PAGE_SIZE - 1) - s->len)) + if (s->full) + return 0; + + if (len > ((PAGE_SIZE - 1) - s->len)) { + s->full = 1; return NULL; + } ret = s->buffer + s->len; s->len += len; @@ -241,8 +270,14 @@ int trace_seq_path(struct trace_seq *s, struct path *path) { unsigned char *p; - if (s->len >= (PAGE_SIZE - 1)) + if (s->full) return 0; + + if (s->len >= (PAGE_SIZE - 1)) { + s->full = 1; + return 0; + } + p = d_path(path, s->buffer + s->len, PAGE_SIZE - s->len); if (!IS_ERR(p)) { p = mangle_path(s->buffer + s->len, p, "\n"); @@ -255,6 +290,7 @@ int trace_seq_path(struct trace_seq *s, struct path *path) return 1; } + s->full = 1; return 0; } @@ -381,6 +417,9 @@ int seq_print_user_ip(struct trace_seq *s, struct mm_struct *mm, unsigned long vmstart = 0; int ret = 1; + if (s->full) + return 0; + if (mm) { const struct vm_area_struct *vma; From be1eca39319689aed7d3aedb9c3bece9469fe10f Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Tue, 24 Nov 2009 13:57:38 +0100 Subject: [PATCH 5/6] tracing: Fix function graph trace_pipe to properly display failed entries There is a case where the graph tracer might get confused and omits displaying of a single record. This applies mostly with the trace_pipe since it is unlikely that the trace_seq buffer will overflow with the trace file. As the function_graph tracer goes through the trace entries keeping a pointer to the current record: current -> func1 ENTRY func2 ENTRY func2 RETURN func1 RETURN When an function ENTRY is encountered, it moves the pointer to the next entry to check if the function is a nested or leaf function. func1 ENTRY current -> func2 ENTRY func2 RETURN func1 RETURN If the rest of the writing of the function fills the trace_seq buffer, then the trace_pipe read will ignore this entry. The next read will Now start at the current location, but the first entry (func1) will be discarded. This patch keeps a copy of the current entry in the iterator private storage and will keep track of when the trace_seq buffer fills. When the trace_seq buffer fills, it will reuse the copy of the entry in the next iteration. [ This patch has been largely modified by Steven Rostedt in order to clean it up and simplify it. The original idea and concept was from Jirka and for that, this patch will go under his name to give him the credit he deserves. But because this was modify by Steven Rostedt anything wrong with the patch should be blamed on Steven. ] Signed-off-by: Jiri Olsa Cc: Frederic Weisbecker LKML-Reference: <1259067458-27143-1-git-send-email-jolsa@redhat.com> Signed-off-by: Steven Rostedt --- kernel/trace/trace_functions_graph.c | 167 +++++++++++++++++++++------ 1 file changed, 132 insertions(+), 35 deletions(-) diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c index 45e6c01b2e4..a43d009c561 100644 --- a/kernel/trace/trace_functions_graph.c +++ b/kernel/trace/trace_functions_graph.c @@ -14,9 +14,20 @@ #include "trace.h" #include "trace_output.h" -struct fgraph_data { +struct fgraph_cpu_data { pid_t last_pid; int depth; + int ignore; +}; + +struct fgraph_data { + struct fgraph_cpu_data *cpu_data; + + /* Place to preserve last processed entry. */ + struct ftrace_graph_ent_entry ent; + struct ftrace_graph_ret_entry ret; + int failed; + int cpu; }; #define TRACE_GRAPH_INDENT 2 @@ -384,7 +395,7 @@ verif_pid(struct trace_seq *s, pid_t pid, int cpu, struct fgraph_data *data) if (!data) return TRACE_TYPE_HANDLED; - last_pid = &(per_cpu_ptr(data, cpu)->last_pid); + last_pid = &(per_cpu_ptr(data->cpu_data, cpu)->last_pid); if (*last_pid == pid) return TRACE_TYPE_HANDLED; @@ -435,27 +446,50 @@ static struct ftrace_graph_ret_entry * get_return_for_leaf(struct trace_iterator *iter, struct ftrace_graph_ent_entry *curr) { - struct ring_buffer_iter *ring_iter; + struct fgraph_data *data = iter->private; + struct ring_buffer_iter *ring_iter = NULL; struct ring_buffer_event *event; struct ftrace_graph_ret_entry *next; - ring_iter = iter->buffer_iter[iter->cpu]; + /* + * If the previous output failed to write to the seq buffer, + * then we just reuse the data from before. + */ + if (data && data->failed) { + curr = &data->ent; + next = &data->ret; + } else { - /* First peek to compare current entry and the next one */ - if (ring_iter) - event = ring_buffer_iter_peek(ring_iter, NULL); - else { - /* We need to consume the current entry to see the next one */ - ring_buffer_consume(iter->tr->buffer, iter->cpu, NULL); - event = ring_buffer_peek(iter->tr->buffer, iter->cpu, - NULL); + ring_iter = iter->buffer_iter[iter->cpu]; + + /* First peek to compare current entry and the next one */ + if (ring_iter) + event = ring_buffer_iter_peek(ring_iter, NULL); + else { + /* + * We need to consume the current entry to see + * the next one. + */ + ring_buffer_consume(iter->tr->buffer, iter->cpu, NULL); + event = ring_buffer_peek(iter->tr->buffer, iter->cpu, + NULL); + } + + if (!event) + return NULL; + + next = ring_buffer_event_data(event); + + if (data) { + /* + * Save current and next entries for later reference + * if the output fails. + */ + data->ent = *curr; + data->ret = *next; + } } - if (!event) - return NULL; - - next = ring_buffer_event_data(event); - if (next->ent.type != TRACE_GRAPH_RET) return NULL; @@ -640,7 +674,7 @@ print_graph_entry_leaf(struct trace_iterator *iter, if (data) { int cpu = iter->cpu; - int *depth = &(per_cpu_ptr(data, cpu)->depth); + int *depth = &(per_cpu_ptr(data->cpu_data, cpu)->depth); /* * Comments display at + 1 to depth. Since @@ -688,7 +722,7 @@ print_graph_entry_nested(struct trace_iterator *iter, if (data) { int cpu = iter->cpu; - int *depth = &(per_cpu_ptr(data, cpu)->depth); + int *depth = &(per_cpu_ptr(data->cpu_data, cpu)->depth); *depth = call->depth; } @@ -782,19 +816,34 @@ static enum print_line_t print_graph_entry(struct ftrace_graph_ent_entry *field, struct trace_seq *s, struct trace_iterator *iter) { - int cpu = iter->cpu; + struct fgraph_data *data = iter->private; struct ftrace_graph_ent *call = &field->graph_ent; struct ftrace_graph_ret_entry *leaf_ret; + static enum print_line_t ret; + int cpu = iter->cpu; if (print_graph_prologue(iter, s, TRACE_GRAPH_ENT, call->func)) return TRACE_TYPE_PARTIAL_LINE; leaf_ret = get_return_for_leaf(iter, field); if (leaf_ret) - return print_graph_entry_leaf(iter, field, leaf_ret, s); + ret = print_graph_entry_leaf(iter, field, leaf_ret, s); else - return print_graph_entry_nested(iter, field, s, cpu); + ret = print_graph_entry_nested(iter, field, s, cpu); + if (data) { + /* + * If we failed to write our output, then we need to make + * note of it. Because we already consumed our entry. + */ + if (s->full) { + data->failed = 1; + data->cpu = cpu; + } else + data->failed = 0; + } + + return ret; } static enum print_line_t @@ -810,7 +859,7 @@ print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s, if (data) { int cpu = iter->cpu; - int *depth = &(per_cpu_ptr(data, cpu)->depth); + int *depth = &(per_cpu_ptr(data->cpu_data, cpu)->depth); /* * Comments display at + 1 to depth. This is the @@ -873,7 +922,7 @@ print_graph_comment(struct trace_seq *s, struct trace_entry *ent, int i; if (data) - depth = per_cpu_ptr(data, iter->cpu)->depth; + depth = per_cpu_ptr(data->cpu_data, iter->cpu)->depth; if (print_graph_prologue(iter, s, 0, 0)) return TRACE_TYPE_PARTIAL_LINE; @@ -941,8 +990,33 @@ print_graph_comment(struct trace_seq *s, struct trace_entry *ent, enum print_line_t print_graph_function(struct trace_iterator *iter) { + struct ftrace_graph_ent_entry *field; + struct fgraph_data *data = iter->private; struct trace_entry *entry = iter->ent; struct trace_seq *s = &iter->seq; + int cpu = iter->cpu; + int ret; + + if (data && per_cpu_ptr(data->cpu_data, cpu)->ignore) { + per_cpu_ptr(data->cpu_data, cpu)->ignore = 0; + return TRACE_TYPE_HANDLED; + } + + /* + * If the last output failed, there's a possibility we need + * to print out the missing entry which would never go out. + */ + if (data && data->failed) { + field = &data->ent; + iter->cpu = data->cpu; + ret = print_graph_entry(field, s, iter); + if (ret == TRACE_TYPE_HANDLED && iter->cpu != cpu) { + per_cpu_ptr(data->cpu_data, iter->cpu)->ignore = 1; + ret = TRACE_TYPE_NO_CONSUME; + } + iter->cpu = cpu; + return ret; + } switch (entry->type) { case TRACE_GRAPH_ENT: { @@ -952,7 +1026,7 @@ print_graph_function(struct trace_iterator *iter) * sizeof(struct ftrace_graph_ent_entry) is very small, * it can be safely saved at the stack. */ - struct ftrace_graph_ent_entry *field, saved; + struct ftrace_graph_ent_entry saved; trace_assign_type(field, entry); saved = *field; return print_graph_entry(&saved, s, iter); @@ -1030,31 +1104,54 @@ static void print_graph_headers(struct seq_file *s) static void graph_trace_open(struct trace_iterator *iter) { /* pid and depth on the last trace processed */ - struct fgraph_data *data = alloc_percpu(struct fgraph_data); + struct fgraph_data *data; int cpu; + iter->private = NULL; + + data = kzalloc(sizeof(*data), GFP_KERNEL); if (!data) - pr_warning("function graph tracer: not enough memory\n"); - else - for_each_possible_cpu(cpu) { - pid_t *pid = &(per_cpu_ptr(data, cpu)->last_pid); - int *depth = &(per_cpu_ptr(data, cpu)->depth); - *pid = -1; - *depth = 0; - } + goto out_err; + + data->cpu_data = alloc_percpu(struct fgraph_cpu_data); + if (!data->cpu_data) + goto out_err_free; + + for_each_possible_cpu(cpu) { + pid_t *pid = &(per_cpu_ptr(data->cpu_data, cpu)->last_pid); + int *depth = &(per_cpu_ptr(data->cpu_data, cpu)->depth); + int *ignore = &(per_cpu_ptr(data->cpu_data, cpu)->ignore); + *pid = -1; + *depth = 0; + *ignore = 0; + } iter->private = data; + + return; + + out_err_free: + kfree(data); + out_err: + pr_warning("function graph tracer: not enough memory\n"); } static void graph_trace_close(struct trace_iterator *iter) { - free_percpu(iter->private); + struct fgraph_data *data = iter->private; + + if (data) { + free_percpu(data->cpu_data); + kfree(data); + } } static struct tracer graph_trace __read_mostly = { .name = "function_graph", .open = graph_trace_open, + .pipe_open = graph_trace_open, .close = graph_trace_close, + .pipe_close = graph_trace_close, .wait_pipe = poll_wait_pipe, .init = graph_trace_init, .reset = graph_trace_reset, From f2942487ffb0c0a80b2312f667ea30dd55a24bb0 Mon Sep 17 00:00:00 2001 From: Carsten Emde Date: Sun, 6 Dec 2009 14:02:44 +0100 Subject: [PATCH 6/6] tracing: Remove comparing of NULL to va_list in trace_array_vprintk() Olof Johansson stated the following: Comparing a va_list with NULL is bogus. It's supposed to be treated like an opaque type and only be manipulated with va_* accessors. Olof noticed that this code broke the ARM builds: kernel/trace/trace.c: In function 'trace_array_vprintk': kernel/trace/trace.c:1364: error: invalid operands to binary == (have 'va_list' and 'void *') kernel/trace/trace.c: In function 'tracing_mark_write': kernel/trace/trace.c:3349: error: incompatible type for argument 3 of 'trace_vprintk' This patch partly reverts c13d2f7c3231e873f30db92b96c8caa48f100f33 and re-installs the original mark_printk() mechanism. Reported-by: Olof Johansson Signed-off-by: Carsten Emde LKML-Reference: <4B1BAB74.104@osadl.org> Signed-off-by: Steven Rostedt --- kernel/trace/trace.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 484114d7074..88bd9ae2a9e 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1361,11 +1361,7 @@ int trace_array_vprintk(struct trace_array *tr, pause_graph_tracing(); raw_local_irq_save(irq_flags); __raw_spin_lock(&trace_buf_lock); - if (args == NULL) { - strncpy(trace_buf, fmt, TRACE_BUF_SIZE); - len = strlen(trace_buf); - } else - len = vsnprintf(trace_buf, TRACE_BUF_SIZE, fmt, args); + len = vsnprintf(trace_buf, TRACE_BUF_SIZE, fmt, args); size = sizeof(*entry) + len + 1; buffer = tr->buffer; @@ -3353,6 +3349,16 @@ tracing_entries_write(struct file *filp, const char __user *ubuf, return cnt; } +static int mark_printk(const char *fmt, ...) +{ + int ret; + va_list args; + va_start(args, fmt); + ret = trace_vprintk(0, fmt, args); + va_end(args); + return ret; +} + static ssize_t tracing_mark_write(struct file *filp, const char __user *ubuf, size_t cnt, loff_t *fpos) @@ -3379,7 +3385,7 @@ tracing_mark_write(struct file *filp, const char __user *ubuf, } else buf[cnt] = '\0'; - cnt = trace_vprintk(0, buf, NULL); + cnt = mark_printk("%s", buf); kfree(buf); *fpos += cnt;