* [for-linus][PATCH 1/4] tracing: Inform kmemleak of saved_cmdlines allocation
2024-02-15 21:39 [for-linus][PATCH 0/4] tracing: More fixes for v6.8 Steven Rostedt
@ 2024-02-15 21:39 ` Steven Rostedt
2024-02-15 21:39 ` [for-linus][PATCH 2/4] tracing/synthetic: Fix trace_string() return value Steven Rostedt
` (2 subsequent siblings)
3 siblings, 0 replies; 5+ messages in thread
From: Steven Rostedt @ 2024-02-15 21:39 UTC (permalink / raw)
To: linux-kernel
Cc: Masami Hiramatsu, Mark Rutland, Mathieu Desnoyers, Andrew Morton,
Catalin Marinas, Kalle Valo
From: "Steven Rostedt (Google)" <rostedt@goodmis.org>
The allocation of the struct saved_cmdlines_buffer structure changed from:
s = kmalloc(sizeof(*s), GFP_KERNEL);
s->saved_cmdlines = kmalloc_array(TASK_COMM_LEN, val, GFP_KERNEL);
to:
orig_size = sizeof(*s) + val * TASK_COMM_LEN;
order = get_order(orig_size);
size = 1 << (order + PAGE_SHIFT);
page = alloc_pages(GFP_KERNEL, order);
if (!page)
return NULL;
s = page_address(page);
memset(s, 0, sizeof(*s));
s->saved_cmdlines = kmalloc_array(TASK_COMM_LEN, val, GFP_KERNEL);
Where that s->saved_cmdlines allocation looks to be a dangling allocation
to kmemleak. That's because kmemleak only keeps track of kmalloc()
allocations. For allocations that use page_alloc() directly, the kmemleak
needs to be explicitly informed about it.
Add kmemleak_alloc() and kmemleak_free() around the page allocation so
that it doesn't give the following false positive:
unreferenced object 0xffff8881010c8000 (size 32760):
comm "swapper", pid 0, jiffies 4294667296
hex dump (first 32 bytes):
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................
backtrace (crc ae6ec1b9):
[<ffffffff86722405>] kmemleak_alloc+0x45/0x80
[<ffffffff8414028d>] __kmalloc_large_node+0x10d/0x190
[<ffffffff84146ab1>] __kmalloc+0x3b1/0x4c0
[<ffffffff83ed7103>] allocate_cmdlines_buffer+0x113/0x230
[<ffffffff88649c34>] tracer_alloc_buffers.isra.0+0x124/0x460
[<ffffffff8864a174>] early_trace_init+0x14/0xa0
[<ffffffff885dd5ae>] start_kernel+0x12e/0x3c0
[<ffffffff885f5758>] x86_64_start_reservations+0x18/0x30
[<ffffffff885f582b>] x86_64_start_kernel+0x7b/0x80
[<ffffffff83a001c3>] secondary_startup_64_no_verify+0x15e/0x16b
Link: https://lore.kernel.org/linux-trace-kernel/87r0hfnr9r.fsf@kernel.org/
Link: https://lore.kernel.org/linux-trace-kernel/20240214112046.09a322d6@gandalf.local.home
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Fixes: 44dc5c41b5b1 ("tracing: Fix wasted memory in saved_cmdlines logic")
Reported-by: Kalle Valo <kvalo@kernel.org>
Tested-by: Kalle Valo <kvalo@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
kernel/trace/trace.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index aa54810e8b56..8198bfc54b58 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -39,6 +39,7 @@
#include <linux/ctype.h>
#include <linux/init.h>
#include <linux/panic_notifier.h>
+#include <linux/kmemleak.h>
#include <linux/poll.h>
#include <linux/nmi.h>
#include <linux/fs.h>
@@ -2339,6 +2340,7 @@ static void free_saved_cmdlines_buffer(struct saved_cmdlines_buffer *s)
int order = get_order(sizeof(*s) + s->cmdline_num * TASK_COMM_LEN);
kfree(s->map_cmdline_to_pid);
+ kmemleak_free(s);
free_pages((unsigned long)s, order);
}
@@ -2358,6 +2360,7 @@ static struct saved_cmdlines_buffer *allocate_cmdlines_buffer(unsigned int val)
return NULL;
s = page_address(page);
+ kmemleak_alloc(s, size, 1, GFP_KERNEL);
memset(s, 0, sizeof(*s));
/* Round up to actual allocation */
--
2.43.0
^ permalink raw reply related [flat|nested] 5+ messages in thread* [for-linus][PATCH 4/4] seq_buf: Fix kernel documentation
2024-02-15 21:39 [for-linus][PATCH 0/4] tracing: More fixes for v6.8 Steven Rostedt
` (2 preceding siblings ...)
2024-02-15 21:39 ` [for-linus][PATCH 3/4] seq_buf: Dont use "proxy" headers Steven Rostedt
@ 2024-02-15 21:39 ` Steven Rostedt
3 siblings, 0 replies; 5+ messages in thread
From: Steven Rostedt @ 2024-02-15 21:39 UTC (permalink / raw)
To: linux-kernel
Cc: Masami Hiramatsu, Mark Rutland, Mathieu Desnoyers, Andrew Morton,
Andy Shevchenko, Randy Dunlap
From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
There are plenty of issues with the kernel documentation here:
- misspelled word "sequence"
- different style of returned value descriptions
- missed Return sections
- unaligned style of ASCII / NUL-terminated / etc
- wrong function references
Fix all these.
Link: https://lkml.kernel.org/r/20240215152506.598340-1-andriy.shevchenko@linux.intel.com
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
include/linux/seq_buf.h | 12 ++++++------
lib/seq_buf.c | 35 ++++++++++++++++++-----------------
2 files changed, 24 insertions(+), 23 deletions(-)
diff --git a/include/linux/seq_buf.h b/include/linux/seq_buf.h
index 07b26e751060..fe41da005970 100644
--- a/include/linux/seq_buf.h
+++ b/include/linux/seq_buf.h
@@ -13,7 +13,7 @@
*/
/**
- * seq_buf - seq buffer structure
+ * struct seq_buf - seq buffer structure
* @buffer: pointer to the buffer
* @size: size of the buffer
* @len: the amount of data inside the buffer
@@ -80,10 +80,10 @@ static inline unsigned int seq_buf_used(struct seq_buf *s)
}
/**
- * seq_buf_str - get %NUL-terminated C string from seq_buf
+ * seq_buf_str - get NUL-terminated C string from seq_buf
* @s: the seq_buf handle
*
- * This makes sure that the buffer in @s is nul terminated and
+ * This makes sure that the buffer in @s is NUL-terminated and
* safe to read as a string.
*
* Note, if this is called when the buffer has overflowed, then
@@ -93,7 +93,7 @@ static inline unsigned int seq_buf_used(struct seq_buf *s)
* After this function is called, s->buffer is safe to use
* in string operations.
*
- * Returns @s->buf after making sure it is terminated.
+ * Returns: @s->buf after making sure it is terminated.
*/
static inline const char *seq_buf_str(struct seq_buf *s)
{
@@ -113,7 +113,7 @@ static inline const char *seq_buf_str(struct seq_buf *s)
* @s: the seq_buf handle
* @bufp: the beginning of the buffer is stored here
*
- * Return the number of bytes available in the buffer, or zero if
+ * Returns: the number of bytes available in the buffer, or zero if
* there's no space.
*/
static inline size_t seq_buf_get_buf(struct seq_buf *s, char **bufp)
@@ -135,7 +135,7 @@ static inline size_t seq_buf_get_buf(struct seq_buf *s, char **bufp)
* @num: the number of bytes to commit
*
* Commit @num bytes of data written to a buffer previously acquired
- * by seq_buf_get. To signal an error condition, or that the data
+ * by seq_buf_get_buf(). To signal an error condition, or that the data
* didn't fit in the available space, pass a negative @num value.
*/
static inline void seq_buf_commit(struct seq_buf *s, int num)
diff --git a/lib/seq_buf.c b/lib/seq_buf.c
index dfbfdc497d85..f3f3436d60a9 100644
--- a/lib/seq_buf.c
+++ b/lib/seq_buf.c
@@ -32,7 +32,7 @@
* @s: the seq_buf descriptor
* @len: The length to see if it can fit in the current buffer
*
- * Returns true if there's enough unused space in the seq_buf buffer
+ * Returns: true if there's enough unused space in the seq_buf buffer
* to fit the amount of new data according to @len.
*/
static bool seq_buf_can_fit(struct seq_buf *s, size_t len)
@@ -45,7 +45,7 @@ static bool seq_buf_can_fit(struct seq_buf *s, size_t len)
* @m: the seq_file descriptor that is the destination
* @s: the seq_buf descriptor that is the source.
*
- * Returns zero on success, non zero otherwise
+ * Returns: zero on success, non-zero otherwise.
*/
int seq_buf_print_seq(struct seq_file *m, struct seq_buf *s)
{
@@ -60,9 +60,9 @@ int seq_buf_print_seq(struct seq_file *m, struct seq_buf *s)
* @fmt: printf format string
* @args: va_list of arguments from a printf() type function
*
- * Writes a vnprintf() format into the sequencce buffer.
+ * Writes a vnprintf() format into the sequence buffer.
*
- * Returns zero on success, -1 on overflow.
+ * Returns: zero on success, -1 on overflow.
*/
int seq_buf_vprintf(struct seq_buf *s, const char *fmt, va_list args)
{
@@ -88,7 +88,7 @@ int seq_buf_vprintf(struct seq_buf *s, const char *fmt, va_list args)
*
* Writes a printf() format into the sequence buffer.
*
- * Returns zero on success, -1 on overflow.
+ * Returns: zero on success, -1 on overflow.
*/
int seq_buf_printf(struct seq_buf *s, const char *fmt, ...)
{
@@ -104,12 +104,12 @@ int seq_buf_printf(struct seq_buf *s, const char *fmt, ...)
EXPORT_SYMBOL_GPL(seq_buf_printf);
/**
- * seq_buf_do_printk - printk seq_buf line by line
+ * seq_buf_do_printk - printk() seq_buf line by line
* @s: seq_buf descriptor
* @lvl: printk level
*
* printk()-s a multi-line sequential buffer line by line. The function
- * makes sure that the buffer in @s is nul terminated and safe to read
+ * makes sure that the buffer in @s is NUL-terminated and safe to read
* as a string.
*/
void seq_buf_do_printk(struct seq_buf *s, const char *lvl)
@@ -149,7 +149,7 @@ EXPORT_SYMBOL_GPL(seq_buf_do_printk);
* This function will take the format and the binary array and finish
* the conversion into the ASCII string within the buffer.
*
- * Returns zero on success, -1 on overflow.
+ * Returns: zero on success, -1 on overflow.
*/
int seq_buf_bprintf(struct seq_buf *s, const char *fmt, const u32 *binary)
{
@@ -177,7 +177,7 @@ int seq_buf_bprintf(struct seq_buf *s, const char *fmt, const u32 *binary)
*
* Copy a simple string into the sequence buffer.
*
- * Returns zero on success, -1 on overflow
+ * Returns: zero on success, -1 on overflow.
*/
int seq_buf_puts(struct seq_buf *s, const char *str)
{
@@ -206,7 +206,7 @@ EXPORT_SYMBOL_GPL(seq_buf_puts);
*
* Copy a single character into the sequence buffer.
*
- * Returns zero on success, -1 on overflow
+ * Returns: zero on success, -1 on overflow.
*/
int seq_buf_putc(struct seq_buf *s, unsigned char c)
{
@@ -222,7 +222,7 @@ int seq_buf_putc(struct seq_buf *s, unsigned char c)
EXPORT_SYMBOL_GPL(seq_buf_putc);
/**
- * seq_buf_putmem - write raw data into the sequenc buffer
+ * seq_buf_putmem - write raw data into the sequence buffer
* @s: seq_buf descriptor
* @mem: The raw memory to copy into the buffer
* @len: The length of the raw memory to copy (in bytes)
@@ -231,7 +231,7 @@ EXPORT_SYMBOL_GPL(seq_buf_putc);
* buffer and a strcpy() would not work. Using this function allows
* for such cases.
*
- * Returns zero on success, -1 on overflow
+ * Returns: zero on success, -1 on overflow.
*/
int seq_buf_putmem(struct seq_buf *s, const void *mem, unsigned int len)
{
@@ -259,7 +259,7 @@ int seq_buf_putmem(struct seq_buf *s, const void *mem, unsigned int len)
* raw memory into the buffer it writes its ASCII representation of it
* in hex characters.
*
- * Returns zero on success, -1 on overflow
+ * Returns: zero on success, -1 on overflow.
*/
int seq_buf_putmem_hex(struct seq_buf *s, const void *mem,
unsigned int len)
@@ -307,7 +307,7 @@ int seq_buf_putmem_hex(struct seq_buf *s, const void *mem,
*
* Write a path name into the sequence buffer.
*
- * Returns the number of written bytes on success, -1 on overflow
+ * Returns: the number of written bytes on success, -1 on overflow.
*/
int seq_buf_path(struct seq_buf *s, const struct path *path, const char *esc)
{
@@ -342,6 +342,7 @@ int seq_buf_path(struct seq_buf *s, const struct path *path, const char *esc)
* or until it reaches the end of the content in the buffer (@s->len),
* whichever comes first.
*
+ * Returns:
* On success, it returns a positive number of the number of bytes
* it copied.
*
@@ -392,11 +393,11 @@ int seq_buf_to_user(struct seq_buf *s, char __user *ubuf, size_t start, int cnt)
* linebuf size is maximal length for one line.
* 32 * 3 - maximum bytes per line, each printed into 2 chars + 1 for
* separating space
- * 2 - spaces separating hex dump and ascii representation
- * 32 - ascii representation
+ * 2 - spaces separating hex dump and ASCII representation
+ * 32 - ASCII representation
* 1 - terminating '\0'
*
- * Returns zero on success, -1 on overflow
+ * Returns: zero on success, -1 on overflow.
*/
int seq_buf_hex_dump(struct seq_buf *s, const char *prefix_str, int prefix_type,
int rowsize, int groupsize,
--
2.43.0
^ permalink raw reply related [flat|nested] 5+ messages in thread