[PATCH RFC 1/2] tracing/block: cleanup rwbs filling in trace events

From: Konstantin Khlebnikov
Date: Mon May 04 2020 - 11:16:25 EST


Define BLK_RWBS_LEN in blktrace_api.h
Bcache events use shorter 6 char buffer which could overflow.

Also remove unsed "bytes" argument.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@xxxxxxxxxxxxxx>
---
include/linux/blktrace_api.h | 4 +-
include/trace/events/bcache.h | 20 +++++-----
include/trace/events/block.h | 84 ++++++++++++++++++++---------------------
kernel/trace/blktrace.c | 2 -
4 files changed, 55 insertions(+), 55 deletions(-)

diff --git a/include/linux/blktrace_api.h b/include/linux/blktrace_api.h
index 3b6ff5902edc..ea9da15d32d9 100644
--- a/include/linux/blktrace_api.h
+++ b/include/linux/blktrace_api.h
@@ -120,7 +120,9 @@ struct compat_blk_user_trace_setup {

#endif

-extern void blk_fill_rwbs(char *rwbs, unsigned int op, int bytes);
+#define BLK_RWBS_LEN 8
+
+extern void blk_fill_rwbs(char *rwbs, unsigned int op);

static inline sector_t blk_rq_trace_sector(struct request *rq)
{
diff --git a/include/trace/events/bcache.h b/include/trace/events/bcache.h
index 0bddea663b3b..7440d704c200 100644
--- a/include/trace/events/bcache.h
+++ b/include/trace/events/bcache.h
@@ -18,7 +18,7 @@ DECLARE_EVENT_CLASS(bcache_request,
__field(sector_t, sector )
__field(dev_t, orig_sector )
__field(unsigned int, nr_sector )
- __array(char, rwbs, 6 )
+ __array(char, rwbs, BLK_RWBS_LEN )
),

TP_fast_assign(
@@ -28,7 +28,7 @@ DECLARE_EVENT_CLASS(bcache_request,
__entry->sector = bio->bi_iter.bi_sector;
__entry->orig_sector = bio->bi_iter.bi_sector - 16;
__entry->nr_sector = bio->bi_iter.bi_size >> 9;
- blk_fill_rwbs(__entry->rwbs, bio->bi_opf, bio->bi_iter.bi_size);
+ blk_fill_rwbs(__entry->rwbs, bio->bi_opf);
),

TP_printk("%d,%d %s %llu + %u (from %d,%d @ %llu)",
@@ -95,14 +95,14 @@ DECLARE_EVENT_CLASS(bcache_bio,
__field(dev_t, dev )
__field(sector_t, sector )
__field(unsigned int, nr_sector )
- __array(char, rwbs, 6 )
+ __array(char, rwbs, BLK_RWBS_LEN )
),

TP_fast_assign(
__entry->dev = bio_dev(bio);
__entry->sector = bio->bi_iter.bi_sector;
__entry->nr_sector = bio->bi_iter.bi_size >> 9;
- blk_fill_rwbs(__entry->rwbs, bio->bi_opf, bio->bi_iter.bi_size);
+ blk_fill_rwbs(__entry->rwbs, bio->bi_opf);
),

TP_printk("%d,%d %s %llu + %u",
@@ -128,7 +128,7 @@ TRACE_EVENT(bcache_read,
__field(dev_t, dev )
__field(sector_t, sector )
__field(unsigned int, nr_sector )
- __array(char, rwbs, 6 )
+ __array(char, rwbs, BLK_RWBS_LEN )
__field(bool, cache_hit )
__field(bool, bypass )
),
@@ -137,7 +137,7 @@ TRACE_EVENT(bcache_read,
__entry->dev = bio_dev(bio);
__entry->sector = bio->bi_iter.bi_sector;
__entry->nr_sector = bio->bi_iter.bi_size >> 9;
- blk_fill_rwbs(__entry->rwbs, bio->bi_opf, bio->bi_iter.bi_size);
+ blk_fill_rwbs(__entry->rwbs, bio->bi_opf);
__entry->cache_hit = hit;
__entry->bypass = bypass;
),
@@ -158,7 +158,7 @@ TRACE_EVENT(bcache_write,
__field(u64, inode )
__field(sector_t, sector )
__field(unsigned int, nr_sector )
- __array(char, rwbs, 6 )
+ __array(char, rwbs, BLK_RWBS_LEN )
__field(bool, writeback )
__field(bool, bypass )
),
@@ -168,7 +168,7 @@ TRACE_EVENT(bcache_write,
__entry->inode = inode;
__entry->sector = bio->bi_iter.bi_sector;
__entry->nr_sector = bio->bi_iter.bi_size >> 9;
- blk_fill_rwbs(__entry->rwbs, bio->bi_opf, bio->bi_iter.bi_size);
+ blk_fill_rwbs(__entry->rwbs, bio->bi_opf);
__entry->writeback = writeback;
__entry->bypass = bypass;
),
@@ -229,7 +229,7 @@ TRACE_EVENT(bcache_journal_write,
__field(dev_t, dev )
__field(sector_t, sector )
__field(unsigned int, nr_sector )
- __array(char, rwbs, 6 )
+ __array(char, rwbs, BLK_RWBS_LEN )
__field(u32, nr_keys )
),

@@ -238,7 +238,7 @@ TRACE_EVENT(bcache_journal_write,
__entry->sector = bio->bi_iter.bi_sector;
__entry->nr_sector = bio->bi_iter.bi_size >> 9;
__entry->nr_keys = keys;
- blk_fill_rwbs(__entry->rwbs, bio->bi_opf, bio->bi_iter.bi_size);
+ blk_fill_rwbs(__entry->rwbs, bio->bi_opf);
),

TP_printk("%d,%d %s %llu + %u keys %u",
diff --git a/include/trace/events/block.h b/include/trace/events/block.h
index 81b43f5bdf23..aac9a5c0e2cc 100644
--- a/include/trace/events/block.h
+++ b/include/trace/events/block.h
@@ -10,7 +10,6 @@
#include <linux/buffer_head.h>
#include <linux/tracepoint.h>

-#define RWBS_LEN 8

DECLARE_EVENT_CLASS(block_buffer,

@@ -81,7 +80,7 @@ TRACE_EVENT(block_rq_requeue,
__field( dev_t, dev )
__field( sector_t, sector )
__field( unsigned int, nr_sector )
- __array( char, rwbs, RWBS_LEN )
+ __array( char, rwbs, BLK_RWBS_LEN )
__dynamic_array( char, cmd, 1 )
),

@@ -90,7 +89,7 @@ TRACE_EVENT(block_rq_requeue,
__entry->sector = blk_rq_trace_sector(rq);
__entry->nr_sector = blk_rq_trace_nr_sectors(rq);

- blk_fill_rwbs(__entry->rwbs, rq->cmd_flags, blk_rq_bytes(rq));
+ blk_fill_rwbs(__entry->rwbs, rq->cmd_flags);
__get_str(cmd)[0] = '\0';
),

@@ -124,7 +123,7 @@ TRACE_EVENT(block_rq_complete,
__field( sector_t, sector )
__field( unsigned int, nr_sector )
__field( int, error )
- __array( char, rwbs, RWBS_LEN )
+ __array( char, rwbs, BLK_RWBS_LEN )
__dynamic_array( char, cmd, 1 )
),

@@ -134,7 +133,7 @@ TRACE_EVENT(block_rq_complete,
__entry->nr_sector = nr_bytes >> 9;
__entry->error = error;

- blk_fill_rwbs(__entry->rwbs, rq->cmd_flags, nr_bytes);
+ blk_fill_rwbs(__entry->rwbs, rq->cmd_flags);
__get_str(cmd)[0] = '\0';
),

@@ -156,7 +155,7 @@ DECLARE_EVENT_CLASS(block_rq,
__field( sector_t, sector )
__field( unsigned int, nr_sector )
__field( unsigned int, bytes )
- __array( char, rwbs, RWBS_LEN )
+ __array( char, rwbs, BLK_RWBS_LEN )
__array( char, comm, TASK_COMM_LEN )
__dynamic_array( char, cmd, 1 )
),
@@ -167,7 +166,7 @@ DECLARE_EVENT_CLASS(block_rq,
__entry->nr_sector = blk_rq_trace_nr_sectors(rq);
__entry->bytes = blk_rq_bytes(rq);

- blk_fill_rwbs(__entry->rwbs, rq->cmd_flags, blk_rq_bytes(rq));
+ blk_fill_rwbs(__entry->rwbs, rq->cmd_flags);
__get_str(cmd)[0] = '\0';
memcpy(__entry->comm, current->comm, TASK_COMM_LEN);
),
@@ -232,7 +231,7 @@ TRACE_EVENT(block_bio_bounce,
__field( dev_t, dev )
__field( sector_t, sector )
__field( unsigned int, nr_sector )
- __array( char, rwbs, RWBS_LEN )
+ __array( char, rwbs, BLK_RWBS_LEN )
__array( char, comm, TASK_COMM_LEN )
),

@@ -240,7 +239,7 @@ TRACE_EVENT(block_bio_bounce,
__entry->dev = bio_dev(bio);
__entry->sector = bio->bi_iter.bi_sector;
__entry->nr_sector = bio_sectors(bio);
- blk_fill_rwbs(__entry->rwbs, bio->bi_opf, bio->bi_iter.bi_size);
+ blk_fill_rwbs(__entry->rwbs, bio->bi_opf);
memcpy(__entry->comm, current->comm, TASK_COMM_LEN);
),

@@ -266,11 +265,11 @@ TRACE_EVENT(block_bio_complete,
TP_ARGS(q, bio, error),

TP_STRUCT__entry(
- __field( dev_t, dev )
- __field( sector_t, sector )
- __field( unsigned, nr_sector )
- __field( int, error )
- __array( char, rwbs, RWBS_LEN)
+ __field( dev_t, dev )
+ __field( sector_t, sector )
+ __field( unsigned, nr_sector )
+ __field( int, error )
+ __array( char, rwbs, BLK_RWBS_LEN )
),

TP_fast_assign(
@@ -278,7 +277,7 @@ TRACE_EVENT(block_bio_complete,
__entry->sector = bio->bi_iter.bi_sector;
__entry->nr_sector = bio_sectors(bio);
__entry->error = error;
- blk_fill_rwbs(__entry->rwbs, bio->bi_opf, bio->bi_iter.bi_size);
+ blk_fill_rwbs(__entry->rwbs, bio->bi_opf);
),

TP_printk("%d,%d %s %llu + %u [%d]",
@@ -297,7 +296,7 @@ DECLARE_EVENT_CLASS(block_bio_merge,
__field( dev_t, dev )
__field( sector_t, sector )
__field( unsigned int, nr_sector )
- __array( char, rwbs, RWBS_LEN )
+ __array( char, rwbs, BLK_RWBS_LEN )
__array( char, comm, TASK_COMM_LEN )
),

@@ -305,7 +304,7 @@ DECLARE_EVENT_CLASS(block_bio_merge,
__entry->dev = bio_dev(bio);
__entry->sector = bio->bi_iter.bi_sector;
__entry->nr_sector = bio_sectors(bio);
- blk_fill_rwbs(__entry->rwbs, bio->bi_opf, bio->bi_iter.bi_size);
+ blk_fill_rwbs(__entry->rwbs, bio->bi_opf);
memcpy(__entry->comm, current->comm, TASK_COMM_LEN);
),

@@ -364,7 +363,7 @@ TRACE_EVENT(block_bio_queue,
__field( dev_t, dev )
__field( sector_t, sector )
__field( unsigned int, nr_sector )
- __array( char, rwbs, RWBS_LEN )
+ __array( char, rwbs, BLK_RWBS_LEN )
__array( char, comm, TASK_COMM_LEN )
),

@@ -372,7 +371,7 @@ TRACE_EVENT(block_bio_queue,
__entry->dev = bio_dev(bio);
__entry->sector = bio->bi_iter.bi_sector;
__entry->nr_sector = bio_sectors(bio);
- blk_fill_rwbs(__entry->rwbs, bio->bi_opf, bio->bi_iter.bi_size);
+ blk_fill_rwbs(__entry->rwbs, bio->bi_opf);
memcpy(__entry->comm, current->comm, TASK_COMM_LEN);
),

@@ -392,7 +391,7 @@ DECLARE_EVENT_CLASS(block_get_rq,
__field( dev_t, dev )
__field( sector_t, sector )
__field( unsigned int, nr_sector )
- __array( char, rwbs, RWBS_LEN )
+ __array( char, rwbs, BLK_RWBS_LEN )
__array( char, comm, TASK_COMM_LEN )
),

@@ -400,8 +399,7 @@ DECLARE_EVENT_CLASS(block_get_rq,
__entry->dev = bio ? bio_dev(bio) : 0;
__entry->sector = bio ? bio->bi_iter.bi_sector : 0;
__entry->nr_sector = bio ? bio_sectors(bio) : 0;
- blk_fill_rwbs(__entry->rwbs,
- bio ? bio->bi_opf : 0, __entry->nr_sector);
+ blk_fill_rwbs(__entry->rwbs, bio ? bio->bi_opf : 0);
memcpy(__entry->comm, current->comm, TASK_COMM_LEN);
),

@@ -524,18 +522,18 @@ TRACE_EVENT(block_split,
TP_ARGS(q, bio, new_sector),

TP_STRUCT__entry(
- __field( dev_t, dev )
- __field( sector_t, sector )
- __field( sector_t, new_sector )
- __array( char, rwbs, RWBS_LEN )
- __array( char, comm, TASK_COMM_LEN )
+ __field( dev_t, dev )
+ __field( sector_t, sector )
+ __field( sector_t, new_sector )
+ __array( char, rwbs, BLK_RWBS_LEN )
+ __array( char, comm, TASK_COMM_LEN )
),

TP_fast_assign(
__entry->dev = bio_dev(bio);
__entry->sector = bio->bi_iter.bi_sector;
__entry->new_sector = new_sector;
- blk_fill_rwbs(__entry->rwbs, bio->bi_opf, bio->bi_iter.bi_size);
+ blk_fill_rwbs(__entry->rwbs, bio->bi_opf);
memcpy(__entry->comm, current->comm, TASK_COMM_LEN);
),

@@ -564,12 +562,12 @@ TRACE_EVENT(block_bio_remap,
TP_ARGS(q, bio, dev, from),

TP_STRUCT__entry(
- __field( dev_t, dev )
- __field( sector_t, sector )
- __field( unsigned int, nr_sector )
- __field( dev_t, old_dev )
- __field( sector_t, old_sector )
- __array( char, rwbs, RWBS_LEN)
+ __field( dev_t, dev )
+ __field( sector_t, sector )
+ __field( unsigned int, nr_sector )
+ __field( dev_t, old_dev )
+ __field( sector_t, old_sector )
+ __array( char, rwbs, BLK_RWBS_LEN )
),

TP_fast_assign(
@@ -578,7 +576,7 @@ TRACE_EVENT(block_bio_remap,
__entry->nr_sector = bio_sectors(bio);
__entry->old_dev = dev;
__entry->old_sector = from;
- blk_fill_rwbs(__entry->rwbs, bio->bi_opf, bio->bi_iter.bi_size);
+ blk_fill_rwbs(__entry->rwbs, bio->bi_opf);
),

TP_printk("%d,%d %s %llu + %u <- (%d,%d) %llu",
@@ -608,13 +606,13 @@ TRACE_EVENT(block_rq_remap,
TP_ARGS(q, rq, dev, from),

TP_STRUCT__entry(
- __field( dev_t, dev )
- __field( sector_t, sector )
- __field( unsigned int, nr_sector )
- __field( dev_t, old_dev )
- __field( sector_t, old_sector )
- __field( unsigned int, nr_bios )
- __array( char, rwbs, RWBS_LEN)
+ __field( dev_t, dev )
+ __field( sector_t, sector )
+ __field( unsigned int, nr_sector )
+ __field( dev_t, old_dev )
+ __field( sector_t, old_sector )
+ __field( unsigned int, nr_bios )
+ __array( char, rwbs, BLK_RWBS_LEN )
),

TP_fast_assign(
@@ -624,7 +622,7 @@ TRACE_EVENT(block_rq_remap,
__entry->old_dev = dev;
__entry->old_sector = from;
__entry->nr_bios = blk_rq_count_bios(rq);
- blk_fill_rwbs(__entry->rwbs, rq->cmd_flags, blk_rq_bytes(rq));
+ blk_fill_rwbs(__entry->rwbs, rq->cmd_flags);
),

TP_printk("%d,%d %s %llu + %u <- (%d,%d) %llu %u",
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index ca39dc3230cb..dd10667d4164 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -1935,7 +1935,7 @@ void blk_trace_remove_sysfs(struct device *dev)

#ifdef CONFIG_EVENT_TRACING

-void blk_fill_rwbs(char *rwbs, unsigned int op, int bytes)
+void blk_fill_rwbs(char *rwbs, unsigned int op)
{
int i = 0;