diff options
author | Jens Axboe <axboe@kernel.dk> | 2017-11-05 17:13:48 +0100 |
---|---|---|
committer | Jens Axboe <axboe@kernel.dk> | 2017-11-11 03:53:25 +0100 |
commit | 1f2cac107c591c24b60b115d6050adc213d10fc0 (patch) | |
tree | 958d22ca65748177f3d3de85af6ef468fe5826c7 /kernel/trace | |
parent | null_blk: add an usage for shared tags in documentation (diff) | |
download | linux-1f2cac107c591c24b60b115d6050adc213d10fc0.tar.xz linux-1f2cac107c591c24b60b115d6050adc213d10fc0.zip |
blktrace: fix unlocked access to init/start-stop/teardown
sg.c calls into the blktrace functions without holding the proper queue
mutex for doing setup, start/stop, or teardown.
Add internal unlocked variants, and export the ones that do the proper
locking.
Fixes: 6da127ad0918 ("blktrace: Add blktrace ioctls to SCSI generic devices")
Tested-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'kernel/trace')
-rw-r--r-- | kernel/trace/blktrace.c | 58 |
1 files changed, 48 insertions, 10 deletions
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c index 45a3928544ce..ea57dd94b2b2 100644 --- a/kernel/trace/blktrace.c +++ b/kernel/trace/blktrace.c @@ -336,7 +336,7 @@ static void blk_trace_cleanup(struct blk_trace *bt) blk_unregister_tracepoints(); } -int blk_trace_remove(struct request_queue *q) +static int __blk_trace_remove(struct request_queue *q) { struct blk_trace *bt; @@ -349,6 +349,17 @@ int blk_trace_remove(struct request_queue *q) return 0; } + +int blk_trace_remove(struct request_queue *q) +{ + int ret; + + mutex_lock(&q->blk_trace_mutex); + ret = __blk_trace_remove(q); + mutex_unlock(&q->blk_trace_mutex); + + return ret; +} EXPORT_SYMBOL_GPL(blk_trace_remove); static ssize_t blk_dropped_read(struct file *filp, char __user *buffer, @@ -550,9 +561,8 @@ err: return ret; } -int blk_trace_setup(struct request_queue *q, char *name, dev_t dev, - struct block_device *bdev, - char __user *arg) +static int __blk_trace_setup(struct request_queue *q, char *name, dev_t dev, + struct block_device *bdev, char __user *arg) { struct blk_user_trace_setup buts; int ret; @@ -571,6 +581,19 @@ int blk_trace_setup(struct request_queue *q, char *name, dev_t dev, } return 0; } + +int blk_trace_setup(struct request_queue *q, char *name, dev_t dev, + struct block_device *bdev, + char __user *arg) +{ + int ret; + + mutex_lock(&q->blk_trace_mutex); + ret = __blk_trace_setup(q, name, dev, bdev, arg); + mutex_unlock(&q->blk_trace_mutex); + + return ret; +} EXPORT_SYMBOL_GPL(blk_trace_setup); #if defined(CONFIG_COMPAT) && defined(CONFIG_X86_64) @@ -607,7 +630,7 @@ static int compat_blk_trace_setup(struct request_queue *q, char *name, } #endif -int blk_trace_startstop(struct request_queue *q, int start) +static int __blk_trace_startstop(struct request_queue *q, int start) { int ret; struct blk_trace *bt = q->blk_trace; @@ -646,6 +669,17 @@ int blk_trace_startstop(struct request_queue *q, int start) return ret; } + +int blk_trace_startstop(struct request_queue *q, int start) +{ + int ret; + + mutex_lock(&q->blk_trace_mutex); + ret = __blk_trace_startstop(q, start); + mutex_unlock(&q->blk_trace_mutex); + + return ret; +} EXPORT_SYMBOL_GPL(blk_trace_startstop); /* @@ -676,7 +710,7 @@ int blk_trace_ioctl(struct block_device *bdev, unsigned cmd, char __user *arg) switch (cmd) { case BLKTRACESETUP: bdevname(bdev, b); - ret = blk_trace_setup(q, b, bdev->bd_dev, bdev, arg); + ret = __blk_trace_setup(q, b, bdev->bd_dev, bdev, arg); break; #if defined(CONFIG_COMPAT) && defined(CONFIG_X86_64) case BLKTRACESETUP32: @@ -687,10 +721,10 @@ int blk_trace_ioctl(struct block_device *bdev, unsigned cmd, char __user *arg) case BLKTRACESTART: start = 1; case BLKTRACESTOP: - ret = blk_trace_startstop(q, start); + ret = __blk_trace_startstop(q, start); break; case BLKTRACETEARDOWN: - ret = blk_trace_remove(q); + ret = __blk_trace_remove(q); break; default: ret = -ENOTTY; @@ -708,10 +742,14 @@ int blk_trace_ioctl(struct block_device *bdev, unsigned cmd, char __user *arg) **/ void blk_trace_shutdown(struct request_queue *q) { + mutex_lock(&q->blk_trace_mutex); + if (q->blk_trace) { - blk_trace_startstop(q, 0); - blk_trace_remove(q); + __blk_trace_startstop(q, 0); + __blk_trace_remove(q); } + + mutex_unlock(&q->blk_trace_mutex); } #ifdef CONFIG_BLK_CGROUP |