From: Qian Cai <cai@xxxxxx>
Subject: include/trace/events/writeback.h: fix -Wstringop-truncation warnings
There are many of those warnings.
In file included from ./arch/powerpc/include/asm/paca.h:15,
from ./arch/powerpc/include/asm/current.h:13,
from ./include/linux/thread_info.h:21,
from ./include/asm-generic/preempt.h:5,
from ./arch/powerpc/include/generated/asm/preempt.h:1,
from ./include/linux/preempt.h:78,
from ./include/linux/spinlock.h:51,
from fs/fs-writeback.c:19:
In function 'strncpy',
inlined from 'perf_trace_writeback_page_template' at
./include/trace/events/writeback.h:56:1:
./include/linux/string.h:260:9: warning: '__builtin_strncpy' specified
bound 32 equals destination size [-Wstringop-truncation]
return __builtin_strncpy(p, q, size);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Fix it by using the new strscpy_pad() which was introduced in "lib/string:
Add strscpy_pad() function" and will always be NUL-terminated instead of
strncpy(). Also, change strlcpy() to use strscpy_pad() in this file for
consistency.
Link: http://lkml.kernel.org/r/1564075099-27750-1-git-send-email-cai@xxxxxx
Fixes: 455b2864686d ("writeback: Initial tracing support")
Fixes: 028c2dd184c0 ("writeback: Add tracing to balance_dirty_pages")
Fixes: e84d0a4f8e39 ("writeback: trace event writeback_queue_io")
Fixes: b48c104d2211 ("writeback: trace event bdi_dirty_ratelimit")
Fixes: cc1676d917f3 ("writeback: Move requeueing when I_SYNC set to writeback_sb_inodes()")
Fixes: 9fb0a7da0c52 ("writeback: add more tracepoints")
Signed-off-by: Qian Cai <cai@xxxxxx>
Reviewed-by: Jan Kara <jack@xxxxxxx>
Cc: Tobin C. Harding <tobin@xxxxxxxxxx>
Cc: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Tejun Heo <tj@xxxxxxxxxx>
Cc: Dave Chinner <dchinner@xxxxxxxxxx>
Cc: Fengguang Wu <fengguang.wu@xxxxxxxxx>
Cc: Jens Axboe <axboe@xxxxxxxxx>
Cc: Joe Perches <joe@xxxxxxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Jann Horn <jannh@xxxxxxxxxx>
Cc: Jonathan Corbet <corbet@xxxxxxx>
Cc: Nitin Gote <nitin.r.gote@xxxxxxxxx>
Cc: Rasmus Villemoes <rasmus.villemoes@xxxxxxxxx>
Cc: Stephen Kitt <steve@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/trace/events/writeback.h | 38 +++++++++++++++--------------
1 file changed, 20 insertions(+), 18 deletions(-)
--- a/include/trace/events/writeback.h~writeback-fix-wstringop-truncation-warnings
+++ a/include/trace/events/writeback.h
@@ -66,8 +66,9 @@ DECLARE_EVENT_CLASS(writeback_page_templ
),
TP_fast_assign(
- strncpy(__entry->name,
- mapping ? dev_name(inode_to_bdi(mapping->host)->dev) : "(unknown)", 32);
+ strscpy_pad(__entry->name,
+ mapping ? dev_name(inode_to_bdi(mapping->host)->dev) : "(unknown)",
+ 32);
__entry->ino = mapping ? mapping->host->i_ino : 0;
__entry->index = page->index;
),
@@ -110,8 +111,8 @@ DECLARE_EVENT_CLASS(writeback_dirty_inod
struct backing_dev_info *bdi = inode_to_bdi(inode);
/* may be called for files on pseudo FSes w/ unregistered bdi */
- strncpy(__entry->name,
- bdi->dev ? dev_name(bdi->dev) : "(unknown)", 32);
+ strscpy_pad(__entry->name,
+ bdi->dev ? dev_name(bdi->dev) : "(unknown)", 32);
__entry->ino = inode->i_ino;
__entry->state = inode->i_state;
__entry->flags = flags;
@@ -316,8 +317,8 @@ DECLARE_EVENT_CLASS(writeback_write_inod
),
TP_fast_assign(
- strncpy(__entry->name,
- dev_name(inode_to_bdi(inode)->dev), 32);
+ strscpy_pad(__entry->name,
+ dev_name(inode_to_bdi(inode)->dev), 32);
__entry->ino = inode->i_ino;
__entry->sync_mode = wbc->sync_mode;
__entry->cgroup_ino = __trace_wbc_assign_cgroup(wbc);
@@ -360,8 +361,9 @@ DECLARE_EVENT_CLASS(writeback_work_class
__field(unsigned int, cgroup_ino)
),
TP_fast_assign(
- strncpy(__entry->name,
- wb->bdi->dev ? dev_name(wb->bdi->dev) : "(unknown)", 32);
+ strscpy_pad(__entry->name,
+ wb->bdi->dev ? dev_name(wb->bdi->dev) :
+ "(unknown)", 32);
__entry->nr_pages = work->nr_pages;
__entry->sb_dev = work->sb ? work->sb->s_dev : 0;
__entry->sync_mode = work->sync_mode;
@@ -414,7 +416,7 @@ DECLARE_EVENT_CLASS(writeback_class,
__field(unsigned int, cgroup_ino)
),
TP_fast_assign(
- strncpy(__entry->name, dev_name(wb->bdi->dev), 32);
+ strscpy_pad(__entry->name, dev_name(wb->bdi->dev), 32);
__entry->cgroup_ino = __trace_wb_assign_cgroup(wb);
),
TP_printk("bdi %s: cgroup_ino=%u",
@@ -436,7 +438,7 @@ TRACE_EVENT(writeback_bdi_register,
__array(char, name, 32)
),
TP_fast_assign(
- strncpy(__entry->name, dev_name(bdi->dev), 32);
+ strscpy_pad(__entry->name, dev_name(bdi->dev), 32);
),
TP_printk("bdi %s",
__entry->name
@@ -461,7 +463,7 @@ DECLARE_EVENT_CLASS(wbc_class,
),
TP_fast_assign(
- strncpy(__entry->name, dev_name(bdi->dev), 32);
+ strscpy_pad(__entry->name, dev_name(bdi->dev), 32);
__entry->nr_to_write = wbc->nr_to_write;
__entry->pages_skipped = wbc->pages_skipped;
__entry->sync_mode = wbc->sync_mode;
@@ -512,7 +514,7 @@ TRACE_EVENT(writeback_queue_io,
),
TP_fast_assign(
unsigned long *older_than_this = work->older_than_this;
- strncpy(__entry->name, dev_name(wb->bdi->dev), 32);
+ strscpy_pad(__entry->name, dev_name(wb->bdi->dev), 32);
__entry->older = older_than_this ? *older_than_this : 0;
__entry->age = older_than_this ?
(jiffies - *older_than_this) * 1000 / HZ : -1;
@@ -598,7 +600,7 @@ TRACE_EVENT(bdi_dirty_ratelimit,
),
TP_fast_assign(
- strlcpy(__entry->bdi, dev_name(wb->bdi->dev), 32);
+ strscpy_pad(__entry->bdi, dev_name(wb->bdi->dev), 32);
__entry->write_bw = KBps(wb->write_bandwidth);
__entry->avg_write_bw = KBps(wb->avg_write_bandwidth);
__entry->dirty_rate = KBps(dirty_rate);
@@ -663,7 +665,7 @@ TRACE_EVENT(balance_dirty_pages,
TP_fast_assign(
unsigned long freerun = (thresh + bg_thresh) / 2;
- strlcpy(__entry->bdi, dev_name(wb->bdi->dev), 32);
+ strscpy_pad(__entry->bdi, dev_name(wb->bdi->dev), 32);
__entry->limit = global_wb_domain.dirty_limit;
__entry->setpoint = (global_wb_domain.dirty_limit +
@@ -723,8 +725,8 @@ TRACE_EVENT(writeback_sb_inodes_requeue,
),
TP_fast_assign(
- strncpy(__entry->name,
- dev_name(inode_to_bdi(inode)->dev), 32);
+ strscpy_pad(__entry->name,
+ dev_name(inode_to_bdi(inode)->dev), 32);
__entry->ino = inode->i_ino;
__entry->state = inode->i_state;
__entry->dirtied_when = inode->dirtied_when;
@@ -797,8 +799,8 @@ DECLARE_EVENT_CLASS(writeback_single_ino
),
TP_fast_assign(
- strncpy(__entry->name,
- dev_name(inode_to_bdi(inode)->dev), 32);
+ strscpy_pad(__entry->name,
+ dev_name(inode_to_bdi(inode)->dev), 32);
__entry->ino = inode->i_ino;
__entry->state = inode->i_state;
__entry->dirtied_when = inode->dirtied_when;
_
