From: Qian Cai cai@lca.pw
[ Upstream commit d1a445d3b86c9341ce7a0954c23be0edb5c9bec5 ]
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@lca.pw 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@lca.pw Reviewed-by: Jan Kara jack@suse.cz Cc: Tobin C. Harding tobin@kernel.org Cc: Steven Rostedt (VMware) rostedt@goodmis.org Cc: Ingo Molnar mingo@redhat.com Cc: Tejun Heo tj@kernel.org Cc: Dave Chinner dchinner@redhat.com Cc: Fengguang Wu fengguang.wu@intel.com Cc: Jens Axboe axboe@kernel.dk Cc: Joe Perches joe@perches.com Cc: Kees Cook keescook@chromium.org Cc: Jann Horn jannh@google.com Cc: Jonathan Corbet corbet@lwn.net Cc: Nitin Gote nitin.r.gote@intel.com Cc: Rasmus Villemoes rasmus.villemoes@prevas.dk Cc: Stephen Kitt steve@sk2.org Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- include/trace/events/writeback.h | 38 +++++++++++++++++--------------- 1 file changed, 20 insertions(+), 18 deletions(-)
diff --git a/include/trace/events/writeback.h b/include/trace/events/writeback.h index ec964a924cd2f..c6cea40e6e6fc 100644 --- a/include/trace/events/writeback.h +++ b/include/trace/events/writeback.h @@ -65,8 +65,9 @@ TRACE_EVENT(writeback_dirty_page, ),
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; ), @@ -95,8 +96,8 @@ DECLARE_EVENT_CLASS(writeback_dirty_inode_template, 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; @@ -175,8 +176,8 @@ DECLARE_EVENT_CLASS(writeback_write_inode_template, ),
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); @@ -219,8 +220,9 @@ 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; @@ -273,7 +275,7 @@ 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", @@ -296,7 +298,7 @@ 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 @@ -321,7 +323,7 @@ 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; @@ -372,7 +374,7 @@ TRACE_EVENT(writeback_queue_io, __field(unsigned int, cgroup_ino) ), TP_fast_assign( - strncpy(__entry->name, dev_name(wb->bdi->dev), 32); + strncpy_pad(__entry->name, dev_name(wb->bdi->dev), 32); __entry->older = dirtied_before; __entry->age = (jiffies - dirtied_before) * 1000 / HZ; __entry->moved = moved; @@ -457,7 +459,7 @@ 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); @@ -522,7 +524,7 @@ 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 + @@ -582,8 +584,8 @@ 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; @@ -656,8 +658,8 @@ DECLARE_EVENT_CLASS(writeback_single_inode_template, ),
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;