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authorLinus Torvalds <torvalds@linux-foundation.org>2015-03-10 04:44:06 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2015-03-10 04:44:06 +0300
commite7901af14398bf0272e523936d0774b4469741a8 (patch)
tree1259f6f2632ea31673ddf7bcee0315aca2810cbb /lib
parent36bef88380037288d5b575ed2029de694533b1ec (diff)
parent524a38682573b2e15ab6317ccfe50280441514be (diff)
downloadlinux-e7901af14398bf0272e523936d0774b4469741a8.tar.xz
Merge tag 'trace-fixes-v4.0-rc2-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull seq-buf/ftrace fixes from Steven Rostedt: "This includes fixes for seq_buf_bprintf() truncation issue. It also contains fixes to ftrace when /proc/sys/kernel/ftrace_enabled and function tracing are started. Doing the following causes some issues: # echo 0 > /proc/sys/kernel/ftrace_enabled # echo function_graph > /sys/kernel/debug/tracing/current_tracer # echo 1 > /proc/sys/kernel/ftrace_enabled # echo nop > /sys/kernel/debug/tracing/current_tracer # echo function_graph > /sys/kernel/debug/tracing/current_tracer As well as with function tracing too. Pratyush Anand first reported this issue to me and supplied a patch. When I tested this on my x86 test box, it caused thousands of backtraces and warnings to appear in dmesg, which also caused a denial of service (a warning for every function that was listed). I applied Pratyush's patch but it did not fix the issue for me. I looked into it and found a slight problem with trampoline accounting. I fixed it and sent Pratyush a patch, but he said that it did not fix the issue for him. I later learned tha Pratyush was using an ARM64 server, and when I tested on my ARM board, I was able to reproduce the same issue as Pratyush. After applying his patch, it fixed the problem. The above test uncovered two different bugs, one in x86 and one in ARM and ARM64. As this looked like it would affect PowerPC, I tested it on my PPC64 box. It too broke, but neither the patch that fixed ARM or x86 fixed this box (the changes were all in generic code!). The above test, uncovered two more bugs that affected PowerPC. Again, the changes were only done to generic code. It's the way the arch code expected things to be done that was different between the archs. Some where more sensitive than others. The rest of this series fixes the PPC bugs as well" * tag 'trace-fixes-v4.0-rc2-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: ftrace: Fix ftrace enable ordering of sysctl ftrace_enabled ftrace: Fix en(dis)able graph caller when en(dis)abling record via sysctl ftrace: Clear REGS_EN and TRAMP_EN flags on disabling record via sysctl seq_buf: Fix seq_buf_bprintf() truncation seq_buf: Fix seq_buf_vprintf() truncation
Diffstat (limited to 'lib')
-rw-r--r--lib/seq_buf.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/lib/seq_buf.c b/lib/seq_buf.c
index 88c0854bd752..5c94e1012a91 100644
--- a/lib/seq_buf.c
+++ b/lib/seq_buf.c
@@ -61,7 +61,7 @@ int seq_buf_vprintf(struct seq_buf *s, const char *fmt, va_list args)
if (s->len < s->size) {
len = vsnprintf(s->buffer + s->len, s->size - s->len, fmt, args);
- if (seq_buf_can_fit(s, len)) {
+ if (s->len + len < s->size) {
s->len += len;
return 0;
}
@@ -118,7 +118,7 @@ int seq_buf_bprintf(struct seq_buf *s, const char *fmt, const u32 *binary)
if (s->len < s->size) {
ret = bstr_printf(s->buffer + s->len, len, fmt, binary);
- if (seq_buf_can_fit(s, ret)) {
+ if (s->len + ret < s->size) {
s->len += ret;
return 0;
}