| Message ID | 20210427112958.773132-1-revest@chromium.org (mailing list archive) |
|---|---|
| State | Accepted |
| Delegated to: | BPF |
| Headers | show |
| Series | [bpf-next] bpf: Lock bpf_trace_printk's tmp buf before it is written to | expand |
| Context | Check | Description |
|---|---|---|
| netdev/cover_letter | success | Link |
| netdev/fixes_present | success | Link |
| netdev/patch_count | success | Link |
| netdev/tree_selection | success | Clearly marked for bpf-next |
| netdev/subject_prefix | success | Link |
| netdev/cc_maintainers | warning | 7 maintainers not CCed: netdev@vger.kernel.org yhs@fb.com mingo@redhat.com kafai@fb.com rostedt@goodmis.org john.fastabend@gmail.com songliubraving@fb.com |
| netdev/source_inline | success | Was 0 now: 0 |
| netdev/verify_signedoff | success | Link |
| netdev/module_param | success | Was 0 now: 0 |
| netdev/build_32bit | success | Errors and warnings before: 6 this patch: 6 |
| netdev/kdoc | success | Errors and warnings before: 0 this patch: 0 |
| netdev/verify_fixes | success | Link |
| netdev/checkpatch | success | total: 0 errors, 0 warnings, 0 checks, 14 lines checked |
| netdev/build_allmodconfig_warn | success | Errors and warnings before: 6 this patch: 6 |
| netdev/header_inline | success | Link |
On Tue, Apr 27, 2021 at 4:30 AM Florent Revest <revest@chromium.org> wrote: > > bpf_trace_printk uses a shared static buffer to hold strings before they > are printed. A recent refactoring moved the locking of that buffer after > it gets filled by mistake. > > Fixes: d9c9e4db186a ("bpf: Factorize bpf_trace_printk and bpf_seq_printf") > Reported-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> > Signed-off-by: Florent Revest <revest@chromium.org> Applied. Pls send v2 of bstr_printf series as soon as possible. Thanks!
On Tue, Apr 27, 2021 at 5:08 PM Alexei Starovoitov <alexei.starovoitov@gmail.com> wrote: > > On Tue, Apr 27, 2021 at 4:30 AM Florent Revest <revest@chromium.org> wrote: > > > > bpf_trace_printk uses a shared static buffer to hold strings before they > > are printed. A recent refactoring moved the locking of that buffer after > > it gets filled by mistake. > > > > Fixes: d9c9e4db186a ("bpf: Factorize bpf_trace_printk and bpf_seq_printf") > > Reported-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> > > Signed-off-by: Florent Revest <revest@chromium.org> > > Applied. Thanks! > Pls send v2 of bstr_printf series as soon as possible. Thanks! Sure, I just assumed there would be more reviews on v1. The feedback I'll address is only about the commit description wording but I can send a v2 today.
On Tue, Apr 27, 2021 at 8:20 AM Florent Revest <revest@chromium.org> wrote: > > On Tue, Apr 27, 2021 at 5:08 PM Alexei Starovoitov > <alexei.starovoitov@gmail.com> wrote: > > > > On Tue, Apr 27, 2021 at 4:30 AM Florent Revest <revest@chromium.org> wrote: > > > > > > bpf_trace_printk uses a shared static buffer to hold strings before they > > > are printed. A recent refactoring moved the locking of that buffer after > > > it gets filled by mistake. > > > > > > Fixes: d9c9e4db186a ("bpf: Factorize bpf_trace_printk and bpf_seq_printf") > > > Reported-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> > > > Signed-off-by: Florent Revest <revest@chromium.org> > > > > Applied. > > Thanks! > > > Pls send v2 of bstr_printf series as soon as possible. Thanks! > > Sure, I just assumed there would be more reviews on v1. The feedback > I'll address is only about the commit description wording but I can > send a v2 today. Yes. Please.
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 2a8bcdc927c7..0e67d12a8f40 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -391,13 +391,13 @@ BPF_CALL_5(bpf_trace_printk, char *, fmt, u32, fmt_size, u64, arg1, if (ret < 0) return ret; + raw_spin_lock_irqsave(&trace_printk_lock, flags); ret = snprintf(buf, sizeof(buf), fmt, BPF_CAST_FMT_ARG(0, args, mod), BPF_CAST_FMT_ARG(1, args, mod), BPF_CAST_FMT_ARG(2, args, mod)); /* snprintf() will not append null for zero-length strings */ if (ret == 0) buf[0] = '\0'; - raw_spin_lock_irqsave(&trace_printk_lock, flags); trace_bpf_trace_printk(buf); raw_spin_unlock_irqrestore(&trace_printk_lock, flags);
bpf_trace_printk uses a shared static buffer to hold strings before they are printed. A recent refactoring moved the locking of that buffer after it gets filled by mistake. Fixes: d9c9e4db186a ("bpf: Factorize bpf_trace_printk and bpf_seq_printf") Reported-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Florent Revest <revest@chromium.org> --- kernel/trace/bpf_trace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)