Messages in this thread | | | Subject | Re: [Potential Spoof] [PATCH v2 bpf-next 3/4] bpf: allow %pB in bpf_seq_printf() and bpf_trace_printk() | From | Yonghong Song <> | Date | Fri, 26 Jun 2020 08:44:16 -0700 |
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On 6/25/20 5:13 PM, Song Liu wrote: > This makes it easy to dump stack trace in text. > > Signed-off-by: Song Liu <songliubraving@fb.com>
Ack with a small nit below. Acked-by: Yonghong Song <yhs@fb.com>
> --- > kernel/trace/bpf_trace.c | 12 +++++++++--- > 1 file changed, 9 insertions(+), 3 deletions(-) > > diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c > index 65fa62723e2f8..1cb90b0868817 100644 > --- a/kernel/trace/bpf_trace.c > +++ b/kernel/trace/bpf_trace.c > @@ -376,7 +376,7 @@ static void bpf_trace_copy_string(char *buf, void *unsafe_ptr, char fmt_ptype, > > /* > * Only limited trace_printk() conversion specifiers allowed: > - * %d %i %u %x %ld %li %lu %lx %lld %lli %llu %llx %p %pks %pus %s > + * %d %i %u %x %ld %li %lu %lx %lld %lli %llu %llx %p %pB %pks %pus %s > */ > BPF_CALL_5(bpf_trace_printk, char *, fmt, u32, fmt_size, u64, arg1, > u64, arg2, u64, arg3) > @@ -420,6 +420,11 @@ BPF_CALL_5(bpf_trace_printk, char *, fmt, u32, fmt_size, u64, arg1, > goto fmt_str; > } > > + if (fmt[i + 1] == 'B') { > + i++; > + goto fmt_next; > + } > + > /* disallow any further format extensions */ > if (fmt[i + 1] != 0 && > !isspace(fmt[i + 1]) && > @@ -479,7 +484,7 @@ BPF_CALL_5(bpf_trace_printk, char *, fmt, u32, fmt_size, u64, arg1, > #define __BPF_TP_EMIT() __BPF_ARG3_TP() > #define __BPF_TP(...) \ > __trace_printk(0 /* Fake ip */, \ > - fmt, ##__VA_ARGS__) > + fmt, ##__VA_ARGS__)\
Accidental change?
> > #define __BPF_ARG1_TP(...) \ > ((mod[0] == 2 || (mod[0] == 1 && __BITS_PER_LONG == 64)) \ > @@ -636,7 +641,8 @@ BPF_CALL_5(bpf_seq_printf, struct seq_file *, m, char *, fmt, u32, fmt_size, > if (fmt[i] == 'p') { > if (fmt[i + 1] == 0 || > fmt[i + 1] == 'K' || > - fmt[i + 1] == 'x') { > + fmt[i + 1] == 'x' || > + fmt[i + 1] == 'B') { > /* just kernel pointers */ > params[fmt_cnt] = args[fmt_cnt]; > fmt_cnt++; >
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