Re: [PATCH v8 tip 5/9] tracing: allow BPF programs to call bpf_trace_printk()

2015-03-20 Thread Alexei Starovoitov
On 3/20/15 2:22 PM, Steven Rostedt wrote: +/* limited trace_printk() + * only %d %u %x %ld %lu %lx %lld %llu %llx %p conversion specifiers allowed + */ Ah! Again, don't contaminate the rest of the kernel with net comment styles! :-) ok :) + } else if (fmt[i] == 'p') { +

Re: [PATCH v8 tip 5/9] tracing: allow BPF programs to call bpf_trace_printk()

2015-03-20 Thread Steven Rostedt
On Thu, 19 Mar 2015 18:59:43 -0700 Alexei Starovoitov wrote: > Debugging of BPF programs needs some form of printk from the program, > so let programs call limited trace_printk() with %d %u %x %p modifiers only. > > Similar to kernel modules, during program load verifier checks whether program >

[PATCH v8 tip 5/9] tracing: allow BPF programs to call bpf_trace_printk()

2015-03-19 Thread Alexei Starovoitov
Debugging of BPF programs needs some form of printk from the program, so let programs call limited trace_printk() with %d %u %x %p modifiers only. Similar to kernel modules, during program load verifier checks whether program is calling bpf_trace_printk() and if so, kernel allocates trace_printk b