Messages in this thread |  | | Date | Mon, 24 Feb 2014 18:36:40 +0100 | From | Jiri Olsa <> | Subject | Re: [perf tool] record failure with 3.14-rc4 |
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On Mon, Feb 24, 2014 at 05:24:41PM +0000, Will Deacon wrote: > Hi guys, > > If I try to run perf record as a non-root user, I end up with the following > (unhelpful) error: > > $ perf record -e cycles ls > [...] > Not enough memory for reading perf file header > > This is because the addresses in /proc/kallsyms always read as 0x0 when > viewed by a non-privileged user, causing kallsyms__get_function_start to > return 0x0 in args.start. machine__create_kernel_maps then treats this as > an error an returns -1 to perf_session__create_kernel_maps, causing > perf_session__new to fail and perf to exit. > > The perf tool code in 3.13 is perfectly happy creating maps at 0x0, but I > can see this has changed quite substantially in the recent merge window. > > Any ideas? We could fix kallsyms__get_function_start to return < 0 on > failure then fix the checks in the callers. Adrian? hi, not sure it's related, but i sent out rfc some time ago for similar bad error messages: http://marc.info/?l=linux-kernel&m=138572558210216&w=2
maybe it could be updated for your case as well, I'll try to check deeply later
jirka
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