Messages in this thread | | | Subject | Re: [PATCH v2] perf probe: Fix add event failed when 32-bit perf running in 64-bit kernel | From | Yang Jihong <> | Date | Thu, 15 Jul 2021 19:40:57 +0800 |
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Hello Hiramatsu,
On 2021/7/15 17:05, Masami Hiramatsu wrote: > On Thu, 15 Jul 2021 14:37:23 +0800 > Yang Jihong <yangjihong1@huawei.com> wrote: > >> The "address" member of "struct probe_trace_point" uses long data type. >> If kernel is 64-bit and perf program is 32-bit, size of "address" variable is >> 32 bits. As a result, upper 32 bits of address read from kernel are truncated, >> An error occurs during address comparison in kprobe_warn_out_range function. >> >> Before: >> >> # perf probe -a schedule >> schedule is out of .text, skip it. >> Error: Failed to add events. >> >> Solution: >> Change data type of "address" variable to u64 and change corresponding >> address printing and value assignment. >> >> After: >> >> # perf.new.new probe -a schedule >> Added new event: >> probe:schedule (on schedule) >> >> You can now use it in all perf tools, such as: >> >> perf record -e probe:schedule -aR sleep 1 >> >> # perf probe -l >> probe:schedule (on schedule@kernel/sched/core.c) >> # perf record -e probe:schedule -aR sleep 1 >> [ perf record: Woken up 1 times to write data ] >> [ perf record: Captured and wrote 0.156 MB perf.data (1366 samples) ] >> # perf report --stdio >> # To display the perf.data header info, please use --header/--header-only options. >> # >> # >> # Total Lost Samples: 0 >> # >> # Samples: 1K of event 'probe:schedule' >> # Event count (approx.): 1366 >> # >> # Overhead Command Shared Object Symbol >> # ........ ............... ................. ............ >> # >> 6.22% migration/0 [kernel.kallsyms] [k] schedule >> 6.22% migration/1 [kernel.kallsyms] [k] schedule >> 6.22% migration/2 [kernel.kallsyms] [k] schedule >> 6.22% migration/3 [kernel.kallsyms] [k] schedule >> 6.15% migration/10 [kernel.kallsyms] [k] schedule >> 6.15% migration/11 [kernel.kallsyms] [k] schedule >> 6.15% migration/12 [kernel.kallsyms] [k] schedule >> 6.15% migration/13 [kernel.kallsyms] [k] schedule >> 6.15% migration/14 [kernel.kallsyms] [k] schedule >> 6.15% migration/15 [kernel.kallsyms] [k] schedule >> 6.15% migration/4 [kernel.kallsyms] [k] schedule >> 6.15% migration/5 [kernel.kallsyms] [k] schedule >> 6.15% migration/6 [kernel.kallsyms] [k] schedule >> 6.15% migration/7 [kernel.kallsyms] [k] schedule >> 6.15% migration/8 [kernel.kallsyms] [k] schedule >> 6.15% migration/9 [kernel.kallsyms] [k] schedule >> 0.22% rcu_sched [kernel.kallsyms] [k] schedule >> ... >> # >> # (Cannot load tips.txt file, please install perf!) >> # >> > > OK, this looks good to me :) > > Acked-by: Masami Hiramatsu <mhiramat@kernel.org> > Thanks for the Acked :)
Jihong
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