Try use new API to create [k,u]probe with perf_event_open #1518
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[buildbot, ok to test] |
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src/cc/libbpf.c
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| char buf[64]; | ||
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| snprintf(buf, sizeof(buf), PMU_TYPE_FILE, event_type); | ||
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Do you need to check the return value of snprintf? Is it possible that it may fail in the future?
src/cc/libbpf.c
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| int ret; | ||
| char buf[64]; | ||
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| snprintf(buf, sizeof(buf), PMU_RETPROBE_FILE, event_type); |
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The same here, check snprintf return status?
src/cc/libbpf.c
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| struct perf_reader *reader, int pid, | ||
| int pfd) | ||
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| int efd, cpu = 0; | ||
| ssize_t bytes; | ||
| char buf[256]; |
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Not related to your patch, but for long file path, the buffer size may not be enough. Could you help change it to PATH_MAX?
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Teng just fixed it :)
| goto error; | ||
| } | ||
| res = snprintf(event_alias, sizeof(event_alias), "%s_bcc_%d", ev_name, getpid()); | ||
| if (res < 0 || res >= sizeof(event_alias)) { |
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Not sure what these solid green block is? Is this due to using TAB? In bcc non-kernel code, we use spaces instead of TABs.
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This is because we moved many lines into if (pfd < 0). Diff broke it into several sections, but it is just adding 2 more spaces for the whole chunk (
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Please rebase on top of trunk as there is a conflict for ready-to-merge. |
The new [k,u]probe API allows creating [k,u]probe together with perf_event_open. This patch adds functions to use the new API. Note: these new functions are not used until next patch, so this patch doesn't change the behavior. The change is splitted into two patches for cleaner review. Signed-off-by: Song Liu <[email protected]>
New kernel API allows creating [k,u]probe with perf_event_open. This patch tries to use the new API. If the new API doesn't work, we fall back to old API. bpf_detach_probe() looks up the event being removed. If the event is not found, we skip the clean up procedure. Signed-off-by: Song Liu <[email protected]>
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New kernel API allows creating [k,u]probe with perf_event_open.
This patch tries to use the new API. If the new API doesn't work,
we fall back to old API.
The kernel part of this work is available for test at:
git:https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git perf/core
Thanks,
Song