* [PATCH v2 0/2] perf: Fix bpf prologue generation, uaccess @ 2020-06-09 8:10 Sumanth Korikkar 2020-06-09 8:10 ` [PATCH v2 1/2] perf: Fix user attribute access in kprobes Sumanth Korikkar 2020-06-09 8:10 ` [PATCH v2 2/2] perf: Fix bpf prologue generation Sumanth Korikkar 0 siblings, 2 replies; 6+ messages in thread From: Sumanth Korikkar @ 2020-06-09 8:10 UTC (permalink / raw) To: linux-perf-users, acme Cc: bpf, jolsa, tmricht, heiko.carstens, mhiramat, iii, Sumanth Korikkar Patches: 1. Fix bpf prologue generation. bpf_probe_read is unavailable for arch with overlapping address space. If uaccess, use bpf_probe_read_user. Otherwise, use bpf_probe_read_kernel. 2. Fix uaccess in kprobes. Now perf probe add with @user attribute works v1->v2: - Split the patches and add Acked-By Thank you. Sumanth Korikkar (2): perf: Fix user attribute access in kprobes perf: Fix bpf prologue generation tools/perf/util/bpf-prologue.c | 14 ++++++++++---- tools/perf/util/probe-event.c | 7 +++++-- tools/perf/util/probe-file.c | 2 +- 3 files changed, 16 insertions(+), 7 deletions(-) -- 2.17.1 ^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH v2 1/2] perf: Fix user attribute access in kprobes 2020-06-09 8:10 [PATCH v2 0/2] perf: Fix bpf prologue generation, uaccess Sumanth Korikkar @ 2020-06-09 8:10 ` Sumanth Korikkar 2020-06-09 15:09 ` Arnaldo Carvalho de Melo 2020-06-09 8:10 ` [PATCH v2 2/2] perf: Fix bpf prologue generation Sumanth Korikkar 1 sibling, 1 reply; 6+ messages in thread From: Sumanth Korikkar @ 2020-06-09 8:10 UTC (permalink / raw) To: linux-perf-users, acme Cc: bpf, jolsa, tmricht, heiko.carstens, mhiramat, iii, Sumanth Korikkar Issue: perf probe -a 'do_sched_setscheduler pid policy param->sched_priority@user' did not work before. Fix: Make (perf probe -a 'do_sched_setscheduler pid policy param->sched_priority@user') output equivalent to ftrace ('p:probe/do_sched_setscheduler _text+517384 pid=%r2:s32 policy=%r3:s32 sched_priority=+u0(%r4):s32' > kprobe_events) Other: 1. Right now, __match_glob() does not handle [u]<offset>. For now, use *u]<offset>. 2. @user attribute was introduced in commit 1e032f7cfa14 ("perf-probe: Add user memory access attribute support") Test: 1. perf probe -a 'do_sched_setscheduler pid policy param->sched_priority@user' 2 ./perf script sched 305669 [000] 1614458.838675: perf_bpf_probe:func: (2904e508) pid=261614 policy=2 sched_priority=1 3. cat /sys/kernel/debug/tracing/trace <...>-309956 [006] .... 1616098.093957: 0: prio: 1 Signed-off-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Reviewed-by: Thomas Richter <tmricht@linux.ibm.com> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> --- tools/perf/util/probe-event.c | 7 +++++-- tools/perf/util/probe-file.c | 2 +- 2 files changed, 6 insertions(+), 3 deletions(-) diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c index a08f373d3305..df713a5d1e26 100644 --- a/tools/perf/util/probe-event.c +++ b/tools/perf/util/probe-event.c @@ -1575,7 +1575,7 @@ static int parse_perf_probe_arg(char *str, struct perf_probe_arg *arg) } tmp = strchr(str, '@'); - if (tmp && tmp != str && strcmp(tmp + 1, "user")) { /* user attr */ + if (tmp && tmp != str && !strcmp(tmp + 1, "user")) { /* user attr */ if (!user_access_is_supported()) { semantic_error("ftrace does not support user access\n"); return -EINVAL; @@ -1995,7 +1995,10 @@ static int __synthesize_probe_trace_arg_ref(struct probe_trace_arg_ref *ref, if (depth < 0) return depth; } - err = strbuf_addf(buf, "%+ld(", ref->offset); + if (ref->user_access) + err = strbuf_addf(buf, "%s%ld(", "+u", ref->offset); + else + err = strbuf_addf(buf, "%+ld(", ref->offset); return (err < 0) ? err : depth; } diff --git a/tools/perf/util/probe-file.c b/tools/perf/util/probe-file.c index 8c852948513e..064b63a6a3f3 100644 --- a/tools/perf/util/probe-file.c +++ b/tools/perf/util/probe-file.c @@ -1044,7 +1044,7 @@ static struct { DEFINE_TYPE(FTRACE_README_PROBE_TYPE_X, "*type: * x8/16/32/64,*"), DEFINE_TYPE(FTRACE_README_KRETPROBE_OFFSET, "*place (kretprobe): *"), DEFINE_TYPE(FTRACE_README_UPROBE_REF_CTR, "*ref_ctr_offset*"), - DEFINE_TYPE(FTRACE_README_USER_ACCESS, "*[u]<offset>*"), + DEFINE_TYPE(FTRACE_README_USER_ACCESS, "*u]<offset>*"), DEFINE_TYPE(FTRACE_README_MULTIPROBE_EVENT, "*Create/append/*"), DEFINE_TYPE(FTRACE_README_IMMEDIATE_VALUE, "*\\imm-value,*"), }; -- 2.17.1 ^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH v2 1/2] perf: Fix user attribute access in kprobes 2020-06-09 8:10 ` [PATCH v2 1/2] perf: Fix user attribute access in kprobes Sumanth Korikkar @ 2020-06-09 15:09 ` Arnaldo Carvalho de Melo 2020-06-09 15:13 ` Arnaldo Carvalho de Melo 0 siblings, 1 reply; 6+ messages in thread From: Arnaldo Carvalho de Melo @ 2020-06-09 15:09 UTC (permalink / raw) To: Sumanth Korikkar Cc: Steven Rostedt, linux-perf-users, bpf, jolsa, tmricht, heiko.carstens, mhiramat, iii Em Tue, Jun 09, 2020 at 10:10:18AM +0200, Sumanth Korikkar escreveu: > Issue: > perf probe -a 'do_sched_setscheduler pid policy > param->sched_priority@user' did not work before. > > Fix: > Make (perf probe -a 'do_sched_setscheduler pid policy > param->sched_priority@user') output equivalent to ftrace > ('p:probe/do_sched_setscheduler _text+517384 pid=%r2:s32 policy=%r3:s32 > sched_priority=+u0(%r4):s32' > kprobe_events) > > Other: > 1. Right now, __match_glob() does not handle [u]<offset>. For now, use > *u]<offset>. > 2. @user attribute was introduced in commit 1e032f7cfa14 ("perf-probe: > Add user memory access attribute support") > > Test: > 1. perf probe -a 'do_sched_setscheduler pid policy > param->sched_priority@user' > > 2 ./perf script > sched 305669 [000] 1614458.838675: perf_bpf_probe:func: (2904e508) > pid=261614 policy=2 sched_priority=1 > > 3. cat /sys/kernel/debug/tracing/trace > <...>-309956 [006] .... 1616098.093957: 0: prio: 1 Thanks, I'm adding this: Fixes: 1e032f7cfa14 ("perf-probe: Add user memory access attribute support") Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> So that the stable guys pick this up eventually, That first hunk with the strcmp() return check could have gone into a separate patch, but I'll process it as-is for expediency, - Arnaldo > Signed-off-by: Sumanth Korikkar <sumanthk@linux.ibm.com> > Reviewed-by: Thomas Richter <tmricht@linux.ibm.com> > Acked-by: Masami Hiramatsu <mhiramat@kernel.org> > --- > tools/perf/util/probe-event.c | 7 +++++-- > tools/perf/util/probe-file.c | 2 +- > 2 files changed, 6 insertions(+), 3 deletions(-) > > diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c > index a08f373d3305..df713a5d1e26 100644 > --- a/tools/perf/util/probe-event.c > +++ b/tools/perf/util/probe-event.c > @@ -1575,7 +1575,7 @@ static int parse_perf_probe_arg(char *str, struct perf_probe_arg *arg) > } > > tmp = strchr(str, '@'); > - if (tmp && tmp != str && strcmp(tmp + 1, "user")) { /* user attr */ > + if (tmp && tmp != str && !strcmp(tmp + 1, "user")) { /* user attr */ > if (!user_access_is_supported()) { > semantic_error("ftrace does not support user access\n"); > return -EINVAL; > @@ -1995,7 +1995,10 @@ static int __synthesize_probe_trace_arg_ref(struct probe_trace_arg_ref *ref, > if (depth < 0) > return depth; > } > - err = strbuf_addf(buf, "%+ld(", ref->offset); > + if (ref->user_access) > + err = strbuf_addf(buf, "%s%ld(", "+u", ref->offset); > + else > + err = strbuf_addf(buf, "%+ld(", ref->offset); > return (err < 0) ? err : depth; > } > > diff --git a/tools/perf/util/probe-file.c b/tools/perf/util/probe-file.c > index 8c852948513e..064b63a6a3f3 100644 > --- a/tools/perf/util/probe-file.c > +++ b/tools/perf/util/probe-file.c > @@ -1044,7 +1044,7 @@ static struct { > DEFINE_TYPE(FTRACE_README_PROBE_TYPE_X, "*type: * x8/16/32/64,*"), > DEFINE_TYPE(FTRACE_README_KRETPROBE_OFFSET, "*place (kretprobe): *"), > DEFINE_TYPE(FTRACE_README_UPROBE_REF_CTR, "*ref_ctr_offset*"), > - DEFINE_TYPE(FTRACE_README_USER_ACCESS, "*[u]<offset>*"), > + DEFINE_TYPE(FTRACE_README_USER_ACCESS, "*u]<offset>*"), > DEFINE_TYPE(FTRACE_README_MULTIPROBE_EVENT, "*Create/append/*"), > DEFINE_TYPE(FTRACE_README_IMMEDIATE_VALUE, "*\\imm-value,*"), > }; > -- > 2.17.1 > -- - Arnaldo ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v2 1/2] perf: Fix user attribute access in kprobes 2020-06-09 15:09 ` Arnaldo Carvalho de Melo @ 2020-06-09 15:13 ` Arnaldo Carvalho de Melo 0 siblings, 0 replies; 6+ messages in thread From: Arnaldo Carvalho de Melo @ 2020-06-09 15:13 UTC (permalink / raw) To: Sumanth Korikkar Cc: Steven Rostedt, linux-perf-users, bpf, jolsa, tmricht, heiko.carstens, mhiramat, iii, Linux Kernel Mailing List Em Tue, Jun 09, 2020 at 12:09:31PM -0300, Arnaldo Carvalho de Melo escreveu: > Em Tue, Jun 09, 2020 at 10:10:18AM +0200, Sumanth Korikkar escreveu: > > Issue: > > perf probe -a 'do_sched_setscheduler pid policy > > param->sched_priority@user' did not work before. > > > > Fix: > > Make (perf probe -a 'do_sched_setscheduler pid policy > > param->sched_priority@user') output equivalent to ftrace > > ('p:probe/do_sched_setscheduler _text+517384 pid=%r2:s32 policy=%r3:s32 > > sched_priority=+u0(%r4):s32' > kprobe_events) > > > > Other: > > 1. Right now, __match_glob() does not handle [u]<offset>. For now, use > > *u]<offset>. > > 2. @user attribute was introduced in commit 1e032f7cfa14 ("perf-probe: > > Add user memory access attribute support") > > > > Test: > > 1. perf probe -a 'do_sched_setscheduler pid policy > > param->sched_priority@user' > > > > 2 ./perf script > > sched 305669 [000] 1614458.838675: perf_bpf_probe:func: (2904e508) > > pid=261614 policy=2 sched_priority=1 > > > > 3. cat /sys/kernel/debug/tracing/trace > > <...>-309956 [006] .... 1616098.093957: 0: prio: 1 > > Thanks, I'm adding this: > > Fixes: 1e032f7cfa14 ("perf-probe: Add user memory access attribute support") > Cc: Masami Hiramatsu <mhiramat@kernel.org> > Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> > > So that the stable guys pick this up eventually, > > That first hunk with the strcmp() return check could have gone into a > separate patch, but I'll process it as-is for expediency, I also added this: ommitter testing: Before: # perf probe -a 'do_sched_setscheduler pid policy param->sched_priority@user' param(type:sched_param) has no member sched_priority@user. Error: Failed to add events. # pahole sched_param struct sched_param { int sched_priority; /* 0 4 */ /* size: 4, cachelines: 1, members: 1 */ /* last cacheline: 4 bytes */ }; # After: # perf probe -a 'do_sched_setscheduler pid policy param->sched_priority@user' Added new event: probe:do_sched_setscheduler (on do_sched_setscheduler with pid policy sched_priority=param->sched_priority) You can now use it in all perf tools, such as: perf record -e probe:do_sched_setscheduler -aR sleep 1 # cat /sys/kernel/debug/tracing/kprobe_events p:probe/do_sched_setscheduler _text+1113792 pid=%di:s32 policy=%si:s32 sched_priority=+u0(%dx):s32 # > - Arnaldo > > > Signed-off-by: Sumanth Korikkar <sumanthk@linux.ibm.com> > > Reviewed-by: Thomas Richter <tmricht@linux.ibm.com> > > Acked-by: Masami Hiramatsu <mhiramat@kernel.org> > > --- > > tools/perf/util/probe-event.c | 7 +++++-- > > tools/perf/util/probe-file.c | 2 +- > > 2 files changed, 6 insertions(+), 3 deletions(-) > > > > diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c > > index a08f373d3305..df713a5d1e26 100644 > > --- a/tools/perf/util/probe-event.c > > +++ b/tools/perf/util/probe-event.c > > @@ -1575,7 +1575,7 @@ static int parse_perf_probe_arg(char *str, struct perf_probe_arg *arg) > > } > > > > tmp = strchr(str, '@'); > > - if (tmp && tmp != str && strcmp(tmp + 1, "user")) { /* user attr */ > > + if (tmp && tmp != str && !strcmp(tmp + 1, "user")) { /* user attr */ > > if (!user_access_is_supported()) { > > semantic_error("ftrace does not support user access\n"); > > return -EINVAL; > > @@ -1995,7 +1995,10 @@ static int __synthesize_probe_trace_arg_ref(struct probe_trace_arg_ref *ref, > > if (depth < 0) > > return depth; > > } > > - err = strbuf_addf(buf, "%+ld(", ref->offset); > > + if (ref->user_access) > > + err = strbuf_addf(buf, "%s%ld(", "+u", ref->offset); > > + else > > + err = strbuf_addf(buf, "%+ld(", ref->offset); > > return (err < 0) ? err : depth; > > } > > > > diff --git a/tools/perf/util/probe-file.c b/tools/perf/util/probe-file.c > > index 8c852948513e..064b63a6a3f3 100644 > > --- a/tools/perf/util/probe-file.c > > +++ b/tools/perf/util/probe-file.c > > @@ -1044,7 +1044,7 @@ static struct { > > DEFINE_TYPE(FTRACE_README_PROBE_TYPE_X, "*type: * x8/16/32/64,*"), > > DEFINE_TYPE(FTRACE_README_KRETPROBE_OFFSET, "*place (kretprobe): *"), > > DEFINE_TYPE(FTRACE_README_UPROBE_REF_CTR, "*ref_ctr_offset*"), > > - DEFINE_TYPE(FTRACE_README_USER_ACCESS, "*[u]<offset>*"), > > + DEFINE_TYPE(FTRACE_README_USER_ACCESS, "*u]<offset>*"), > > DEFINE_TYPE(FTRACE_README_MULTIPROBE_EVENT, "*Create/append/*"), > > DEFINE_TYPE(FTRACE_README_IMMEDIATE_VALUE, "*\\imm-value,*"), > > }; > > -- > > 2.17.1 > > > > -- > > - Arnaldo -- - Arnaldo ^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH v2 2/2] perf: Fix bpf prologue generation 2020-06-09 8:10 [PATCH v2 0/2] perf: Fix bpf prologue generation, uaccess Sumanth Korikkar 2020-06-09 8:10 ` [PATCH v2 1/2] perf: Fix user attribute access in kprobes Sumanth Korikkar @ 2020-06-09 8:10 ` Sumanth Korikkar 2020-06-09 15:27 ` Arnaldo Carvalho de Melo 1 sibling, 1 reply; 6+ messages in thread From: Sumanth Korikkar @ 2020-06-09 8:10 UTC (permalink / raw) To: linux-perf-users, acme Cc: bpf, jolsa, tmricht, heiko.carstens, mhiramat, iii, Sumanth Korikkar Issue: bpf_probe_read is no longer available for architecture which has overlapping address space. Hence bpf prologue generation fails Fix: Use bpf_probe_read_kernel for kernel member access. For user attribute access in kprobes, use bpf_probe_read_user. Other: @user attribute was introduced in commit 1e032f7cfa14 ("perf-probe: Add user memory access attribute support") Test: 1. ulimit -l 128 ; ./perf record -e tests/bpf_sched_setscheduler.c 2. cat tests/bpf_sched_setscheduler.c static void (*bpf_trace_printk)(const char *fmt, int fmt_size, ...) = (void *) 6; static int (*bpf_probe_read_user)(void *dst, __u32 size, const void *unsafe_ptr) = (void *) 112; static int (*bpf_probe_read_kernel)(void *dst, __u32 size, const void *unsafe_ptr) = (void *) 113; SEC("func=do_sched_setscheduler pid policy param->sched_priority@user") int bpf_func__setscheduler(void *ctx, int err, pid_t pid, int policy, int param) { char fmt[] = "prio: %ld"; bpf_trace_printk(fmt, sizeof(fmt), param); return 1; } char _license[] SEC("license") = "GPL"; int _version SEC("version") = LINUX_VERSION_CODE; 3. ./perf script sched 305669 [000] 1614458.838675: perf_bpf_probe:func: (2904e508) pid=261614 policy=2 sched_priority=1 4. cat /sys/kernel/debug/tracing/trace <...>-309956 [006] .... 1616098.093957: 0: prio: 1 Signed-off-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Reviewed-by: Thomas Richter <tmricht@linux.ibm.com> --- tools/perf/util/bpf-prologue.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/tools/perf/util/bpf-prologue.c b/tools/perf/util/bpf-prologue.c index b020a8678eb9..9887ae09242d 100644 --- a/tools/perf/util/bpf-prologue.c +++ b/tools/perf/util/bpf-prologue.c @@ -142,7 +142,8 @@ static int gen_read_mem(struct bpf_insn_pos *pos, int src_base_addr_reg, int dst_addr_reg, - long offset) + long offset, + int probeid) { /* mov arg3, src_base_addr_reg */ if (src_base_addr_reg != BPF_REG_ARG3) @@ -159,7 +160,7 @@ gen_read_mem(struct bpf_insn_pos *pos, ins(BPF_MOV64_REG(BPF_REG_ARG1, dst_addr_reg), pos); /* Call probe_read */ - ins(BPF_EMIT_CALL(BPF_FUNC_probe_read), pos); + ins(BPF_EMIT_CALL(probeid), pos); /* * Error processing: if read fail, goto error code, * will be relocated. Target should be the start of @@ -241,7 +242,7 @@ static int gen_prologue_slowpath(struct bpf_insn_pos *pos, struct probe_trace_arg *args, int nargs) { - int err, i; + int err, i, probeid; for (i = 0; i < nargs; i++) { struct probe_trace_arg *arg = &args[i]; @@ -276,11 +277,16 @@ gen_prologue_slowpath(struct bpf_insn_pos *pos, stack_offset), pos); ref = arg->ref; + probeid = BPF_FUNC_probe_read_kernel; while (ref) { pr_debug("prologue: arg %d: offset %ld\n", i, ref->offset); + + if (ref->user_access) + probeid = BPF_FUNC_probe_read_user; + err = gen_read_mem(pos, BPF_REG_3, BPF_REG_7, - ref->offset); + ref->offset, probeid); if (err) { pr_err("prologue: failed to generate probe_read function call\n"); goto errout; -- 2.17.1 ^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH v2 2/2] perf: Fix bpf prologue generation 2020-06-09 8:10 ` [PATCH v2 2/2] perf: Fix bpf prologue generation Sumanth Korikkar @ 2020-06-09 15:27 ` Arnaldo Carvalho de Melo 0 siblings, 0 replies; 6+ messages in thread From: Arnaldo Carvalho de Melo @ 2020-06-09 15:27 UTC (permalink / raw) To: Sumanth Korikkar Cc: linux-perf-users, bpf, Jiri Olsa, tmricht, heiko.carstens, mhiramat, iii, Steven Rostedt, Namhyung Kim, Wang Nan, Linux Kernel Mailing List Em Tue, Jun 09, 2020 at 10:10:19AM +0200, Sumanth Korikkar escreveu: > Issue: > bpf_probe_read is no longer available for architecture which has > overlapping address space. Hence bpf prologue generation fails > > Fix: > Use bpf_probe_read_kernel for kernel member access. For user > attribute access in kprobes, use bpf_probe_read_user. > > Other: > @user attribute was introduced in commit 1e032f7cfa14 ("perf-probe: > Add user memory access attribute support") > > Test: > 1. ulimit -l 128 ; ./perf record -e tests/bpf_sched_setscheduler.c > 2. cat tests/bpf_sched_setscheduler.c > > static void (*bpf_trace_printk)(const char *fmt, int fmt_size, ...) = > (void *) 6; > static int (*bpf_probe_read_user)(void *dst, __u32 size, > const void *unsafe_ptr) = (void *) 112; > static int (*bpf_probe_read_kernel)(void *dst, __u32 size, > const void *unsafe_ptr) = (void *) 113; > > SEC("func=do_sched_setscheduler pid policy param->sched_priority@user") > int bpf_func__setscheduler(void *ctx, int err, pid_t pid, int policy, > int param) > { > char fmt[] = "prio: %ld"; > bpf_trace_printk(fmt, sizeof(fmt), param); > return 1; > } > > char _license[] SEC("license") = "GPL"; > int _version SEC("version") = LINUX_VERSION_CODE; > > 3. ./perf script > sched 305669 [000] 1614458.838675: perf_bpf_probe:func: (2904e508) > pid=261614 policy=2 sched_priority=1 > > 4. cat /sys/kernel/debug/tracing/trace > <...>-309956 [006] .... 1616098.093957: 0: prio: 1 Thanks for providing a detailed set of steps to test your patch, that is great! I added this, an alterenative way to test it, combining all the aspects in one 'perf trace' call: Committer testing: I had to add some missing headers in the bpf_sched_setscheduler.c test proggie, then instead of using record+script I used 'perf trace' to drive everything in one go: # cat bpf_sched_setscheduler.c #include <linux/types.h> #include <bpf.h> static void (*bpf_trace_printk)(const char *fmt, int fmt_size, ...) = (void *) 6; static int (*bpf_probe_read_user)(void *dst, __u32 size, const void *unsafe_ptr) = (void *) 112; static int (*bpf_probe_read_kernel)(void *dst, __u32 size, const void *unsafe_ptr) = (void *) 113; SEC("func=do_sched_setscheduler pid policy param->sched_priority@user") int bpf_func__setscheduler(void *ctx, int err, pid_t pid, int policy, int param) { char fmt[] = "prio: %ld"; bpf_trace_printk(fmt, sizeof(fmt), param); return 1; } char _license[] SEC("license") = "GPL"; int _version SEC("version") = LINUX_VERSION_CODE; # # # perf trace -e bpf_sched_setscheduler.c chrt -f 42 sleep 1 0.000 chrt/80125 perf_bpf_probe:func(__probe_ip: -1676607808, policy: 1, sched_priority: 42) # And even with backtraces :-) # perf trace -e bpf_sched_setscheduler.c/max-stack=8/ chrt -f 42 sleep 1 0.000 chrt/79805 perf_bpf_probe:func(__probe_ip: -1676607808, policy: 1, sched_priority: 42) do_sched_setscheduler ([kernel.kallsyms]) __x64_sys_sched_setscheduler ([kernel.kallsyms]) do_syscall_64 ([kernel.kallsyms]) entry_SYSCALL_64 ([kernel.kallsyms]) __GI___sched_setscheduler (/usr/lib64/libc-2.30.so) # - Arnaldo ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2020-06-09 15:27 UTC | newest] Thread overview: 6+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2020-06-09 8:10 [PATCH v2 0/2] perf: Fix bpf prologue generation, uaccess Sumanth Korikkar 2020-06-09 8:10 ` [PATCH v2 1/2] perf: Fix user attribute access in kprobes Sumanth Korikkar 2020-06-09 15:09 ` Arnaldo Carvalho de Melo 2020-06-09 15:13 ` Arnaldo Carvalho de Melo 2020-06-09 8:10 ` [PATCH v2 2/2] perf: Fix bpf prologue generation Sumanth Korikkar 2020-06-09 15:27 ` Arnaldo Carvalho de Melo
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