6.15-stable review patch. If anyone has any objections, please let me know.
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From: Tomas Glozar tglozar@redhat.com
[ Upstream commit 8020361d51eea5145402e450d91b083bccdcd874 ]
Newer versions of glibc include a definition of struct sched_attr in bits/sched.h (included through sched.h which is included by rtla). Commit 0eecee340672 ("tools/rtla: fix collision with glibc sched_attr/sched_set_attr") has modified the definition of struct sched_attr in utils.h, so that it is only applied with older versions of glibc that do not define it, in order to prevent build failure.
The definition in bits/sched.h depends on _GNU_SOURCE. timerlat_bpf.c does not define _GNU_SOURCE, making it fall back to the definition in utils.h. The latter has two fields less, leading to shifted offsets of struct timerlat_params in timerlat_bpf_init.
Because of the shift, timerlat_bpf_init incorrectly reads params->entries as 0 for timerlat-hist and disables the creation of histogram maps, causing breakage in BPF sample collection mode:
$ rtla timerlat hist -d 1s Error pulling BPF data
Fix the issue by also defining _GNU_SOURCE in timerlat_bpf.c.
Cc: John Kacur jkacur@redhat.com Cc: Luis Goncalves lgoncalv@redhat.com Link: https://lore.kernel.org/20250430144651.621766-1-tglozar@redhat.com Fixes: e34293ddcebd ("rtla/timerlat: Add BPF skeleton to collect samples") Signed-off-by: Tomas Glozar tglozar@redhat.com Signed-off-by: Steven Rostedt (Google) rostedt@goodmis.org Signed-off-by: Sasha Levin sashal@kernel.org --- tools/tracing/rtla/src/timerlat_bpf.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/tools/tracing/rtla/src/timerlat_bpf.c b/tools/tracing/rtla/src/timerlat_bpf.c index 5abee884037ae..0bc44ce5d69bd 100644 --- a/tools/tracing/rtla/src/timerlat_bpf.c +++ b/tools/tracing/rtla/src/timerlat_bpf.c @@ -1,5 +1,6 @@ // SPDX-License-Identifier: GPL-2.0 #ifdef HAVE_BPF_SKEL +#define _GNU_SOURCE #include "timerlat.h" #include "timerlat_bpf.h" #include "timerlat.skel.h"