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2022-11-04perf bpf: Remove now unused BPF headersIan Rogers6-146/+0
Example code has migrated to use standard BPF header files, remove unnecessary perf equivalents. Update install step to not try to copy these. Signed-off-by: Ian Rogers <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Leo Yan <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Stephane Eranian <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2022-11-04perf trace: 5sec fix libbpf 1.0+ compatibilityIan Rogers1-3/+5
Avoid use of tools/perf/include/bpf/bpf.h and use the more regular BPF headers. Committer testing: # perf trace -e ~acme/git/perf/tools/perf/examples/bpf/5sec.c sleep 5 0.000 perf_bpf_probe:hrtimer_nanosleep(__probe_ip: -1474734416, rqtp: 5000000000) # perf trace -e ~acme/git/perf/tools/perf/examples/bpf/5sec.c/max-stack=7/ sleep 5 0.000 perf_bpf_probe:hrtimer_nanosleep(__probe_ip: -1474734416, rqtp: 5000000000) hrtimer_nanosleep ([kernel.kallsyms]) common_nsleep ([kernel.kallsyms]) __x64_sys_clock_nanosleep ([kernel.kallsyms]) do_syscall_64 ([kernel.kallsyms]) entry_SYSCALL_64_after_hwframe ([kernel.kallsyms]) __GI___clock_nanosleep (/usr/lib64/libc.so.6) [0] ([unknown]) # Signed-off-by: Ian Rogers <[email protected]> Tested-by: Arnaldo Carvalho de Melo <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Leo Yan <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Stephane Eranian <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2022-11-04perf trace: empty fix libbpf 1.0+ compatibilityIan Rogers1-2/+11
Avoid use of tools/perf/include/bpf/bpf.h and use the more regular BPF headers. Add raw_syscalls:sys_enter to avoid the evlist being empty. Committer testing: # time perf trace -e ~acme/git/perf/tools/perf/examples/bpf/empty.c sleep 5 real 0m5.697s user 0m0.217s sys 0m0.453s # I.e. it sets up everything successfully (use -v to see the details) and filters out all syscalls, then exits when the workload (sleep 5) finishes. Signed-off-by: Ian Rogers <[email protected]> Tested-by: Arnaldo Carvalho de Melo <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Leo Yan <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Stephane Eranian <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2022-11-04perf trace: hello fix libbpf 1.0+ compatibilityIan Rogers1-3/+21
Don't use deprecated and now broken map style. Avoid use of tools/perf/include/bpf/bpf.h and use the more regular BPF headers. Switch to raw_syscalls:sys_enter to avoid the evlist being empty and fixing generating output. Committer testing: # perf trace -e ~acme/git/perf/tools/perf/examples/bpf/hello.c --call-graph=dwarf --max-events 5 0.000 perf/206852 __bpf_stdout__(Hello, world) syscall_trace_enter.constprop.0 ([kernel.kallsyms]) syscall_trace_enter.constprop.0 ([kernel.kallsyms]) do_syscall_64 ([kernel.kallsyms]) entry_SYSCALL_64_after_hwframe ([kernel.kallsyms]) __GI___sched_setaffinity_new (/usr/lib64/libc.so.6) 8.561 pipewire/2290 __bpf_stdout__(Hello, world) syscall_trace_enter.constprop.0 ([kernel.kallsyms]) syscall_trace_enter.constprop.0 ([kernel.kallsyms]) do_syscall_64 ([kernel.kallsyms]) entry_SYSCALL_64_after_hwframe ([kernel.kallsyms]) __libc_read (/usr/lib64/libc.so.6) 8.571 pipewire/2290 __bpf_stdout__(Hello, world) syscall_trace_enter.constprop.0 ([kernel.kallsyms]) syscall_trace_enter.constprop.0 ([kernel.kallsyms]) do_syscall_64 ([kernel.kallsyms]) entry_SYSCALL_64_after_hwframe ([kernel.kallsyms]) __GI___ioctl (/usr/lib64/libc.so.6) 8.586 pipewire/2290 __bpf_stdout__(Hello, world) syscall_trace_enter.constprop.0 ([kernel.kallsyms]) syscall_trace_enter.constprop.0 ([kernel.kallsyms]) do_syscall_64 ([kernel.kallsyms]) entry_SYSCALL_64_after_hwframe ([kernel.kallsyms]) __GI___write (/usr/lib64/libc.so.6) 8.592 pipewire/2290 __bpf_stdout__(Hello, world) syscall_trace_enter.constprop.0 ([kernel.kallsyms]) syscall_trace_enter.constprop.0 ([kernel.kallsyms]) do_syscall_64 ([kernel.kallsyms]) entry_SYSCALL_64_after_hwframe ([kernel.kallsyms]) __timerfd_settime (/usr/lib64/libc.so.6) # Signed-off-by: Ian Rogers <[email protected]> Tested-by: Arnaldo Carvalho de Melo <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Leo Yan <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Stephane Eranian <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2022-11-04perf trace: Raw augmented syscalls fix libbpf 1.0+ compatibilityIan Rogers3-19/+89
Don't use deprecated and now broken map style. Avoid use of tools/perf/include/bpf/bpf.h and use the more regular BPF headers. Committer notes: Add /usr/include to the include path so that bpf/bpf_helpers.h can be found, remove sys/socket.h, adding the sockaddr_storage definition, also remove stdbool.h, both were preventing building the augmented_raw_syscalls.c file with clang, revisit later. Testing it: Asking for syscalls that have string arguments: # perf trace -e ~acme/git/perf/tools/perf/examples/bpf/augmented_raw_syscalls.c,string --max-events 10 0.000 thermald/1144 openat(dfd: CWD, filename: "/sys/class/powercap/intel-rapl/intel-rapl:0/intel-rapl:0:2/energy_uj", flags: RDONLY) = 13 0.158 thermald/1144 openat(dfd: CWD, filename: "/sys/class/powercap/intel-rapl/intel-rapl:0/energy_uj", flags: RDONLY) = 13 0.215 thermald/1144 openat(dfd: CWD, filename: "/sys/class/thermal/thermal_zone3/temp", flags: RDONLY) = 13 16.448 cgroupify/36478 openat(dfd: 4, filename: ".", flags: RDONLY|CLOEXEC|DIRECTORY|NONBLOCK) = 5 16.468 cgroupify/36478 newfstatat(dfd: 5, filename: "", statbuf: 0x7fffca5b4130, flag: 4096) = 0 16.473 systemd-oomd/972 openat(dfd: CWD, filename: "/proc/meminfo", flags: RDONLY|CLOEXEC) = 12 16.499 systemd-oomd/972 newfstatat(dfd: 12, filename: "", statbuf: 0x7ffd2bc73cc0, flag: 4096) = 0 16.516 abrt-dump-jour/1370 openat(dfd: CWD, filename: "/var/log/journal/d6a97235307247e09f13f326fb607e3c/system.journal", flags: RDONLY|CLOEXEC|NONBLOCK) = 21 16.538 abrt-dump-jour/1370 newfstatat(dfd: 21, filename: "", statbuf: 0x7ffc651b8980, flag: 4096) = 0 16.540 abrt-dump-jour/1371 openat(dfd: CWD, filename: "/var/log/journal/d6a97235307247e09f13f326fb607e3c/system.journal", flags: RDONLY|CLOEXEC|NONBLOCK) = 21 # Networking syscalls: # perf trace -e ~acme/git/perf/tools/perf/examples/bpf/augmented_raw_syscalls.c,sendto*,connect* --max-events 10 0.000 isc-net-0005/1206 connect(fd: 512, uservaddr: { .family: INET, port: 53, addr: 23.211.132.65 }, addrlen: 16) = 0 0.070 isc-net-0002/1203 connect(fd: 515, uservaddr: { .family: INET6, port: 53, addr: 2600:1401:2::43 }, addrlen: 28) = -1 ENETUNREACH (Network is unreachable) 0.031 isc-net-0006/1207 connect(fd: 513, uservaddr: { .family: INET6, port: 53, addr: 2600:1401:2::43 }, addrlen: 28) = -1 ENETUNREACH (Network is unreachable) 0.079 isc-net-0006/1207 sendto(fd: 3, buff: 0x7f73a40611b0, len: 106, flags: NOSIGNAL, addr: { .family: UNSPEC }, addr_len: NULL) = 106 0.180 isc-net-0006/1207 connect(fd: 519, uservaddr: { .family: INET6, port: 53, addr: 2600:1401:1::43 }, addrlen: 28) = -1 ENETUNREACH (Network is unreachable) 0.211 isc-net-0006/1207 sendto(fd: 3, buff: 0x7f73a4061230, len: 106, flags: NOSIGNAL, addr: { .family: UNSPEC }, addr_len: NULL) = 106 0.298 isc-net-0006/1207 connect(fd: 515, uservaddr: { .family: INET, port: 53, addr: 96.7.49.67 }, addrlen: 16) = 0 0.109 isc-net-0004/1205 connect(fd: 518, uservaddr: { .family: INET6, port: 53, addr: 2600:1401:2::43 }, addrlen: 28) = -1 ENETUNREACH (Network is unreachable) 0.164 isc-net-0002/1203 sendto(fd: 3, buff: 0x7f73ac064300, len: 107, flags: NOSIGNAL, addr: { .family: UNSPEC }, addr_len: NULL) = 107 0.247 isc-net-0002/1203 connect(fd: 522, uservaddr: { .family: INET6, port: 53, addr: 2600:1401:1::43 }, addrlen: 28) = -1 ENETUNREACH (Network is unreachable) # Signed-off-by: Ian Rogers <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Leo Yan <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Stephane Eranian <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2022-11-04selftests/net: give more time to udpgro bg processes to complete startupAdrien Thierry3-4/+4
In some conditions, background processes in udpgro don't have enough time to set up the sockets. When foreground processes start, this results in the test failing with "./udpgso_bench_tx: sendmsg: Connection refused". For instance, this happens from time to time on a Qualcomm SA8540P SoC running CentOS Stream 9. To fix this, increase the time given to background processes to complete the startup before foreground processes start. Signed-off-by: Adrien Thierry <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2022-11-03Merge tag 'for-netdev' of ↵Jakub Kicinski4-0/+87
https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf Daniel Borkmann says: ==================== bpf 2022-11-04 We've added 8 non-merge commits during the last 3 day(s) which contain a total of 10 files changed, 113 insertions(+), 16 deletions(-). The main changes are: 1) Fix memory leak upon allocation failure in BPF verifier's stack state tracking, from Kees Cook. 2) Fix address leakage when BPF progs release reference to an object, from Youlin Li. 3) Fix BPF CI breakage from buggy in.h uapi header dependency, from Andrii Nakryiko. 4) Fix bpftool pin sub-command's argument parsing, from Pu Lehui. 5) Fix BPF sockmap lockdep warning by cancelling psock work outside of socket lock, from Cong Wang. 6) Follow-up for BPF sockmap to fix sk_forward_alloc accounting, from Wang Yufen. bpf-for-netdev * tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf: selftests/bpf: Add verifier test for release_reference() bpf: Fix wrong reg type conversion in release_reference() bpf, sock_map: Move cancel_work_sync() out of sock lock tools/headers: Pull in stddef.h to uapi to fix BPF selftests build in CI net/ipv4: Fix linux/in.h header dependencies bpftool: Fix NULL pointer dereference when pin {PROG, MAP, LINK} without FILE bpf, sockmap: Fix the sk->sk_forward_alloc warning of sk_stream_kill_queues bpf, verifier: Fix memory leak in array reallocation for stack state ==================== Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Jakub Kicinski <[email protected]>
2022-11-04selftests/bpf: Add verifier test for release_reference()Youlin Li1-0/+36
Add a test case to ensure that released pointer registers will not be leaked into the map. Before fix: ./test_verifier 984 984/u reference tracking: try to leak released ptr reg FAIL Unexpected success to load! verification time 67 usec stack depth 4 processed 23 insns (limit 1000000) max_states_per_insn 0 total_states 2 peak_states 2 mark_read 1 984/p reference tracking: try to leak released ptr reg OK Summary: 1 PASSED, 0 SKIPPED, 1 FAILED After fix: ./test_verifier 984 984/u reference tracking: try to leak released ptr reg OK 984/p reference tracking: try to leak released ptr reg OK Summary: 2 PASSED, 0 SKIPPED, 0 FAILED Signed-off-by: Youlin Li <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2022-11-03Merge tag 'linux-kselftest-fixes-6.1-rc4' of ↵Linus Torvalds3-3/+15
git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest Pull Kselftest fixes from Shuah Khan: "Fixes to the pidfd test" * tag 'linux-kselftest-fixes-6.1-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest: selftests/pidfd_test: Remove the erroneous ',' selftests: pidfd: Fix compling warnings ksefltests: pidfd: Fix wait_states: Test terminated by timeout
2022-11-03perf trace: Use sig_atomic_t to avoid undefined behaviour in a signal handlerIan Rogers1-2/+2
Use sig_atomic_t for variables written/accessed in signal handlers. This is undefined behavior as per: https://wiki.sei.cmu.edu/confluence/display/c/SIG31-C.+Do+not+access+shared+objects+in+signal+handlers Signed-off-by: Ian Rogers <[email protected]> Cc: Adrian Hunter <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Alexey Bayduraev <[email protected]> Cc: German Gomez <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Leo Yan <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Stephane Eranian <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2022-11-03tools/headers: Pull in stddef.h to uapi to fix BPF selftests build in CIAndrii Nakryiko2-0/+48
With recent sync of linux/in.h tools/include headers are now relying on __DECLARE_FLEX_ARRAY macro, which isn't itself defined inside tools/include headers anywhere and is instead assumed to be present in system-wide UAPI header. This breaks isolated environments that don't have kernel UAPI headers installed system-wide, like BPF CI ([0]). To fix this, bring in include/uapi/linux/stddef.h into tools/include. We can't just copy/paste it, though, it has to be processed with scripts/headers_install.sh, which has a dependency on scripts/unifdef. So the full command to (re-)generate stddef.h for inclusion into tools/include directory is: $ make scripts_unifdef && \ cp $KBUILD_OUTPUT/scripts/unifdef scripts/ && \ scripts/headers_install.sh include/uapi/linux/stddef.h tools/include/uapi/linux/stddef.h This assumes KBUILD_OUTPUT envvar is set and used for out-of-tree builds. [0] https://github.com/kernel-patches/bpf/actions/runs/3379432493/jobs/5610982609 Fixes: 036b8f5b8970 ("tools headers uapi: Update linux/in.h copy") Signed-off-by: Andrii Nakryiko <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Cc: Jakub Kicinski <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2022-11-03perf top: Use sig_atomic_t to avoid undefined behaviour in a signal handlerIan Rogers1-2/+2
Use sig_atomic_t for variables written/accessed in signal handlers. This is undefined behavior as per: https://wiki.sei.cmu.edu/confluence/display/c/SIG31-C.+Do+not+access+shared+objects+in+signal+handlers Signed-off-by: Ian Rogers <[email protected]> Cc: Adrian Hunter <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Alexey Bayduraev <[email protected]> Cc: German Gomez <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Leo Yan <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Stephane Eranian <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2022-11-03perf stat: Use sig_atomic_t to avoid undefined behaviour in a signal handlerIan Rogers1-4/+4
Use sig_atomic_t for variables written/accessed in signal handlers. This is undefined behavior as per: https://wiki.sei.cmu.edu/confluence/display/c/SIG31-C.+Do+not+access+shared+objects+in+signal+handlers Signed-off-by: Ian Rogers <[email protected]> Cc: Adrian Hunter <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Alexey Bayduraev <[email protected]> Cc: German Gomez <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Leo Yan <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Stephane Eranian <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2022-11-03perf session: Change type to avoid undefined behaviour in a signal handlerIan Rogers1-1/+2
The 'session_done' variable is written to inside the signal handler of 'perf report' and 'perf script'. Switch its type to avoid undefined behavior. Signed-off-by: Ian Rogers <[email protected]> Cc: Adrian Hunter <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Alexey Bayduraev <[email protected]> Cc: German Gomez <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Leo Yan <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Stephane Eranian <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2022-11-03perf ftrace: Use sig_atomic_t to avoid UBIan Rogers1-2/+2
Use sig_atomic_t for a variable written to in a signal handler and read elsewhere. This is undefined behavior as per: https://wiki.sei.cmu.edu/confluence/display/c/SIG31-C.+Do+not+access+shared+objects+in+signal+handlers Signed-off-by: Ian Rogers <[email protected]> Cc: Adrian Hunter <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Alexey Bayduraev <[email protected]> Cc: German Gomez <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Leo Yan <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Stephane Eranian <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2022-11-03perf daemon: Use sig_atomic_t to avoid UBIan Rogers1-1/+1
Use sig_atomic_t for a variable written to in a signal handler and read elsewhere. This is undefined behavior as per: https://wiki.sei.cmu.edu/confluence/display/c/SIG31-C.+Do+not+access+shared+objects+in+signal+handlers Signed-off-by: Ian Rogers <[email protected]> Cc: Adrian Hunter <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Alexey Bayduraev <[email protected]> Cc: German Gomez <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Leo Yan <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Stephane Eranian <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2022-11-03perf record: Use sig_atomic_t for signal handlersIan Rogers1-4/+4
This removes undefined behavior as described in: https://wiki.sei.cmu.edu/confluence/display/c/SIG31-C.+Do+not+access+shared+objects+in+signal+handlers Suggested-by: Leo Yan <[email protected]> Signed-off-by: Ian Rogers <[email protected]> Cc: Adrian Hunter <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Alexey Bayduraev <[email protected]> Cc: German Gomez <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Stephane Eranian <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2022-11-03perf build: Update to C standard to gnu11Ian Rogers1-1/+1
C11 has become the standard for mainstream kernel development [1], allowing it in the perf build enables libraries like stdatomic.h to be assumed to be present. This came up in the context of [2]. [1] https://lore.kernel.org/lkml/CAHk-=whWbENRz-vLY6vpESDLj6kGUTKO3khGtVfipHqwewh2HQ@mail.gmail.com/ [2] https://lore.kernel.org/lkml/[email protected]/ Signed-off-by: Ian Rogers <[email protected]> Cc: Adrian Hunter <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Alexey Bayduraev <[email protected]> Cc: German Gomez <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Leo Yan <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Stephane Eranian <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2022-11-03perf probe: Fix to get declared file name from clang DWARF5Masami Hiramatsu (Google)3-22/+42
Fix to get the declared file name even if it uses file index 0 in DWARF5, using custom die_get_decl_file() function. Actually, the DWARF5 standard says file index 0 of the DW_AT_decl_file is invalid(1), but there is a discussion and maybe this will be updated [2]. Anyway, clang generates such DWARF5 file for the linux kernel. Thus it must be handled. Without this, 'perf probe' returns an error: $ ./perf probe -k $BIN_PATH/vmlinux -s $SRC_PATH -L vfs_read:10 Debuginfo analysis failed. Error: Failed to show lines. With this, it can handle the case correctly: $ ./perf probe -k $BIN_PATH/vmlinux -s $SRC_PATH -L vfs_read:10 <vfs_read@$SRC_PATH/fs/read_write.c:10> 11 ret = rw_verify_area(READ, file, pos, count); 12 if (ret) return ret; [1] DWARF5 specification 2.14 says "The value 0 indicates that no source file has been specified.") [2] http://wiki.dwarfstd.org/index.php?title=DWARF5_Line_Table_File_Numbers) Signed-off-by: Masami Hiramatsu <[email protected]> Acked-by: Namhyung Kim <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Steven Rostedt (VMware) <[email protected]> Link: https://lore.kernel.org/r/166731052936.2100653.13380621874859467731.stgit@devnote3 Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2022-11-03perf probe: Use dwarf_attr_integrate as generic DWARF attr accessorMasami Hiramatsu (Google)1-2/+2
Use dwarf_attr_integrate() instead of dwarf_attr() for generic attribute acccessor functions, so that it can find the specified attribute from abstact origin DIE etc. Signed-off-by: Masami Hiramatsu <[email protected]> Acked-by: Namhyung Kim <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Steven Rostedt (VMware) <[email protected]> Link: https://lore.kernel.org/r/166731051988.2100653.13595339994343449770.stgit@devnote3 Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2022-11-03perf probe: Fix to avoid crashing if DW_AT_decl_file is NULLMasami Hiramatsu (Google)2-9/+27
Since clang generates DWARF5 which sets DW_AT_decl_file as 0, dwarf_decl_file() thinks that is invalid and returns NULL. In that case 'perf probe' SIGSEGVs because it doesn't expect a NULL decl_file. This adds a dwarf_decl_file() return value check to avoid such SEGV with clang generated DWARF5 info. Without this, 'perf probe' crashes: $ perf probe -k $BIN_PATH/vmlinux -s $SRC_PATH -L vfs_read:10 Segmentation fault $ With this, it just warns about it: $ perf probe -k $BIN_PATH/vmlinux -s $SRC_PATH -L vfs_read:10 Debuginfo analysis failed. Error: Failed to show lines. $ Signed-off-by: Masami Hiramatsu <[email protected]> Acked-by: Namhyung Kim <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Steven Rostedt (VMware) <[email protected]> Link: https://lore.kernel.org/r/166731051077.2100653.15626653369345128302.stgit@devnote3 Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2022-11-02selftests/net: don't tests batched TCP io_uring zcPavel Begunkov1-1/+1
It doesn't make sense batch submitting io_uring requests to a single TCP socket without linking or some other kind of ordering. Moreover, it causes spurious -EINTR fails due to interaction with task_work. Disable it for now and keep queue depth=1. Signed-off-by: Pavel Begunkov <[email protected]> Link: https://lore.kernel.org/r/b547698d5938b1b1a898af1c260188d8546ded9a.1666700897.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <[email protected]>
2022-11-02bpftool: Fix NULL pointer dereference when pin {PROG, MAP, LINK} without FILEPu Lehui1-0/+3
When using bpftool to pin {PROG, MAP, LINK} without FILE, segmentation fault will occur. The reson is that the lack of FILE will cause strlen to trigger NULL pointer dereference. The corresponding stacktrace is shown below: do_pin do_pin_any do_pin_fd mount_bpffs_for_pin strlen(name) <- NULL pointer dereference Fix it by adding validation to the common process. Fixes: 75a1e792c335 ("tools: bpftool: Allow all prog/map handles for pinning objects") Signed-off-by: Pu Lehui <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Reviewed-by: Quentin Monnet <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2022-11-02selftests/pidfd_test: Remove the erroneous ','Zhao Gongyi1-1/+1
Remove the erroneous ',', otherwise it might result in wrong output and report: ... Bail out! (errno %d) test: Unexpected epoll_wait result (c=4208480, events=2) ... Fixes: 740378dc7834 ("pidfd: add polling selftests") Signed-off-by: Zhao Gongyi <[email protected]> Signed-off-by: Shuah Khan <[email protected]>
2022-11-01Merge tag 'nolibc-urgent.2022.10.28a' of ↵Linus Torvalds1-7/+10
git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu Pull nolibc fixes from Paul McKenney: "This contains a couple of fixes for string-function bugs" * tag 'nolibc-urgent.2022.10.28a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu: tools/nolibc/string: Fix memcmp() implementation tools/nolibc: Fix missing strlen() definition and infinite loop with gcc-12
2022-11-01Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds1-1/+141
Pull kvm fixes from Paolo Bonzini: "x86: - fix lock initialization race in gfn-to-pfn cache (+selftests) - fix two refcounting errors - emulator fixes - mask off reserved bits in CPUID - fix bug with disabling SGX RISC-V: - update MAINTAINERS" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: x86/xen: Fix eventfd error handling in kvm_xen_eventfd_assign() KVM: x86: smm: number of GPRs in the SMRAM image depends on the image format KVM: x86: emulator: update the emulation mode after CR0 write KVM: x86: emulator: update the emulation mode after rsm KVM: x86: emulator: introduce emulator_recalc_and_set_mode KVM: x86: emulator: em_sysexit should update ctxt->mode KVM: selftests: Mark "guest_saw_irq" as volatile in xen_shinfo_test KVM: selftests: Add tests in xen_shinfo_test to detect lock races KVM: Reject attempts to consume or refresh inactive gfn_to_pfn_cache KVM: Initialize gfn_to_pfn_cache locks in dedicated helper KVM: VMX: fully disable SGX if SECONDARY_EXEC_ENCLS_EXITING unavailable KVM: x86: Exempt pending triple fault from event injection sanity check MAINTAINERS: git://github -> https://github.com for kvm-riscv KVM: debugfs: Return retval of simple_attr_open() if it fails KVM: x86: Reduce refcount if single_open() fails in kvm_mmu_rmaps_stat_open() KVM: x86: Mask off reserved bits in CPUID.8000001FH KVM: x86: Mask off reserved bits in CPUID.8000001AH KVM: x86: Mask off reserved bits in CPUID.80000008H KVM: x86: Mask off reserved bits in CPUID.80000006H KVM: x86: Mask off reserved bits in CPUID.80000001H
2022-11-01tools: iio: iio_generic_buffer: Fix read sizeMatti Vaittinen1-2/+2
When noevents is true and small buffer is used the allocated memory for holding the data may be smaller than the hard-coded 64 bytes. This can cause the iio_generic_buffer to crash. Following was recorded on beagle bone black with v6.0 kernel and the digit fix patch: https://lore.kernel.org/all/[email protected]/ using valgrind; ==339== Using Valgrind-3.18.1 and LibVEX; rerun with -h for copyright info ==339== Command: /iio_generic_buffer -n kx022-accel -T0 -e -l 10 -a -w 2000000 ==339== Parent PID: 307 ==339== ==339== Syscall param read(buf) points to unaddressable byte(s) ==339== at 0x496BFA4: read (read.c:26) ==339== by 0x11699: main (iio_generic_buffer.c:724) ==339== Address 0x4ab3518 is 0 bytes after a block of size 160 alloc'd ==339== at 0x4864B70: malloc (vg_replace_malloc.c:381) ==339== by 0x115BB: main (iio_generic_buffer.c:677) Fix this by always using the same size for reading as was used for data storage allocation. Signed-off-by: Matti Vaittinen <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Jonathan Cameron <[email protected]>
2022-10-31Merge remote-tracking branch 'torvalds/master' into perf/coreArnaldo Carvalho de Melo8-122/+705
To pick up fixes and sync with other tools/ libraries. Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2022-10-31perf lock contention: Increase default stack skip to 4Namhyung Kim1-1/+1
In most configurations, it works well with skipping 4 entries by default. If some systems still have 3 BPF internal stack frames, the next frame should be in a lock function which will be skipped later when it tries to find a caller. So increasing to 4 won't affect such systems too. With --stack-skip=0, I can see something like this: 24 49.84 us 7.41 us 2.08 us mutex bpf_prog_e1b85959d520446c_contention_begin+0x12e 0xffffffffc045040e bpf_prog_e1b85959d520446c_contention_begin+0x12e 0xffffffffc045040e bpf_prog_e1b85959d520446c_contention_begin+0x12e 0xffffffff82ea2071 bpf_trace_run2+0x51 0xffffffff82de775b __bpf_trace_contention_begin+0xb 0xffffffff82c02045 __mutex_lock+0x245 0xffffffff82c019e3 __mutex_lock_slowpath+0x13 0xffffffff82c019c0 mutex_lock+0x20 0xffffffff830a083c kernfs_iop_permission+0x2c Signed-off-by: Namhyung Kim <[email protected]> Cc: Adrian Hunter <[email protected]> Cc: Ian Rogers <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Song Liu <[email protected]> Cc: [email protected] Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2022-10-31perf lock contention: Avoid variable length arraysNamhyung Kim1-13/+28
The msan also warns about the use of VLA for stack_trace variable. We can dynamically allocate instead. While at it, simplify the error handle a bit (and fix bugs). Signed-off-by: Namhyung Kim <[email protected]> Cc: Adrian Hunter <[email protected]> Cc: Ian Rogers <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Peter Zijlstra <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2022-10-31perf lock contention: Check --max-stack optionNamhyung Kim1-3/+27
The --max-stack option is used to allocate the BPF stack map and stack trace array in the userspace. Check the value properly before using. Practically it cannot be greater than the sysctl_perf_event_max_stack. Signed-off-by: Namhyung Kim <[email protected]> Cc: Adrian Hunter <[email protected]> Cc: Ian Rogers <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Peter Zijlstra <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2022-10-31perf lock contention: Fix memory sanitizer issueNamhyung Kim1-1/+1
The msan reported a use-of-uninitialized-value warning for the struct lock_contention_data in lock_contention_read(). While it'd be filled by bpf_map_lookup_elem(), let's just initialize it to silence the warning. ==12524==WARNING: MemorySanitizer: use-of-uninitialized-value #0 0x562b0f16b1cd in lock_contention_read util/bpf_lock_contention.c:139:7 #1 0x562b0ef65ec6 in __cmd_contention builtin-lock.c:1737:3 #2 0x562b0ef65ec6 in cmd_lock builtin-lock.c:1992:8 #3 0x562b0ee7f50b in run_builtin perf.c:322:11 #4 0x562b0ee7efc1 in handle_internal_command perf.c:376:8 #5 0x562b0ee7e1e9 in run_argv perf.c:420:2 #6 0x562b0ee7e1e9 in main perf.c:550:3 #7 0x7f065f10e632 in __libc_start_main (/usr/lib64/libc.so.6+0x61632) #8 0x562b0edf2fa9 in _start (perf+0xfa9) SUMMARY: MemorySanitizer: use-of-uninitialized-value (perf+0xe15160) in lock_contention_read Signed-off-by: Namhyung Kim <[email protected]> Cc: Adrian Hunter <[email protected]> Cc: Ian Rogers <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Peter Zijlstra <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2022-10-31perf test: Parse events workaround for dash/minusIan Rogers1-0/+13
Skip an event configuration for event names with a dash/minus in them. Events with a dash/minus in their name cause parsing issues as legacy encoding of events would use a dash/minus as a separator. The parser separates events with dashes into prefixes and suffixes and then recombines them. Unfortunately if an event has part of its name that matches a legacy token then the recombining fails. This is seen for branch-brs where branch is a legacy token. branch-brs was introduced to sysfs in: https://lore.kernel.org/all/[email protected]/ The failure is shown below as well as the workaround to use a config where the dash/minus isn't treated specially: ``` $ perf stat -e branch-brs true event syntax error: 'branch-brs' \___ parser error $ perf stat -e cpu/branch-brs/ true Performance counter stats for 'true': 46,179 cpu/branch-brs/ ``` Signed-off-by: Ian Rogers <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: John Garry <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Ravi Bangoria <[email protected]> Cc: Stephane Eranian <[email protected]> Link: http://lore.kernel.org/lkml/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2022-10-31perf evlist: Add missing util/event.h headerArnaldo Carvalho de Melo1-0/+1
Needed to get the event_attr_init() and perf_event_paranoid() prototypes that were being obtained indirectly, by sheer luck. Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2022-10-31perf mmap: Remove several unneeded includes from util/mmap.hArnaldo Carvalho de Melo1-5/+0
Those headers are not needed in util/mmap.h, remove them. Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2022-10-31perf tests: Add missing event.h includeArnaldo Carvalho de Melo2-0/+2
It uses things like perf_event__name() but were not including event.h, where its prototype lives, fix it. Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2022-10-31perf thread: Move thread__resolve() from event.hArnaldo Carvalho de Melo2-5/+3
Its a thread method, so move it to thread.h, this way some places that were using event.h just to get this prototype may stop doing so and speed up building and disentanble the header dependency graph. Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2022-10-31perf symbol: Move addr_location__put() from event.hArnaldo Carvalho de Melo2-3/+2
Its a addr_location method, so move it to symbol.h, where 'struct addr_location' is, this way some places that were using event.h just to get this prototype may stop doing so and speed up building and disentanble the header dependency graph. Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2022-10-31perf machine: Move machine__resolve() from event.hArnaldo Carvalho de Melo2-3/+3
Its a machine method, so move it to machine.h, this way some places that were using event.h just to get this prototype may stop doing so and speed up building and disentanble the header dependency graph. Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2022-10-31perf kwork: Remove includes not needed in kwork.hArnaldo Carvalho de Melo3-6/+15
Leave just some forward declarations for pointers, move the includes to where they are really needed. Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2022-10-31perf tools: Move 'struct perf_sample' to a separate header file to ↵Arnaldo Carvalho de Melo31-118/+147
disentangle headers Some places were including event.h just to get 'struct perf_sample', move it to a separate place so that we speed up a bit the build. Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2022-10-31perf branch: Remove some needless headers, add a needed oneArnaldo Carvalho de Melo1-3/+1
map_symbol.h is needed because we have structs that contains 'struct addr_map_symbol', so add it, remove the others. Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2022-10-31perf bpf: No need to include headers just use forward declarationsArnaldo Carvalho de Melo1-3/+3
In the bpf-prologue.h header we are just using pointers, so no need to include headers for that, just provide forward declarations for those types. Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
2022-10-30Merge tag 'char-misc-6.1-rc3' of ↵Linus Torvalds1-0/+4
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc Pull char/misc fixes from Greg KH: "Some small driver fixes for 6.1-rc3. They include: - iio driver bugfixes - counter driver bugfixes - coresight bugfixes, including a revert and then a second fix to get it right. All of these have been in linux-next with no reported problems" * tag 'char-misc-6.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (21 commits) misc: sgi-gru: use explicitly signed char coresight: cti: Fix hang in cti_disable_hw() Revert "coresight: cti: Fix hang in cti_disable_hw()" counter: 104-quad-8: Fix race getting function mode and direction counter: microchip-tcb-capture: Handle Signal1 read and Synapse coresight: cti: Fix hang in cti_disable_hw() coresight: Fix possible deadlock with lock dependency counter: ti-ecap-capture: fix IS_ERR() vs NULL check counter: Reduce DEFINE_COUNTER_ARRAY_POLARITY() to defining counter_array iio: bmc150-accel-core: Fix unsafe buffer attributes iio: adxl367: Fix unsafe buffer attributes iio: adxl372: Fix unsafe buffer attributes iio: at91-sama5d2_adc: Fix unsafe buffer attributes iio: temperature: ltc2983: allocate iio channels once tools: iio: iio_utils: fix digit calculation iio: adc: stm32-adc: fix channel sampling time init iio: adc: mcp3911: mask out device ID in debug prints iio: adc: mcp3911: use correct id bits iio: adc: mcp3911: return proper error code on failure to allocate trigger iio: adc: mcp3911: fix sizeof() vs ARRAY_SIZE() bug ...
2022-10-30selftests: pidfd: Fix compling warningsLi Zhijian3-2/+4
Fix warnings and enable Wall. pidfd_wait.c: In function ‘wait_nonblock’: pidfd_wait.c:150:13: warning: unused variable ‘status’ [-Wunused-variable] 150 | int pidfd, status = 0; | ^~~~~~ ... pidfd_test.c: In function ‘child_poll_exec_test’: pidfd_test.c:438:1: warning: no return statement in function returning non-void [-Wreturn-type] 438 | } | ^ Signed-off-by: Li Zhijian <[email protected]> v2: fix mistake assignment to pidfd Signed-off-by: Shuah Khan <[email protected]>
2022-10-30ksefltests: pidfd: Fix wait_states: Test terminated by timeoutLi Zhijian1-0/+10
0Day/LKP observed that the kselftest blocks forever since one of the pidfd_wait doesn't terminate in 1 of 30 runs. After digging into the source, we found that it blocks at: ASSERT_EQ(sys_waitid(P_PIDFD, pidfd, &info, WCONTINUED, NULL), 0); wait_states has below testing flow: CHILD PARENT ---------------+-------------- 1 STOP itself 2 WAIT for CHILD STOPPED 3 SIGNAL CHILD to CONT 4 CONT 5 STOP itself 5' WAIT for CHILD CONT 6 WAIT for CHILD STOPPED The problem is that the kernel cannot ensure the order of 5 and 5', once 5 goes first, the test will fail. we can reproduce it by: $ while true; do make run_tests -C pidfd; done Introduce a blocking read in child process to make sure the parent can check its WCONTINUED. CC: Philip Li <[email protected]> Reported-by: kernel test robot <[email protected]> Signed-off-by: Li Zhijian <[email protected]> Reviewed-by: Christian Brauner (Microsoft) <[email protected]> Signed-off-by: Shuah Khan <[email protected]>
2022-10-28Merge tag 'pm-6.1-rc3' of ↵Linus Torvalds3-122/+118
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull power management fixes from Rafael Wysocki: "These make the intel_pstate driver work as expected on all hybrid platforms to date (regardless of possible platform firmware issues), fix hybrid sleep on systems using suspend-to-idle by default, make the generic power domains code handle disabled idle states properly and update pm-graph. Specifics: - Make intel_pstate use what is known about the hardware instead of relying on information from the platform firmware (ACPI CPPC in particular) to establish the relationship between the HWP CPU performance levels and frequencies on all hybrid platforms available to date (Rafael Wysocki) - Allow hybrid sleep to use suspend-to-idle as a system suspend method if it is the current suspend method of choice (Mario Limonciello) - Fix handling of unavailable/disabled idle states in the generic power domains code (Sudeep Holla) - Update the pm-graph suite of utilities to version 5.10 which is fixes-mostly and does not add any new features (Todd Brandt)" * tag 'pm-6.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: PM: domains: Fix handling of unavailable/disabled idle states pm-graph v5.10 cpufreq: intel_pstate: hybrid: Use known scaling factor for P-cores cpufreq: intel_pstate: Read all MSRs on the target CPU PM: hibernate: Allow hybrid sleep to work with s2idle
2022-10-28tools/nolibc/string: Fix memcmp() implementationRasmus Villemoes1-2/+2
The C standard says that memcmp() must treat the buffers as consisting of "unsigned chars". If char happens to be unsigned, the casts are ok, but then obviously the c1 variable can never contain a negative value. And when char is signed, the casts are wrong, and there's still a problem with using an 8-bit quantity to hold the difference, because that can range from -255 to +255. For example, assuming char is signed, comparing two 1-byte buffers, one containing 0x00 and another 0x80, the current implementation would return -128 for both memcmp(a, b, 1) and memcmp(b, a, 1), whereas one of those should of course return something positive. Signed-off-by: Rasmus Villemoes <[email protected]> Fixes: 66b6f755ad45 ("rcutorture: Import a copy of nolibc") Cc: [email protected] # v5.0+ Signed-off-by: Willy Tarreau <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]>
2022-10-28tools/nolibc: Fix missing strlen() definition and infinite loop with gcc-12Willy Tarreau1-5/+8
When built at -Os, gcc-12 recognizes an strlen() pattern in nolibc_strlen() and replaces it with a jump to strlen(), which is not defined as a symbol and breaks compilation. Worse, when the function is called strlen(), the function is simply replaced with a jump to itself, hence becomes an infinite loop. One way to avoid this is to always set -ffreestanding, but the calling code doesn't know this and there's no way (either via attributes or pragmas) to globally enable it from include files, effectively leaving a painful situation for the caller. Alexey suggested to place an empty asm() statement inside the loop to stop gcc from recognizing a well-known pattern, which happens to work pretty fine. At least it allows us to make sure our local definition is not replaced with a self jump. The function only needs to be renamed back to strlen() so that the symbol exists, which implies that nolibc_strlen() which is used on variable strings has to be declared as a macro that points back to it before the strlen() macro is redifined. It was verified to produce valid code with gcc 3.4 to 12.1 at different optimization levels, and both with constant and variable strings. In case this problem surfaces again in the future, an alternate approach consisting in adding an optimize("no-tree-loop-distribute-patterns") function attribute for gcc>=12 worked as well but is less pretty. Reported-by: kernel test robot <[email protected]> Link: https://lore.kernel.org/r/[email protected] Fixes: 66b6f755ad45 ("rcutorture: Import a copy of nolibc") Fixes: 96980b833a21 ("tools/nolibc/string: do not use __builtin_strlen() at -O0") Cc: "Paul E. McKenney" <[email protected]> Cc: Alexey Dobriyan <[email protected]> Signed-off-by: Willy Tarreau <[email protected]> Signed-off-by: Paul E. McKenney <[email protected]>
2022-10-28KVM: selftests: Mark "guest_saw_irq" as volatile in xen_shinfo_testSean Christopherson1-1/+1
Tag "guest_saw_irq" as "volatile" to ensure that the compiler will never optimize away lookups. Relying on the compiler thinking that the flag is global and thus might change also works, but it's subtle, less robust, and looks like a bug at first glance, e.g. risks being "fixed" and breaking the test. Make the flag "static" as well since convincing the compiler it's global is no longer necessary. Alternatively, the flag could be accessed with {READ,WRITE}_ONCE(), but literally every access would need the wrappers, and eking out performance isn't exactly top priority for selftests. Signed-off-by: Sean Christopherson <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>