summaryrefslogtreecommitdiff
path: root/tools
AgeCommit message (Collapse)Author
2025-12-19resolve_btfids: Change in-place update with raw binary outputIhor Solodrai
Currently resolve_btfids updates .BTF_ids section of an ELF file in-place, based on the contents of provided BTF, usually within the same input file, and optionally a BTF base. Change resolve_btfids behavior to enable BTF transformations as part of its main operation. To achieve this, in-place ELF write in resolve_btfids is replaced with generation of the following binaries: * ${1}.BTF with .BTF section data * ${1}.BTF_ids with .BTF_ids section data if it existed in ${1} * ${1}.BTF.base with .BTF.base section data for out-of-tree modules The execution of resolve_btfids and consumption of its output is orchestrated by scripts/gen-btf.sh introduced in this patch. The motivation for emitting binary data is that it allows simplifying resolve_btfids implementation by delegating ELF update to the $OBJCOPY tool [1], which is already widely used across the codebase. There are two distinct paths for BTF generation and resolve_btfids application in the kernel build: for vmlinux and for kernel modules. For the vmlinux binary a .BTF section is added in a roundabout way to ensure correct linking. The patch doesn't change this approach, only the implementation is a little different. Before this patch it worked as follows: * pahole consumed .tmp_vmlinux1 [2] and added .BTF section with llvm-objcopy [3] to it * then everything except the .BTF section was stripped from .tmp_vmlinux1 into a .tmp_vmlinux1.bpf.o object [2], later linked into vmlinux * resolve_btfids was executed later on vmlinux.unstripped [4], updating it in-place After this patch gen-btf.sh implements the following: * pahole consumes .tmp_vmlinux1 and produces a *detached* file with raw BTF data * resolve_btfids consumes .tmp_vmlinux1 and detached BTF to produce (potentially modified) .BTF, and .BTF_ids sections data * a .tmp_vmlinux1.bpf.o object is then produced with objcopy copying BTF output of resolve_btfids * .BTF_ids data gets embedded into vmlinux.unstripped in link-vmlinux.sh by objcopy --update-section For kernel modules, creating a special .bpf.o file is not necessary, and so embedding of sections data produced by resolve_btfids is straightforward with objcopy. With this patch an ELF file becomes effectively read-only within resolve_btfids, which allows deleting elf_update() call and satellite code (like compressed_section_fix [5]). Endianness handling of .BTF_ids data is also changed. Previously the "flags" part of the section was bswapped in sets_patch() [6], and then Elf_Type was modified before elf_update() to signal to libelf that bswap may be necessary. With this patch we explicitly bswap entire data buffer on load and on dump. [1] https://lore.kernel.org/bpf/131b4190-9c49-4f79-a99d-c00fac97fa44@linux.dev/ [2] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/scripts/link-vmlinux.sh?h=v6.18#n110 [3] https://git.kernel.org/pub/scm/devel/pahole/pahole.git/tree/btf_encoder.c?h=v1.31#n1803 [4] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/scripts/link-vmlinux.sh?h=v6.18#n284 [5] https://lore.kernel.org/bpf/20200819092342.259004-1-jolsa@kernel.org/ [6] https://lore.kernel.org/bpf/cover.1707223196.git.vmalik@redhat.com/ Signed-off-by: Ihor Solodrai <ihor.solodrai@linux.dev> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Tested-by: Alan Maguire <alan.maguire@oracle.com> Acked-by: Eduard Zingerman <eddyz87@gmail.com> Link: https://lore.kernel.org/bpf/20251219181825.1289460-3-ihor.solodrai@linux.dev
2025-12-19selftests/bpf: Run resolve_btfids only for relevant .test.o objectsIhor Solodrai
A selftest targeting resolve_btfids functionality relies on a resolved .BTF_ids section to be available in the TRUNNER_BINARY. The underlying BTF data is taken from a special BPF program (btf_data.c), and so resolve_btfids is executed as a part of a TRUNNER_BINARY build recipe on the final binary. Subsequent patches in this series allow resolve_btfids to modify BTF before resolving the symbols, which means that the test needs access to that modified BTF [1]. Currently the test simply reads in btf_data.bpf.o on the assumption that BTF hasn't changed. Implement resolve_btfids call only for particular test objects (just resolve_btfids.test.o for now). The test objects are linked into the TRUNNER_BINARY, and so .BTF_ids section will be available there. This will make it trivial for the resolve_btfids test to access BTF modified by resolve_btfids. [1] https://lore.kernel.org/bpf/CAErzpmvsgSDe-QcWH8SFFErL6y3p3zrqNri5-UHJ9iK2ChyiBw@mail.gmail.com/ Signed-off-by: Ihor Solodrai <ihor.solodrai@linux.dev> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Tested-by: Alan Maguire <alan.maguire@oracle.com> Acked-by: Eduard Zingerman <eddyz87@gmail.com> Link: https://lore.kernel.org/bpf/20251219181825.1289460-2-ihor.solodrai@linux.dev
2025-12-19lib/Kconfig.debug: Set the minimum required pahole version to v1.22Ihor Solodrai
Subsequent patches in the series change vmlinux linking scripts to unconditionally pass --btf_encode_detached to pahole, which was introduced in v1.22 [1][2]. This change allows to remove PAHOLE_HAS_SPLIT_BTF Kconfig option and other checks of older pahole versions. [1] https://github.com/acmel/dwarves/releases/tag/v1.22 [2] https://lore.kernel.org/bpf/cbafbf4e-9073-4383-8ee6-1353f9e5869c@oracle.com/ Signed-off-by: Ihor Solodrai <ihor.solodrai@linux.dev> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Tested-by: Alan Maguire <alan.maguire@oracle.com> Acked-by: Eduard Zingerman <eddyz87@gmail.com> Acked-by: Nicolas Schier <nsc@kernel.org> Link: https://lore.kernel.org/bpf/20251219181825.1289460-1-ihor.solodrai@linux.dev
2025-12-19resolve_btfids: Always build with -Wall -WerrorIhor Solodrai
resolve_btfids builds without compiler warnings currently, so let's enforce this for future changes with '-Wall -Werror' flags [1]. [1] https://lore.kernel.org/bpf/1957a60b-6c45-42a7-b525-a6e335a735ff@linux.dev/ Signed-off-by: Ihor Solodrai <ihor.solodrai@linux.dev> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Tested-by: Alan Maguire <alan.maguire@oracle.com> Link: https://lore.kernel.org/bpf/20251219181321.1283664-5-ihor.solodrai@linux.dev
2025-12-19resolve_btfids: Introduce enum btf_id_kindIhor Solodrai
Instead of using multiple flags, make struct btf_id tagged with an enum value indicating its kind in the context of resolve_btfids. Signed-off-by: Ihor Solodrai <ihor.solodrai@linux.dev> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Tested-by: Alan Maguire <alan.maguire@oracle.com> Acked-by: Eduard Zingerman <eddyz87@gmail.com> Link: https://lore.kernel.org/bpf/20251219181321.1283664-4-ihor.solodrai@linux.dev
2025-12-19resolve_btfids: Factor out load_btf()Ihor Solodrai
Increase the lifetime of parsed BTF in resolve_btfids by factoring load_btf() routine out of symbols_resolve() and storing the base_btf and btf pointers in the struct object. Signed-off-by: Ihor Solodrai <ihor.solodrai@linux.dev> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Tested-by: Alan Maguire <alan.maguire@oracle.com> Acked-by: Eduard Zingerman <eddyz87@gmail.com> Link: https://lore.kernel.org/bpf/20251219181321.1283664-3-ihor.solodrai@linux.dev
2025-12-19resolve_btfids: Rename object btf field to btf_pathIhor Solodrai
Rename the member of `struct object` holding the path to BTF data if provided via --btf arg. `btf_path` is less ambiguous. Signed-off-by: Ihor Solodrai <ihor.solodrai@linux.dev> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Tested-by: Alan Maguire <alan.maguire@oracle.com> Acked-by: Eduard Zingerman <eddyz87@gmail.com> Link: https://lore.kernel.org/bpf/20251219181321.1283664-2-ihor.solodrai@linux.dev
2025-12-19Merge tag 'for-linus-iommufd' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jgg/iommufd Pull iommufd fixes from Jason Gunthorpe: "A few minor fixes, other than the randconfig fix this is only relevant to test code, not releases: - Randconfig failure if CONFIG_DMA_SHARED_BUFFER is not set - Remove gcc warning in kselftest - Fix a refcount leak on an error path in the selftest support code - Fix missing overflow checks in the selftest support code" * tag 'for-linus-iommufd' of git://git.kernel.org/pub/scm/linux/kernel/git/jgg/iommufd: iommufd/selftest: Check for overflow in IOMMU_TEST_OP_ADD_RESERVED iommufd/selftest: Do not leak the hwpt if IOMMU_TEST_OP_MD_CHECK_MAP fails iommufd/selftest: Make it clearer to gcc that the access is not out of bounds iommufd: Fix building without dmabuf
2025-12-19Merge tag 'net-6.19-rc2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net Pull networking fixes from Paolo Abeni: "Including fixes from netfilter and CAN. Current release - regressions: - netfilter: nf_conncount: fix leaked ct in error paths - sched: act_mirred: fix loop detection - sctp: fix potential deadlock in sctp_clone_sock() - can: fix build dependency - eth: mlx5e: do not update BQL of old txqs during channel reconfiguration Previous releases - regressions: - sched: ets: always remove class from active list before deleting it - inet: frags: flush pending skbs in fqdir_pre_exit() - netfilter: nf_nat: remove bogus direction check - mptcp: - schedule rtx timer only after pushing data - avoid deadlock on fallback while reinjecting - can: gs_usb: fix error handling - eth: - mlx5e: - avoid unregistering PSP twice - fix double unregister of HCA_PORTS component - bnxt_en: fix XDP_TX path - mlxsw: fix use-after-free when updating multicast route stats Previous releases - always broken: - ethtool: avoid overflowing userspace buffer on stats query - openvswitch: fix middle attribute validation in push_nsh() action - eth: - mlx5: fw_tracer, validate format string parameters - mlxsw: spectrum_router: fix neighbour use-after-free - ipvlan: ignore PACKET_LOOPBACK in handle_mode_l2() Misc: - Jozsef Kadlecsik retires from maintaining netfilter - tools: ynl: fix build on systems with old kernel headers" * tag 'net-6.19-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (83 commits) net: hns3: add VLAN id validation before using net: hns3: using the num_tqps to check whether tqp_index is out of range when vf get ring info from mbx net: hns3: using the num_tqps in the vf driver to apply for resources net: enetc: do not transmit redirected XDP frames when the link is down selftests/tc-testing: Test case exercising potential mirred redirect deadlock net/sched: act_mirred: fix loop detection sctp: Clear inet_opt in sctp_v6_copy_ip_options(). sctp: Fetch inet6_sk() after setting ->pinet6 in sctp_clone_sock(). net/handshake: duplicate handshake cancellations leak socket net/mlx5e: Don't include PSP in the hard MTU calculations net/mlx5e: Do not update BQL of old txqs during channel reconfiguration net/mlx5e: Trigger neighbor resolution for unresolved destinations net/mlx5e: Use ip6_dst_lookup instead of ipv6_dst_lookup_flow for MAC init net/mlx5: Serialize firmware reset with devlink net/mlx5: fw_tracer, Handle escaped percent properly net/mlx5: fw_tracer, Validate format string parameters net/mlx5: Drain firmware reset in shutdown callback net/mlx5: fw reset, clear reset requested on drain_fw_reset net: dsa: mxl-gsw1xx: manually clear RANEG bit net: dsa: mxl-gsw1xx: fix .shutdown driver operation ...
2025-12-18Merge tag 'kvm-x86-fixes-6.19-rc1' of https://github.com/kvm-x86/linux into HEADPaolo Bonzini
KVM fixes for 6.19-rc1 - Add a missing "break" to fix param parsing in the rseq selftest. - Apply runtime updates to the _current_ CPUID when userspace is setting CPUID, e.g. as part of vCPU hotplug, to fix a false positive and to avoid dropping the pending update. - Disallow toggling KVM_MEM_GUEST_MEMFD on an existing memslot, as it's not supported by KVM and leads to a use-after-free due to KVM failing to unbind the memslot from the previously-associated guest_memfd instance. - Harden against similar KVM_MEM_GUEST_MEMFD goofs, and prepare for supporting flags-only changes on KVM_MEM_GUEST_MEMFD memlslots, e.g. for dirty logging. - Set exit_code[63:32] to -1 (all 0xffs) when synthesizing a nested SVM_EXIT_ERR (a.k.a. VMEXIT_INVALID) #VMEXIT, as VMEXIT_INVALID is defined as -1ull (a 64-bit value). - Update SVI when activating APICv to fix a bug where a post-activation EOI for an in-service IRQ would effective be lost due to SVI being stale. - Immediately refresh APICv controls (if necessary) on a nested VM-Exit instead of deferring the update via KVM_REQ_APICV_UPDATE, as the request is effectively ignored because KVM thinks the vCPU already has the correct APICv settings.
2025-12-18selftests/tc-testing: Test case exercising potential mirred redirect deadlockVictor Nogueira
Add a test case that reproduces deadlock scenario where the user has a drr qdisc attached to root and has a mirred action that redirects to self on egress Signed-off-by: Victor Nogueira <victor@mojatatu.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Link: https://patch.msgid.link/20251210162255.1057663-2-jhs@mojatatu.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-12-17perf symbol: Fix ENOENT case for filename__read_build_idIan Rogers
Some callers of filename__read_build_id assume the error value must be -1, fix by making them handle all < 0 values. If is_regular_file fails in filename__read_build_id then it could be the file is missing (ENOENT) and it would be wrong to return -EWOULDBLOCK in that case. Fix the logic so -EWOULDBLOCK is only reported if other errors with stat haven't occurred. Fixes: 834ebb5678d7 ("perf tools: Don't read build-ids from non-regular files") Signed-off-by: Ian Rogers <irogers@google.com> Reviewed-by: James Clark <james.clark@linaro.org> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2025-12-17perf tools: Disable BPF skeleton if no libopenssl foundNamhyung Kim
The libopenssl is required by bpftool which is needed to generate BPF skeleton. Disable it by setting BUILD_BPF_SKEL to 0 otherwise it'll see build errors like below: CC /build/util/bpf_skel/.tmp/bootstrap/sign.o sign.c:16:10: fatal error: openssl/opensslv.h: No such file or directory 16 | #include <openssl/opensslv.h> | ^~~~~~~~~~~~~~~~~~~~ compilation terminated. make[3]: *** [Makefile:256: /build/util/bpf_skel/.tmp/bootstrap/sign.o] Error 1 make[3]: *** Waiting for unfinished jobs.... make[2]: *** [Makefile.perf:1211: /build/util/bpf_skel/.tmp/bootstrap/bpftool] Error 2 make[1]: *** [Makefile.perf:287: sub-make] Error 2 make: *** [Makefile:76: all] Error 2 Now it'll skip the build with the following message: Makefile.config:729: Warning: Disabled BPF skeletons as libopenssl is required Closes: https://lore.kernel.org/r/aP7uq6eVieG8v_v4@google.com Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2025-12-17tools/build: Add a feature test for libopensslNamhyung Kim
It's used by bpftool and the kernel build. Let's add a feature test so that perf can decide what to do based on the availability. Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2025-12-17perf/x86/core: Register a new vector for handling mediated guest PMIsSean Christopherson
Wire up system vector 0xf5 for handling PMIs (i.e. interrupts delivered through the LVTPC) while running KVM guests with a mediated PMU. Perf currently delivers all PMIs as NMIs, e.g. so that events that trigger while IRQs are disabled aren't delayed and generate useless records, but due to the multiplexing of NMIs throughout the system, correctly identifying NMIs for a mediated PMU is practically infeasible. To (greatly) simplify identifying guest mediated PMU PMIs, perf will switch the CPU's LVTPC between PERF_GUEST_MEDIATED_PMI_VECTOR and NMI when guest PMU context is loaded/put. I.e. PMIs that are generated by the CPU while the guest is active will be identified purely based on the IRQ vector. Route the vector through perf, e.g. as opposed to letting KVM attach a handler directly a la posted interrupt notification vectors, as perf owns the LVTPC and thus is the rightful owner of PERF_GUEST_MEDIATED_PMI_VECTOR. Functionally, having KVM directly own the vector would be fine (both KVM and perf will be completely aware of when a mediated PMU is active), but would lead to an undesirable split in ownership: perf would be responsible for installing the vector, but not handling the resulting IRQs. Add a new perf_guest_info_callbacks hook (and static call) to allow KVM to register its handler with perf when running guests with mediated PMUs. Note, because KVM always runs guests with host IRQs enabled, there is no danger of a PMI being delayed from the guest's perspective due to using a regular IRQ instead of an NMI. Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Xudong Hao <xudong.hao@intel.com> Link: https://patch.msgid.link/20251206001720.468579-9-seanjc@google.com
2025-12-17perf report: Update sort key state from -F optionNamhyung Kim
Factor out __sort_dimension__update() so that it can be called from -s and -F option parsing logics. Otherwise the following command cannot go into the annotation mode. $ perf report -F overhead,type,sym Warning: Annotation is only available for symbolic views, include "sym*" in --sort to use it. Reviewed-by: Ian Rogers <irogers@google.com> Signed-off-by: Namhyung Kim <namhyung@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: James Clark <james.clark@linaro.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2025-12-17perf report: Fix histogram entry collapsing for -F optionNamhyung Kim
Users can use -F/--fields option to set output fields and sort keys together. But it missed to set perf_hpp_list->need_collapse for sort entries that have se_collapse callbacks. So it ends up with having duplicated entries separately. For example, let's run this command first. $ perf mem record -t load -U -- perf test -w datasym This will record samples for memory access (load) to struct 'buf' and a loop condition ('sig_atomic_t') types. So the following two commands should have identical output. $ perf report -s type --stdio --percent-limit=1 -q 87.80% perf buf 12.17% perf sig_atomic_t But using -F option didn't collapse the entries based on types so the result looked like below: $ perf report -F overhead,type --stdio --percent-limit=1 -q 23.31% perf buf 22.84% perf buf 21.26% perf buf 20.39% perf buf 12.17% perf sig_atomic_t Reviewed-by: Ian Rogers <irogers@google.com> Signed-off-by: Namhyung Kim <namhyung@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: James Clark <james.clark@linaro.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2025-12-17perf report: Enable data-type profiling with -F option tooNamhyung Kim
It checked -s/--sort options only. As the sort keys can be setup using the -F/--fields option as well, it should enable data-type profiling with it too. The following two commands should have the same output. $ perf report -s type $ perf report -F overhead,type But there's another problem on this. I'll handle it in the next commit. Reviewed-by: Ian Rogers <irogers@google.com> Signed-off-by: Namhyung Kim <namhyung@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: James Clark <james.clark@linaro.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2025-12-17perf record: Split --data-mmap optionNamhyung Kim
Currently -d/--data option controls both PERF_SAMPLE_ADDR bit and perf_event_attr.mmap_data flag. Separate them using new --data-mmap option to support recording only one of them. For data-type profiling, data MMAP is unnecessary but it wastes a lot of space in the ring buffer and data file. Committer testing: On an idle system: root@x1:~# perf record -d -a sleep 1 [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 5.672 MB perf.data (1075 samples) ] root@x1:~# ls -la perf.data -rw-------. 1 root root 5982480 Dec 16 15:34 perf.data root@x1:~# perf evlist -v cpu_atom/cycles/P: type: 0 (PERF_TYPE_HARDWARE), size: 144, config: 0xa00000000 (cpu_atom/PERF_COUNT_HW_CPU_CYCLES/), { sample_period, sample_freq }: 4000, sample_type: IP|TID|TIME|ADDR|CPU|PERIOD|IDENTIFIER|DATA_SRC, read_format: ID|LOST, disabled: 1, freq: 1, precise_ip: 3, sample_id_all: 1 cpu_core/cycles/P: type: 0 (PERF_TYPE_HARDWARE), size: 144, config: 0x400000000 (cpu_core/PERF_COUNT_HW_CPU_CYCLES/), { sample_period, sample_freq }: 4000, sample_type: IP|TID|TIME|ADDR|CPU|PERIOD|IDENTIFIER|DATA_SRC, read_format: ID|LOST, disabled: 1, freq: 1, precise_ip: 3, sample_id_all: 1 dummy:u: type: 1 (PERF_TYPE_SOFTWARE), size: 144, config: 0x9 (PERF_COUNT_SW_DUMMY), { sample_period, sample_freq }: 1, sample_type: IP|TID|TIME|ADDR|CPU|IDENTIFIER|DATA_SRC, read_format: ID|LOST, exclude_kernel: 1, exclude_hv: 1, mmap: 1, comm: 1, task: 1, mmap_data: 1, sample_id_all: 1, exclude_guest: 1, mmap2: 1, comm_exec: 1, ksymbol: 1, bpf_event: 1, build_id: 1 root@x1:~# Now with just --data-mmap we will not save that much, as only DATA_SRC will not be enabled in sample_type: root@x1:~# perf record --data-mmap -a sleep 1 [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 5.576 MB perf.data (716 samples) ] root@x1:~# ls -la perf.data -rw-------. 1 root root 5880112 Dec 16 15:37 perf.data root@x1:~# perf evlist -v cpu_atom/cycles/P: type: 0 (PERF_TYPE_HARDWARE), size: 144, config: 0xa00000000 (cpu_atom/PERF_COUNT_HW_CPU_CYCLES/), { sample_period, sample_freq }: 4000, sample_type: IP|TID|TIME|CPU|PERIOD|IDENTIFIER, read_format: ID|LOST, disabled: 1, freq: 1, precise_ip: 3, sample_id_all: 1 cpu_core/cycles/P: type: 0 (PERF_TYPE_HARDWARE), size: 144, config: 0x400000000 (cpu_core/PERF_COUNT_HW_CPU_CYCLES/), { sample_period, sample_freq }: 4000, sample_type: IP|TID|TIME|CPU|PERIOD|IDENTIFIER, read_format: ID|LOST, disabled: 1, freq: 1, precise_ip: 3, sample_id_all: 1 dummy:u: type: 1 (PERF_TYPE_SOFTWARE), size: 144, config: 0x9 (PERF_COUNT_SW_DUMMY), { sample_period, sample_freq }: 1, sample_type: IP|TID|TIME|CPU|IDENTIFIER, read_format: ID|LOST, exclude_kernel: 1, exclude_hv: 1, mmap: 1, comm: 1, task: 1, mmap_data: 1, sample_id_all: 1, exclude_guest: 1, mmap2: 1, comm_exec: 1, ksymbol: 1, bpf_event: 1, build_id: 1 root@x1:~# To complete, just with DATA_SRC, no mmap_data: root@x1:~# perf record --sample-mem-info -a sleep 1 [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 1.407 MB perf.data (1311 samples) ] root@x1:~# ls -la perf.data -rw-------. 1 root root 1509224 Dec 16 15:40 perf.data root@x1:~# perf evlist -v cpu_atom/cycles/P: type: 0 (PERF_TYPE_HARDWARE), size: 144, config: 0xa00000000 (cpu_atom/PERF_COUNT_HW_CPU_CYCLES/), { sample_period, sample_freq }: 4000, sample_type: IP|TID|TIME|CPU|PERIOD|IDENTIFIER|DATA_SRC, read_format: ID|LOST, disabled: 1, freq: 1, precise_ip: 3, sample_id_all: 1 cpu_core/cycles/P: type: 0 (PERF_TYPE_HARDWARE), size: 144, config: 0x400000000 (cpu_core/PERF_COUNT_HW_CPU_CYCLES/), { sample_period, sample_freq }: 4000, sample_type: IP|TID|TIME|CPU|PERIOD|IDENTIFIER|DATA_SRC, read_format: ID|LOST, disabled: 1, freq: 1, precise_ip: 3, sample_id_all: 1 dummy:u: type: 1 (PERF_TYPE_SOFTWARE), size: 144, config: 0x9 (PERF_COUNT_SW_DUMMY), { sample_period, sample_freq }: 1, sample_type: IP|TID|TIME|CPU|IDENTIFIER|DATA_SRC, read_format: ID|LOST, exclude_kernel: 1, exclude_hv: 1, mmap: 1, comm: 1, task: 1, sample_id_all: 1, exclude_guest: 1, mmap2: 1, comm_exec: 1, ksymbol: 1, bpf_event: 1, build_id: 1 root@x1:~# Reviewed-by: Ian Rogers <irogers@google.com> Signed-off-by: Namhyung Kim <namhyung@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: James Clark <james.clark@linaro.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2025-12-17perf vendor power9 nest metrics: Correct unit from MB to MiBIan Rogers
6.1e-5 is very close to 1/16384, where 16384 is 2^14, i.e. a power of 2. When units are in powers of 2 the IEC unit is MiB (mebibytes) rather than MB (megabytes) where the values are powers of 10. This patch corrects the unit for uniformity and because such units may be pattern matched against. Reviewed-by: Madhavan Srinivasan <maddy@linux.ibm.com> Signed-off-by: Ian Rogers <irogers@google.com> Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com> Cc: Kajol Jain <kjain@linux.ibm.com> Link: https://lore.kernel.org/r/20251031162637.1456191-1-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2025-12-17perf trace: Don't change const char stringsArnaldo Carvalho de Melo
We got away with this so far but now with fedora 44 complaining about the return value of strchr et all, lets use strdup for good measure. Reviewed-by: Ian Rogers <irogers@google.com> Link: https://lore.kernel.org/r/20251211221756.96294-5-acme@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2025-12-17perf tools: Use const for variables receiving str{str,r?chr}() returnsArnaldo Carvalho de Melo
Newer glibc versions return const char for str{str,chr}() where the haystack/s is const so to avoid warnings like these on fedora 44 change some variables to const: 36 8.17 fedora:44 : FAIL gcc version 15.2.1 20251111 (Red Hat 15.2.1-4) (GCC) libbpf.c: In function 'kallsyms_cb': libbpf.c:8489:13: error: assignment discards 'const' qualifier from pointer target type [-Werror=discarded-qualifiers] 8489 | res = strstr(sym_name, ".llvm."); Reviewed-by: Ian Rogers <irogers@google.com> Link: https://lore.kernel.org/r/20251211221756.96294-4-acme@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2025-12-17perf diff: Constify strchr() return variablesArnaldo Carvalho de Melo
Newer glibc versions return const char for strchr() when the 's' arg is const, change the return variable to const to match that. Also we don't need to turn that ',' into a '\0', as strtol() will stop in the first invalid char. No need to touch read only memory. First noticed with fedora 44. Reviewed-by: Ian Rogers <irogers@google.com> Link: https://lore.kernel.org/r/20251211221756.96294-3-acme@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2025-12-17perf list: Remove unused 'sep' variableArnaldo Carvalho de Melo
It is just being set to the return of strchr() but never used, just ditch it and with it get rid of a warning about it not being const on fedora 44. Reviewed-by: Ian Rogers <irogers@google.com> Link: https://lore.kernel.org/r/20251211221756.96294-2-acme@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2025-12-16Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf after 6.19-rc1Alexei Starovoitov
Cross-merge BPF and other fixes after downstream PR. Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-12-17Merge tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpfLinus Torvalds
Pull bpf fixes from Alexei Starovoitov: - Fix BPF builds due to -fms-extensions. selftests (Alexei Starovoitov), bpftool (Quentin Monnet). - Fix build of net/smc when CONFIG_BPF_SYSCALL=y, but CONFIG_BPF_JIT=n (Geert Uytterhoeven) - Fix livepatch/BPF interaction and support reliable unwinding through BPF stack frames (Josh Poimboeuf) - Do not audit capability check in arm64 JIT (Ondrej Mosnacek) - Fix truncated dmabuf BPF iterator reads (T.J. Mercier) - Fix verifier assumptions of bpf_d_path's output buffer (Shuran Liu) - Fix warnings in libbpf when built with -Wdiscarded-qualifiers under C23 (Mikhail Gavrilov) * tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf: selftests/bpf: add regression test for bpf_d_path() bpf: Fix verifier assumptions of bpf_d_path's output buffer selftests/bpf: Add test for truncated dmabuf_iter reads bpf: Fix truncated dmabuf iterator reads x86/unwind/orc: Support reliable unwinding through BPF stack frames bpf: Add bpf_has_frame_pointer() bpf, arm64: Do not audit capability check in do_jit() libbpf: Fix -Wdiscarded-qualifiers under C23 bpftool: Fix build warnings due to MS extensions net: smc: SMC_HS_CTRL_BPF should depend on BPF_JIT selftests/bpf: Add -fms-extensions to bpf build flags
2025-12-16selftests/bpf: Add tests for the arena offset of globalsEmil Tsalapatis
Add tests for the new libbpf globals arena offset logic. The tests cover the case of globals being as large as the arena itself, and being smaller than the arena. In that case, the data is placed at the end of the arena, and the beginning of the arena is free. Signed-off-by: Emil Tsalapatis <emil@etsalapatis.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20251216173325.98465-6-emil@etsalapatis.com
2025-12-16libbpf: Move arena globals to the end of the arenaEmil Tsalapatis
Arena globals are currently placed at the beginning of the arena by libbpf. This is convenient, but prevents users from reserving guard pages in the beginning of the arena to identify NULL pointer dereferences. Adjust the load logic to place the globals at the end of the arena instead. Also modify bpftool to set the arena pointer in the program's BPF skeleton to point to the globals. Users now call bpf_map__initial_value() to find the beginning of the arena mapping and use the arena pointer in the skeleton to determine which part of the mapping holds the arena globals and which part is free. Suggested-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Emil Tsalapatis <emil@etsalapatis.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Eduard Zingerman <eddyz87@gmail.com> Link: https://lore.kernel.org/bpf/20251216173325.98465-5-emil@etsalapatis.com
2025-12-16libbpf: Turn relo_core->sym_off unsignedEmil Tsalapatis
The symbols' relocation offsets in BPF are stored in an int field, but cannot actually be negative. When in the next patch libbpf relocates globals to the end of the arena, it is also possible to have valid offsets > 2GiB that are used to calculate the final relo offsets. Avoid accidentally interpreting large offsets as negative by turning the sym_off field unsigned. Signed-off-by: Emil Tsalapatis <emil@etsalapatis.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Eduard Zingerman <eddyz87@gmail.com> Link: https://lore.kernel.org/bpf/20251216173325.98465-4-emil@etsalapatis.com
2025-12-16bpf/verifier: Do not limit maximum direct offset into arena mapEmil Tsalapatis
The verifier currently limits direct offsets into a map to 512MiB to avoid overflow during pointer arithmetic. However, this prevents arena maps from using direct addressing instructions to access data at the end of > 512MiB arena maps. This is necessary when moving arena globals to the end of the arena instead of the front. Refactor the verifier code to remove the offset calculation during direct value access calculations. This is possible because the only two map types that implement .map_direct_value_addr() are arrays and arenas, and they both do their own internal checks to ensure the offset is within bounds. Adjust selftests that expect the old error. These tests still fail because the verifier identifies the access as out of bounds for the map, so change them to expect an "invalid access to map value pointer" error instead. Signed-off-by: Emil Tsalapatis <emil@etsalapatis.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20251216173325.98465-3-emil@etsalapatis.com
2025-12-16selftests/bpf: Explicitly account for globals in verifier_arena_largeEmil Tsalapatis
The big_alloc1 test in verifier_arena_large assumes that the arena base and the first page allocated by bpf_arena_alloc_pages are identical. This is not the case, because the first page in the arena is populated by global arena data. The test still passes because the code makes the tacit assumption that the first page is on offset PAGE_SIZE instead of 0. Make this distinction explicit in the code, and adjust the page offsets requested during the test to count from the beginning of the arena instead of using the address of the first allocated page. Signed-off-by: Emil Tsalapatis <emil@etsalapatis.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Reviewed-by: Eduard Zingerman <eddyz87@gmail.com> Link: https://lore.kernel.org/bpf/20251216173325.98465-2-emil@etsalapatis.com
2025-12-16Merge tag 'sched_ext-for-6.19-rc1-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext Pull sched_ext fixes from Tejun Heo: - Fix memory leak when destroying helper kthread workers during scheduler disable - Fix bypass depth accounting on scx_enable() failure which could leave the system permanently in bypass mode - Fix missing preemption handling when moving tasks to local DSQs via scx_bpf_dsq_move() - Misc fixes including NULL check for put_prev_task(), flushing stdout in selftests, and removing unused code * tag 'sched_ext-for-6.19-rc1-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext: sched_ext: Remove unused code in the do_pick_task_scx() selftests/sched_ext: flush stdout before test to avoid log spam sched_ext: Fix missing post-enqueue handling in move_local_task_to_local_dsq() sched_ext: Factor out local_dsq_post_enq() from dispatch_enqueue() sched_ext: Fix bypass depth leak on scx_enable() failure sched/ext: Avoid null ptr traversal when ->put_prev_task() is called with NULL next sched_ext: Fix the memleak for sch->helper objects
2025-12-15iommufd/selftest: Make it clearer to gcc that the access is not out of boundsJason Gunthorpe
GCC gets a bit confused and reports: In function '_test_cmd_get_hw_info', inlined from 'iommufd_ioas_get_hw_info' at iommufd.c:779:3, inlined from 'wrapper_iommufd_ioas_get_hw_info' at iommufd.c:752:1: >> iommufd_utils.h:804:37: warning: array subscript 'struct iommu_test_hw_info[0]' is partly outside array bounds of 'struct iommu_test_hw_info_buffer_smaller[1]' [-Warray-bounds=] 804 | assert(!info->flags); | ~~~~^~~~~~~ iommufd.c: In function 'wrapper_iommufd_ioas_get_hw_info': iommufd.c:761:11: note: object 'buffer_smaller' of size 4 761 | } buffer_smaller; | ^~~~~~~~~~~~~~ While it is true that "struct iommu_test_hw_info[0]" is partly out of bounds of the input pointer, it is not true that info->flags is out of bounds. Unclear why it warns on this. Reuse an existing properly sized stack buffer and pass a truncated length instead to test the same thing. Fixes: af4fde93c319 ("iommufd/selftest: Add coverage for IOMMU_GET_HW_INFO ioctl") Link: https://patch.msgid.link/r/0-v1-63a2cffb09da+4486-iommufd_gcc_bounds_jgg@nvidia.com Reviewed-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Nicolin Chen <nicolinc@nvidia.com> Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202512032344.kaAcKFIM-lkp@intel.com/ Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2025-12-15tools/power cpupower: Show C0 in idle-info dumpKaushlendra Kumar
`cpupower idle-info -o` skipped C0 because the loop began at 1: before: states: C1 ... latency[002] residency[00002] C2 ... latency[010] residency[00020] C3 ... latency[133] residency[00600] after: states: C0 ... latency[000] residency[00000] C1 ... latency[002] residency[00002] C2 ... latency[010] residency[00020] C3 ... latency[133] residency[00600] Start iterating at index 0 so the idle report mirrors sysfs and includes C0 stats. Link: https://lore.kernel.org/r/20251202065403.1492807-1-kaushlendra.kumar@intel.com Signed-off-by: Kaushlendra Kumar <kaushlendra.kumar@intel.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2025-12-15tools/power cpupower: Reset errno before strtoull()Kaushlendra Kumar
cpuidle_state_get_one_value() never cleared errno before calling strtoull(), so a prior ERANGE caused every cpuidle counter read to return zero. Reset errno to 0 before the conversion so each sysfs read is evaluated independently. Link: https://lore.kernel.org/r/20251201121745.3776703-1-kaushlendra.kumar@intel.com Signed-off-by: Kaushlendra Kumar <kaushlendra.kumar@intel.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2025-12-15tools/cpupower: Use strcspn() to strip trailing newlineKaushlendra Kumar
Replace manual newline removal with strcspn() which is safer and cleaner. This avoids potential out-of-bounds access on empty strings and handles the case where no newline exists. Link: https://lore.kernel.org/r/20251127044536.715722-1-kaushlendra.kumar@intel.com Signed-off-by: Kaushlendra Kumar <kaushlendra.kumar@intel.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2025-12-15tools/cpupower: Fix inverted APERF capability checkKaushlendra Kumar
The capability check was inverted, causing the function to return error when APERF support is available and proceed when it is not. Negate the condition to return error only when APERF capability is absent. Link: https://lore.kernel.org/r/20251126091613.567480-1-kaushlendra.kumar@intel.com Signed-off-by: Kaushlendra Kumar <kaushlendra.kumar@intel.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2025-12-15cpupower: idle_monitor: fix incorrect value logged after stopKaushlendra Kumar
The cpuidle sysfs monitor printed the previous sample’s counter value in cpuidle_stop() instead of the freshly read one. The dprint line used previous_count[cpu][state] while current_count[cpu][state] had just been populated. This caused misleading debug output. Switch the logging to current_count so the post-interval snapshot matches the displayed value. Link: https://lore.kernel.org/r/20251202044012.3844790-1-kaushlendra.kumar@intel.com Signed-off-by: Kaushlendra Kumar <kaushlendra.kumar@intel.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2025-12-15selftests: netfilter: packetdrill: avoid failure on HZ=100 kernelFlorian Westphal
packetdrill --ip_version=ipv4 --mtu=1500 --tolerance_usecs=1000000 --non_fatal packet conntrack_syn_challenge_ack.pkt conntrack v1.4.8 (conntrack-tools): 1 flow entries have been shown. conntrack_syn_challenge_ack.pkt:32: error executing `conntrack -f $NFCT_IP_VERSION \ -L -p tcp --dport 8080 | grep UNREPLIED | grep -q SYN_SENT` command: non-zero status 1 Affected kernel had CONFIG_HZ=100; reset packet was still sitting in backlog. Reported-by: Yi Chen <yiche@redhat.com> Fixes: a8a388c2aae4 ("selftests: netfilter: add packetdrill based conntrack tests") Signed-off-by: Florian Westphal <fw@strlen.de>
2025-12-15selftests: statmount: tests for STATMOUNT_BY_FDBhavik Sachdev
Add tests for STATMOUNT_BY_FD flag, which adds support for passing a file descriptors to statmount(). The fd can also be on a "unmounted" mount (mount unmounted with MNT_DETACH), we also include tests for that. Co-developed-by: Andrei Vagin <avagin@gmail.com> Signed-off-by: Andrei Vagin <avagin@gmail.com> Signed-off-by: Bhavik Sachdev <b.sachdev1904@gmail.com> Link: https://patch.msgid.link/20251129091455.757724-4-b.sachdev1904@gmail.com Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-12-15lkdtm/bugs: Add cases for BUG and PANIC occurring in hardirq contextArd Biesheuvel
Add lkdtm cases to trigger a BUG() or panic() from hardirq context. This is useful for testing pstore behavior being invoked from such contexts. Reviewed-by: Kees Cook <kees@kernel.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2025-12-12selftests: ublk: add user copy test casesCaleb Sander Mateos
The ublk selftests cover every data copy mode except user copy. Add tests for user copy based on the existing test suite: - generic_14 ("basic recover function verification (user copy)") based on generic_04 and generic_05 - null_03 ("basic IO test with user copy") based on null_01 and null_02 - loop_06 ("write and verify over user copy") based on loop_01 and loop_03 - loop_07 ("mkfs & mount & umount with user copy") based on loop_02 and loop_04 - stripe_05 ("write and verify test on user copy") based on stripe_03 - stripe_06 ("mkfs & mount & umount on user copy") based on stripe_02 and stripe_04 - stress_06 ("run IO and remove device (user copy)") based on stress_01 and stress_03 - stress_07 ("run IO and kill ublk server (user copy)") based on stress_02 and stress_04 Signed-off-by: Caleb Sander Mateos <csander@purestorage.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-12-12selftests: ublk: add support for user copy to kublkCaleb Sander Mateos
The ublk selftests mock ublk server kublk supports every data copy mode except user copy. Add support for user copy to kublk, enabled via the --user_copy (-u) command line argument. On writes, issue pread() calls to copy the write data into the ublk_io's buffer before dispatching the write to the target implementation. On reads, issue pwrite() calls to copy read data from the ublk_io's buffer before committing the request. Copy in 2 KB chunks to provide some coverage of the offseting logic. Signed-off-by: Caleb Sander Mateos <csander@purestorage.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-12-12selftests: ublk: forbid multiple data copy modesCaleb Sander Mateos
The kublk mock ublk server allows multiple data copy mode arguments to be passed on the command line (--zero_copy, --get_data, and --auto_zc). The ublk device will be created with all the requested feature flags, however kublk will only use one of the modes to interact with request data (arbitrarily preferring auto_zc over zero_copy over get_data). To clarify the intent of the test, don't allow multiple data copy modes to be specified. --zero_copy and --auto_zc are allowed together for --auto_zc_fallback, which uses both copy modes. Don't set UBLK_F_USER_COPY for zero_copy, as it's a separate feature. Fix the test cases in test_stress_05 passing --get_data along with --zero_copy or --auto_zc. Signed-off-by: Caleb Sander Mateos <csander@purestorage.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-12-12selftests: ublk: don't share backing files between ublk serversCaleb Sander Mateos
stress_04 is missing a wait between blocks of tests, meaning multiple ublk servers will be running in parallel using the same backing files. Add a wait after each section to ensure each backing file is in use by a single ublk server at a time. Signed-off-by: Caleb Sander Mateos <csander@purestorage.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-12-12selftests: ublk: use auto_zc for PER_IO_DAEMON tests in stress_04Caleb Sander Mateos
stress_04 is described as "run IO and kill ublk server(zero copy)" but the --per_io_tasks tests cases don't use zero copy. Plus, one of the test cases is duplicated. Add --auto_zc to these test cases and --auto_zc_fallback to one of the duplicated ones. This matches the test cases in stress_03. Signed-off-by: Caleb Sander Mateos <csander@purestorage.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-12-12selftests: ublk: fix fio arguments in run_io_and_recover()Caleb Sander Mateos
run_io_and_recover() invokes fio with --size="${size}", but the variable size doesn't exist. Thus, the argument expands to --size=, which causes fio to exit immediately with an error without issuing any I/O. Pass the value for size as the first argument to the function. Signed-off-by: Caleb Sander Mateos <csander@purestorage.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-12-12selftests: ublk: remove unused ios map in seq_io.btCaleb Sander Mateos
The ios map populated by seq_io.bt is never read, so remove it. Signed-off-by: Caleb Sander Mateos <csander@purestorage.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-12-12selftests: ublk: correct last_rw map type in seq_io.btCaleb Sander Mateos
The last_rw map is initialized with a value of 0 but later assigned the value args.sector + args.nr_sector, which has type sector_t = u64. bpftrace complains about the type mismatch between int64 and uint64: trace/seq_io.bt:18:3-59: ERROR: Type mismatch for @last_rw: trying to assign value of type 'uint64' when map already contains a value of type 'int64' @last_rw[$dev, str($2)] = (args.sector + args.nr_sector); Cast the initial value to uint64 so bpftrace will load the program. Signed-off-by: Caleb Sander Mateos <csander@purestorage.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-12-12selftests: ublk: fix overflow in ublk_queue_auto_zc_fallback()Ming Lei
The functions ublk_queue_use_zc(), ublk_queue_use_auto_zc(), and ublk_queue_auto_zc_fallback() were returning int, but performing bitwise AND on q->flags which is __u64. When a flag bit is set in the upper 32 bits (beyond INT_MAX), the result of the bitwise AND operation could overflow when cast to int, leading to incorrect boolean evaluation. For example, if UBLKS_Q_AUTO_BUF_REG_FALLBACK is 0x8000000000000000: - (u64)flags & 0x8000000000000000 = 0x8000000000000000 - Cast to int: undefined behavior / incorrect value - Used in if(): may evaluate incorrectly Fix by: 1. Changing return type from int to bool for semantic correctness 2. Using !! to explicitly convert to boolean (0 or 1) This ensures the functions return proper boolean values regardless of which bit position the flags occupy in the 64-bit field. Fixes: c3a6d48f86da ("selftests: ublk: remove ublk queue self-defined flags") Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
generated by cgit v1.2.3 (git 2.39.1) at 2026-08-03 17:33:01 +0000