June 2024 - Linux-kselftest-mirror

[PATCH net-next v7 00/10] net: openvswitch: Add sample multicasting.

by Adrian Moreno

** Background ** Currently, OVS supports several packet sampling mechanisms (sFlow, per-bridge IPFIX, per-flow IPFIX). These end up being translated into a userspace action that needs to be handled by ovs-vswitchd's handler threads only to be forwarded to some third party application that will somehow process the sample and provide observability on the datapath. A particularly interesting use-case is controller-driven per-flow IPFIX sampling where the OpenFlow controller can add metadata to samples (via two 32bit integers) and this metadata is then available to the sample-collecting system for correlation. ** Problem ** The fact that sampled traffic share netlink sockets and handler thread time with upcalls, apart from being a performance bottleneck in the sample extraction itself, can severely compromise the datapath, yielding this solution unfit for highly loaded production systems. Users are left with little options other than guessing what sampling rate will be OK for their traffic pattern and system load and dealing with the lost accuracy. Looking at available infrastructure, an obvious candidated would be to use psample. However, it's current state does not help with the use-case at stake because sampled packets do not contain user-defined metadata. ** Proposal ** This series is an attempt to fix this situation by extending the existing psample infrastructure to carry a variable length user-defined cookie. The main existing user of psample is tc's act_sample. It is also extended to forward the action's cookie to psample. Finally, a new OVS action (OVS_SAMPLE_ATTR_PSAMPLE) is created. It accepts a group and an optional cookie and uses psample to multicast the packet and the metadata. -- v6 -> v7: - Rebased - Fixed typo in comment. v5 -> v6: - Renamed emit_sample -> psample - Addressed unused variable and conditionally compilation of function. v4 -> v5: - Rebased. - Removed lefover enum value and wrapped some long lines in selftests. v3 -> v4: - Rebased. - Addressed Jakub's comment on private and unused nla attributes. v2 -> v3: - Addressed comments from Simon, Aaron and Ilya. - Dropped probability propagation in nested sample actions. - Dropped patch v2's 7/9 in favor of a userspace implementation and consume skb if emit_sample is the last action, same as we do with userspace. - Split ovs-dpctl.py features in independent patches. v1 -> v2: - Create a new action ("emit_sample") rather than reuse existing "sample" one. - Add probability semantics to psample's sampling rate. - Store sampling probability in skb's cb area and use it in emit_sample. - Test combining "emit_sample" with "trunc" - Drop group_id filtering and tracepoint in psample. rfc_v2 -> v1: - Accommodate Ilya's comments. - Split OVS's attribute in two attributes and simplify internal handling of psample arguments. - Extend psample and tc with a user-defined cookie. - Add a tracepoint to psample to facilitate troubleshooting. rfc_v1 -> rfc_v2: - Use psample instead of a new OVS-only multicast group. - Extend psample and tc with a user-defined cookie. Adrian Moreno (10): net: psample: add user cookie net: sched: act_sample: add action cookie to sample net: psample: skip packet copy if no listeners net: psample: allow using rate as probability net: openvswitch: add psample action net: openvswitch: store sampling probability in cb. selftests: openvswitch: add psample action selftests: openvswitch: add userspace parsing selftests: openvswitch: parse trunc action selftests: openvswitch: add psample test Documentation/netlink/specs/ovs_flow.yaml | 17 ++ include/net/psample.h | 5 +- include/uapi/linux/openvswitch.h | 31 +- include/uapi/linux/psample.h | 11 +- net/openvswitch/Kconfig | 1 + net/openvswitch/actions.c | 65 ++++- net/openvswitch/datapath.h | 3 + net/openvswitch/flow_netlink.c | 32 ++- net/openvswitch/vport.c | 1 + net/psample/psample.c | 16 +- net/sched/act_sample.c | 12 + .../selftests/net/openvswitch/openvswitch.sh | 115 +++++++- .../selftests/net/openvswitch/ovs-dpctl.py | 272 +++++++++++++++++- 13 files changed, 565 insertions(+), 16 deletions(-) -- 2.45.2 Adrian Moreno (10): net: psample: add user cookie net: sched: act_sample: add action cookie to sample net: psample: skip packet copy if no listeners net: psample: allow using rate as probability net: openvswitch: add psample action net: openvswitch: store sampling probability in cb. selftests: openvswitch: add psample action selftests: openvswitch: add userspace parsing selftests: openvswitch: parse trunc action selftests: openvswitch: add psample test Documentation/netlink/specs/ovs_flow.yaml | 17 ++ include/net/psample.h | 5 +- include/uapi/linux/openvswitch.h | 31 +- include/uapi/linux/psample.h | 11 +- net/openvswitch/Kconfig | 1 + net/openvswitch/actions.c | 65 ++++- net/openvswitch/datapath.h | 3 + net/openvswitch/flow_netlink.c | 32 ++- net/openvswitch/vport.c | 1 + net/psample/psample.c | 16 +- net/sched/act_sample.c | 12 + .../selftests/net/openvswitch/openvswitch.sh | 115 +++++++- .../selftests/net/openvswitch/ovs-dpctl.py | 272 +++++++++++++++++- 13 files changed, 565 insertions(+), 16 deletions(-) -- 2.45.2

1 year, 3 months

4
9
0 0

[PATCH v1 0/2] riscv: Expose orig_a0 to userspace for ptrace to set the actual a0

by zhouquan＠iscas.ac.cn

From: Quan Zhou <zhouquan(a)iscas.ac.cn> Due to the path that modifies a0 in syscall_enter_from_user_mode before the actual execution of syscall_handler [1], the kernel currently saves a0 to orig_a0 at the entry point of do_trap_ecall_u as an original copy of a0. Once the syscall is interrupted and later resumed, the restarted syscall will use orig_a0 to continue execution. The above rules generally apply except for ptrace(PTRACE_SETREGSET,), where the kernel will ignore the tracer's setting of tracee/a0 and will restart with the tracee/orig_a0. For the current kernel implementation of ptrace, projects like CRIU/Proot will encounter issues where the a0 setting becomes ineffective when performing ptrace(PTRACE_SETREGSET,). Here is a suggested solution, expose orig_a0 to userspace so that ptrace can choose whether to set orig_a0 based on the actual scenario. In fact, x86/orig_eax and loongArch/orig_a0 have adopted similar solutions. [1] link: https://lore.kernel.org/lkml/20230403-crisping-animosity-04ed8a45c625@spud/… --- Changes from RFC->v1: - Rebased on Linux 6.10-rc5. - Updated the patch description. - Adjust MAX_REG_OFFSET to match the new bottom of pt_regs (Charlie). - Simplify selftest to verify if a0 can be set (Charlie). - Fix .gitignore error (Charlie). --- RFC link: https://lore.kernel.org/all/cover.1718693532.git.zhouquan@iscas.ac.cn/ Quan Zhou (2): riscv: Expose orig_a0 in the user_regs_struct structure riscv: selftests: Add a ptrace test to verify syscall parameter modification arch/riscv/include/asm/ptrace.h | 7 +- arch/riscv/include/uapi/asm/ptrace.h | 2 + tools/testing/selftests/riscv/Makefile | 2 +- tools/testing/selftests/riscv/abi/.gitignore | 1 + tools/testing/selftests/riscv/abi/Makefile | 12 ++ tools/testing/selftests/riscv/abi/ptrace.c | 124 +++++++++++++++++++ 6 files changed, 144 insertions(+), 4 deletions(-) create mode 100644 tools/testing/selftests/riscv/abi/.gitignore create mode 100644 tools/testing/selftests/riscv/abi/Makefile create mode 100644 tools/testing/selftests/riscv/abi/ptrace.c base-commit: f2661062f16b2de5d7b6a5c42a9a5c96326b8454 -- 2.34.1

1 year, 3 months

2
4
0 0

[PATCH] kunit/usercopy: Add missing MODULE_DESCRIPTION()

by Kees Cook

From: Jeff Johnson <quic_jjohnson(a)quicinc.com> Fix warning seen with: $ make allmodconfig && make W=1 C=1 lib/usercopy_kunit.ko WARNING: modpost: missing MODULE_DESCRIPTION() in lib/usercopy_kunit.o Signed-off-by: Jeff Johnson <quic_jjohnson(a)quicinc.com> Signed-off-by: Kees Cook <kees(a)kernel.org> --- At Jeff's reminder, I've split this out of: https://lore.kernel.org/all/20240601-md-lib-test-v1-1-a728620e37d8@quicinc.… since the file got renamed. --- Cc: Shuah Khan <skhan(a)linuxfoundation.org> Cc: Jeff Johnson <quic_jjohnson(a)quicinc.com> Cc: Brendan Higgins <brendan.higgins(a)linux.dev> Cc: David Gow <davidgow(a)google.com> Cc: Rae Moar <rmoar(a)google.com> Cc: "Gustavo A. R. Silva" <gustavoars(a)kernel.org> Cc: Andrew Morton <akpm(a)linux-foundation.org> Cc: linux-kselftest(a)vger.kernel.org Cc: kunit-dev(a)googlegroups.com Cc: linux-hardening(a)vger.kernel.org Cc: linux-mm(a)kvack.org --- lib/usercopy_kunit.c | 1 + 1 file changed, 1 insertion(+) diff --git a/lib/usercopy_kunit.c b/lib/usercopy_kunit.c index e819561a540d..77fa00a13df7 100644 --- a/lib/usercopy_kunit.c +++ b/lib/usercopy_kunit.c @@ -331,4 +331,5 @@ static struct kunit_suite usercopy_test_suite = { kunit_test_suites(&usercopy_test_suite); MODULE_AUTHOR("Kees Cook <kees(a)kernel.org>"); +MODULE_DESCRIPTION("Kernel module for testing copy_to/from_user infrastructure"); MODULE_LICENSE("GPL"); -- 2.34.1

1 year, 3 months

3
2
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[PATCH] selftests: tpm2: conform test to TAP output

by Muhammad Usama Anjum

The python unittest is being used for executing tests. TAP output cannot be added in the unittest framework. The python unittest is being run from a script. Add the output TAP logs to the script. Add "#" prefix to the python unittest output which will mark all output as informational TAP messages. Check exit status of the python unittest to decide if test passed or failed. Not sure why but python unittest outputs logs in stderr. So redirect the logs to stdout and then add prefix. Specify the bash explicitly instead of sh to run these tests as all of the kselftests are shifting towards using bash explicitly. Some interpreters have different syntax and cause issues. Signed-off-by: Muhammad Usama Anjum <usama.anjum(a)collabora.com> --- tools/testing/selftests/tpm2/test_async.sh | 24 ++++++++++++++++------ tools/testing/selftests/tpm2/test_smoke.sh | 19 ++++++++++++++--- tools/testing/selftests/tpm2/test_space.sh | 19 ++++++++++++++--- 3 files changed, 50 insertions(+), 12 deletions(-) diff --git a/tools/testing/selftests/tpm2/test_async.sh b/tools/testing/selftests/tpm2/test_async.sh index 43bf5bd772fd4..0e6e5d9d649fb 100755 --- a/tools/testing/selftests/tpm2/test_async.sh +++ b/tools/testing/selftests/tpm2/test_async.sh @@ -1,10 +1,22 @@ -#!/bin/sh +#!/bin/bash # SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) -# Kselftest framework requirement - SKIP code is 4. -ksft_skip=4 +DIR="$(dirname $(readlink -f "$0"))" +source "${DIR}"/../kselftest/ktap_helpers.sh -[ -e /dev/tpm0 ] || exit $ksft_skip -[ -e /dev/tpmrm0 ] || exit $ksft_skip +ktap_print_header -python3 -m unittest -v tpm2_tests.AsyncTest +[ -e /dev/tpm0 ] || ktap_finished +[ -e /dev/tpmrm0 ] || ktap_finished + +ktap_set_plan 1 + +python3 -m unittest -v tpm2_tests.AsyncTest 2>&1 | sed "s/^/# /" + +if [ ${PIPESTATUS[0]} -eq $ksft_pass ]; then + ktap_test_pass "tpm2_tests.AsyncTest" +else + ktap_test_fail "tpm2_tests.AsyncTest" +fi + +ktap_finished diff --git a/tools/testing/selftests/tpm2/test_smoke.sh b/tools/testing/selftests/tpm2/test_smoke.sh index 58af963e5b55a..2219a180de91d 100755 --- a/tools/testing/selftests/tpm2/test_smoke.sh +++ b/tools/testing/selftests/tpm2/test_smoke.sh @@ -1,9 +1,22 @@ -#!/bin/sh +#!/bin/bash # SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) # Kselftest framework requirement - SKIP code is 4. -ksft_skip=4 +DIR="$(dirname $(readlink -f "$0"))" +source "${DIR}"/../kselftest/ktap_helpers.sh + +ktap_print_header [ -e /dev/tpm0 ] || exit $ksft_skip -python3 -m unittest -v tpm2_tests.SmokeTest +ktap_set_plan 1 + +python3 -m unittest -v tpm2_tests.SmokeTest 2>&1 | sed "s/^/# /" + +if [ ${PIPESTATUS[0]} -eq $ksft_pass ]; then + ktap_test_pass "tpm2_tests.AsyncTest" +else + ktap_test_fail "tpm2_tests.AsyncTest" +fi + +ktap_finished diff --git a/tools/testing/selftests/tpm2/test_space.sh b/tools/testing/selftests/tpm2/test_space.sh index 04c47b13fe8ac..6a55d13d74983 100755 --- a/tools/testing/selftests/tpm2/test_space.sh +++ b/tools/testing/selftests/tpm2/test_space.sh @@ -1,9 +1,22 @@ -#!/bin/sh +#!/bin/bash # SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) # Kselftest framework requirement - SKIP code is 4. -ksft_skip=4 +DIR="$(dirname $(readlink -f "$0"))" +source "${DIR}"/../kselftest/ktap_helpers.sh + +ktap_print_header [ -e /dev/tpmrm0 ] || exit $ksft_skip -python3 -m unittest -v tpm2_tests.SpaceTest +ktap_set_plan 1 + +python3 -m unittest -v tpm2_tests.SpaceTest 2>&1 | sed "s/^/# /" + +if [ ${PIPESTATUS[0]} -eq $ksft_pass ]; then + ktap_test_pass "tpm2_tests.AsyncTest" +else + ktap_test_fail "tpm2_tests.AsyncTest" +fi + +ktap_finished -- 2.39.2

1 year, 3 months

2
3
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[PATCH] selftests/bpf:Delete extra blank Lines

by Zhu Jun

Delete extra blank lines inside of test_selftest() Signed-off-by: Zhu Jun <zhujun2(a)cmss.chinamobile.com> --- tools/testing/selftests/bpf/test_sockmap.c | 1 - 1 file changed, 1 deletion(-) diff --git a/tools/testing/selftests/bpf/test_sockmap.c b/tools/testing/selftests/bpf/test_sockmap.c index 92752f5eeded..a34e95040994 100644 --- a/tools/testing/selftests/bpf/test_sockmap.c +++ b/tools/testing/selftests/bpf/test_sockmap.c @@ -1970,7 +1970,6 @@ static void test_selftests_ktls(int cg_fd, struct sockmap_options *opt) static int test_selftest(int cg_fd, struct sockmap_options *opt) { - test_selftests_sockmap(cg_fd, opt); test_selftests_sockhash(cg_fd, opt); test_selftests_ktls(cg_fd, opt); -- 2.17.1

1 year, 3 months

2
1
0 0

[PATCH] selftests/bpf:fix a resource leak

by Zhu Jun

The requested resources should be closed before return in main(), otherwise resource leak will occur Signed-off-by: Zhu Jun <zhujun2(a)cmss.chinamobile.com> --- tools/testing/selftests/bpf/test_sockmap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/testing/selftests/bpf/test_sockmap.c b/tools/testing/selftests/bpf/test_sockmap.c index a34e95040994..03d5dd617c4a 100644 --- a/tools/testing/selftests/bpf/test_sockmap.c +++ b/tools/testing/selftests/bpf/test_sockmap.c @@ -2092,7 +2092,7 @@ int main(int argc, char **argv) if (err) { fprintf(stderr, "populate program: (%s) %s\n", bpf_file, strerror(errno)); - return 1; + goto out; } running = 1; -- 2.17.1

1 year, 3 months

3
3
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[PATCH v7 0/1] Centralize _GNU_SOURCE definition into lib.mk

by Edward Liaw

Centralizes the definition of _GNU_SOURCE into lib.mk and addresses all resulting macro redefinition warnings. The initial attempt at this patch was abandoned because it affected lines in many source files and caused a large amount of churn. However, from earlier discussions, centralizing _GNU_SOURCE is still desireable. This attempt limits the changes to 1 source file and 14 Makefiles. This is condensed into a single commit to avoid redefinition warnings from partial merges. v1: https://lore.kernel.org/linux-kselftest/20240430235057.1351993-1-edliaw@goo… v2: https://lore.kernel.org/linux-kselftest/20240507214254.2787305-1-edliaw@goo… - Add -D_GNU_SOURCE to KHDR_INCLUDES so that it is in a single location. - Remove #define _GNU_SOURCE from source code to resolve redefinition warnings. v3: https://lore.kernel.org/linux-kselftest/20240509200022.253089-1-edliaw@goog… - Rebase onto linux-next 20240508. - Split patches by directory. - Add -D_GNU_SOURCE directly to CFLAGS in lib.mk. - Delete additional _GNU_SOURCE definitions from source code in linux-next. - Delete additional -D_GNU_SOURCE flags from Makefiles. v4: https://lore.kernel.org/linux-kselftest/20240510000842.410729-1-edliaw@goog… - Rebase onto linux-next 20240509. - Remove Fixes tag from patches that drop _GNU_SOURCE definition. - Restore space between comment and includes for selftests/damon. v5: https://lore.kernel.org/linux-kselftest/20240522005913.3540131-1-edliaw@goo… - Rebase onto linux-next 20240521 - Drop initial patches that modify KHDR_INCLUDES. - Incorporate Mark Brown's patch to replace static_assert with warning. - Don't drop #define _GNU_SOURCE from nolibc and wireguard. - Change Makefiles for x86 and vDSO to append to CFLAGS. v6: https://lore.kernel.org/linux-kselftest/20240624232718.1154427-1-edliaw@goo… - Rewrite patch to use -D_GNU_SOURCE= form in lib.mk. - Reduce the amount of churn significantly by allowing definition to coexist with source code macro defines. v7: - Squash patch into a single commit. Edward Liaw (1): selftests: Centralize -D_GNU_SOURCE= to CFLAGS in lib.mk tools/testing/selftests/exec/Makefile | 1 - tools/testing/selftests/futex/functional/Makefile | 2 +- tools/testing/selftests/intel_pstate/Makefile | 2 +- tools/testing/selftests/iommu/Makefile | 2 -- tools/testing/selftests/kvm/Makefile | 2 +- tools/testing/selftests/lib.mk | 3 +++ tools/testing/selftests/mm/thuge-gen.c | 2 +- tools/testing/selftests/net/Makefile | 2 +- tools/testing/selftests/net/tcp_ao/Makefile | 2 +- tools/testing/selftests/proc/Makefile | 1 - tools/testing/selftests/resctrl/Makefile | 2 +- tools/testing/selftests/ring-buffer/Makefile | 1 - tools/testing/selftests/riscv/mm/Makefile | 2 +- tools/testing/selftests/sgx/Makefile | 2 +- tools/testing/selftests/tmpfs/Makefile | 1 - 15 files changed, 12 insertions(+), 15 deletions(-) -- 2.45.2.803.g4e1b14247a-goog

1 year, 3 months

3
3
0 0

[PATCH v7 0/4] Userspace controls soft-offline pages

by Jiaqi Yan

Correctable memory errors are very common on servers with large amount of memory, and are corrected by ECC, but with two pain points to users: 1. Correction usually happens on the fly and adds latency overhead 2. Not-fully-proved theory states excessive correctable memory errors can develop into uncorrectable memory error. Soft offline is kernel's additional solution for memory pages having (excessive) corrected memory errors. Impacted page is migrated to healthy page if it is in use, then the original page is discarded for any future use. The actual policy on whether (and when) to soft offline should be maintained by userspace, especially in case of an 1G HugeTLB page. Soft-offline dissolves the HugeTLB page, either in-use or free, into chunks of 4K pages, reducing HugeTLB pool capacity by 1 hugepage. If userspace has not acknowledged such behavior, it may be surprised when later mmap hugepages MAP_FAILED due to lack of hugepages. In case of a transparent hugepage, it will be split into 4K pages as well; userspace will stop enjoying the transparent performance. In addition, discarding the entire 1G HugeTLB page only because of corrected memory errors sounds very costly and kernel better not doing under the hood. But today there are at least 2 such cases: 1. GHES driver sees both GHES_SEV_CORRECTED and CPER_SEC_ERROR_THRESHOLD_EXCEEDED after parsing CPER. 2. RAS Correctable Errors Collector counts correctable errors per PFN and when the counter for a PFN reaches threshold In both cases, userspace has no control of the soft offline performed by kernel's memory failure recovery. This patch series give userspace the control of softofflining any page: kernel only soft offlines raw page / transparent hugepage / HugeTLB hugepage if userspace has agreed to. The interface to userspace is a new sysctl called enable_soft_offline under /proc/sys/vm. By default enable_soft_line is 1 to preserve existing behavior in kernel. Changelog v6 => v7 * incorporate feedbacks from Miaohe Lin <linmiaohe(a)huawei.com> and David Rientjes <rientjes(a)google.com> * remove PFN value from enable_soft_offline log * save/restore enable_soft_offline in run_vmtests.sh * v7 is based on commit 7c89bdbd3778 ("khugepaged: simplify the allocation of slab caches") v5 => v6: * incorporate feedbacks from Miaohe Lin <linmiaohe(a)huawei.com> * add a ':' in soft offline log. * close hugetlbfs file descriptor in selftest. * no need to "return" after ksft_exit_fail_msg. v4 => v5: * incorporate feedbacks from Muhammad Usama Anjum <usama.anjum(a)collabora.com> * refactor selftest to use what available in kselftest.h v3 => v4: * incorporate feedbacks from Miaohe Lin <linmiaohe(a)huawei.com>, Andrew Morton <akpm(a)linux-foundation.org>, and Oscar Salvador <osalvador(a)suse.de>. * insert a refactor commit to unify soft offline's logs to follow "Soft offline: 0x${pfn}: ${message}" format. * some rewords in document: fail => will not perform. * v4 is still based on commit 83a7eefedc9b ("Linux 6.10-rc3"), akpm/mm-stable. v2 => v3: * incorporate feedbacks from Miaohe Lin <linmiaohe(a)huawei.com>, Lance Yang <ioworker0(a)gmail.com>, Oscar Salvador <osalvador(a)suse.de>, and David Rientjes <rientjes(a)google.com>. * release potential refcount if enable_soft_offline is 0. * soft_offline_page() returns EOPNOTSUPP if enable_soft_offline is 0. * refactor hugetlb-soft-offline.c, for example, introduce test_soft_offline_common to reduce repeated code. * rewrite enable_soft_offline's documentation, adds more details about the cost of soft-offline for transparent and hugetlb hugepages, and components that are impacted when enable_soft_offline becomes 0. * fix typos in commit messages. * v3 is still based on commit 83a7eefedc9b ("Linux 6.10-rc3"). v1 => v2: * incorporate feedbacks from both Miaohe Lin <linmiaohe(a)huawei.com> and Jane Chu <jane.chu(a)oracle.com>. * make the switch to control all pages, instead of HugeTLB specific. * change the API from /sys/kernel/mm/hugepages/hugepages-${size}kB/softoffline_corrected_errors to /proc/sys/vm/enable_soft_offline. * minor update to test code. * update documentation of the user control API. * v2 is based on commit 83a7eefedc9b ("Linux 6.10-rc3"). Jiaqi Yan (4): mm/memory-failure: refactor log format in soft offline code mm/memory-failure: userspace controls soft-offlining pages selftest/mm: test enable_soft_offline behaviors docs: mm: add enable_soft_offline sysctl Documentation/admin-guide/sysctl/vm.rst | 32 +++ mm/memory-failure.c | 37 ++- tools/testing/selftests/mm/.gitignore | 1 + tools/testing/selftests/mm/Makefile | 1 + .../selftests/mm/hugetlb-soft-offline.c | 228 ++++++++++++++++++ tools/testing/selftests/mm/run_vmtests.sh | 6 + 6 files changed, 297 insertions(+), 8 deletions(-) create mode 100644 tools/testing/selftests/mm/hugetlb-soft-offline.c -- 2.45.2.803.g4e1b14247a-goog

1 year, 3 months

3
7
0 0

[PATCH] selftests/proc: fix unused result warning during test compilation

by Abhinav Jain

Check the return value from write function to get rid of the warning during test compilation, shared below. Tested by compiling after the change, the warning disappears. proc-empty-vm.c:385:17: warning: ignoring return value of ‘write’ declared with attribute ‘warn_unused_result’ [-Wunused-result] 385 | write(1, buf, rv); Signed-off-by: Abhinav Jain <jain.abhinav177(a)gmail.com> --- tools/testing/selftests/proc/proc-empty-vm.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/proc/proc-empty-vm.c b/tools/testing/selftests/proc/proc-empty-vm.c index 56198d4ca2bf..510ab4a5330a 100644 --- a/tools/testing/selftests/proc/proc-empty-vm.c +++ b/tools/testing/selftests/proc/proc-empty-vm.c @@ -382,7 +382,12 @@ static int test_proc_pid_statm(pid_t pid) assert(rv >= 0); assert(rv <= sizeof(buf)); if (0) { - write(1, buf, rv); + ssize_t bytes_written = write(1, buf, rv); + + if (bytes_written != rv) { + perror("write"); + return EXIT_FAILURE; + } } const char *p = buf; -- 2.34.1

1 year, 3 months

2
4
0 0

[PATCH v2] selftests/proc: fix unused result warning during test compilation

by Abhinav Jain

Check the return value from write function to get rid of the warning during test compilation, shared below. Tested by compiling after the change, the warning disappears. proc-empty-vm.c:385:17: warning: ignoring return value of ‘write’ declared with attribute ‘warn_unused_result’ [-Wunused-result] 385 | write(1, buf, rv); Signed-off-by: Abhinav Jain <jain.abhinav177(a)gmail.com> --- Changes since v1: - Remove the redundant if(0) block as per the feedback - Patch v1: https://lore.kernel.org/all/20240625152139.16412-1-jain.abhinav177@gmail.co… --- tools/testing/selftests/proc/proc-empty-vm.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/proc/proc-empty-vm.c b/tools/testing/selftests/proc/proc-empty-vm.c index 56198d4ca2bf..123c622cd816 100644 --- a/tools/testing/selftests/proc/proc-empty-vm.c +++ b/tools/testing/selftests/proc/proc-empty-vm.c @@ -381,8 +381,12 @@ static int test_proc_pid_statm(pid_t pid) assert(rv >= 0); assert(rv <= sizeof(buf)); - if (0) { - write(1, buf, rv); + + ssize_t bytes_written = write(1, buf, rv); + + if (bytes_written != rv) { + perror("write"); + return EXIT_FAILURE; } const char *p = buf; -- 2.34.1

1 year, 3 months

1
0
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