October 2023 - Linux-kselftest-mirror

[PATCH v1 0/9] x86/resctrl: Use soft RMIDs for reliable MBM on AMD

by Peter Newman

Hi Reinette, Fenghua, This series introduces a new mount option enabling an alternate mode for MBM to work around an issue on present AMD implementations and any other resctrl implementation where there are more RMIDs (or equivalent) than hardware counters. The L3 External Bandwidth Monitoring feature of the AMD PQoS extension[1] only guarantees that RMIDs currently assigned to a processor will be tracked by hardware. The counters of any other RMIDs which are no longer being tracked will be reset to zero. The MBM event counters return "Unavailable" to indicate when this has happened. An interval for effectively measuring memory bandwidth typically needs to be multiple seconds long. In Google's workloads, it is not feasible to bound the number of jobs with different RMIDs which will run in a cache domain over any period of time. Consequently, on a fully-committed system where all RMIDs are allocated, few groups' counters return non-zero values. To demonstrate the underlying issue, the first patch provides a test case in tools/testing/selftests/resctrl/test_rmids.sh. On an AMD EPYC 7B12 64-Core Processor with the default behavior: # ./test_rmids.sh Created 255 monitoring groups. g1: mbm_total_bytes: Unavailable -> Unavailable (FAIL) g2: mbm_total_bytes: Unavailable -> Unavailable (FAIL) g3: mbm_total_bytes: Unavailable -> Unavailable (FAIL) [..] g238: mbm_total_bytes: Unavailable -> Unavailable (FAIL) g239: mbm_total_bytes: Unavailable -> Unavailable (FAIL) g240: mbm_total_bytes: Unavailable -> Unavailable (FAIL) g241: mbm_total_bytes: Unavailable -> 660497472 g242: mbm_total_bytes: Unavailable -> 660793344 g243: mbm_total_bytes: Unavailable -> 660477312 g244: mbm_total_bytes: Unavailable -> 660495360 g245: mbm_total_bytes: Unavailable -> 660775360 g246: mbm_total_bytes: Unavailable -> 660645504 g247: mbm_total_bytes: Unavailable -> 660696128 g248: mbm_total_bytes: Unavailable -> 660605248 g249: mbm_total_bytes: Unavailable -> 660681280 g250: mbm_total_bytes: Unavailable -> 660834240 g251: mbm_total_bytes: Unavailable -> 660440064 g252: mbm_total_bytes: Unavailable -> 660501504 g253: mbm_total_bytes: Unavailable -> 660590720 g254: mbm_total_bytes: Unavailable -> 660548352 g255: mbm_total_bytes: Unavailable -> 660607296 255 groups, 0 returned counts in first pass, 15 in second successfully measured bandwidth from 15/255 groups To compare, here is the output from an Intel(R) Xeon(R) Platinum 8173M CPU: # ./test_rmids.sh Created 223 monitoring groups. g1: mbm_total_bytes: 0 -> 606126080 g2: mbm_total_bytes: 0 -> 613236736 g3: mbm_total_bytes: 0 -> 610254848 [..] g221: mbm_total_bytes: 0 -> 584679424 g222: mbm_total_bytes: 0 -> 588808192 g223: mbm_total_bytes: 0 -> 587317248 223 groups, 223 returned counts in first pass, 223 in second successfully measured bandwidth from 223/223 groups To make better use of the hardware in such a use case, this patchset introduces a "soft" RMID implementation, where each CPU is permanently assigned a "hard" RMID. On context switches which change the current soft RMID, the difference between each CPU's current event counts and most recent counts is added to the totals for the current or outgoing soft RMID. This technique does not work for cache occupancy counters, so this patch series disables cache occupancy events when soft RMIDs are enabled. This series adds the "mbm_soft_rmid" mount option to allow users to opt-in to the functionaltiy when they deem it helpful. When the same system from the earlier AMD example enables the mbm_soft_rmid mount option: # ./test_rmids.sh Created 255 monitoring groups. g1: mbm_total_bytes: 0 -> 686560576 g2: mbm_total_bytes: 0 -> 668204416 [..] g252: mbm_total_bytes: 0 -> 672651200 g253: mbm_total_bytes: 0 -> 666956800 g254: mbm_total_bytes: 0 -> 665917056 g255: mbm_total_bytes: 0 -> 671049600 255 groups, 255 returned counts in first pass, 255 in second successfully measured bandwidth from 255/255 groups (patches are based on tip/master) [1] https://www.amd.com/system/files/TechDocs/56375_1.03_PUB.pdf Peter Newman (8): selftests/resctrl: Verify all RMIDs count together x86/resctrl: Add resctrl_mbm_flush_cpu() to collect CPUs' MBM events x86/resctrl: Flush MBM event counts on soft RMID change x86/resctrl: Call mon_event_count() directly for soft RMIDs x86/resctrl: Create soft RMID version of __mon_event_count() x86/resctrl: Assign HW RMIDs to CPUs for soft RMID x86/resctrl: Use mbm_update() to push soft RMID counts x86/resctrl: Add mount option to enable soft RMID Stephane Eranian (1): x86/resctrl: Hold a spinlock in __rmid_read() on AMD arch/x86/include/asm/resctrl.h | 29 +++- arch/x86/kernel/cpu/resctrl/core.c | 80 ++++++++- arch/x86/kernel/cpu/resctrl/ctrlmondata.c | 9 +- arch/x86/kernel/cpu/resctrl/internal.h | 19 ++- arch/x86/kernel/cpu/resctrl/monitor.c | 158 +++++++++++++++++- arch/x86/kernel/cpu/resctrl/rdtgroup.c | 52 ++++++ tools/testing/selftests/resctrl/test_rmids.sh | 93 +++++++++++ 7 files changed, 425 insertions(+), 15 deletions(-) create mode 100755 tools/testing/selftests/resctrl/test_rmids.sh base-commit: dd806e2f030e57dd5bac973372aa252b6c175b73 -- 2.40.0.634.g4ca3ef3211-goog

1 year

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[PATCH v3 0/9] RISCV: Add kvm Sstc timer selftests

by Haibo Xu

The RISC-V arch_timer selftests is used to validate Sstc timer functionality in a guest, which sets up periodic timer interrupts and check the basic interrupt status upon its receipt. This KVM selftests was ported from aarch64 arch_timer and tested with Linux v6.6-rc1 on a Qemu riscv64 virt machine. --- Changed since v2: * Rebase to Linux 6.6-rc1 * Add separate patch for kvm/Makefile improvement * Move aarch64 specific macros to aarch64/arch_timer.c * Add -DCONFIG_64BIT to kvm/Makefile CFLAGS to ensure only 64bit registers were available in csr.h * Avoid some #ifdef in kvm/arch_timer.c by setting some aarch64 specific variable to 0 on risc-v Haibo Xu (9): KVM: selftests: Unify the codes for guest exception handling KVM: selftests: Unify the makefile rule for split targets KVM: arm64: selftests: Split arch_timer test code tools: riscv: Add header file csr.h KVM: riscv: selftests: Switch to use macro from csr.h KVM: riscv: selftests: Add exception handling support KVM: riscv: selftests: Add guest helper to get vcpu id KVM: riscv: selftests: Change vcpu_has_ext to a common function KVM: riscv: selftests: Add sstc timer test tools/arch/riscv/include/asm/csr.h | 521 ++++++++++++++++++ tools/testing/selftests/kvm/Makefile | 14 +- .../selftests/kvm/aarch64/arch_timer.c | 291 +--------- .../selftests/kvm/aarch64/debug-exceptions.c | 4 +- .../selftests/kvm/aarch64/page_fault_test.c | 4 +- .../testing/selftests/kvm/aarch64/vgic_irq.c | 4 +- tools/testing/selftests/kvm/arch_timer.c | 250 +++++++++ .../selftests/kvm/include/aarch64/processor.h | 12 +- .../selftests/kvm/include/kvm_util_base.h | 9 + .../selftests/kvm/include/riscv/arch_timer.h | 80 +++ .../selftests/kvm/include/riscv/processor.h | 63 ++- .../testing/selftests/kvm/include/test_util.h | 2 + .../selftests/kvm/include/timer_test.h | 43 ++ .../selftests/kvm/include/x86_64/processor.h | 5 - .../selftests/kvm/lib/aarch64/processor.c | 6 +- .../selftests/kvm/lib/riscv/handlers.S | 101 ++++ .../selftests/kvm/lib/riscv/processor.c | 86 +++ .../selftests/kvm/lib/x86_64/processor.c | 4 +- .../testing/selftests/kvm/riscv/arch_timer.c | 107 ++++ .../selftests/kvm/riscv/get-reg-list.c | 16 +- tools/testing/selftests/kvm/x86_64/amx_test.c | 4 +- .../selftests/kvm/x86_64/fix_hypercall_test.c | 4 +- .../selftests/kvm/x86_64/hyperv_evmcs.c | 4 +- .../selftests/kvm/x86_64/hyperv_features.c | 8 +- .../testing/selftests/kvm/x86_64/hyperv_ipi.c | 6 +- .../selftests/kvm/x86_64/kvm_pv_test.c | 4 +- .../selftests/kvm/x86_64/monitor_mwait_test.c | 4 +- .../kvm/x86_64/pmu_event_filter_test.c | 8 +- .../smaller_maxphyaddr_emulation_test.c | 4 +- .../selftests/kvm/x86_64/svm_int_ctl_test.c | 4 +- .../kvm/x86_64/svm_nested_shutdown_test.c | 4 +- .../kvm/x86_64/svm_nested_soft_inject_test.c | 4 +- .../kvm/x86_64/ucna_injection_test.c | 8 +- .../kvm/x86_64/userspace_msr_exit_test.c | 4 +- .../vmx_exception_with_invalid_guest_state.c | 4 +- .../selftests/kvm/x86_64/vmx_pmu_caps_test.c | 4 +- .../selftests/kvm/x86_64/xapic_ipi_test.c | 4 +- .../selftests/kvm/x86_64/xcr0_cpuid_test.c | 4 +- .../selftests/kvm/x86_64/xen_shinfo_test.c | 4 +- 39 files changed, 1338 insertions(+), 374 deletions(-) create mode 100644 tools/arch/riscv/include/asm/csr.h create mode 100644 tools/testing/selftests/kvm/arch_timer.c create mode 100644 tools/testing/selftests/kvm/include/riscv/arch_timer.h create mode 100644 tools/testing/selftests/kvm/include/timer_test.h create mode 100644 tools/testing/selftests/kvm/lib/riscv/handlers.S create mode 100644 tools/testing/selftests/kvm/riscv/arch_timer.c -- 2.34.1

1 year

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[PATCH v2 RESEND] kunit: debugfs: Handle errors from alloc_string_stream()

by Richard Fitzgerald

In kunit_debugfs_create_suite() give up and skip creating the debugfs file if any of the alloc_string_stream() calls return an error or NULL. Only put a value in the log pointer of kunit_suite and kunit_test if it is a valid pointer to a log. This prevents the potential invalid dereference reported by smatch: lib/kunit/debugfs.c:115 kunit_debugfs_create_suite() error: 'suite->log' dereferencing possible ERR_PTR() lib/kunit/debugfs.c:119 kunit_debugfs_create_suite() error: 'test_case->log' dereferencing possible ERR_PTR() Signed-off-by: Richard Fitzgerald <rf(a)opensource.cirrus.com> Reported-by: Dan Carpenter <dan.carpenter(a)linaro.org> Fixes: 05e2006ce493 ("kunit: Use string_stream for test log") --- lib/kunit/debugfs.c | 30 +++++++++++++++++++++++++----- 1 file changed, 25 insertions(+), 5 deletions(-) diff --git a/lib/kunit/debugfs.c b/lib/kunit/debugfs.c index 270d185737e6..9d167adfa746 100644 --- a/lib/kunit/debugfs.c +++ b/lib/kunit/debugfs.c @@ -109,14 +109,28 @@ static const struct file_operations debugfs_results_fops = { void kunit_debugfs_create_suite(struct kunit_suite *suite) { struct kunit_case *test_case; + struct string_stream *stream; - /* Allocate logs before creating debugfs representation. */ - suite->log = alloc_string_stream(GFP_KERNEL); - string_stream_set_append_newlines(suite->log, true); + /* + * Allocate logs before creating debugfs representation. + * The suite->log and test_case->log pointer are expected to be NULL + * if there isn't a log, so only set it if the log stream was created + * successfully. + */ + stream = alloc_string_stream(GFP_KERNEL); + if (IS_ERR_OR_NULL(stream)) + return; + + string_stream_set_append_newlines(stream, true); + suite->log = stream; kunit_suite_for_each_test_case(suite, test_case) { - test_case->log = alloc_string_stream(GFP_KERNEL); - string_stream_set_append_newlines(test_case->log, true); + stream = alloc_string_stream(GFP_KERNEL); + if (IS_ERR_OR_NULL(stream)) + goto err; + + string_stream_set_append_newlines(stream, true); + test_case->log = stream; } suite->debugfs = debugfs_create_dir(suite->name, debugfs_rootdir); @@ -124,6 +138,12 @@ void kunit_debugfs_create_suite(struct kunit_suite *suite) debugfs_create_file(KUNIT_DEBUGFS_RESULTS, S_IFREG | 0444, suite->debugfs, suite, &debugfs_results_fops); + return; + +err: + string_stream_destroy(suite->log); + kunit_suite_for_each_test_case(suite, test_case) + string_stream_destroy(test_case->log); } void kunit_debugfs_destroy_suite(struct kunit_suite *suite) -- 2.30.2

1 year

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[PATCH RESEND] kunit: string-stream: Allow ERR_PTR to be passed to string_stream_destroy()

by Richard Fitzgerald

Check the stream pointer passed to string_stream_destroy() for IS_ERR_OR_NULL() instead of only NULL. Whatever alloc_string_stream() returns should be safe to pass to string_stream_destroy(), and that will be an ERR_PTR. It's obviously good practise and generally helpful to also check for NULL pointers so that client cleanup code can call string_stream_destroy() unconditionally - which could include pointers that have never been set to anything and so are NULL. Signed-off-by: Richard Fitzgerald <rf(a)opensource.cirrus.com> --- lib/kunit/string-stream.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/lib/kunit/string-stream.c b/lib/kunit/string-stream.c index a6f3616c2048..54f4fdcbfac8 100644 --- a/lib/kunit/string-stream.c +++ b/lib/kunit/string-stream.c @@ -173,7 +173,7 @@ void string_stream_destroy(struct string_stream *stream) { KUNIT_STATIC_STUB_REDIRECT(string_stream_destroy, stream); - if (!stream) + if (IS_ERR_OR_NULL(stream)) return; string_stream_clear(stream); -- 2.30.2

1 year

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[PATCH] selftests: capabilities: namespace create varies for root and normal user

by Swarup Laxman Kotiaklapudi

Change namespace creation for root and non-root user differently in create_and_enter_ns() function Test result with root user: $sudo make TARGETS="capabilities" kselftest ... TAP version 13 1..1 timeout set to 45 selftests: capabilities: test_execve TAP version 13 1..12 [RUN] +++ Tests with uid == 0 +++ [NOTE] Using global UIDs for tests [RUN] Root => ep ... ok 12 Passed Totals: pass:12 fail:0 xfail:0 xpass:0 skip:0 error:0 ================================================== TAP version 13 1..9 [RUN] +++ Tests with uid != 0 +++ [NOTE] Using global UIDs for tests [RUN] Non-root => no caps ... ok 9 Passed Totals: pass:9 fail:0 xfail:0 xpass:0 skip:0 error:0 Test result without root or normal user: $make TARGETS="capabilities" kselftest ... timeout set to 45 selftests: capabilities: test_execve TAP version 13 1..12 [RUN] +++ Tests with uid == 0 +++ [NOTE] Using a user namespace for tests [RUN] Root => ep validate_cap:: Capabilities after execve were correct ok 1 Passed Check cap_ambient manipulation rules ok 2 PR_CAP_AMBIENT_RAISE failed on non-inheritable cap ok 3 PR_CAP_AMBIENT_RAISE failed on non-permitted cap ok 4 PR_CAP_AMBIENT_RAISE worked ok 5 Basic manipulation appears to work [RUN] Root +i => eip validate_cap:: Capabilities after execve were correct ok 6 Passed [RUN] UID 0 +ia => eipa validate_cap:: Capabilities after execve were correct ok 7 Passed ok 8 # SKIP SUID/SGID tests (needs privilege) Planned tests != run tests (12 != 8) Totals: pass:7 fail:0 xfail:0 xpass:0 skip:1 error:0 ================================================== TAP version 13 1..9 [RUN] +++ Tests with uid != 0 +++ [NOTE] Using a user namespace for tests [RUN] Non-root => no caps validate_cap:: Capabilities after execve were correct ok 1 Passed Check cap_ambient manipulation rules ok 2 PR_CAP_AMBIENT_RAISE failed on non-inheritable cap ok 3 PR_CAP_AMBIENT_RAISE failed on non-permitted cap ok 4 PR_CAP_AMBIENT_RAISE worked ok 5 Basic manipulation appears to work [RUN] Non-root +i => i validate_cap:: Capabilities after execve were correct ok 6 Passed [RUN] UID 1 +ia => eipa validate_cap:: Capabilities after execve were correct ok 7 Passed ok 8 # SKIP SUID/SGID tests (needs privilege) Planned tests != run tests (9 != 8) Totals: pass:7 fail:0 xfail:0 xpass:0 skip:1 error:0 Signed-off-by: Swarup Laxman Kotiaklapudi <swarupkotikalapudi(a)gmail.com> --- tools/testing/selftests/capabilities/test_execve.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) diff --git a/tools/testing/selftests/capabilities/test_execve.c b/tools/testing/selftests/capabilities/test_execve.c index df0ef02b4036..8236150d377e 100644 --- a/tools/testing/selftests/capabilities/test_execve.c +++ b/tools/testing/selftests/capabilities/test_execve.c @@ -96,11 +96,7 @@ static bool create_and_enter_ns(uid_t inner_uid) outer_uid = getuid(); outer_gid = getgid(); - /* - * TODO: If we're already root, we could skip creating the userns. - */ - - if (unshare(CLONE_NEWNS) == 0) { + if (outer_uid == 0 && unshare(CLONE_NEWNS) == 0) { ksft_print_msg("[NOTE]\tUsing global UIDs for tests\n"); if (prctl(PR_SET_KEEPCAPS, 1, 0, 0, 0) != 0) ksft_exit_fail_msg("PR_SET_KEEPCAPS - %s\n", -- 2.34.1

1 year

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[PATCH v2] selftests: prctl: Add prctl test for PR_GET_NAME

by Osama Muhammad

This patch covers the testing of PR_GET_NAME by reading it's value from proc/self/task/pid/comm and matching it with the value returned by PR_GET_NAME. If the values are matched then it's successful, otherwise it fails. changes since v1: - Handled fscanf,fopen error checking. - Defined MAX_PATH_LEN. Signed-off-by: Osama Muhammad <osmtendev(a)gmail.com> --- .../selftests/prctl/set-process-name.c | 32 +++++++++++++++++++ 1 file changed, 32 insertions(+) diff --git a/tools/testing/selftests/prctl/set-process-name.c b/tools/testing/selftests/prctl/set-process-name.c index 3bc5e0e09..562f707ba 100644 --- a/tools/testing/selftests/prctl/set-process-name.c +++ b/tools/testing/selftests/prctl/set-process-name.c @@ -12,6 +12,7 @@ #define CHANGE_NAME "changename" #define EMPTY_NAME "" #define TASK_COMM_LEN 16 +#define MAX_PATH_LEN 50 int set_name(char *name) { @@ -47,6 +48,35 @@ int check_null_pointer(char *check_name) return res; } +int check_name(void) +{ + + int pid; + + pid = getpid(); + FILE *fptr = NULL; + char path[MAX_PATH_LEN] = {}; + char name[TASK_COMM_LEN] = {}; + char output[TASK_COMM_LEN] = {}; + int j; + + j = snprintf(path, MAX_PATH_LEN, "/proc/self/task/%d/comm", pid); + fptr = fopen(path, "r"); + if (!fptr) + return -EIO; + + fscanf(fptr, "%s", output); + if (ferror(fptr)) + return -EIO; + + int res = prctl(PR_GET_NAME, name, NULL, NULL, NULL); + + if (res < 0) + return -errno; + + return !strcmp(output, name); +} + TEST(rename_process) { EXPECT_GE(set_name(CHANGE_NAME), 0); @@ -57,6 +87,8 @@ TEST(rename_process) { EXPECT_GE(set_name(CHANGE_NAME), 0); EXPECT_LT(check_null_pointer(CHANGE_NAME), 0); + + EXPECT_TRUE(check_name()); } TEST_HARNESS_MAIN -- 2.34.1

1 year

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[PATCH RESEND] kunit: debugfs: Fix unchecked dereference in debugfs_print_results()

by Richard Fitzgerald

Move the call to kunit_suite_has_succeeded() after the check that the kunit_suite pointer is valid. This was found by smatch: lib/kunit/debugfs.c:66 debugfs_print_results() warn: variable dereferenced before check 'suite' (see line 63) Signed-off-by: Richard Fitzgerald <rf(a)opensource.cirrus.com> Reported-by: Dan Carpenter <dan.carpenter(a)linaro.org> Fixes: 38289a26e1b8 ("kunit: fix debugfs code to use enum kunit_status, not bool") --- lib/kunit/debugfs.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/lib/kunit/debugfs.c b/lib/kunit/debugfs.c index 9d167adfa746..382706dfb47d 100644 --- a/lib/kunit/debugfs.c +++ b/lib/kunit/debugfs.c @@ -60,12 +60,14 @@ static void debugfs_print_result(struct seq_file *seq, struct string_stream *log static int debugfs_print_results(struct seq_file *seq, void *v) { struct kunit_suite *suite = (struct kunit_suite *)seq->private; - enum kunit_status success = kunit_suite_has_succeeded(suite); + enum kunit_status success; struct kunit_case *test_case; if (!suite) return 0; + success = kunit_suite_has_succeeded(suite); + /* Print KTAP header so the debugfs log can be parsed as valid KTAP. */ seq_puts(seq, "KTAP version 1\n"); seq_puts(seq, "1..1\n"); -- 2.30.2

1 year

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[PATCH] KVM: selftests: add -MP to CFLAGS

by David Woodhouse

From: David Woodhouse <dwmw(a)amazon.co.uk> Using -MD without -MP causes build failures when a header file is deleted or moved. With -MP, the compiler will emit phony targets for the header files it lists as dependencies, and the Makefiles won't refuse to attempt to rebuild a C unit which no longer includes the deleted header. Signed-off-by: David Woodhouse <dwmw(a)amazon.co.uk> --- tools/testing/selftests/kvm/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile index a3bb36fb3cfc..20ea549da570 100644 --- a/tools/testing/selftests/kvm/Makefile +++ b/tools/testing/selftests/kvm/Makefile @@ -211,7 +211,7 @@ else LINUX_TOOL_ARCH_INCLUDE = $(top_srcdir)/tools/arch/$(ARCH)/include endif CFLAGS += -Wall -Wstrict-prototypes -Wuninitialized -O2 -g -std=gnu99 \ - -Wno-gnu-variable-sized-type-not-at-end -MD\ + -Wno-gnu-variable-sized-type-not-at-end -MD -MP \ -fno-builtin-memcmp -fno-builtin-memcpy -fno-builtin-memset \ -fno-builtin-strnlen \ -fno-stack-protector -fno-PIE -I$(LINUX_TOOL_INCLUDE) \ -- 2.41.0

1 year

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[RFC] drm/tests: annotate intentional stack trace in drm_test_rect_calc_hscale()

by Dan Carpenter

We have started printing more and more intentional stack traces. Whether it's testing KASAN is able to detect use after frees or it's part of a kunit test. These stack traces can be problematic. They suddenly show up as a new failure. Now the test team has to contact the developers. A bunch of people have to investigate the bug. We finally decide that it's intentional so now the test team has to update their filter scripts to mark it as intentional. These filters are ad-hoc because there is no standard format for warnings. A better way would be to mark it as intentional from the start. Here, I have marked the beginning and the end of the trace. It's more tricky for things like lkdtm_FORTIFY_MEM_MEMBER() where the flow doesn't reach the end of the function. I guess I would print a different warning for stack traces that can't have a "Intentional warning finished\n" message at the end. I haven't actually tested this patch... Daniel, do you have a list of intentional stack traces we could annotate? Signed-off-by: Dan Carpenter <dan.carpenter(a)linaro.org> --- drivers/gpu/drm/tests/drm_rect_test.c | 2 ++ include/kunit/test.h | 3 +++ 2 files changed, 5 insertions(+) diff --git a/drivers/gpu/drm/tests/drm_rect_test.c b/drivers/gpu/drm/tests/drm_rect_test.c index 76332cd2ead8..367738254493 100644 --- a/drivers/gpu/drm/tests/drm_rect_test.c +++ b/drivers/gpu/drm/tests/drm_rect_test.c @@ -409,8 +409,10 @@ static void drm_test_rect_calc_hscale(struct kunit *test) const struct drm_rect_scale_case *params = test->param_value; int scaling_factor; + START_INTENTIONAL_WARNING(); scaling_factor = drm_rect_calc_hscale(&params->src, &params->dst, params->min_range, params->max_range); + END_INTENTIONAL_WARNING(); KUNIT_EXPECT_EQ(test, scaling_factor, params->expected_scaling_factor); } diff --git a/include/kunit/test.h b/include/kunit/test.h index 20ed9f9275c9..1f01d4c81055 100644 --- a/include/kunit/test.h +++ b/include/kunit/test.h @@ -337,6 +337,9 @@ void __kunit_test_suites_exit(struct kunit_suite **suites, int num_suites); void kunit_exec_run_tests(struct kunit_suite_set *suite_set, bool builtin); void kunit_exec_list_tests(struct kunit_suite_set *suite_set, bool include_attr); +#define START_INTENTIONAL_WARNING() pr_info("Triggering a stack trace\n") +#define END_INTENTIONAL_WARNING() pr_info("Intentional warning finished\n") + #if IS_BUILTIN(CONFIG_KUNIT) int kunit_run_all_tests(void); #else -- 2.42.0

1 year

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[PATCH 0/5] pstore: add tty frontend and multi-backend

by Yuanhe Shu

In public cloud scenario, if kdump service works abnormally, users cannot get vmcore. Without vmcore, user has no idea why the kernel crashed. Meanwhile, there is no additional information to find the reason why the kdump service is abnormal. One way is to obtain console messages through VNC. The drawback is that VNC is real-time, if user missed the timing to get the VNC output, the crash needs to be retriggered. Another way is to enable the console frontend of pstore and record the console messages to the pstore backend. On the one hand, the console logs only contain kernel printk logs and does not cover user-mode print logs. Although we can redirect user-mode logs to the pmsg frontend provided by pstore, user-mode information related to booting and kdump service vary from systemd, kdump.sh, and so on which makes redirection troublesome. So we added a tty frontend and save all logs of tty driver to the pstore backend. Another problem is that currently pstore only supports a single backend. For debugging kdump problems, we hope to save the console logs and tty logs to the ramoops backend of pstore, as it will not be lost after rebooting. If the user has enabled another backend, the ramoops backend will not be registered. To this end, we add the multi-backend function to support simultaneous registration of multiple backends. Based on the above changes, we can enable pstore in the crashdump kernel and save the console logs and tty logs to the ramoops backend of pstore. After rebooting, we can view the relevant logs by mounting the pstore file system. Furthermore, we also modified kexec-tools referring to crash-utils for reading memory, so that pstore ramoops information can be read without enabling pstore in first kernel. As we set the address and size of ramoops, as well as the sizes of console and tty, we can infer the physical address of console logs and tty logs in memory. Referring to the read method of crash-utils, the console logs and tty logs are read from the memory, user can get pstore debug information without affecting the first kernel at all. kexec-tools modification can be seen at https://github.com/shuyuanmen/kexec-tools/blob/main/Add-pstore-segment.patch Yuanhe Shu (5): pstore: add tty frontend pstore: add multi-backends support pstore: add subdirs for multi-backends pstore: remove the module parameter "backend" tools/pstore: update pstore selftests drivers/tty/n_tty.c | 1 + fs/pstore/Kconfig | 23 ++ fs/pstore/Makefile | 2 + fs/pstore/blk.c | 10 + fs/pstore/ftrace.c | 22 +- fs/pstore/inode.c | 86 ++++++- fs/pstore/internal.h | 16 +- fs/pstore/platform.c | 238 ++++++++++++-------- fs/pstore/pmsg.c | 23 +- fs/pstore/ram.c | 40 +++- fs/pstore/tty.c | 56 +++++ fs/pstore/zone.c | 42 +++- include/linux/pstore.h | 33 +++ include/linux/pstore_blk.h | 3 + include/linux/pstore_ram.h | 1 + include/linux/pstore_zone.h | 2 + include/linux/tty.h | 14 ++ tools/testing/selftests/pstore/common_tests | 4 - 18 files changed, 500 insertions(+), 116 deletions(-) create mode 100644 fs/pstore/tty.c -- 2.39.3

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Linux-kselftest-mirror October 2023