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[PATCH bpf-next v2 00/15] Improvements for tracking scalars in the BPF verifier

by Maxim Mikityanskiy

From: Maxim Mikityanskiy <maxim(a)isovalent.com> The goal of this series is to extend the verifier's capabilities of tracking scalars when they are spilled to stack, especially when the spill or fill is narrowing. It also contains a fix by Eduard for infinite loop detection and a state pruning optimization by Eduard that compensates for a verification complexity regression introduced by tracking unbounded scalars. These improvements reduce the surface of false rejections that I saw while working on Cilium codebase. Patch 1 (Maxim): Fix for an existing test, it will matter later in the series. Patches 2-3 (Eduard): Fixes for false rejections in infinite loop detection that happen in the selftests when my patches are applied. Patches 4-5 (Maxim): Fix the inconsistency of find_equal_scalars that was possible if 32-bit spills were made. Patches 6-11 (Maxim): Support the case when boundary checks are first performed after the register was spilled to the stack. Patches 12-13 (Maxim): Support narrowing fills. Patches 14-15 (Eduard): Optimization for state pruning in stacksafe() to mitigate the verification complexity regression. veristat -e file,prog,states -f '!states_diff<50' -f '!states_pct<10' -f '!states_a<10' -f '!states_b<10' -C ... * Without patch 14: File Program States (A) States (B) States (DIFF) -------------------- ------------ ---------- ---------- ---------------- bpf_xdp.o tail_lb_ipv6 3877 2936 -941 (-24.27%) pyperf180.bpf.o on_event 8422 10456 +2034 (+24.15%) pyperf600.bpf.o on_event 22259 37319 +15060 (+67.66%) pyperf600_iter.bpf.o on_event 400 540 +140 (+35.00%) strobemeta.bpf.o on_event 4702 13435 +8733 (+185.73%) * With patch 14: File Program States (A) States (B) States (DIFF) -------------------- ------------ ---------- ---------- -------------- bpf_xdp.o tail_lb_ipv6 3877 2937 -940 (-24.25%) pyperf600_iter.bpf.o on_event 400 500 +100 (+25.00%) v2 changes: Fixed comments in patch 1, moved endianness checks to header files in patch 12 where possible, added Eduard's ACKs. Eduard Zingerman (4): bpf: make infinite loop detection in is_state_visited() exact selftests/bpf: check if imprecise stack spills confuse infinite loop detection bpf: Optimize state pruning for spilled scalars selftests/bpf: states pruning checks for scalar vs STACK_{MISC,ZERO} Maxim Mikityanskiy (11): selftests/bpf: Fix the u64_offset_to_skb_data test bpf: Make bpf_for_each_spilled_reg consider narrow spills selftests/bpf: Add a test case for 32-bit spill tracking bpf: Add the assign_scalar_id_before_mov function bpf: Add the get_reg_width function bpf: Assign ID to scalars on spill selftests/bpf: Test assigning ID to scalars on spill bpf: Track spilled unbounded scalars selftests/bpf: Test tracking spilled unbounded scalars bpf: Preserve boundaries and track scalars on narrowing fill selftests/bpf: Add test cases for narrowing fill include/linux/bpf_verifier.h | 4 +- include/linux/filter.h | 12 + kernel/bpf/verifier.c | 155 ++++- .../bpf/progs/verifier_direct_packet_access.c | 2 +- .../selftests/bpf/progs/verifier_loops1.c | 24 + .../selftests/bpf/progs/verifier_spill_fill.c | 533 +++++++++++++++++- .../testing/selftests/bpf/verifier/precise.c | 6 +- 7 files changed, 685 insertions(+), 51 deletions(-) -- 2.43.0

1 year, 10 months

5
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[PATCH] selftests/livepatch: fix and refactor new dmesg message code

by Joe Lawrence

The livepatching kselftests rely on comparing expected vs. observed dmesg output. After each test, new dmesg entries are determined by the 'comm' utility comparing a saved, pre-test copy of dmesg to post-test dmesg output. Alexander reports that the 'comm --nocheck-order -13' invocation used by the tests can be confused when dmesg entry timestamps vary in magnitude (ie, "[ 98.820331]" vs. "[ 100.031067]"), in which case, additional messages are reported as new. The unexpected entries then spoil the test results. Instead of relying on 'comm' or 'diff' to determine new testing dmesg entries, refactor the code: - pre-test : log a unique canary dmesg entry - test : run tests, log messages - post-test : filter dmesg starting from pre-test message Reported-by: Alexander Gordeev <agordeev(a)linux.ibm.com> Closes: https://lore.kernel.org/live-patching/ZYAimyPYhxVA9wKg@li-008a6a4c-3549-11b… Signed-off-by: Joe Lawrence <joe.lawrence(a)redhat.com> --- .../testing/selftests/livepatch/functions.sh | 37 +++++++++---------- 1 file changed, 17 insertions(+), 20 deletions(-) diff --git a/tools/testing/selftests/livepatch/functions.sh b/tools/testing/selftests/livepatch/functions.sh index c8416c54b463..b1fd7362c2fe 100644 --- a/tools/testing/selftests/livepatch/functions.sh +++ b/tools/testing/selftests/livepatch/functions.sh @@ -42,17 +42,6 @@ function die() { exit 1 } -# save existing dmesg so we can detect new content -function save_dmesg() { - SAVED_DMESG=$(mktemp --tmpdir -t klp-dmesg-XXXXXX) - dmesg > "$SAVED_DMESG" -} - -# cleanup temporary dmesg file from save_dmesg() -function cleanup_dmesg_file() { - rm -f "$SAVED_DMESG" -} - function push_config() { DYNAMIC_DEBUG=$(grep '^kernel/livepatch' /sys/kernel/debug/dynamic_debug/control | \ awk -F'[: ]' '{print "file " $1 " line " $2 " " $4}') @@ -99,7 +88,6 @@ function set_ftrace_enabled() { function cleanup() { pop_config - cleanup_dmesg_file } # setup_config - save the current config and set a script exit trap that @@ -280,7 +268,15 @@ function set_pre_patch_ret { function start_test { local test="$1" - save_dmesg + # Dump something unique into the dmesg log, then stash the entry + # in LAST_DMESG. The check_result() function will use it to + # find new kernel messages since the test started. + local last_dmesg_msg="livepatch kselftest timestamp: $(date --rfc-3339=ns)" + log "$last_dmesg_msg" + loop_until 'dmesg | grep -q "$last_dmesg_msg"' || + die "buffer busy? can't find canary dmesg message: $last_dmesg_msg" + LAST_DMESG=$(dmesg | grep "$last_dmesg_msg") + echo -n "TEST: $test ... " log "===== TEST: $test =====" } @@ -291,23 +287,24 @@ function check_result { local expect="$*" local result - # Note: when comparing dmesg output, the kernel log timestamps - # help differentiate repeated testing runs. Remove them with a - # post-comparison sed filter. - - result=$(dmesg | comm --nocheck-order -13 "$SAVED_DMESG" - | \ + # Test results include any new dmesg entry since LAST_DMESG, then: + # - include lines matching keywords + # - exclude lines matching keywords + # - filter out dmesg timestamp prefixes + result=$(dmesg | awk -v last_dmesg="$LAST_DMESG" 'p; $0 == last_dmesg { p=1 }' | \ grep -e 'livepatch:' -e 'test_klp' | \ grep -v '$tainting\|taints$ kernel' | \ sed 's/^\[[ 0-9.]*\] //') if [[ "$expect" == "$result" ]] ; then echo "ok" + elif [[ "$result" == "" ]] ; then + echo -e "not ok\n\nbuffer overrun? can't find canary dmesg entry: $LAST_DMESG\n" + die "livepatch kselftest(s) failed" else echo -e "not ok\n\n$(diff -upr --label expected --label result <(echo "$expect") <(echo "$result"))\n" die "livepatch kselftest(s) failed" fi - - cleanup_dmesg_file } # check_sysfs_rights(modname, rel_path, expected_rights) - check sysfs -- 2.41.0

1 year, 10 months

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[PATCH 0/3] Update LLVM Phabricator and Bugzilla links

by Nathan Chancellor

This series updates all instances of LLVM Phabricator and Bugzilla links to point to GitHub commits directly and LLVM's Bugzilla to GitHub issue shortlinks respectively. I split up the Phabricator patch into BPF selftests and the rest of the kernel in case the BPF folks want to take it separately from the rest of the series, there are obviously no dependency issues in that case. The Bugzilla change was mechanical enough and should have no conflicts. I am aiming this at Andrew and CC'ing other lists, in case maintainers want to chime in, but I think this is pretty uncontroversial (famous last words...). --- Nathan Chancellor (3): selftests/bpf: Update LLVM Phabricator links arch and include: Update LLVM Phabricator links treewide: Update LLVM Bugzilla links arch/arm64/Kconfig | 4 +-- arch/powerpc/Makefile | 4 +-- arch/powerpc/kvm/book3s_hv_nested.c | 2 +- arch/riscv/Kconfig | 2 +- arch/riscv/include/asm/ftrace.h | 2 +- arch/s390/include/asm/ftrace.h | 2 +- arch/x86/power/Makefile | 2 +- crypto/blake2b_generic.c | 2 +- drivers/firmware/efi/libstub/Makefile | 2 +- drivers/gpu/drm/amd/amdgpu/sdma_v4_4_2.c | 2 +- drivers/media/test-drivers/vicodec/codec-fwht.c | 2 +- drivers/regulator/Kconfig | 2 +- include/asm-generic/vmlinux.lds.h | 2 +- include/linux/compiler-clang.h | 2 +- lib/Kconfig.kasan | 2 +- lib/raid6/Makefile | 2 +- lib/stackinit_kunit.c | 2 +- mm/slab_common.c | 2 +- net/bridge/br_multicast.c | 2 +- security/Kconfig | 2 +- tools/testing/selftests/bpf/README.rst | 32 +++++++++++----------- tools/testing/selftests/bpf/prog_tests/xdpwall.c | 2 +- .../selftests/bpf/progs/test_core_reloc_type_id.c | 2 +- 23 files changed, 40 insertions(+), 40 deletions(-) --- base-commit: 0dd3ee31125508cd67f7e7172247f05b7fd1753a change-id: 20240109-update-llvm-links-d03f9d649e1e Best regards, -- Nathan Chancellor <nathan(a)kernel.org>

1 year, 10 months

7
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[PATCH V13 0/7] amd-pstate preferred core

by Meng Li

Hi all: The core frequency is subjected to the process variation in semiconductors. Not all cores are able to reach the maximum frequency respecting the infrastructure limits. Consequently, AMD has redefined the concept of maximum frequency of a part. This means that a fraction of cores can reach maximum frequency. To find the best process scheduling policy for a given scenario, OS needs to know the core ordering informed by the platform through highest performance capability register of the CPPC interface. Earlier implementations of amd-pstate preferred core only support a static core ranking and targeted performance. Now it has the ability to dynamically change the preferred core based on the workload and platform conditions and accounting for thermals and aging. Amd-pstate driver utilizes the functions and data structures provided by the ITMT architecture to enable the scheduler to favor scheduling on cores which can be get a higher frequency with lower voltage. We call it amd-pstate preferred core. Here sched_set_itmt_core_prio() is called to set priorities and sched_set_itmt_support() is called to enable ITMT feature. Amd-pstate driver uses the highest performance value to indicate the priority of CPU. The higher value has a higher priority. Amd-pstate driver will provide an initial core ordering at boot time. It relies on the CPPC interface to communicate the core ranking to the operating system and scheduler to make sure that OS is choosing the cores with highest performance firstly for scheduling the process. When amd-pstate driver receives a message with the highest performance change, it will update the core ranking. Changes from V12->V13: - ACPI: CPPC: - - modify commit message. - - modify handle function of the notify(0x85). - cpufreq: amd-pstate: - - implement update_limits() callback function. - x86: - - pick up Acked-By flag added by Petkov. Changes from V11->V12: - all: - - pick up Reviewed-By flag added by Perry. - cpufreq: amd-pstate: - - rebase the latest linux-next and fixed conflicts. - - fixed the issue about cpudata without init in amd_pstate_update_highest_perf(). Changes from V10->V11: - cpufreq: amd-pstate: - - according Perry's commnts, I replace the string with str_enabled_disable(). Changes from V9->V10: - cpufreq: amd-pstate: - - add judgement for highest_perf. When it is less than 255, the preferred core feature is enabled. And it will set the priority. - - deleset "static u32 max_highest_perf" etc, because amd p-state perferred coe does not require specail process for hotpulg. Changes form V8->V9: - all: - - pick up Tested-By flag added by Oleksandr. - cpufreq: amd-pstate: - - pick up Review-By flag added by Wyes. - - ignore modification of bug. - - add a attribute of prefcore_ranking. - - modify data type conversion from u32 to int. - Documentation: amd-pstate: - - pick up Review-By flag added by Wyes. Changes form V7->V8: - all: - - pick up Review-By flag added by Mario and Ray. - cpufreq: amd-pstate: - - use hw_prefcore embeds into cpudata structure. - - delete preferred core init from cpu online/off. Changes form V6->V7: - x86: - - Modify kconfig about X86_AMD_PSTATE. - cpufreq: amd-pstate: - - modify incorrect comments about scheduler_work(). - - convert highest_perf data type. - - modify preferred core init when cpu init and online. - ACPI: CPPC: - - modify link of CPPC highest performance. - cpufreq: - - modify link of CPPC highest performance changed. Changes form V5->V6: - cpufreq: amd-pstate: - - modify the wrong tag order. - - modify warning about hw_prefcore sysfs attribute. - - delete duplicate comments. - - modify the variable name cppc_highest_perf to prefcore_ranking. - - modify judgment conditions for setting highest_perf. - - modify sysfs attribute for CPPC highest perf to pr_debug message. - Documentation: amd-pstate: - - modify warning: title underline too short. Changes form V4->V5: - cpufreq: amd-pstate: - - modify sysfs attribute for CPPC highest perf. - - modify warning about comments - - rebase linux-next - cpufreq: - - Moidfy warning about function declarations. - Documentation: amd-pstate: - - align with ``amd-pstat`` Changes form V3->V4: - Documentation: amd-pstate: - - Modify inappropriate descriptions. Changes form V2->V3: - x86: - - Modify kconfig and description. - cpufreq: amd-pstate: - - Add Co-developed-by tag in commit message. - cpufreq: - - Modify commit message. - Documentation: amd-pstate: - - Modify inappropriate descriptions. Changes form V1->V2: - ACPI: CPPC: - - Add reference link. - cpufreq: - - Moidfy link error. - cpufreq: amd-pstate: - - Init the priorities of all online CPUs - - Use a single variable to represent the status of preferred core. - Documentation: - - Default enabled preferred core. - Documentation: amd-pstate: - - Modify inappropriate descriptions. - - Default enabled preferred core. - - Use a single variable to represent the status of preferred core. *** BLURB HERE *** Meng Li (7): x86: Drop CPU_SUP_INTEL from SCHED_MC_PRIO for the expansion. ACPI: CPPC: Add get the highest performance cppc control cpufreq: amd-pstate: Enable amd-pstate preferred core supporting. cpufreq: Add a notification message that the highest perf has changed cpufreq: amd-pstate: Update amd-pstate preferred core ranking dynamically Documentation: amd-pstate: introduce amd-pstate preferred core Documentation: introduce amd-pstate preferrd core mode kernel command line options .../admin-guide/kernel-parameters.txt | 5 + Documentation/admin-guide/pm/amd-pstate.rst | 59 +++++- arch/x86/Kconfig | 5 +- drivers/acpi/cppc_acpi.c | 13 ++ drivers/acpi/processor_driver.c | 6 + drivers/cpufreq/amd-pstate.c | 183 +++++++++++++++++- include/acpi/cppc_acpi.h | 5 + include/linux/amd-pstate.h | 10 + 8 files changed, 274 insertions(+), 12 deletions(-) -- 2.34.1

1 year, 10 months

1
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[PATCH v2] selftests/ftrace: Add test to exercize function tracer across cpu hotplug

by Naveen N Rao

Add a test to exercize cpu hotplug with the function tracer active to ensure that sensitive functions in idle path are excluded from being traced. This helps catch issues such as the one fixed by commit 4b3338aaa74d ("powerpc/ftrace: Fix stack teardown in ftrace_no_trace"). Signed-off-by: Naveen N Rao <naveen(a)kernel.org> --- v2: Add a check for next available online cpu, as suggested by Masami. .../ftrace/test.d/ftrace/func_hotplug.tc | 42 +++++++++++++++++++ 1 file changed, 42 insertions(+) create mode 100644 tools/testing/selftests/ftrace/test.d/ftrace/func_hotplug.tc diff --git a/tools/testing/selftests/ftrace/test.d/ftrace/func_hotplug.tc b/tools/testing/selftests/ftrace/test.d/ftrace/func_hotplug.tc new file mode 100644 index 000000000000..ccfbfde3d942 --- /dev/null +++ b/tools/testing/selftests/ftrace/test.d/ftrace/func_hotplug.tc @@ -0,0 +1,42 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0-or-later +# description: ftrace - function trace across cpu hotplug +# requires: function:tracer + +if ! which nproc ; then + nproc() { + ls -d /sys/devices/system/cpu/cpu[0-9]* | wc -l + } +fi + +NP=`nproc` + +if [ $NP -eq 1 ] ;then + echo "We cannot test cpu hotplug in UP environment" + exit_unresolved +fi + +# Find online cpu +for i in /sys/devices/system/cpu/cpu[1-9]*; do + if [ -f $i/online ] && [ "$(cat $i/online)" = "1" ]; then + cpu=$i + break + fi +done + +if [ -z "$cpu" ]; then + echo "We cannot test cpu hotplug with a single cpu online" + exit_unresolved +fi + +echo 0 > tracing_on +echo > trace + +: "Set $(basename $cpu) offline/online with function tracer enabled" +echo function > current_tracer +echo 1 > tracing_on +(echo 0 > $cpu/online) +(echo "forked"; sleep 1) +(echo 1 > $cpu/online) +echo 0 > tracing_on +echo nop > current_tracer base-commit: b85ea95d086471afb4ad062012a4d73cd328fa86 -- 2.43.0

1 year, 10 months

3
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[PATCH v2] selftests/mm: mremap_test: fix build warning

by Muhammad Usama Anjum

Use 2 separate variables of types int and unsigned long long instead of confusing them. This corrects the correct print format for each of them and removes the build warning: warning: format ‘%d’ expects argument of type ‘int’, but argument 2 has type ‘long long unsigned int’ Fixes: a4cb3b243343 ("selftests: mm: add a test for remapping to area immediately after existing mapping") Signed-off-by: Muhammad Usama Anjum <usama.anjum(a)collabora.com> --- Changes since v1: - Don't just fix the print format, instead use different variables --- tools/testing/selftests/mm/mremap_test.c | 27 ++++++++++++------------ 1 file changed, 14 insertions(+), 13 deletions(-) diff --git a/tools/testing/selftests/mm/mremap_test.c b/tools/testing/selftests/mm/mremap_test.c index 1d4c1589c305..2f8b991f78cb 100644 --- a/tools/testing/selftests/mm/mremap_test.c +++ b/tools/testing/selftests/mm/mremap_test.c @@ -360,7 +360,8 @@ static long long remap_region(struct config c, unsigned int threshold_mb, char pattern_seed) { void *addr, *src_addr, *dest_addr, *dest_preamble_addr; - unsigned long long i; + int d; + unsigned long long t; struct timespec t_start = {0, 0}, t_end = {0, 0}; long long start_ns, end_ns, align_mask, ret, offset; unsigned long long threshold; @@ -378,8 +379,8 @@ static long long remap_region(struct config c, unsigned int threshold_mb, /* Set byte pattern for source block. */ srand(pattern_seed); - for (i = 0; i < threshold; i++) - memset((char *) src_addr + i, (char) rand(), 1); + for (t = 0; t < threshold; t++) + memset((char *) src_addr + t, (char) rand(), 1); /* Mask to zero out lower bits of address for alignment */ align_mask = ~(c.dest_alignment - 1); @@ -420,8 +421,8 @@ static long long remap_region(struct config c, unsigned int threshold_mb, /* Set byte pattern for the dest preamble block. */ srand(pattern_seed); - for (i = 0; i < c.dest_preamble_size; i++) - memset((char *) dest_preamble_addr + i, (char) rand(), 1); + for (d = 0; d < c.dest_preamble_size; d++) + memset((char *) dest_preamble_addr + d, (char) rand(), 1); } clock_gettime(CLOCK_MONOTONIC, &t_start); @@ -437,14 +438,14 @@ static long long remap_region(struct config c, unsigned int threshold_mb, /* Verify byte pattern after remapping */ srand(pattern_seed); - for (i = 0; i < threshold; i++) { + for (t = 0; t < threshold; t++) { char c = (char) rand(); - if (((char *) dest_addr)[i] != c) { + if (((char *) dest_addr)[t] != c) { ksft_print_msg("Data after remap doesn't match at offset %llu\n", - i); + t); ksft_print_msg("Expected: %#x\t Got: %#x\n", c & 0xff, - ((char *) dest_addr)[i] & 0xff); + ((char *) dest_addr)[t] & 0xff); ret = -1; goto clean_up_dest; } @@ -453,14 +454,14 @@ static long long remap_region(struct config c, unsigned int threshold_mb, /* Verify the dest preamble byte pattern after remapping */ if (c.dest_preamble_size) { srand(pattern_seed); - for (i = 0; i < c.dest_preamble_size; i++) { + for (d = 0; d < c.dest_preamble_size; d++) { char c = (char) rand(); - if (((char *) dest_preamble_addr)[i] != c) { + if (((char *) dest_preamble_addr)[d] != c) { ksft_print_msg("Preamble data after remap doesn't match at offset %d\n", - i); + d); ksft_print_msg("Expected: %#x\t Got: %#x\n", c & 0xff, - ((char *) dest_preamble_addr)[i] & 0xff); + ((char *) dest_preamble_addr)[d] & 0xff); ret = -1; goto clean_up_dest; } -- 2.42.0

1 year, 10 months

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[PATCH] selftests/mm: mremap_test: fix build warning

by Muhammad Usama Anjum

Fix following build warning: warning: format ‘%d’ expects argument of type ‘int’, but argument 2 has type ‘long long unsigned int’ Fixes: a4cb3b243343 ("selftests: mm: add a test for remapping to area immediately after existing mapping") Signed-off-by: Muhammad Usama Anjum <usama.anjum(a)collabora.com> --- tools/testing/selftests/mm/mremap_test.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/testing/selftests/mm/mremap_test.c b/tools/testing/selftests/mm/mremap_test.c index 1d4c1589c305..dd1cbb068982 100644 --- a/tools/testing/selftests/mm/mremap_test.c +++ b/tools/testing/selftests/mm/mremap_test.c @@ -457,7 +457,7 @@ static long long remap_region(struct config c, unsigned int threshold_mb, char c = (char) rand(); if (((char *) dest_preamble_addr)[i] != c) { - ksft_print_msg("Preamble data after remap doesn't match at offset %d\n", + ksft_print_msg("Preamble data after remap doesn't match at offset %llu\n", i); ksft_print_msg("Expected: %#x\t Got: %#x\n", c & 0xff, ((char *) dest_preamble_addr)[i] & 0xff); -- 2.42.0

1 year, 10 months

2
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[PATCH 0/5] tools: selftests: riscv: Fix compiler warnings

by Christoph Muellner

From: Christoph Müllner <christoph.muellner(a)vrull.eu> When building the RISC-V selftests with a riscv32 compiler I ran into a couple of compiler warnings. While riscv32 support for these tests is questionable, the fixes are so trivial that it is probably best to simply apply them. Note that the missing-include patch and some format string warnings are also relevant for riscv64. Christoph Müllner (5): tools: selftests: riscv: Fix compile warnings in hwprobe tools: selftests: riscv: Fix compile warnings in cbo tools: selftests: riscv: Add missing include for vector test tools: selftests: riscv: Fix compile warnings in vector tests tools: selftests: riscv: Fix compile warnings in mm tests tools/testing/selftests/riscv/hwprobe/cbo.c | 6 +++--- tools/testing/selftests/riscv/hwprobe/hwprobe.c | 4 ++-- tools/testing/selftests/riscv/mm/mmap_test.h | 3 +++ tools/testing/selftests/riscv/vector/v_initval_nolibc.c | 2 +- tools/testing/selftests/riscv/vector/vstate_exec_nolibc.c | 3 +++ tools/testing/selftests/riscv/vector/vstate_prctl.c | 4 ++-- 6 files changed, 14 insertions(+), 8 deletions(-) -- 2.41.0

1 year, 10 months

6
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[PATCH v2] KVM: selftests: Fix the dirty_log_test semaphore imbalance

by Shaoqin Huang

When execute the dirty_log_test on some aarch64 machine, it sometimes trigger the ASSERT: ==== Test Assertion Failure ==== dirty_log_test.c:384: dirty_ring_vcpu_ring_full pid=14854 tid=14854 errno=22 - Invalid argument 1 0x00000000004033eb: dirty_ring_collect_dirty_pages at dirty_log_test.c:384 2 0x0000000000402d27: log_mode_collect_dirty_pages at dirty_log_test.c:505 3 (inlined by) run_test at dirty_log_test.c:802 4 0x0000000000403dc7: for_each_guest_mode at guest_modes.c:100 5 0x0000000000401dff: main at dirty_log_test.c:941 (discriminator 3) 6 0x0000ffff9be173c7: ?? ??:0 7 0x0000ffff9be1749f: ?? ??:0 8 0x000000000040206f: _start at ??:? Didn't continue vcpu even without ring full The dirty_log_test fails when execute the dirty-ring test, this is because the sem_vcpu_cont and the sem_vcpu_stop is non-zero value when execute the dirty_ring_collect_dirty_pages() function. When those two sem_t variables are non-zero, the dirty_ring_wait_vcpu() at the beginning of the dirty_ring_collect_dirty_pages() will not wait for the vcpu to stop, but continue to execute the following code. In this case, before vcpu stop, if the dirty_ring_vcpu_ring_full is true, and the dirty_ring_collect_dirty_pages() has passed the check for the dirty_ring_vcpu_ring_full but hasn't execute the check for the continued_vcpu, the vcpu stop, and set the dirty_ring_vcpu_ring_full to false. Then dirty_ring_collect_dirty_pages() will trigger the ASSERT. Why sem_vcpu_cont and sem_vcpu_stop can be non-zero value? It's because the dirty_ring_before_vcpu_join() execute the sem_post(&sem_vcpu_cont) at the end of each dirty-ring test. It can cause two cases: 1. sem_vcpu_cont be non-zero. When we set the host_quit to be true, the vcpu_worker directly see the host_quit to be true, it quit. So the log_mode_before_vcpu_join() function will set the sem_vcpu_cont to 1, since the vcpu_worker has quit, it won't consume it. 2. sem_vcpu_stop be non-zero. When we set the host_quit to be true, the vcpu_worker has entered the guest state, the next time it exit from guest state, it will set the sem_vcpu_stop to 1, and then see the host_quit, no one will consume the sem_vcpu_stop. When execute more and more dirty-ring tests, the sem_vcpu_cont and sem_vcpu_stop can be larger and larger, which makes many code paths don't wait for the sem_t. Thus finally cause the problem. To fix this problem, we can wait a while before set the host_quit to true, which gives the vcpu time to enter the guest state, so it will exit again. Then we can wait the vcpu to exit, and let it continue again, then the vcpu will see the host_quit. Thus the sem_vcpu_cont and sem_vcpu_stop will be both zero when test finished. Signed-off-by: Shaoqin Huang <shahuang(a)redhat.com> --- v1->v2: - Fix the real logic bug, not just fresh the context. v1: https://lore.kernel.org/all/20231116093536.22256-1-shahuang@redhat.com/ --- tools/testing/selftests/kvm/dirty_log_test.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/kvm/dirty_log_test.c b/tools/testing/selftests/kvm/dirty_log_test.c index 936f3a8d1b83..a6e0ff46a07c 100644 --- a/tools/testing/selftests/kvm/dirty_log_test.c +++ b/tools/testing/selftests/kvm/dirty_log_test.c @@ -417,7 +417,8 @@ static void dirty_ring_after_vcpu_run(struct kvm_vcpu *vcpu, int ret, int err) static void dirty_ring_before_vcpu_join(void) { - /* Kick another round of vcpu just to make sure it will quit */ + /* Wait vcpu exit, and let it continue to see the host_quit. */ + dirty_ring_wait_vcpu(); sem_post(&sem_vcpu_cont); } @@ -719,6 +720,7 @@ static void run_test(enum vm_guest_mode mode, void *arg) struct kvm_vm *vm; unsigned long *bmap; uint32_t ring_buf_idx = 0; + int sem_val; if (!log_mode_supported()) { print_skip("Log mode '%s' not supported", @@ -726,6 +728,11 @@ static void run_test(enum vm_guest_mode mode, void *arg) return; } + sem_getvalue(&sem_vcpu_stop, &sem_val); + assert(sem_val == 0); + sem_getvalue(&sem_vcpu_cont, &sem_val); + assert(sem_val == 0); + /* * We reserve page table for 2 times of extra dirty mem which * will definitely cover the original (1G+) test range. Here @@ -825,6 +832,13 @@ static void run_test(enum vm_guest_mode mode, void *arg) sync_global_to_guest(vm, iteration); } + /* + * + * Before we set the host_quit, let the vcpu has time to run, to make + * sure we consume the sem_vcpu_stop and the vcpu consume the + * sem_vcpu_cont, to keep the semaphore balance. + */ + usleep(p->interval * 1000); /* Tell the vcpu thread to quit */ host_quit = true; log_mode_before_vcpu_join(); -- 2.40.1

1 year, 10 months

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[PATCH] kunit: Fix a NULL vs IS_ERR() bug

by Dan Carpenter

The kunit_device_register() function doesn't return NULL, it returns error pointers. Change the KUNIT_ASSERT_NOT_NULL() to check for ERR_OR_NULL(). Fixes: d03c720e03bd ("kunit: Add APIs for managing devices") Signed-off-by: Dan Carpenter <dan.carpenter(a)linaro.org> --- It's a pity that there isn't a KUNIT_ASSERT_NOT_ERR_PTR() macro... lib/kunit/kunit-test.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/lib/kunit/kunit-test.c b/lib/kunit/kunit-test.c index c4259d910356..f7980ef236a3 100644 --- a/lib/kunit/kunit-test.c +++ b/lib/kunit/kunit-test.c @@ -720,7 +720,7 @@ static void kunit_device_cleanup_test(struct kunit *test) long action_was_run = 0; test_device = kunit_device_register(test, "my_device"); - KUNIT_ASSERT_NOT_NULL(test, test_device); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, test_device); /* Add an action to verify cleanup. */ devm_add_action(test_device, test_dev_action, &action_was_run); -- 2.43.0

1 year, 10 months

3
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