- Linux-kselftest-mirror - lists.linaro.org

by syzbot

Hello, syzbot found the following crash on: HEAD commit: 0c0ddd6a Merge tag 'linux-watchdog-5.6-rc3' of git://www.l.. git tree: net console output: https://syzkaller.appspot.com/x/log.txt?x=17c0fde9e00000 kernel config: https://syzkaller.appspot.com/x/.config?x=3b8906eb6a7d6028 dashboard link: https://syzkaller.appspot.com/bug?extid=fbe81b56f7df4c0fb21b compiler: gcc (GCC) 9.0.0 20181231 (experimental) syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12025de9e00000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16a4d245e00000 The bug was bisected to: commit fb99bce7120014307dde57b3d7def6977a9a62a1 Author: Dave Watson <davejwatson(a)fb.com> Date: Wed Jan 30 21:58:05 2019 +0000 net: tls: Support 256 bit keys bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=14898931e00000 final crash: https://syzkaller.appspot.com/x/report.txt?x=16898931e00000 console output: https://syzkaller.appspot.com/x/log.txt?x=12898931e00000 IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+fbe81b56f7df4c0fb21b(a)syzkaller.appspotmail.com Fixes: fb99bce71200 ("net: tls: Support 256 bit keys") ------------[ cut here ]------------ WARNING: CPU: 1 PID: 9607 at net/core/stream.c:208 sk_stream_kill_queues+0x40d/0x590 net/core/stream.c:208 Kernel panic - not syncing: panic_on_warn set ... CPU: 1 PID: 9607 Comm: syz-executor386 Not tainted 5.6.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x197/0x210 lib/dump_stack.c:118 panic+0x2e3/0x75c kernel/panic.c:221 __warn.cold+0x2f/0x3e kernel/panic.c:582 report_bug+0x289/0x300 lib/bug.c:195 fixup_bug arch/x86/kernel/traps.c:174 [inline] fixup_bug arch/x86/kernel/traps.c:169 [inline] do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:267 do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:286 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1027 RIP: 0010:sk_stream_kill_queues+0x40d/0x590 net/core/stream.c:208 Code: 48 c1 ea 03 0f b6 04 02 84 c0 74 04 3c 03 7e 41 44 8b a3 f8 01 00 00 e9 5f ff ff ff e8 0c 7f 40 fb 0f 0b eb 96 e8 03 7f 40 fb <0f> 0b eb a1 e8 fa 7e 40 fb 0f 0b e9 9f fe ff ff 4c 89 ef e8 7b 24 RSP: 0018:ffffc9000c6efb30 EFLAGS: 00010293 RAX: ffff8880a3102380 RBX: 0000000000000000 RCX: ffffffff8635085d RDX: 0000000000000000 RSI: ffffffff863508bd RDI: 0000000000000005 RBP: ffffc9000c6efb70 R08: ffff8880a3102380 R09: ffffed1015d2707c R10: ffffed1015d2707b R11: ffff8880ae9383db R12: 0000000000000fe3 R13: ffff88808f618238 R14: ffffffff8c406240 R15: ffff88808f618178 inet_csk_destroy_sock+0x1b7/0x4c0 net/ipv4/inet_connection_sock.c:846 tcp_close+0xe17/0x12b0 net/ipv4/tcp.c:2503 inet_release+0xed/0x200 net/ipv4/af_inet.c:427 __sock_release+0xce/0x280 net/socket.c:605 sock_close+0x1e/0x30 net/socket.c:1283 __fput+0x2ff/0x890 fs/file_table.c:280 ____fput+0x16/0x20 fs/file_table.c:313 task_work_run+0x145/0x1c0 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0xba9/0x2f50 kernel/exit.c:801 do_group_exit+0x135/0x360 kernel/exit.c:899 __do_sys_exit_group kernel/exit.c:910 [inline] __se_sys_exit_group kernel/exit.c:908 [inline] __x64_sys_exit_group+0x44/0x50 kernel/exit.c:908 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x43eff8 Code: Bad RIP value. RSP: 002b:00007ffca386cb68 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043eff8 RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 RBP: 00000000004be808 R08: 00000000000000e7 R09: ffffffffffffffd0 R10: 00000000200001c0 R11: 0000000000000246 R12: 0000000000000001 R13: 00000000006d0180 R14: 0000000000000000 R15: 0000000000000000 Kernel Offset: disabled Rebooting in 86400 seconds.. --- This bug is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller(a)googlegroups.com. syzbot will keep track of this bug report. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. For information about bisection process see: https://goo.gl/tpsmEJ#bisection syzbot can test patches for this bug, for details see: https://goo.gl/tpsmEJ#testing-patches

4 years, 9 months

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Re: runqslower build failed on Debian9

by Andrii Nakryiko

On 3/29/20 5:48 PM, Liu Yiding wrote: > Add attachment. > Your BTF seems to be invalid. It has struct perf_ibs, which has a first field `struct pmu pmu` field with valid-looking size of 296 bytes, **but** the type that field points to is not a complete `struct pmu` definition, but rather just forward declaration. The way it is it shouldn't be even compilable, because forward declaration of a struct doesn't specify the size of a struct, so compiler should have rejected it. So it must be that either DWARF generated by compiler isn't correct, or there is DWARF -> BTF conversion bug somewhere. Are you using any special DWARF Kconfig settings? Maybe you can share your full .config and I might try to repro it on my machine. But either way, that warning you get is a valid one, it should be illegal to have non-pointer forward-declared struct as a type for a struct member. > > On 3/30/20 8:46 AM, Liu Yiding wrote: >> Something wrong with my smtp and this email missed. >> >> Send again. >> >> >> On 3/27/20 11:09 AM, Liu Yiding wrote: >>> Hi, Andrii. >>> >>> Thanks for your prompt reply! >>> >>> Please check attatchment for my_btf.bin. >>> >>> >>> On 3/27/20 4:28 AM, Andrii Nakryiko wrote: >>>> Would you be able to share BTF of vmlinux that is used to generate >>>> vmlinux.h? Please run in verbose mode: `make V=1` and search for >>>> `bpftool btf dump file` command. It should point either to >>>> /sys/kernel/btf/vmlinux or some other location, depending on how >>>> things are set up on your side. >>>> >>>> If it's /sys/kernel/btf/vmlinux, you can just `cat >>>> /sys/kernel/btf/vmlinux > my_btf.bin`. If it's some other file, >>>> easiest would be to just share that file. If not, it's possible to >>>> extract .BTF ELF section, let me know if you need help with that. >>>

4 years, 9 months

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Re: runqslower build failed on Debian9

by Liu Yiding

Something wrong with my smtp and this email missed. Send again. On 3/27/20 11:09 AM, Liu Yiding wrote: > Hi, Andrii. > > Thanks for your prompt reply! > > Please check attatchment for my_btf.bin. > > > On 3/27/20 4:28 AM, Andrii Nakryiko wrote: >> Would you be able to share BTF of vmlinux that is used to generate >> vmlinux.h? Please run in verbose mode: `make V=1` and search for >> `bpftool btf dump file` command. It should point either to >> /sys/kernel/btf/vmlinux or some other location, depending on how >> things are set up on your side. >> >> If it's /sys/kernel/btf/vmlinux, you can just `cat >> /sys/kernel/btf/vmlinux > my_btf.bin`. If it's some other file, >> easiest would be to just share that file. If not, it's possible to >> extract .BTF ELF section, let me know if you need help with that. > -- Best Regards. Liu Yiding

4 years, 9 months

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[for-next][PATCH 20/21] selftests/ftrace: Add test to test new set_event_notrace_pid file

by Steven Rostedt

From: "Steven Rostedt (VMware)" <rostedt(a)goodmis.org> A new file was added to the tracing directory that will allow a user to place a PID into it and the task associated to that PID will not have its events traced. If the event-fork option is enabled, then neither will the children of that task have its events traced. Cc: linux-kselftest(a)vger.kernel.org Cc: Shuah Khan <skhan(a)linuxfoundation.org> Signed-off-by: Steven Rostedt (VMware) <rostedt(a)goodmis.org> --- .../ftrace/test.d/event/event-no-pid.tc | 125 ++++++++++++++++++ 1 file changed, 125 insertions(+) create mode 100644 tools/testing/selftests/ftrace/test.d/event/event-no-pid.tc diff --git a/tools/testing/selftests/ftrace/test.d/event/event-no-pid.tc b/tools/testing/selftests/ftrace/test.d/event/event-no-pid.tc new file mode 100644 index 000000000000..f0f366f18d0c --- /dev/null +++ b/tools/testing/selftests/ftrace/test.d/event/event-no-pid.tc @@ -0,0 +1,125 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 +# description: event tracing - restricts events based on pid notrace filtering +# flags: instance + +do_reset() { + echo > set_event + echo > set_event_pid + echo > set_event_notrace_pid + echo 0 > options/event-fork + echo 0 > events/enable + clear_trace + echo 1 > tracing_on +} + +fail() { #msg + cat trace + do_reset + echo $1 + exit_fail +} + +count_pid() { + pid=$@ + cat trace | grep -v '^#' | sed -e 's/[^-]*-$[0-9]*$.*/\1/' | grep $pid | wc -l +} + +count_no_pid() { + pid=$1 + cat trace | grep -v '^#' | sed -e 's/[^-]*-$[0-9]*$.*/\1/' | grep -v $pid | wc -l +} + +enable_system() { + system=$1 + + if [ -d events/$system ]; then + echo 1 > events/$system/enable + fi +} + +enable_events() { + echo 0 > tracing_on + # Enable common groups of events, as all events can allow for + # events to be traced via scheduling that we don't care to test. + enable_system syscalls + enable_system rcu + enable_system block + enable_system exceptions + enable_system irq + enable_system net + enable_system power + enable_system signal + enable_system sock + enable_system timer + enable_system thermal + echo 1 > tracing_on +} + +if [ ! -f set_event -o ! -d events/sched ]; then + echo "event tracing is not supported" + exit_unsupported +fi + +if [ ! -f set_event_pid -o ! -f set_event_notrace_pid ]; then + echo "event pid notrace filtering is not supported" + exit_unsupported +fi + +echo 0 > options/event-fork + +do_reset + +read mypid rest < /proc/self/stat + +echo $mypid > set_event_notrace_pid +grep -q $mypid set_event_notrace_pid + +enable_events + +yield + +echo 0 > tracing_on + +cnt=`count_pid $mypid` +if [ $cnt -ne 0 ]; then + fail "Filtered out task has events" +fi + +cnt=`count_no_pid $mypid` +if [ $cnt -eq 0 ]; then + fail "No other events were recorded" +fi + +do_reset + +echo $mypid > set_event_notrace_pid +echo 1 > options/event-fork + +enable_events + +yield & +child=$! +echo "child = $child" +wait $child + +echo 0 > tracing_on + +cnt=`count_pid $mypid` +if [ $cnt -ne 0 ]; then + fail "Filtered out task has events" +fi + +cnt=`count_pid $child` +if [ $cnt -ne 0 ]; then + fail "Child of filtered out taskhas events" +fi + +cnt=`count_no_pid $mypid` +if [ $cnt -eq 0 ]; then + fail "No other events were recorded" +fi + +do_reset + +exit 0 -- 2.25.1

4 years, 9 months

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[for-next][PATCH 19/21] selftests/ftrace: Add test to test new set_ftrace_notrace_pid file

by Steven Rostedt

From: "Steven Rostedt (VMware)" <rostedt(a)goodmis.org> A new file was added to the tracing directory that will allow a user to place a PID into it and the task associated to that PID will not be traced by the function tracer. If the function-fork option is enabled, then neither will the children of that task be traced by the function tracer. Cc: linux-kselftest(a)vger.kernel.org Cc: Shuah Khan <skhan(a)linuxfoundation.org> Signed-off-by: Steven Rostedt (VMware) <rostedt(a)goodmis.org> --- .../test.d/ftrace/func-filter-notrace-pid.tc | 108 ++++++++++++++++++ 1 file changed, 108 insertions(+) create mode 100644 tools/testing/selftests/ftrace/test.d/ftrace/func-filter-notrace-pid.tc diff --git a/tools/testing/selftests/ftrace/test.d/ftrace/func-filter-notrace-pid.tc b/tools/testing/selftests/ftrace/test.d/ftrace/func-filter-notrace-pid.tc new file mode 100644 index 000000000000..8aa46a2ea133 --- /dev/null +++ b/tools/testing/selftests/ftrace/test.d/ftrace/func-filter-notrace-pid.tc @@ -0,0 +1,108 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 +# description: ftrace - function pid notrace filters +# flags: instance + +# Make sure that function pid matching filter with notrace works. + +if ! grep -q function available_tracers; then + echo "no function tracer configured" + exit_unsupported +fi + +if [ ! -f set_ftrace_notrace_pid ]; then + echo "set_ftrace_notrace_pid not found? Is function tracer not set?" + exit_unsupported +fi + +if [ ! -f set_ftrace_filter ]; then + echo "set_ftrace_filter not found? Is function tracer not set?" + exit_unsupported +fi + +do_function_fork=1 + +if [ ! -f options/function-fork ]; then + do_function_fork=0 + echo "no option for function-fork found. Option will not be tested." +fi + +read PID _ < /proc/self/stat + +if [ $do_function_fork -eq 1 ]; then + # default value of function-fork option + orig_value=`grep function-fork trace_options` +fi + +do_reset() { + if [ $do_function_fork -eq 0 ]; then + return + fi + + echo > set_ftrace_notrace_pid + echo $orig_value > trace_options +} + +fail() { # msg + do_reset + echo $1 + exit_fail +} + +do_test() { + disable_tracing + + echo do_execve* > set_ftrace_filter + echo *do_fork >> set_ftrace_filter + + echo $PID > set_ftrace_notrace_pid + echo function > current_tracer + + if [ $do_function_fork -eq 1 ]; then + # don't allow children to be traced + echo nofunction-fork > trace_options + fi + + enable_tracing + yield + + count_pid=`cat trace | grep -v ^# | grep $PID | wc -l` + count_other=`cat trace | grep -v ^# | grep -v $PID | wc -l` + + # count_pid should be 0 + if [ $count_pid -ne 0 -o $count_other -eq 0 ]; then + fail "PID filtering not working? traced task = $count_pid; other tasks = $count_other " + fi + + disable_tracing + clear_trace + + if [ $do_function_fork -eq 0 ]; then + return + fi + + # allow children to be traced + echo function-fork > trace_options + + # With pid in both set_ftrace_pid and set_ftrace_notrace_pid + # there should not be any tasks traced. + + echo $PID > set_ftrace_pid + + enable_tracing + yield + + count_pid=`cat trace | grep -v ^# | grep $PID | wc -l` + count_other=`cat trace | grep -v ^# | grep -v $PID | wc -l` + + # both should be zero + if [ $count_pid -ne 0 -o $count_other -ne 0 ]; then + fail "PID filtering not following fork? traced task = $count_pid; other tasks = $count_other " + fi +} + +do_test + +do_reset + +exit 0 -- 2.25.1

4 years, 9 months

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[for-next][PATCH 02/21] selftest/ftrace: Fix function trigger test to handle trace not disabling the tracer

by Steven Rostedt

From: "Steven Rostedt (VMware)" <rostedt(a)goodmis.org> The ftrace selftest "ftrace - test for function traceon/off triggers" enables all events and reads the trace file. Now that the trace file does not disable tracing, and will attempt to continually read new data that is added, the selftest gets stuck reading the trace file. This is because the data added to the trace file will fill up quicker than the reading of it. By only enabling scheduling events, the read can keep up with the writes. Instead of enabling all events, only enable the scheduler events. Link: http://lkml.kernel.org/r/20200318111345.0516642e@gandalf.local.home Cc: Shuah Khan <skhan(a)linuxfoundation.org> Cc: linux-kselftest(a)vger.kernel.org Acked-by: Masami Hiramatsu <mhiramat(a)kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt(a)goodmis.org> --- .../selftests/ftrace/test.d/ftrace/func_traceonoff_triggers.tc | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/testing/selftests/ftrace/test.d/ftrace/func_traceonoff_triggers.tc b/tools/testing/selftests/ftrace/test.d/ftrace/func_traceonoff_triggers.tc index 0c04282d33dd..1947387fe976 100644 --- a/tools/testing/selftests/ftrace/test.d/ftrace/func_traceonoff_triggers.tc +++ b/tools/testing/selftests/ftrace/test.d/ftrace/func_traceonoff_triggers.tc @@ -41,7 +41,7 @@ fi echo '** ENABLE EVENTS' -echo 1 > events/enable +echo 1 > events/sched/enable echo '** ENABLE TRACING' enable_tracing -- 2.25.1

4 years, 9 months

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[PATCH][next] selftests/harness: fix spelling mistake "SIGARLM" -> "SIGALRM"

by Colin King

From: Colin Ian King <colin.king(a)canonical.com> There a few identical spelling mistakes, fix these. Signed-off-by: Colin Ian King <colin.king(a)canonical.com> --- tools/testing/selftests/kselftest_harness.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/tools/testing/selftests/kselftest_harness.h b/tools/testing/selftests/kselftest_harness.h index 2902f6a78f8a..2bb8c81fc0b4 100644 --- a/tools/testing/selftests/kselftest_harness.h +++ b/tools/testing/selftests/kselftest_harness.h @@ -705,7 +705,7 @@ static void __timeout_handler(int sig, siginfo_t *info, void *ucontext) /* Sanity check handler execution environment. */ if (!t) { fprintf(TH_LOG_STREAM, - "no active test in SIGARLM handler!?\n"); + "no active test in SIGALRM handler!?\n"); abort(); } if (sig != SIGALRM || sig != info->si_signo) { @@ -731,7 +731,7 @@ void __wait_for_test(struct __test_metadata *t) if (sigaction(SIGALRM, &action, &saved_action)) { t->passed = 0; fprintf(TH_LOG_STREAM, - "%s: unable to install SIGARLM handler\n", + "%s: unable to install SIGALRM handler\n", t->name); return; } @@ -743,7 +743,7 @@ void __wait_for_test(struct __test_metadata *t) if (sigaction(SIGALRM, &saved_action, NULL)) { t->passed = 0; fprintf(TH_LOG_STREAM, - "%s: unable to uninstall SIGARLM handler\n", + "%s: unable to uninstall SIGALRM handler\n", t->name); return; } -- 2.25.1

4 years, 9 months

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[PATCH] selftests: Fix memfd to support relocatable build (O=objdir)

by Shuah Khan

Fix memfd to support relocatable build (O=objdir). This calls out source files necessary to build tests and simplfies the dependency enforcement. Tested the following: Note that cross-build for fuse_mnt has dependency on -lfuse. make all make clean make kselftest-install O=/arm64_build/ ARCH=arm64 HOSTCC=gcc \ CROSS_COMPILE=aarch64-linux-gnu- TARGETS=memfd Signed-off-by: Shuah Khan <skhan(a)linuxfoundation.org> --- tools/testing/selftests/memfd/Makefile | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/tools/testing/selftests/memfd/Makefile b/tools/testing/selftests/memfd/Makefile index 53a848109f7b..0a15f9e23431 100644 --- a/tools/testing/selftests/memfd/Makefile +++ b/tools/testing/selftests/memfd/Makefile @@ -4,9 +4,8 @@ CFLAGS += -I../../../../include/uapi/ CFLAGS += -I../../../../include/ CFLAGS += -I../../../../usr/include/ -TEST_GEN_PROGS := memfd_test +TEST_GEN_PROGS := memfd_test fuse_test fuse_mnt TEST_PROGS := run_fuse_test.sh run_hugetlbfs_test.sh -TEST_GEN_FILES := fuse_mnt fuse_test fuse_mnt.o: CFLAGS += $(shell pkg-config fuse --cflags) @@ -14,7 +13,7 @@ include ../lib.mk $(OUTPUT)/fuse_mnt: LDLIBS += $(shell pkg-config fuse --libs) -$(OUTPUT)/memfd_test: memfd_test.c common.o -$(OUTPUT)/fuse_test: fuse_test.c common.o +$(OUTPUT)/memfd_test: memfd_test.c common.c +$(OUTPUT)/fuse_test: fuse_test.c common.c -EXTRA_CLEAN = common.o +EXTRA_CLEAN = $(OUTPUT)/common.o -- 2.20.1

4 years, 9 months

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runqslower build failed on Debian9

by Liu Yiding

Hi, Andrii. I noticed you had added runqslower tool to tools/bpf, so drop this problem to you. Now i failed to run bpf tests since i can't build runqslower. Testing env: "Debian GNU/Linux 9 (stretch)" kernel: 5.6.0-rc5 gcc: gcc 6.3 clang: clang-11. Description: Build runqslower failed due to build error "incomplete type" and libbpf show unsupported BTF_KIND:7. Whole build log please see the attatchment. Error info ``` root@vm-snb-144 ~/linus/tools/bpf# make Auto-detecting system features: ... libbfd: [ on ] ... disassembler-four-args: [ OFF ] [snip] INSTALL bpftool LINK bpf_asm GEN vmlinux.h libbpf: unsupported BTF_KIND:7 (Many unsupported errors) libbpf: unsupported BTF_KIND:7 libbpf: unsupported BTF_KIND:7 [snip] (Many incomplete type errors) .output/vmlinux.h:8401:18: error: field has incomplete type 'struct idt_bits' struct idt_bits bits; ^ .output/vmlinux.h:8396:8: note: forward declaration of 'struct idt_bits' struct idt_bits; ^ .output/vmlinux.h:8598:21: error: field has incomplete type 'struct trace_entry' struct trace_entry ent; ^ .output/vmlinux.h:8595:8: note: forward declaration of 'struct trace_entry' struct trace_entry; ^ .output/vmlinux.h:9006:25: error: array has incomplete element type 'struct cyc2ns_data' struct cyc2ns_data data[2]; ^ .output/vmlinux.h:3669:8: note: forward declaration of 'struct cyc2ns_data' struct cyc2ns_data; ^ fatal error: too many errors emitted, stopping now [-ferror-limit=] 20 errors generated. Makefile:56: recipe for target '.output/runqslower.bpf.o' failed make[1]: *** [.output/runqslower.bpf.o] Error 1 Makefile:119: recipe for target 'runqslower' failed make: *** [runqslower] Error 2 ``` -- Best Regards. Liu Yiding

4 years, 9 months

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[PATCH] tools/testing/selftests/vm/mlock2-tests: fix mlock2 false-negative errors

by Rafael Aquini

Changes for commit 9c4e6b1a7027f ("mm, mlock, vmscan: no more skipping pagevecs") break this test expectations on the behavior of mlock syscall family immediately inserting the recently faulted pages into the UNEVICTABLE_LRU, when MCL_ONFAULT is passed to the syscall as part of its flag-set. There is no functional error introduced by the aforementioned commit, but it opens up a time window where the recently faulted and locked pages might yet not be put back into the UNEVICTABLE_LRU, thus causing a subsequent and immediate PFN flag check for the UNEVICTABLE bit to trip on false-negative errors, as it happens with this test. This patch fix the false negative by forcefully resorting to a code path that will call a CPU pagevec drain right after the fault but before the PFN flag check takes place, sorting out the race that way. Fixes: 9c4e6b1a7027f ("mm, mlock, vmscan: no more skipping pagevecs") Signed-off-by: Rafael Aquini <aquini(a)redhat.com> --- tools/testing/selftests/vm/mlock2-tests.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) diff --git a/tools/testing/selftests/vm/mlock2-tests.c b/tools/testing/selftests/vm/mlock2-tests.c index 637b6d0ac0d0..26dc320ca3c9 100644 --- a/tools/testing/selftests/vm/mlock2-tests.c +++ b/tools/testing/selftests/vm/mlock2-tests.c @@ -7,6 +7,7 @@ #include <sys/time.h> #include <sys/resource.h> #include <stdbool.h> +#include <sched.h> #include "mlock2.h" #include "../kselftest.h" @@ -328,6 +329,22 @@ static int test_mlock_lock() return ret; } +/* + * After commit 9c4e6b1a7027f ("mm, mlock, vmscan: no more skipping pagevecs") + * changes made by calls to mlock* family might not be immediately reflected + * on the LRUs, thus checking the PFN flags might race against pagevec drain. + * + * In order to sort out that race, and get the after fault checks consistent, + * the "quick and dirty" trick below is required in order to force a call to + * lru_add_drain_all() to get the recently MLOCK_ONFAULT pages moved to + * the unevictable LRU, as expected by the checks in this selftest. + */ +static void force_lru_add_drain_all(void) +{ + sched_yield(); + system("echo 1 > /proc/sys/vm/compact_memory"); +} + static int onfault_check(char *map) { unsigned long page_size = getpagesize(); @@ -343,6 +360,9 @@ static int onfault_check(char *map) } *map = 'a'; + + force_lru_add_drain_all(); + page1_flags = get_pageflags((unsigned long)map); page2_flags = get_pageflags((unsigned long)map + page_size); @@ -465,6 +485,8 @@ static int test_lock_onfault_of_present() goto unmap; } + force_lru_add_drain_all(); + page1_flags = get_pageflags((unsigned long)map); page2_flags = get_pageflags((unsigned long)map + page_size); page1_flags = get_kpageflags(page1_flags & PFN_MASK); -- 2.24.1

4 years, 9 months

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