* Re: BUG: core dump in selftest of proc fs [not found] <fd9206f6-3ec4-cafc-e313-dfddf957bd5e@alu.unizg.hr> @ 2023-01-04 18:36 ` Alexey Dobriyan 2023-01-06 13:49 ` Mirsad Goran Todorovac 2023-01-06 10:39 ` Alexey Dobriyan 2023-01-06 19:30 ` [PATCH] proc: fix PIE proc-empty-vm, proc-pid-vm tests Alexey Dobriyan 2 siblings, 1 reply; 8+ messages in thread From: Alexey Dobriyan @ 2023-01-04 18:36 UTC (permalink / raw) To: Mirsad Goran Todorovac Cc: linux-kselftest, Shuah Khan, Andrew Morton, Brian Foster, Guo Zhengkui, linux-fsdevel, linux-kernel, Thorsten Leemhuis On Wed, Jan 04, 2023 at 07:27:40PM +0100, Mirsad Goran Todorovac wrote: > Trying to complete `make kselftest` for the first time, so maybe I'm doing something wrong? > > Or we are having a regression in 6.2-rc2 release candidate ... > > However, the output of selftest run is: > # proc-empty-vm: proc-empty-vm.c:184: test_proc_pid_maps: Assertion `rv == 0' failed. > # /usr/bin/timeout: the monitored command dumped core > # Aborted > not ok 5 selftests: proc: proc-empty-vm # exit=134 > # selftests: proc: proc-pid-vm > # proc-pid-vm: proc-pid-vm.c:365: main: Assertion `rv == len' failed. > # /usr/bin/timeout: the monitored command dumped core > # Aborted > > Please find attached lshw output, dmesg, config and lsmod. > > I am available for further diagnostics. > > The platform is Ubuntu 22.10 kinetic kudu on a Lenovo Ideapad 3 15ITL6 laptop. What the output of "cat /proc/self/maps" ? ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: BUG: core dump in selftest of proc fs 2023-01-04 18:36 ` BUG: core dump in selftest of proc fs Alexey Dobriyan @ 2023-01-06 13:49 ` Mirsad Goran Todorovac 0 siblings, 0 replies; 8+ messages in thread From: Mirsad Goran Todorovac @ 2023-01-06 13:49 UTC (permalink / raw) To: Alexey Dobriyan Cc: linux-kselftest, Shuah Khan, Andrew Morton, Brian Foster, Guo Zhengkui, linux-fsdevel, linux-kernel, Thorsten Leemhuis On 04. 01. 2023. 19:36, Alexey Dobriyan wrote: > On Wed, Jan 04, 2023 at 07:27:40PM +0100, Mirsad Goran Todorovac wrote: >> Trying to complete `make kselftest` for the first time, so maybe I'm doing something wrong? >> >> Or we are having a regression in 6.2-rc2 release candidate ... >> >> However, the output of selftest run is: > >> # proc-empty-vm: proc-empty-vm.c:184: test_proc_pid_maps: Assertion `rv == 0' failed. >> # /usr/bin/timeout: the monitored command dumped core >> # Aborted >> not ok 5 selftests: proc: proc-empty-vm # exit=134 >> # selftests: proc: proc-pid-vm >> # proc-pid-vm: proc-pid-vm.c:365: main: Assertion `rv == len' failed. >> # /usr/bin/timeout: the monitored command dumped core >> # Aborted >> >> Please find attached lshw output, dmesg, config and lsmod. >> >> I am available for further diagnostics. >> >> The platform is Ubuntu 22.10 kinetic kudu on a Lenovo Ideapad 3 15ITL6 laptop. > > What the output of "cat /proc/self/maps" ? root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds# cat /proc/self/maps 5606e3099000-5606e309b000 r--p 00000000 103:04 5505728 /usr/bin/cat 5606e309b000-5606e309f000 r-xp 00002000 103:04 5505728 /usr/bin/cat 5606e309f000-5606e30a1000 r--p 00006000 103:04 5505728 /usr/bin/cat 5606e30a1000-5606e30a2000 r--p 00007000 103:04 5505728 /usr/bin/cat 5606e30a2000-5606e30a3000 rw-p 00008000 103:04 5505728 /usr/bin/cat 5606e4804000-5606e4825000 rw-p 00000000 00:00 0 [heap] 7f9833400000-7f9833c42000 r--p 00000000 103:04 5505206 /usr/lib/locale/locale-archive 7f9833e00000-7f9833e22000 r--p 00000000 103:04 5506045 /usr/lib/x86_64-linux-gnu/libc.so.6 7f9833e22000-7f9833f9b000 r-xp 00022000 103:04 5506045 /usr/lib/x86_64-linux-gnu/libc.so.6 7f9833f9b000-7f9833ff2000 r--p 0019b000 103:04 5506045 /usr/lib/x86_64-linux-gnu/libc.so.6 7f9833ff2000-7f9833ff6000 r--p 001f1000 103:04 5506045 /usr/lib/x86_64-linux-gnu/libc.so.6 7f9833ff6000-7f9833ff8000 rw-p 001f5000 103:04 5506045 /usr/lib/x86_64-linux-gnu/libc.so.6 7f9833ff8000-7f9834005000 rw-p 00000000 00:00 0 7f983401e000-7f9834040000 rw-p 00000000 00:00 0 7f9834040000-7f9834097000 r--p 00000000 103:04 5636099 /usr/lib/locale/C.utf8/LC_CTYPE 7f9834097000-7f983409a000 rw-p 00000000 00:00 0 7f983409d000-7f983409e000 r--p 00000000 103:04 5636115 /usr/lib/locale/C.utf8/LC_NUMERIC 7f983409e000-7f983409f000 r--p 00000000 103:04 5636123 /usr/lib/locale/C.utf8/LC_TIME 7f983409f000-7f98340a0000 r--p 00000000 103:04 5636098 /usr/lib/locale/C.utf8/LC_COLLATE 7f98340a0000-7f98340a1000 r--p 00000000 103:04 5636111 /usr/lib/locale/C.utf8/LC_MONETARY 7f98340a1000-7f98340a2000 r--p 00000000 103:04 5636109 /usr/lib/locale/C.utf8/LC_MESSAGES/SYS_LC_MESSAGES 7f98340a2000-7f98340a3000 r--p 00000000 103:04 5636117 /usr/lib/locale/C.utf8/LC_PAPER 7f98340a3000-7f98340a4000 r--p 00000000 103:04 5636113 /usr/lib/locale/C.utf8/LC_NAME 7f98340a4000-7f98340a5000 r--p 00000000 103:04 5636097 /usr/lib/locale/C.utf8/LC_ADDRESS 7f98340a5000-7f98340a6000 r--p 00000000 103:04 5636121 /usr/lib/locale/C.utf8/LC_TELEPHONE 7f98340a6000-7f98340a7000 r--p 00000000 103:04 5636107 /usr/lib/locale/C.utf8/LC_MEASUREMENT 7f98340a7000-7f98340ae000 r--s 00000000 103:04 6164284 /usr/lib/x86_64-linux-gnu/gconv/gconv-modules.cache 7f98340ae000-7f98340af000 r--p 00000000 103:04 5636106 /usr/lib/locale/C.utf8/LC_IDENTIFICATION 7f98340af000-7f98340b1000 rw-p 00000000 00:00 0 7f98340b1000-7f98340b2000 r--p 00000000 103:04 5505669 /usr/lib/x86_64-linux-gnu/ld-linux-x86-64.so.2 7f98340b2000-7f98340db000 r-xp 00001000 103:04 5505669 /usr/lib/x86_64-linux-gnu/ld-linux-x86-64.so.2 7f98340db000-7f98340e5000 r--p 0002a000 103:04 5505669 /usr/lib/x86_64-linux-gnu/ld-linux-x86-64.so.2 7f98340e5000-7f98340e7000 r--p 00034000 103:04 5505669 /usr/lib/x86_64-linux-gnu/ld-linux-x86-64.so.2 7f98340e7000-7f98340e9000 rw-p 00036000 103:04 5505669 /usr/lib/x86_64-linux-gnu/ld-linux-x86-64.so.2 7ffd0e771000-7ffd0e792000 rw-p 00000000 00:00 0 [stack] 7ffd0e7ec000-7ffd0e7f0000 r--p 00000000 00:00 0 [vvar] 7ffd0e7f0000-7ffd0e7f2000 r-xp 00000000 00:00 0 [vdso] ffffffffff600000-ffffffffff601000 --xp 00000000 00:00 0 [vsyscall] root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds# Sorry, overlooked your reply in the bunch of msgs. :( Thanks, Mirsad -- Mirsad Goran Todorovac Sistem inženjer Grafički fakultet | Akademija likovnih umjetnosti Sveučilište u Zagrebu -- System engineer Faculty of Graphic Arts | Academy of Fine Arts University of Zagreb, Republic of Croatia The European Union ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: BUG: core dump in selftest of proc fs [not found] <fd9206f6-3ec4-cafc-e313-dfddf957bd5e@alu.unizg.hr> 2023-01-04 18:36 ` BUG: core dump in selftest of proc fs Alexey Dobriyan @ 2023-01-06 10:39 ` Alexey Dobriyan 2023-01-06 13:53 ` Mirsad Goran Todorovac 2023-01-06 19:30 ` [PATCH] proc: fix PIE proc-empty-vm, proc-pid-vm tests Alexey Dobriyan 2 siblings, 1 reply; 8+ messages in thread From: Alexey Dobriyan @ 2023-01-06 10:39 UTC (permalink / raw) To: Mirsad Goran Todorovac Cc: linux-kselftest, Shuah Khan, Andrew Morton, Brian Foster, Guo Zhengkui, linux-fsdevel, linux-kernel, Thorsten Leemhuis On Wed, Jan 04, 2023 at 07:27:40PM +0100, Mirsad Goran Todorovac wrote: > Dear all, > > Trying to complete `make kselftest` for the first time, so maybe I'm doing something wrong? > > Or we are having a regression in 6.2-rc2 release candidate ... > > However, the output of selftest run is: > > make[2]: Entering directory '.../linux_torvalds/tools/testing/selftests/proc' > TAP version 13 > 1..21 > # selftests: proc: fd-001-lookup > ok 1 selftests: proc: fd-001-lookup > # selftests: proc: fd-002-posix-eq > ok 2 selftests: proc: fd-002-posix-eq > # selftests: proc: fd-003-kthread > ok 3 selftests: proc: fd-003-kthread > # selftests: proc: proc-loadavg-001 > ok 4 selftests: proc: proc-loadavg-001 > # selftests: proc: proc-empty-vm > # proc-empty-vm: proc-empty-vm.c:184: test_proc_pid_maps: Assertion `rv == 0' failed. > # /usr/bin/timeout: the monitored command dumped core > # Aborted > not ok 5 selftests: proc: proc-empty-vm # exit=134 > # selftests: proc: proc-pid-vm > # proc-pid-vm: proc-pid-vm.c:365: main: Assertion `rv == len' failed. > # /usr/bin/timeout: the monitored command dumped core > # Aborted > > Please find attached lshw output, dmesg, config and lsmod. > > I am available for further diagnostics. > > The platform is Ubuntu 22.10 kinetic kudu on a Lenovo Ideapad 3 15ITL6 laptop. The "bug" is that "call rel32" instruction testing for executable vsyscall page which should be relocated to "call 0xffffffffff600000" is messed up. Ubuntu 22.10 ships with "vsyscall=xonly" so there should not be any faults when executing from it. But segfault happens with normal randomised userspace address. I'll change it to "call *rax" which should be more robust (and works) and free from relocations. ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: BUG: core dump in selftest of proc fs 2023-01-06 10:39 ` Alexey Dobriyan @ 2023-01-06 13:53 ` Mirsad Goran Todorovac 0 siblings, 0 replies; 8+ messages in thread From: Mirsad Goran Todorovac @ 2023-01-06 13:53 UTC (permalink / raw) To: Alexey Dobriyan Cc: linux-kselftest, Shuah Khan, Andrew Morton, Brian Foster, Guo Zhengkui, linux-fsdevel, linux-kernel, Thorsten Leemhuis On 06. 01. 2023. 11:39, Alexey Dobriyan wrote: > On Wed, Jan 04, 2023 at 07:27:40PM +0100, Mirsad Goran Todorovac wrote: >> Dear all, >> >> Trying to complete `make kselftest` for the first time, so maybe I'm doing something wrong? >> >> Or we are having a regression in 6.2-rc2 release candidate ... >> >> However, the output of selftest run is: >> >> make[2]: Entering directory '.../linux_torvalds/tools/testing/selftests/proc' >> TAP version 13 >> 1..21 >> # selftests: proc: fd-001-lookup >> ok 1 selftests: proc: fd-001-lookup >> # selftests: proc: fd-002-posix-eq >> ok 2 selftests: proc: fd-002-posix-eq >> # selftests: proc: fd-003-kthread >> ok 3 selftests: proc: fd-003-kthread >> # selftests: proc: proc-loadavg-001 >> ok 4 selftests: proc: proc-loadavg-001 >> # selftests: proc: proc-empty-vm >> # proc-empty-vm: proc-empty-vm.c:184: test_proc_pid_maps: Assertion `rv == 0' failed. >> # /usr/bin/timeout: the monitored command dumped core >> # Aborted >> not ok 5 selftests: proc: proc-empty-vm # exit=134 >> # selftests: proc: proc-pid-vm >> # proc-pid-vm: proc-pid-vm.c:365: main: Assertion `rv == len' failed. >> # /usr/bin/timeout: the monitored command dumped core >> # Aborted >> >> Please find attached lshw output, dmesg, config and lsmod. >> >> I am available for further diagnostics. >> >> The platform is Ubuntu 22.10 kinetic kudu on a Lenovo Ideapad 3 15ITL6 laptop. > > The "bug" is that "call rel32" instruction testing for executable > vsyscall page which should be relocated to "call 0xffffffffff600000" > is messed up. Ubuntu 22.10 ships with "vsyscall=xonly" so there should not be > any faults when executing from it. But segfault happens with normal > randomised userspace address. > > I'll change it to "call *rax" which should be more robust (and works) > and free from relocations. If you will need to test the patch in the same environment where the problem initially occurred, I am ready at your disposal. Thanks, Mirsad -- Mirsad Goran Todorovac Sistem inženjer Grafički fakultet | Akademija likovnih umjetnosti Sveučilište u Zagrebu -- System engineer Faculty of Graphic Arts | Academy of Fine Arts University of Zagreb, Republic of Croatia The European Union ^ permalink raw reply [flat|nested] 8+ messages in thread
* [PATCH] proc: fix PIE proc-empty-vm, proc-pid-vm tests [not found] <fd9206f6-3ec4-cafc-e313-dfddf957bd5e@alu.unizg.hr> 2023-01-04 18:36 ` BUG: core dump in selftest of proc fs Alexey Dobriyan 2023-01-06 10:39 ` Alexey Dobriyan @ 2023-01-06 19:30 ` Alexey Dobriyan 2023-01-06 20:53 ` Mirsad Goran Todorovac 2023-01-06 21:18 ` BUG: assert spuriously fails in selftest/proc/proc-uptime-001.c Mirsad Goran Todorovac 2 siblings, 2 replies; 8+ messages in thread From: Alexey Dobriyan @ 2023-01-06 19:30 UTC (permalink / raw) To: Andrew Morton Cc: linux-kselftest, Shuah Khan, Mirsad Goran Todorovac, Brian Foster, Guo Zhengkui, linux-fsdevel, linux-kernel, Thorsten Leemhuis vsyscall detection code uses direct call to the beginning of the vsyscall page: asm ("call %P0" :: "i" (0xffffffffff600000)) It generates "call rel32" instruction but it is not relocated if binary is PIE, so binary segfaults into random userspace address and vsyscall page status is detected incorrectly. Do more direct: asm ("call *%rax") which doesn't do need any relocaltions. Mark g_vsyscall as volatile for a good measure, I didn't find instruction setting it to 0. Now the code is obviously correct: xor eax, eax mov rdi, rbp mov rsi, rbp mov DWORD PTR [rip+0x2d15], eax # g_vsyscall = 0 mov rax, 0xffffffffff600000 call rax mov DWORD PTR [rip+0x2d02], 1 # g_vsyscall = 1 mov eax, DWORD PTR ds:0xffffffffff600000 mov DWORD PTR [rip+0x2cf1], 2 # g_vsyscall = 2 mov edi, [rip+0x2ceb] # exit(g_vsyscall) call exit Note: fixed proc-empty-vm test oopses 5.19.0-28-generic kernel but this is separate story. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Reported-by: Mirsad Goran Todorovac <mirsad.todorovac@alu.unizg.hr> --- tools/testing/selftests/proc/proc-empty-vm.c | 12 +++++++----- tools/testing/selftests/proc/proc-pid-vm.c | 9 +++++---- 2 files changed, 12 insertions(+), 9 deletions(-) --- a/tools/testing/selftests/proc/proc-empty-vm.c +++ b/tools/testing/selftests/proc/proc-empty-vm.c @@ -25,6 +25,7 @@ #undef NDEBUG #include <assert.h> #include <errno.h> +#include <stdint.h> #include <stdio.h> #include <stdlib.h> #include <string.h> @@ -41,7 +42,7 @@ * 1: vsyscall VMA is --xp vsyscall=xonly * 2: vsyscall VMA is r-xp vsyscall=emulate */ -static int g_vsyscall; +static volatile int g_vsyscall; static const char *g_proc_pid_maps_vsyscall; static const char *g_proc_pid_smaps_vsyscall; @@ -147,11 +148,12 @@ static void vsyscall(void) g_vsyscall = 0; /* gettimeofday(NULL, NULL); */ + uint64_t rax = 0xffffffffff600000; asm volatile ( - "call %P0" - : - : "i" (0xffffffffff600000), "D" (NULL), "S" (NULL) - : "rax", "rcx", "r11" + "call *%[rax]" + : [rax] "+a" (rax) + : "D" (NULL), "S" (NULL) + : "rcx", "r11" ); g_vsyscall = 1; --- a/tools/testing/selftests/proc/proc-pid-vm.c +++ b/tools/testing/selftests/proc/proc-pid-vm.c @@ -257,11 +257,12 @@ static void vsyscall(void) g_vsyscall = 0; /* gettimeofday(NULL, NULL); */ + uint64_t rax = 0xffffffffff600000; asm volatile ( - "call %P0" - : - : "i" (0xffffffffff600000), "D" (NULL), "S" (NULL) - : "rax", "rcx", "r11" + "call *%[rax]" + : [rax] "+a" (rax) + : "D" (NULL), "S" (NULL) + : "rcx", "r11" ); g_vsyscall = 1; ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] proc: fix PIE proc-empty-vm, proc-pid-vm tests 2023-01-06 19:30 ` [PATCH] proc: fix PIE proc-empty-vm, proc-pid-vm tests Alexey Dobriyan @ 2023-01-06 20:53 ` Mirsad Goran Todorovac 2023-01-06 21:18 ` BUG: assert spuriously fails in selftest/proc/proc-uptime-001.c Mirsad Goran Todorovac 1 sibling, 0 replies; 8+ messages in thread From: Mirsad Goran Todorovac @ 2023-01-06 20:53 UTC (permalink / raw) To: Alexey Dobriyan, Andrew Morton Cc: linux-kselftest, Shuah Khan, Brian Foster, Guo Zhengkui, linux-fsdevel, linux-kernel, Thorsten Leemhuis Hi, On 06. 01. 2023. 20:30, Alexey Dobriyan wrote: > vsyscall detection code uses direct call to the beginning of > the vsyscall page: > > asm ("call %P0" :: "i" (0xffffffffff600000)) > > It generates "call rel32" instruction but it is not relocated if binary > is PIE, so binary segfaults into random userspace address and vsyscall > page status is detected incorrectly. > > Do more direct: > > asm ("call *%rax") > > which doesn't do need any relocaltions. > > Mark g_vsyscall as volatile for a good measure, I didn't find instruction > setting it to 0. Now the code is obviously correct: > > xor eax, eax > mov rdi, rbp > mov rsi, rbp > mov DWORD PTR [rip+0x2d15], eax # g_vsyscall = 0 > mov rax, 0xffffffffff600000 > call rax > mov DWORD PTR [rip+0x2d02], 1 # g_vsyscall = 1 > mov eax, DWORD PTR ds:0xffffffffff600000 > mov DWORD PTR [rip+0x2cf1], 2 # g_vsyscall = 2 > mov edi, [rip+0x2ceb] # exit(g_vsyscall) > call exit > > Note: fixed proc-empty-vm test oopses 5.19.0-28-generic kernel > but this is separate story. > > Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> > Reported-by: Mirsad Goran Todorovac <mirsad.todorovac@alu.unizg.hr> > --- > > tools/testing/selftests/proc/proc-empty-vm.c | 12 +++++++----- > tools/testing/selftests/proc/proc-pid-vm.c | 9 +++++---- > 2 files changed, 12 insertions(+), 9 deletions(-) > > --- a/tools/testing/selftests/proc/proc-empty-vm.c > +++ b/tools/testing/selftests/proc/proc-empty-vm.c > @@ -25,6 +25,7 @@ > #undef NDEBUG > #include <assert.h> > #include <errno.h> > +#include <stdint.h> > #include <stdio.h> > #include <stdlib.h> > #include <string.h> > @@ -41,7 +42,7 @@ > * 1: vsyscall VMA is --xp vsyscall=xonly > * 2: vsyscall VMA is r-xp vsyscall=emulate > */ > -static int g_vsyscall; > +static volatile int g_vsyscall; > static const char *g_proc_pid_maps_vsyscall; > static const char *g_proc_pid_smaps_vsyscall; > > @@ -147,11 +148,12 @@ static void vsyscall(void) > > g_vsyscall = 0; > /* gettimeofday(NULL, NULL); */ > + uint64_t rax = 0xffffffffff600000; > asm volatile ( > - "call %P0" > - : > - : "i" (0xffffffffff600000), "D" (NULL), "S" (NULL) nt> - : "rax", "rcx", "r11" > + "call *%[rax]" > + : [rax] "+a" (rax) > + : "D" (NULL), "S" (NULL) > + : "rcx", "r11" > ); > > g_vsyscall = 1; > --- a/tools/testing/selftests/proc/proc-pid-vm.c > +++ b/tools/testing/selftests/proc/proc-pid-vm.c > @@ -257,11 +257,12 @@ static void vsyscall(void) > > g_vsyscall = 0; > /* gettimeofday(NULL, NULL); */ > + uint64_t rax = 0xffffffffff600000; > asm volatile ( > - "call %P0" > - : > - : "i" (0xffffffffff600000), "D" (NULL), "S" (NULL) > - : "rax", "rcx", "r11" > + "call *%[rax]" > + : [rax] "+a" (rax) > + : "D" (NULL), "S" (NULL) > + : "rcx", "r11" > ); > > g_vsyscall = 1; I can confirm that the patch fixed the core dump in the exact environment that used to reproduce the bug. Apparently, it seems that gcc 12.2.0 -O2 optimiser on Ubuntu 22.10 kinetic kudu did some new creative stuff to Alexey's code. For someone interested, I have saved the assembly with and w/o -O2 ... However, I have just found some spurious bug in proc-uptime-001. But, this is another story ... Thanks, Mirsad -- Mirsad Goran Todorovac Sistem inženjer Grafički fakultet | Akademija likovnih umjetnosti Sveučilište u Zagrebu -- System engineer Faculty of Graphic Arts | Academy of Fine Arts University of Zagreb, Republic of Croatia The European Union ^ permalink raw reply [flat|nested] 8+ messages in thread
* BUG: assert spuriously fails in selftest/proc/proc-uptime-001.c 2023-01-06 19:30 ` [PATCH] proc: fix PIE proc-empty-vm, proc-pid-vm tests Alexey Dobriyan 2023-01-06 20:53 ` Mirsad Goran Todorovac @ 2023-01-06 21:18 ` Mirsad Goran Todorovac 2023-01-06 22:06 ` Mirsad Goran Todorovac 1 sibling, 1 reply; 8+ messages in thread From: Mirsad Goran Todorovac @ 2023-01-06 21:18 UTC (permalink / raw) To: Alexey Dobriyan Cc: linux-kselftest, Shuah Khan, Brian Foster, Guo Zhengkui, linux-fsdevel, linux-kernel, Thorsten Leemhuis, Andrew Morton Hi all, In the same environment as the previous bug report (Lenovo Ideapad 3 15ITL6 laptop running Ubuntu 22.10 kinetic kudu and 6.2-rc2 vanilla Torvalds tree kernel), the next test in the ...selftest/proc/* sequence spuriously fails in assert (i1 <= i0). Please note that the compiler is the novelty GCC 12.2.0-3ubuntu1. This was previously hidden by premature hang in the `make kselftest` run due to proc-empty-vm an proc-pid-vm problems that are now fixed. root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc# ./proc-uptime-001 root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc# ./proc-uptime-001 root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc# ./proc-uptime-001 proc-uptime-001: proc-uptime-001.c:39: main: Assertion `i1 >= i0' failed. Aborted (core dumped) root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc# ./proc-uptime-001 proc-uptime-001: proc-uptime-001.c:39: main: Assertion `i1 >= i0' failed. Aborted (core dumped) root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc# ./proc-uptime-001 root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc# ./proc-uptime-001 root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc# ./proc-uptime-001 root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc# ./proc-uptime-001 root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc# ./proc-uptime-001 proc-uptime-001: proc-uptime-001.c:39: main: Assertion `i1 >= i0' failed. Aborted (core dumped) root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc# ./proc-uptime-001 root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc# ./proc-uptime-001 proc-uptime-001: proc-uptime-001.c:39: main: Assertion `i1 >= i0' failed. Aborted (core dumped) root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc# ./proc-uptime-001 root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc# ./proc-uptime-001 proc-uptime-001: proc-uptime-001.c:39: main: Assertion `i1 >= i0' failed. Aborted (core dumped) root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc# ./proc-uptime-001 root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc# ./proc-uptime-001 root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc# ./proc-uptime-001 proc-uptime-001: proc-uptime-001.c:39: main: Assertion `i1 >= i0' failed. Aborted (core dumped) root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc# ./proc-uptime-001 proc-uptime-001: proc-uptime-001.c:39: main: Assertion `i1 >= i0' failed. Aborted (core dumped) root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc# ./proc-uptime-001 proc-uptime-001: proc-uptime-001.c:39: main: Assertion `i1 >= i0' failed. Aborted (core dumped) root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc# ./proc-uptime-001 proc-uptime-001: proc-uptime-001.c:39: main: Assertion `i1 >= i0' failed. Aborted (core dumped) root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc# ./proc-uptime-001 proc-uptime-001: proc-uptime-001.c:39: main: Assertion `i1 >= i0' failed. Aborted (core dumped) root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc# ./proc-uptime-001 proc-uptime-001: proc-uptime-001.c:39: main: Assertion `i1 >= i0' failed. Aborted (core dumped) root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc# ./proc-uptime-001 It happens about half of the times the program is called. The source seems OK, I can't tell why the idle counter doesn't look monotonic to the program. Hope this helps. BTW, good news: this time I have checked independently, and this is the last test from the .../selftest/proc group that doesn't have clean exit code 0. Thanks, Mirsad -- Mirsad Goran Todorovac Sistem inženjer Grafički fakultet | Akademija likovnih umjetnosti Sveučilište u Zagrebu -- System engineer Faculty of Graphic Arts | Academy of Fine Arts University of Zagreb, Republic of Croatia The European Union ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: BUG: assert spuriously fails in selftest/proc/proc-uptime-001.c 2023-01-06 21:18 ` BUG: assert spuriously fails in selftest/proc/proc-uptime-001.c Mirsad Goran Todorovac @ 2023-01-06 22:06 ` Mirsad Goran Todorovac 0 siblings, 0 replies; 8+ messages in thread From: Mirsad Goran Todorovac @ 2023-01-06 22:06 UTC (permalink / raw) To: Alexey Dobriyan Cc: linux-kselftest, Shuah Khan, Brian Foster, Guo Zhengkui, linux-fsdevel, linux-kernel, Thorsten Leemhuis, Andrew Morton On 06. 01. 2023. 22:18, Mirsad Goran Todorovac wrote: > Hi all, > > In the same environment as the previous bug report (Lenovo Ideapad 3 15ITL6 laptop > running Ubuntu 22.10 kinetic kudu and 6.2-rc2 vanilla Torvalds tree kernel), the > next test in the ...selftest/proc/* sequence spuriously fails in assert (i1 <= i0). > > Please note that the compiler is the novelty GCC 12.2.0-3ubuntu1. > > This was previously hidden by premature hang in the `make kselftest` run due to > proc-empty-vm an proc-pid-vm problems that are now fixed. > > root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc# ./proc-uptime-001 > root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc# ./proc-uptime-001 > root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc# ./proc-uptime-001 > proc-uptime-001: proc-uptime-001.c:39: main: Assertion `i1 >= i0' failed. > Aborted (core dumped) > root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc# ./proc-uptime-001 > proc-uptime-001: proc-uptime-001.c:39: main: Assertion `i1 >= i0' failed. > Aborted (core dumped) > root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc# ./proc-uptime-001 > root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc# ./proc-uptime-001 > root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc# ./proc-uptime-001 > root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc# ./proc-uptime-001 > root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc# ./proc-uptime-001 > proc-uptime-001: proc-uptime-001.c:39: main: Assertion `i1 >= i0' failed. > Aborted (core dumped) > root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc# ./proc-uptime-001 > root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc# ./proc-uptime-001 > proc-uptime-001: proc-uptime-001.c:39: main: Assertion `i1 >= i0' failed. > Aborted (core dumped) > root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc# ./proc-uptime-001 > root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc# ./proc-uptime-001 > proc-uptime-001: proc-uptime-001.c:39: main: Assertion `i1 >= i0' failed. > Aborted (core dumped) > root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc# ./proc-uptime-001 > root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc# ./proc-uptime-001 > root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc# ./proc-uptime-001 > proc-uptime-001: proc-uptime-001.c:39: main: Assertion `i1 >= i0' failed. > Aborted (core dumped) > root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc# ./proc-uptime-001 > proc-uptime-001: proc-uptime-001.c:39: main: Assertion `i1 >= i0' failed. > Aborted (core dumped) > root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc# ./proc-uptime-001 > proc-uptime-001: proc-uptime-001.c:39: main: Assertion `i1 >= i0' failed. > Aborted (core dumped) > root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc# ./proc-uptime-001 > proc-uptime-001: proc-uptime-001.c:39: main: Assertion `i1 >= i0' failed. > Aborted (core dumped) > root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc# ./proc-uptime-001 > proc-uptime-001: proc-uptime-001.c:39: main: Assertion `i1 >= i0' failed. > Aborted (core dumped) > root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc# ./proc-uptime-001 > proc-uptime-001: proc-uptime-001.c:39: main: Assertion `i1 >= i0' failed. > Aborted (core dumped) > root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc# ./proc-uptime-001 > > It happens about half of the times the program is called. > > The source seems OK, I can't tell why the idle counter doesn't look monotonic to > the program. > > Hope this helps. > > BTW, good news: this time I have checked independently, and this is the last test from the .../selftest/proc > group that doesn't have clean exit code 0. UPDATE: The same behavior independently occurred with GCC 10.4.0, 9.5.0, 8.5.0 and 6.5.0. Apparently this happens in 30% to 50% of attempts. Perhaps that's why it wasn't discovered yet: root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc# make CC=gcc-10 gcc-10 -Wall -O2 -Wno-unused-function -D_GNU_SOURCE -pthread fd-001-lookup.c -o /home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc/fd-001-lookup gcc-10 -Wall -O2 -Wno-unused-function -D_GNU_SOURCE -pthread fd-002-posix-eq.c -o /home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc/fd-002-posix-eq gcc-10 -Wall -O2 -Wno-unused-function -D_GNU_SOURCE -pthread fd-003-kthread.c -o /home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc/fd-003-kthread gcc-10 -Wall -O2 -Wno-unused-function -D_GNU_SOURCE -pthread proc-loadavg-001.c -o /home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc/proc-loadavg-001 gcc-10 -Wall -O2 -Wno-unused-function -D_GNU_SOURCE -pthread proc-empty-vm.c -o /home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc/proc-empty-vm gcc-10 -Wall -O2 -Wno-unused-function -D_GNU_SOURCE -pthread proc-pid-vm.c -o /home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc/proc-pid-vm gcc-10 -Wall -O2 -Wno-unused-function -D_GNU_SOURCE -pthread proc-self-map-files-001.c -o /home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc/proc-self-map-files-001 gcc-10 -Wall -O2 -Wno-unused-function -D_GNU_SOURCE -pthread proc-self-map-files-002.c -o /home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc/proc-self-map-files-002 gcc-10 -Wall -O2 -Wno-unused-function -D_GNU_SOURCE -pthread proc-self-syscall.c -o /home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc/proc-self-syscall gcc-10 -Wall -O2 -Wno-unused-function -D_GNU_SOURCE -pthread proc-self-wchan.c -o /home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc/proc-self-wchan gcc-10 -Wall -O2 -Wno-unused-function -D_GNU_SOURCE -pthread proc-subset-pid.c -o /home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc/proc-subset-pid gcc-10 -Wall -O2 -Wno-unused-function -D_GNU_SOURCE -pthread proc-tid0.c -o /home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc/proc-tid0 gcc-10 -Wall -O2 -Wno-unused-function -D_GNU_SOURCE -pthread proc-uptime-001.c -o /home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc/proc-uptime-001 gcc-10 -Wall -O2 -Wno-unused-function -D_GNU_SOURCE -pthread proc-uptime-002.c -o /home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc/proc-uptime-002 gcc-10 -Wall -O2 -Wno-unused-function -D_GNU_SOURCE -pthread read.c -o /home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc/read gcc-10 -Wall -O2 -Wno-unused-function -D_GNU_SOURCE -pthread self.c -o /home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc/self gcc-10 -Wall -O2 -Wno-unused-function -D_GNU_SOURCE -pthread setns-dcache.c -o /home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc/setns-dcache gcc-10 -Wall -O2 -Wno-unused-function -D_GNU_SOURCE -pthread setns-sysvipc.c -o /home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc/setns-sysvipc gcc-10 -Wall -O2 -Wno-unused-function -D_GNU_SOURCE -pthread thread-self.c -o /home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc/thread-self gcc-10 -Wall -O2 -Wno-unused-function -D_GNU_SOURCE -pthread proc-multiple-procfs.c -o /home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc/proc-multiple-procfs gcc-10 -Wall -O2 -Wno-unused-function -D_GNU_SOURCE -pthread proc-fsconfig-hidepid.c -o /home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc/proc-fsconfig-hidepid root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc# for exe in `ls -l | grep -e -x | awk '{ print $9 }'`; do echo -n ${exe}':'; ./$exe ; echo "exit=$?" ; done fd-001-lookup:exit=0 fd-002-posix-eq:exit=0 fd-003-kthread:exit=0 proc-empty-vm:exit=0 proc-fsconfig-hidepid:exit=0 proc-loadavg-001:exit=0 proc-multiple-procfs:exit=0 proc-pid-vm:exit=0 proc-self-map-files-001:exit=0 proc-self-map-files-002:exit=0 proc-self-syscall:exit=0 proc-self-wchan:exit=0 proc-subset-pid:exit=0 proc-tid0:exit=0 proc-uptime-001:exit=0 proc-uptime-002:exit=0 read:exit=0 self:exit=0 setns-dcache:exit=0 setns-sysvipc:exit=0 thread-self:exit=0 root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc# ./proc-uptime-001 proc-uptime-001: proc-uptime-001.c:39: main: Assertion `i1 >= i0' failed. Aborted (core dumped) root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc# ./proc-uptime-001 root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc# ./proc-uptime-001 root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc# ./proc-uptime-001 root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc# ./proc-uptime-001 root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc# ./proc-uptime-001 proc-uptime-001: proc-uptime-001.c:39: main: Assertion `i1 >= i0' failed. Aborted (core dumped) root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc# ./proc-uptime-001 root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc# ./proc-uptime-001 proc-uptime-001: proc-uptime-001.c:39: main: Assertion `i1 >= i0' failed. Aborted (core dumped) root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc# ./proc-uptime-001 root@marvin-IdeaPad-3-15ITL6:/home/marvin/linux/kernel/linux_torvalds/tools/testing/selftests/proc# ./proc-uptime-001 The conclusion (to state the obvious) is that the GCC 12.2.0 optimisations are not the culprit this time :-/ Thanks, Mirsad -- Mirsad Goran Todorovac Sistem inženjer Grafički fakultet | Akademija likovnih umjetnosti Sveučilište u Zagrebu -- System engineer Faculty of Graphic Arts | Academy of Fine Arts University of Zagreb, Republic of Croatia The European Union ^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2023-01-06 22:06 UTC | newest]
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2023-01-04 18:36 ` BUG: core dump in selftest of proc fs Alexey Dobriyan
2023-01-06 13:49 ` Mirsad Goran Todorovac
2023-01-06 10:39 ` Alexey Dobriyan
2023-01-06 13:53 ` Mirsad Goran Todorovac
2023-01-06 19:30 ` [PATCH] proc: fix PIE proc-empty-vm, proc-pid-vm tests Alexey Dobriyan
2023-01-06 20:53 ` Mirsad Goran Todorovac
2023-01-06 21:18 ` BUG: assert spuriously fails in selftest/proc/proc-uptime-001.c Mirsad Goran Todorovac
2023-01-06 22:06 ` Mirsad Goran Todorovac
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