diff options
| author | Thomas Richter <tmricht@linux.ibm.com> | 2021-03-10 14:26:48 +0100 |
|---|---|---|
| committer | Heiko Carstens <hca@linux.ibm.com> | 2021-03-15 19:09:25 +0100 |
| commit | c79f01b6eb5dc708573002fb3ba270918bcd1d32 (patch) | |
| tree | 37768d551bbaa7518092a5fa088b6bd76e8915e6 /arch | |
| parent | 1e28eed17697bcf343c6743f0028cc3b5dd88bf0 (diff) | |
s390/cpumf: disable preemption when accessing per-cpu variable
The following BUG message was triggered repeatedly when complete counter
sets are extracted from the CPUMF:
BUG: using smp_processor_id() in preemptible [00000000]
code: psvc-readsets/7759
caller is cf_diag_needspace+0x2c/0x100
CPU: 7 PID: 7759 Comm: psvc-readsets Not tainted 5.12.0
Hardware name: IBM 3906 M03 703 (LPAR)
Call Trace:
[<00000000c7043f78>] show_stack+0x90/0xf8
[<00000000c705776a>] dump_stack+0xba/0x108
[<00000000c705d91c>] check_preemption_disabled+0xec/0xf0
[<00000000c63eb1c4>] cf_diag_needspace+0x2c/0x100
[<00000000c63ecbcc>] cf_diag_ioctl_start+0x10c/0x240
[<00000000c63ece9a>] cf_diag_ioctl+0x19a/0x238
[<00000000c675f3f4>] __s390x_sys_ioctl+0xc4/0x100
[<00000000c63ca762>] do_syscall+0x82/0xd0
[<00000000c705bdd8>] __do_syscall+0xc0/0xd8
[<00000000c706d532>] system_call+0x72/0x98
2 locks held by psvc-readsets/7759:
#0: 00000000c75a57c0 (cpu_hotplug_lock){++++}-{0:0},
at: cf_diag_ioctl+0x44/0x238
#1: 00000000c75a3078 (cf_diag_ctrset_mutex){+.+.}-{3:3},
at: cf_diag_ioctl+0x54/0x238
This issue is a missing get_cpu_ptr/put_cpu_ptr pair in function
cf_diag_needspace. Add it.
Fixes: cf6acb8bdb1d ("s390/cpumf: Add support for complete counter set extraction")
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/s390/kernel/perf_cpum_cf_diag.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/s390/kernel/perf_cpum_cf_diag.c b/arch/s390/kernel/perf_cpum_cf_diag.c index bc302b86ce28..2e3e7edbe3a0 100644 --- a/arch/s390/kernel/perf_cpum_cf_diag.c +++ b/arch/s390/kernel/perf_cpum_cf_diag.c @@ -968,7 +968,7 @@ static int cf_diag_all_start(void) */ static size_t cf_diag_needspace(unsigned int sets) { - struct cpu_cf_events *cpuhw = this_cpu_ptr(&cpu_cf_events); + struct cpu_cf_events *cpuhw = get_cpu_ptr(&cpu_cf_events); size_t bytes = 0; int i; @@ -984,6 +984,7 @@ static size_t cf_diag_needspace(unsigned int sets) sizeof(((struct s390_ctrset_cpudata *)0)->no_sets)); debug_sprintf_event(cf_diag_dbg, 5, "%s bytes %ld\n", __func__, bytes); + put_cpu_ptr(&cpu_cf_events); return bytes; } |