| Message ID | 1434370268-19056-3-git-send-email-khandual@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
> - int bhrb_users; > + unsigned int bhrb_users; OK, so this is a good start. A quick git grep for bhrb_users reveals this: perf/core-book3s.c: WARN_ON_ONCE(cpuhw->bhrb_users < 0); That occurs in power_pmu_bhrb_disable, immediately following a decrement of bhrb_users. Now that the test can never be true, this patch should change the function to check if bhrb_users is 0 before decrementing. > void *bhrb_context; > struct perf_branch_stack bhrb_stack; > struct perf_branch_entry bhrb_entries[BHRB_MAX_ENTRIES];
On 06/25/2015 11:12 AM, Daniel Axtens wrote: >> - int bhrb_users; >> + unsigned int bhrb_users; > > OK, so this is a good start. > > A quick git grep for bhrb_users reveals this: > perf/core-book3s.c: WARN_ON_ONCE(cpuhw->bhrb_users < 0); > > That occurs in power_pmu_bhrb_disable, immediately following a decrement > of bhrb_users. Now that the test can never be true, this patch should > change the function to check if bhrb_users is 0 before decrementing. Sure. Would replace with 'WARN_ON_ONCE(!cpuhw->bhrb_users)' before decrementing bhrb_users in the function.
diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c index c246e65..9798f00 100644 --- a/arch/powerpc/perf/core-book3s.c +++ b/arch/powerpc/perf/core-book3s.c @@ -53,7 +53,7 @@ struct cpu_hw_events { /* BHRB bits */ u64 bhrb_filter; /* BHRB HW branch filter */ - int bhrb_users; + unsigned int bhrb_users; void *bhrb_context; struct perf_branch_stack bhrb_stack; struct perf_branch_entry bhrb_entries[BHRB_MAX_ENTRIES];
This patch just changes data type of bhrb_users variable from int to unsigned int because it never contains a negative value. Reported-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com> --- arch/powerpc/perf/core-book3s.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)