powerpc/hw_brk: Fix off by one error when validating DAWR region end
PATCH 1/1 powerpc/hw_brk: Fix off by one error when validating DAWR region end
The Data Address Watchpoint Register (DAWR) on POWER8 can take a 512 byte range but this range must not cross a 512 byte boundary.
Unfortunately we were off by one when calculating the end of the region, hence we were not allowing some breakpoint regions which were actually valid. This fixes this error.
Signed-off-by Michael Neuling <[email protected]>
Reported-by Edjunior Barbosa Machado <[email protected]>
Cc [email protected] # 3.9+
arch/powerpc/kernel/hw_breakpoint.c +1 -1
@@ -176,7 +176,7 @@ int arch_validate_hwbkpt_settings(struct perf_event *bp) length_max =512 ;/* 64 doublewords */ /* DAWR region can't cross 512 boundary */ if ((bp->attr.bp_addr >>10 ) != - ((bp->attr.bp_addr + bp->attr.bp_len) >>10 )) + ((bp->attr.bp_addr + bp->attr.bp_len -1 ) >>10 ))return -EINVAL ; } if (info->len >