DAR is set to the first byte of overlap between actual access and watched range at DSI on Book3S processor. But actual access range might or might not be within user asked range. So for Book3S, it must not call dar_within_range().
This revert portion of commit 39413ae00967 ("powerpc/hw_breakpoints: Rewrite 8xx breakpoints to allow any address range size."). Before patch: # ./tools/testing/selftests/powerpc/ptrace/perf-hwbreak ... TESTED: No overlap FAILED: Partial overlap: 0 != 2 TESTED: Partial overlap TESTED: No overlap FAILED: Full overlap: 0 != 2 failure: perf_hwbreak After patch: TESTED: No overlap TESTED: Partial overlap TESTED: Partial overlap TESTED: No overlap TESTED: Full overlap success: perf_hwbreak Fixes: 39413ae00967 ("powerpc/hw_breakpoints: Rewrite 8xx breakpoints to allow any address range size.") Reported-by: Michael Ellerman <m...@ellerman.id.au> Signed-off-by: Ravi Bangoria <ravi.bango...@linux.ibm.com> --- arch/powerpc/kernel/hw_breakpoint.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/arch/powerpc/kernel/hw_breakpoint.c b/arch/powerpc/kernel/hw_breakpoint.c index 2462cd7c565c..d0854320bb50 100644 --- a/arch/powerpc/kernel/hw_breakpoint.c +++ b/arch/powerpc/kernel/hw_breakpoint.c @@ -331,11 +331,13 @@ int hw_breakpoint_handler(struct die_args *args) } info->type &= ~HW_BRK_TYPE_EXTRANEOUS_IRQ; - if (!dar_within_range(regs->dar, info)) - info->type |= HW_BRK_TYPE_EXTRANEOUS_IRQ; - - if (!IS_ENABLED(CONFIG_PPC_8xx) && !stepping_handler(regs, bp, info)) - goto out; + if (IS_ENABLED(CONFIG_PPC_8xx)) { + if (!dar_within_range(regs->dar, info)) + info->type |= HW_BRK_TYPE_EXTRANEOUS_IRQ; + } else { + if (!stepping_handler(regs, bp, info)) + goto out; + } /* * As a policy, the callback is invoked in a 'trigger-after-execute' -- 2.21.1