Messages in this thread | | | Date | Sun, 21 Apr 2013 19:02:02 +0200 | From | Oleg Nesterov <> | Subject | Re: [PATCH 1/5] perf: Add hardware breakpoint address mask |
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On 04/20, Jacob Shin wrote: > > On Sat, Apr 20, 2013 at 06:53:34PM +0200, Oleg Nesterov wrote: > > > > And does attr.bp_len "contribute" to the mask? > > > > I mean, if bp_len == X86_BREAKPOINT_LEN_8, does this mean that > > bp_bp_addr_mask and (bp_bp_addr_mask | 7) have the same effect? > > Yes it has the same effect.
OK, thanks...
So this is the "natural" extension. Given that currently bp_addr should be aligned, bp_len could be already bp_mask but I guess it is too late to change this, so we need another field.
Hmm. Perhaps arch_has_hw_breakpoint_addr_mask(void) should be turned into arch_validate_hw_breakpoint_addr_mask(bp) which should also check that (bp_addr & bp_addr_mask) == 0. But I won't insist.
Oleg.
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