Messages in this thread | | | Date | Mon, 22 Apr 2013 16:37:15 -0500 | From | Jacob Shin <> | Subject | Re: [PATCH 1/5] perf: Add hardware breakpoint address mask |
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On Sun, Apr 21, 2013 at 07:02:02PM +0200, Oleg Nesterov wrote: > 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.
Yes I can do that .. in that case should the Kconfig CONFIG_HAVE_HW_BREAKPOINT_ADDR_MASK go away, and in every non-x86 hw_breakpoint.c do:
bool arch_validate_hw_breakpoint_addr_mask(struct perf_event *bp) { return false; }
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Or keep CONFIG_HAVE_HW_BREAKPOINT_ADDR_MASK and in include/linux/hw_breakpoint.h do:
#ifndef CONFIG_HAVE_HW_BREAKPOINT_ADDR_MASK static inline bool arch_validate_hw_breakpoint_addr_mask(struct perf_event *bp) { return falase; } #endif
?
Thanks,
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