perf/hwbp: Simplify the perf-hwbp code, fix documentation
Annoyingly, modify_user_hw_breakpoint() unnecessarily complicates the modification of a breakpoint - simplify it and remove the pointless local variables. Also update the stale Docbook while at it. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: <stable@vger.kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Ingo Molnar <mingo@kernel.org>
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@ -427,16 +427,9 @@ EXPORT_SYMBOL_GPL(register_user_hw_breakpoint);
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* modify_user_hw_breakpoint - modify a user-space hardware breakpoint
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* modify_user_hw_breakpoint - modify a user-space hardware breakpoint
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* @bp: the breakpoint structure to modify
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* @bp: the breakpoint structure to modify
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* @attr: new breakpoint attributes
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* @attr: new breakpoint attributes
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* @triggered: callback to trigger when we hit the breakpoint
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* @tsk: pointer to 'task_struct' of the process to which the address belongs
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*/
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*/
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int modify_user_hw_breakpoint(struct perf_event *bp, struct perf_event_attr *attr)
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int modify_user_hw_breakpoint(struct perf_event *bp, struct perf_event_attr *attr)
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{
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{
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u64 old_addr = bp->attr.bp_addr;
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u64 old_len = bp->attr.bp_len;
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int old_type = bp->attr.bp_type;
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int err = 0;
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/*
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/*
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* modify_user_hw_breakpoint can be invoked with IRQs disabled and hence it
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* modify_user_hw_breakpoint can be invoked with IRQs disabled and hence it
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* will not be possible to raise IPIs that invoke __perf_event_disable.
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* will not be possible to raise IPIs that invoke __perf_event_disable.
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@ -451,27 +444,18 @@ int modify_user_hw_breakpoint(struct perf_event *bp, struct perf_event_attr *att
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bp->attr.bp_addr = attr->bp_addr;
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bp->attr.bp_addr = attr->bp_addr;
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bp->attr.bp_type = attr->bp_type;
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bp->attr.bp_type = attr->bp_type;
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bp->attr.bp_len = attr->bp_len;
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bp->attr.bp_len = attr->bp_len;
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bp->attr.disabled = 1;
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if (attr->disabled)
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if (!attr->disabled) {
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goto end;
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int err = validate_hw_breakpoint(bp);
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if (err)
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return err;
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err = validate_hw_breakpoint(bp);
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if (!err)
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perf_event_enable(bp);
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perf_event_enable(bp);
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bp->attr.disabled = 0;
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if (err) {
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bp->attr.bp_addr = old_addr;
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bp->attr.bp_type = old_type;
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bp->attr.bp_len = old_len;
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if (!bp->attr.disabled)
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perf_event_enable(bp);
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return err;
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}
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}
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end:
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bp->attr.disabled = attr->disabled;
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return 0;
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return 0;
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}
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}
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EXPORT_SYMBOL_GPL(modify_user_hw_breakpoint);
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EXPORT_SYMBOL_GPL(modify_user_hw_breakpoint);
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