perf/hw_breakpoint: Clean up and consolidate modify_user_hw_breakpoint_check() (26c6ccdf) · Commits · 戴 / test

Remove the dance around old and new attributes. Just don't modify the previous breakpoint at all until we have verified everything. Original-patch-by:

Andy Lutomirski <luto@kernel.org> Reported-by:

Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by:

Frederic Weisbecker <frederic@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Zankel <chris@zankel.net> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Joel Fernandes <joel.opensrc@gmail.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rich Felker <dalias@libc.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Link: http://lkml.kernel.org/r/1529981939-8231-13-git-send-email-frederic@kernel.org Signed-off-by:

Ingo Molnar <mingo@kernel.org>

kernel/events/hw_breakpoint.c

+25 −19

Original line number	Diff line number	Diff line
		@@ -461,37 +461,43 @@ register_user_hw_breakpoint(struct perf_event_attr *attr,
		}
		EXPORT_SYMBOL_GPL(register_user_hw_breakpoint);

		static void hw_breakpoint_copy_attr(struct perf_event_attr *to,
		struct perf_event_attr *from)
		{
		to->bp_addr = from->bp_addr;
		to->bp_type = from->bp_type;
		to->bp_len = from->bp_len;
		to->disabled = from->disabled;
		}

		int
		modify_user_hw_breakpoint_check(struct perf_event bp, struct perf_event_attr attr,
		bool check)
		{
		u64 old_addr = bp->attr.bp_addr;
		u64 old_len = bp->attr.bp_len;
		int old_type = bp->attr.bp_type;
		bool modify = attr->bp_type != old_type;
		struct arch_hw_breakpoint hw;
		int err = 0;
		int err;

		bp->attr.bp_addr = attr->bp_addr;
		bp->attr.bp_type = attr->bp_type;
		bp->attr.bp_len = attr->bp_len;
		err = hw_breakpoint_parse(bp, attr, &hw);
		if (err)
		return err;

		if (check && memcmp(&bp->attr, attr, sizeof(*attr)))
		return -EINVAL;
		if (check) {
		struct perf_event_attr old_attr;

		err = hw_breakpoint_parse(bp, attr, &hw);
		if (!err && modify)
		err = modify_bp_slot(bp, old_type, bp->attr.bp_type);
		old_attr = bp->attr;
		hw_breakpoint_copy_attr(&old_attr, attr);
		if (memcmp(&old_attr, attr, sizeof(*attr)))
		return -EINVAL;
		}

		if (err) {
		bp->attr.bp_addr = old_addr;
		bp->attr.bp_type = old_type;
		bp->attr.bp_len = old_len;
		if (bp->attr.bp_type != attr->bp_type) {
		err = modify_bp_slot(bp, bp->attr.bp_type, attr->bp_type);
		if (err)
		return err;
		}

		hw_breakpoint_copy_attr(&bp->attr, attr);
		bp->hw.info = hw;
		bp->attr.disabled = attr->disabled;

		return 0;
		}

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