Commit 0a196848 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
Browse files

perf: Fix arch_perf_out_copy_user default 



The arch_perf_output_copy_user() default of
__copy_from_user_inatomic() returns bytes not copied, while all other
argument functions given DEFINE_OUTPUT_COPY() return bytes copied.

Since copy_from_user_nmi() is the odd duck out by returning bytes
copied where all other *copy_{to,from}* functions return bytes not
copied, change it over and ammend DEFINE_OUTPUT_COPY() to expect bytes
not copied.

Oddly enough DEFINE_OUTPUT_COPY() already returned bytes not copied
while expecting its worker functions to return bytes copied.

Signed-off-by: default avatarPeter Zijlstra <peterz@infradead.org>
Acked-by: default avatar <will.deacon@arm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/20131030201622.GR16117@laptop.programming.kicks-ass.net


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 394570b7

arch/x86/kernel/cpu/perf_event.c

+2 −2
Original line number Diff line number Diff line
@@ -1989,7 +1989,7 @@ perf_callchain_user32(struct pt_regs *regs, struct perf_callchain_entry *entry) 
		frame.return_address = 0;



		bytes = copy_from_user_nmi(&frame, fp, sizeof(frame));

		if (bytes != sizeof(frame))

		if (bytes != 0)

			break;



		if (!valid_user_frame(fp, sizeof(frame)))
@@ -2041,7 +2041,7 @@ perf_callchain_user(struct perf_callchain_entry *entry, struct pt_regs *regs) 
		frame.return_address = 0;



		bytes = copy_from_user_nmi(&frame, fp, sizeof(frame));

		if (bytes != sizeof(frame))

		if (bytes != 0)

			break;



		if (!valid_user_frame(fp, sizeof(frame)))

arch/x86/kernel/cpu/perf_event_intel_ds.c

+1 −1
Original line number Diff line number Diff line
@@ -789,7 +789,7 @@ static int intel_pmu_pebs_fixup_ip(struct pt_regs *regs) 


		size = ip - to; /* Must fit our buffer, see above */

		bytes = copy_from_user_nmi(buf, (void __user *)to, size);

		if (bytes != size)

		if (bytes != 0)

			return 0;



		kaddr = buf;

arch/x86/kernel/cpu/perf_event_intel_lbr.c

+1 −1
Original line number Diff line number Diff line
@@ -491,7 +491,7 @@ static int branch_type(unsigned long from, unsigned long to, int abort) 


		/* may fail if text not present */

		bytes = copy_from_user_nmi(buf, (void __user *)from, size);

		if (bytes != size)

		if (bytes != 0)

			return X86_BR_NONE;



		addr = buf;

arch/x86/lib/usercopy.c

+1 −1
Original line number Diff line number Diff line
@@ -31,6 +31,6 @@ copy_from_user_nmi(void *to, const void __user *from, unsigned long n) 
	ret = __copy_from_user_inatomic(to, from, n);

	pagefault_enable();



	return n - ret;

	return ret;

}

EXPORT_SYMBOL_GPL(copy_from_user_nmi);

arch/x86/oprofile/backtrace.c

+2 −2
Original line number Diff line number Diff line
@@ -47,7 +47,7 @@ dump_user_backtrace_32(struct stack_frame_ia32 *head) 
	unsigned long bytes;



	bytes = copy_from_user_nmi(bufhead, head, sizeof(bufhead));

	if (bytes != sizeof(bufhead))

	if (bytes != 0)

		return NULL;



	fp = (struct stack_frame_ia32 *) compat_ptr(bufhead[0].next_frame);
@@ -93,7 +93,7 @@ static struct stack_frame *dump_user_backtrace(struct stack_frame *head) 
	unsigned long bytes;



	bytes = copy_from_user_nmi(bufhead, head, sizeof(bufhead));

	if (bytes != sizeof(bufhead))

	if (bytes != 0)

		return NULL;



	oprofile_add_trace(bufhead[0].return_address);

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