Commit 63b75495 authored by David S. Miller's avatar David S. Miller
Browse files

sparc64: Add HAVE_FUNCTION_TRACE_MCOUNT_TEST and tidy up. 



Check function_trace_stop at ftrace_caller

Toss mcount_call and dummy call of ftrace_stub, unnecessary.

Document problems we'll have if the final kernel image link
ever turns on relaxation.

Properly size 'ftrace_call' so it looks right when inspecting
instructions under gdb et al.

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 0c25e9e6

arch/sparc/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -37,6 +37,7 @@ config SPARC64 
	def_bool 64BIT

	select ARCH_SUPPORTS_MSI

	select HAVE_FUNCTION_TRACER

	select HAVE_FUNCTION_TRACE_MCOUNT_TEST

	select HAVE_KRETPROBES

	select HAVE_KPROBES

	select HAVE_LMB

arch/sparc/lib/mcount.S

+15 −7
Original line number Diff line number Diff line
@@ -96,12 +96,11 @@ mcount: 
#endif

#ifdef CONFIG_FUNCTION_TRACER

#ifdef CONFIG_DYNAMIC_FTRACE

	mov		%o7, %o0

	.globl		mcount_call

mcount_call:

	call		ftrace_stub

	 mov		%o0, %o7

	/* Do nothing, the retl/nop below is all we need.  */

#else

	sethi		%hi(function_trace_stop), %g1

	lduw		[%g1 + %lo(function_trace_stop)], %g2

	brnz,pn		%g2, 1f

	 sethi		%hi(ftrace_trace_function), %g1

	sethi		%hi(ftrace_stub), %g2

	ldx		[%g1 + %lo(ftrace_trace_function)], %g1
@@ -131,14 +130,23 @@ ftrace_stub: 
	.globl		ftrace_caller

	.type		ftrace_caller,#function

ftrace_caller:

	sethi		%hi(function_trace_stop), %g1

	mov		%i7, %o1

	lduw		[%g1 + %lo(function_trace_stop)], %g2

	brnz,pn		%g2, ftrace_stub

	 mov		%o7, %o0

	.globl		ftrace_call

ftrace_call:

	/* If the final kernel link ever turns on relaxation, we'll need

	 * to do something about this tail call.  Otherwise the linker

	 * will rewrite the call into a branch and nop out the move

	 * instruction.

	 */

	call		ftrace_stub

	 mov		%o0, %o7

	retl

	 nop

	.size		ftrace_call,.-ftrace_call

	.size		ftrace_caller,.-ftrace_caller

#endif

#endif

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