6fb8656646
ftrace_graph_caller was never run after calling ftrace_trace_function, breaking the function graph tracer. Fix this, bringing it in line with the x86 implementation. While we're at it, also streamline the control flow of _mcount a bit to reduce the number of branches. This issue was reported before: https://www.linux-mips.org/archives/linux-mips/2014-11/msg00295.html Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net> Tested-by: Matt Redfearn <matt.redfearn@mips.com> Patchwork: https://patchwork.linux-mips.org/patch/18929/ Signed-off-by: Paul Burton <paul.burton@mips.com> Cc: stable@vger.kernel.org # v3.17+
220 lines
4.4 KiB
ArmAsm
220 lines
4.4 KiB
ArmAsm
/*
|
|
* MIPS specific _mcount support
|
|
*
|
|
* This file is subject to the terms and conditions of the GNU General Public
|
|
* License. See the file "COPYING" in the main directory of this archive for
|
|
* more details.
|
|
*
|
|
* Copyright (C) 2009 Lemote Inc. & DSLab, Lanzhou University, China
|
|
* Copyright (C) 2010 DSLab, Lanzhou University, China
|
|
* Author: Wu Zhangjin <wuzhangjin@gmail.com>
|
|
*/
|
|
|
|
#include <asm/export.h>
|
|
#include <asm/regdef.h>
|
|
#include <asm/stackframe.h>
|
|
#include <asm/ftrace.h>
|
|
|
|
.text
|
|
.set noreorder
|
|
.set noat
|
|
|
|
.macro MCOUNT_SAVE_REGS
|
|
PTR_SUBU sp, PT_SIZE
|
|
PTR_S ra, PT_R31(sp)
|
|
PTR_S AT, PT_R1(sp)
|
|
PTR_S a0, PT_R4(sp)
|
|
PTR_S a1, PT_R5(sp)
|
|
PTR_S a2, PT_R6(sp)
|
|
PTR_S a3, PT_R7(sp)
|
|
#ifdef CONFIG_64BIT
|
|
PTR_S a4, PT_R8(sp)
|
|
PTR_S a5, PT_R9(sp)
|
|
PTR_S a6, PT_R10(sp)
|
|
PTR_S a7, PT_R11(sp)
|
|
#endif
|
|
.endm
|
|
|
|
.macro MCOUNT_RESTORE_REGS
|
|
PTR_L ra, PT_R31(sp)
|
|
PTR_L AT, PT_R1(sp)
|
|
PTR_L a0, PT_R4(sp)
|
|
PTR_L a1, PT_R5(sp)
|
|
PTR_L a2, PT_R6(sp)
|
|
PTR_L a3, PT_R7(sp)
|
|
#ifdef CONFIG_64BIT
|
|
PTR_L a4, PT_R8(sp)
|
|
PTR_L a5, PT_R9(sp)
|
|
PTR_L a6, PT_R10(sp)
|
|
PTR_L a7, PT_R11(sp)
|
|
#endif
|
|
PTR_ADDIU sp, PT_SIZE
|
|
.endm
|
|
|
|
.macro RETURN_BACK
|
|
jr ra
|
|
move ra, AT
|
|
.endm
|
|
|
|
/*
|
|
* The -mmcount-ra-address option of gcc 4.5 uses register $12 to pass
|
|
* the location of the parent's return address.
|
|
*/
|
|
#define MCOUNT_RA_ADDRESS_REG $12
|
|
|
|
#ifdef CONFIG_DYNAMIC_FTRACE
|
|
|
|
NESTED(ftrace_caller, PT_SIZE, ra)
|
|
.globl _mcount
|
|
_mcount:
|
|
EXPORT_SYMBOL(_mcount)
|
|
b ftrace_stub
|
|
#ifdef CONFIG_32BIT
|
|
addiu sp,sp,8
|
|
#else
|
|
nop
|
|
#endif
|
|
|
|
/* When tracing is activated, it calls ftrace_caller+8 (aka here) */
|
|
MCOUNT_SAVE_REGS
|
|
#ifdef KBUILD_MCOUNT_RA_ADDRESS
|
|
PTR_S MCOUNT_RA_ADDRESS_REG, PT_R12(sp)
|
|
#endif
|
|
|
|
PTR_SUBU a0, ra, 8 /* arg1: self address */
|
|
PTR_LA t1, _stext
|
|
sltu t2, a0, t1 /* t2 = (a0 < _stext) */
|
|
PTR_LA t1, _etext
|
|
sltu t3, t1, a0 /* t3 = (a0 > _etext) */
|
|
or t1, t2, t3
|
|
beqz t1, ftrace_call
|
|
nop
|
|
#if defined(KBUILD_MCOUNT_RA_ADDRESS) && defined(CONFIG_32BIT)
|
|
PTR_SUBU a0, a0, 16 /* arg1: adjust to module's recorded callsite */
|
|
#else
|
|
PTR_SUBU a0, a0, 12
|
|
#endif
|
|
|
|
.globl ftrace_call
|
|
ftrace_call:
|
|
nop /* a placeholder for the call to a real tracing function */
|
|
move a1, AT /* arg2: parent's return address */
|
|
|
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
|
|
.globl ftrace_graph_call
|
|
ftrace_graph_call:
|
|
nop
|
|
nop
|
|
#endif
|
|
|
|
MCOUNT_RESTORE_REGS
|
|
.globl ftrace_stub
|
|
ftrace_stub:
|
|
RETURN_BACK
|
|
END(ftrace_caller)
|
|
|
|
#else /* ! CONFIG_DYNAMIC_FTRACE */
|
|
|
|
NESTED(_mcount, PT_SIZE, ra)
|
|
EXPORT_SYMBOL(_mcount)
|
|
PTR_LA t1, ftrace_stub
|
|
PTR_L t2, ftrace_trace_function /* Prepare t2 for (1) */
|
|
beq t1, t2, fgraph_trace
|
|
nop
|
|
|
|
MCOUNT_SAVE_REGS
|
|
|
|
move a0, ra /* arg1: self return address */
|
|
jalr t2 /* (1) call *ftrace_trace_function */
|
|
move a1, AT /* arg2: parent's return address */
|
|
|
|
MCOUNT_RESTORE_REGS
|
|
|
|
fgraph_trace:
|
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
|
|
PTR_LA t1, ftrace_stub
|
|
PTR_L t3, ftrace_graph_return
|
|
bne t1, t3, ftrace_graph_caller
|
|
nop
|
|
PTR_LA t1, ftrace_graph_entry_stub
|
|
PTR_L t3, ftrace_graph_entry
|
|
bne t1, t3, ftrace_graph_caller
|
|
nop
|
|
#endif
|
|
|
|
#ifdef CONFIG_32BIT
|
|
addiu sp, sp, 8
|
|
#endif
|
|
|
|
.globl ftrace_stub
|
|
ftrace_stub:
|
|
RETURN_BACK
|
|
END(_mcount)
|
|
|
|
#endif /* ! CONFIG_DYNAMIC_FTRACE */
|
|
|
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
|
|
|
|
NESTED(ftrace_graph_caller, PT_SIZE, ra)
|
|
#ifndef CONFIG_DYNAMIC_FTRACE
|
|
MCOUNT_SAVE_REGS
|
|
#endif
|
|
|
|
/* arg1: Get the location of the parent's return address */
|
|
#ifdef KBUILD_MCOUNT_RA_ADDRESS
|
|
#ifdef CONFIG_DYNAMIC_FTRACE
|
|
PTR_L a0, PT_R12(sp)
|
|
#else
|
|
move a0, MCOUNT_RA_ADDRESS_REG
|
|
#endif
|
|
bnez a0, 1f /* non-leaf func: stored in MCOUNT_RA_ADDRESS_REG */
|
|
nop
|
|
#endif
|
|
PTR_LA a0, PT_R1(sp) /* leaf func: the location in current stack */
|
|
1:
|
|
|
|
/* arg2: Get self return address */
|
|
#ifdef CONFIG_DYNAMIC_FTRACE
|
|
PTR_L a1, PT_R31(sp)
|
|
#else
|
|
move a1, ra
|
|
#endif
|
|
|
|
/* arg3: Get frame pointer of current stack */
|
|
#ifdef CONFIG_64BIT
|
|
PTR_LA a2, PT_SIZE(sp)
|
|
#else
|
|
PTR_LA a2, (PT_SIZE+8)(sp)
|
|
#endif
|
|
|
|
jal prepare_ftrace_return
|
|
nop
|
|
MCOUNT_RESTORE_REGS
|
|
#ifndef CONFIG_DYNAMIC_FTRACE
|
|
#ifdef CONFIG_32BIT
|
|
addiu sp, sp, 8
|
|
#endif
|
|
#endif
|
|
RETURN_BACK
|
|
END(ftrace_graph_caller)
|
|
|
|
.align 2
|
|
.globl return_to_handler
|
|
return_to_handler:
|
|
PTR_SUBU sp, PT_SIZE
|
|
PTR_S v0, PT_R2(sp)
|
|
|
|
jal ftrace_return_to_handler
|
|
PTR_S v1, PT_R3(sp)
|
|
|
|
/* restore the real parent address: v0 -> ra */
|
|
move ra, v0
|
|
|
|
PTR_L v0, PT_R2(sp)
|
|
PTR_L v1, PT_R3(sp)
|
|
jr ra
|
|
PTR_ADDIU sp, PT_SIZE
|
|
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
|
|
|
|
.set at
|
|
.set reorder
|