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Commit 72dc43a9 authored by Rabin Vincent's avatar Rabin Vincent Committed by Russell King
Browse files

ARM: 6319/1: ftrace: add Thumb-2 support to dynamic ftrace 



Handle the different nop and call instructions for Thumb-2.  Also, we
need to adjust the recorded mcount_loc addresses because they have the
lsb set.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org> [recordmcount.pl change]
Signed-off-by: default avatarRabin Vincent <rabin@rab.in>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 3b6c223b

arch/arm/include/asm/ftrace.h

+2 −1
Original line number Diff line number Diff line
@@ -18,7 +18,8 @@ struct dyn_arch_ftrace { 


static inline unsigned long ftrace_call_adjust(unsigned long addr)

{

	return addr;

	/* With Thumb-2, the recorded addresses have the lsb set */

	return addr & ~1;

}



extern void ftrace_caller_old(void);

arch/arm/kernel/ftrace.c

+33 −0
Original line number Diff line number Diff line
@@ -18,7 +18,11 @@ 
#include <asm/cacheflush.h>

#include <asm/ftrace.h>



#ifdef CONFIG_THUMB2_KERNEL

#define	NOP		0xeb04f85d	/* pop.w {lr} */

#else

#define	NOP		0xe8bd4000	/* pop {lr} */

#endif



#ifdef CONFIG_OLD_MCOUNT

#define OLD_MCOUNT_ADDR	((unsigned long) mcount)
@@ -56,6 +60,34 @@ static unsigned long adjust_address(struct dyn_ftrace *rec, unsigned long addr) 
#endif



/* construct a branch (BL) instruction to addr */

#ifdef CONFIG_THUMB2_KERNEL

static unsigned long ftrace_call_replace(unsigned long pc, unsigned long addr)

{

	unsigned long s, j1, j2, i1, i2, imm10, imm11;

	unsigned long first, second;

	long offset;



	offset = (long)addr - (long)(pc + 4);

	if (offset < -16777216 || offset > 16777214) {

		WARN_ON_ONCE(1);

		return 0;

	}



	s	= (offset >> 24) & 0x1;

	i1	= (offset >> 23) & 0x1;

	i2	= (offset >> 22) & 0x1;

	imm10	= (offset >> 12) & 0x3ff;

	imm11	= (offset >>  1) & 0x7ff;



	j1 = (!i1) ^ s;

	j2 = (!i2) ^ s;



	first = 0xf000 | (s << 10) | imm10;

	second = 0xd000 | (j1 << 13) | (j2 << 11) | imm11;



	return (second << 16) | first;

}

#else

static unsigned long ftrace_call_replace(unsigned long pc, unsigned long addr)

{

	long offset;
@@ -73,6 +105,7 @@ static unsigned long ftrace_call_replace(unsigned long pc, unsigned long addr) 


	return 0xeb000000 | offset;

}

#endif



static int ftrace_modify_code(unsigned long pc, unsigned long old,

			      unsigned long new)

scripts/recordmcount.pl

+1 −1
Original line number Diff line number Diff line
@@ -270,7 +270,7 @@ if ($arch eq "x86_64") { 
} elsif ($arch eq "arm") {

    $alignment = 2;

    $section_type = '%progbits';

    $mcount_regex = "^\\s*([0-9a-fA-F]+):\\s*R_ARM_(CALL|PC24)" .

    $mcount_regex = "^\\s*([0-9a-fA-F]+):\\s*R_ARM_(CALL|PC24|THM_CALL)" .

			"\\s+(__gnu_mcount_nc|mcount)\$";



} elsif ($arch eq "ia64") {