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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: Rabin Vincent <rabin@rab.in>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Rabin Vincent 2010-08-10 19:52:35 +01:00 committed by Russell King
parent 3b6c223b1b
commit 72dc43a9eb
3 changed files with 36 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
arch/arm/include/asm/ftrace.h
View File

@ -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);

33
arch/arm/kernel/ftrace.c
View File

@ -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)

2
scripts/recordmcount.pl
View File

@ -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") {