From 3b6c223b1b97ad60bbb0f4efda57d649414ac2a2 Mon Sep 17 00:00:00 2001 From: Rabin Vincent Date: Tue, 10 Aug 2010 19:43:28 +0100 Subject: ARM: 6318/1: ftrace: fix and update dynamic ftrace This adds mcount recording and updates dynamic ftrace for ARM to work with the new ftrace dyamic tracing implementation. It also adds support for the mcount format used by newer ARM compilers. With dynamic tracing, mcount() is implemented as a nop. Callsites are patched on startup with nops, and dynamically patched to call to the ftrace_caller() routine as needed. Acked-by: Steven Rostedt [recordmcount.pl change] Signed-off-by: Rabin Vincent Signed-off-by: Russell King --- arch/arm/include/asm/ftrace.h | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-) (limited to 'arch/arm/include/asm/ftrace.h') diff --git a/arch/arm/include/asm/ftrace.h b/arch/arm/include/asm/ftrace.h index 103f7ee9731..4a56a2ee067 100644 --- a/arch/arm/include/asm/ftrace.h +++ b/arch/arm/include/asm/ftrace.h @@ -2,12 +2,29 @@ #define _ASM_ARM_FTRACE #ifdef CONFIG_FUNCTION_TRACER -#define MCOUNT_ADDR ((long)(mcount)) +#define MCOUNT_ADDR ((unsigned long)(__gnu_mcount_nc)) #define MCOUNT_INSN_SIZE 4 /* sizeof mcount call */ #ifndef __ASSEMBLY__ extern void mcount(void); extern void __gnu_mcount_nc(void); + +#ifdef CONFIG_DYNAMIC_FTRACE +struct dyn_arch_ftrace { +#ifdef CONFIG_OLD_MCOUNT + bool old_mcount; +#endif +}; + +static inline unsigned long ftrace_call_adjust(unsigned long addr) +{ + return addr; +} + +extern void ftrace_caller_old(void); +extern void ftrace_call_old(void); +#endif + #endif #endif -- cgit v1.2.3 From 72dc43a9eb123d2742bd413c80dbeab0c588f622 Mon Sep 17 00:00:00 2001 From: Rabin Vincent Date: Tue, 10 Aug 2010 19:52:35 +0100 Subject: 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 Acked-by: Steven Rostedt [recordmcount.pl change] Signed-off-by: Rabin Vincent Signed-off-by: Russell King --- arch/arm/include/asm/ftrace.h | 3 ++- arch/arm/kernel/ftrace.c | 33 +++++++++++++++++++++++++++++++++ scripts/recordmcount.pl | 2 +- 3 files changed, 36 insertions(+), 2 deletions(-) (limited to 'arch/arm/include/asm/ftrace.h') diff --git a/arch/arm/include/asm/ftrace.h b/arch/arm/include/asm/ftrace.h index 4a56a2ee067..f89515adac6 100644 --- a/arch/arm/include/asm/ftrace.h +++ b/arch/arm/include/asm/ftrace.h @@ -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); diff --git a/arch/arm/kernel/ftrace.c b/arch/arm/kernel/ftrace.c index f09014cfbf2..971ac8c36ea 100644 --- a/arch/arm/kernel/ftrace.c +++ b/arch/arm/kernel/ftrace.c @@ -18,7 +18,11 @@ #include #include +#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) diff --git a/scripts/recordmcount.pl b/scripts/recordmcount.pl index 022d4679b1b..1d7963f4ee7 100755 --- a/scripts/recordmcount.pl +++ b/scripts/recordmcount.pl @@ -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") { -- cgit v1.2.3