diff options
Diffstat (limited to 'arch/mips/kernel/ftrace.c')
| -rw-r--r-- | arch/mips/kernel/ftrace.c | 48 |
1 files changed, 41 insertions, 7 deletions
diff --git a/arch/mips/kernel/ftrace.c b/arch/mips/kernel/ftrace.c index 6a2d758..cf5509f 100644 --- a/arch/mips/kernel/ftrace.c +++ b/arch/mips/kernel/ftrace.c @@ -25,6 +25,12 @@ #define MCOUNT_OFFSET_INSNS 4 #endif +/* Arch override because MIPS doesn't need to run this from stop_machine() */ +void arch_ftrace_update_code(int command) +{ + ftrace_modify_all_code(command); +} + /* * Check if the address is in kernel space * @@ -89,6 +95,24 @@ static int ftrace_modify_code(unsigned long ip, unsigned int new_code) return 0; } +#ifndef CONFIG_64BIT +static int ftrace_modify_code_2(unsigned long ip, unsigned int new_code1, + unsigned int new_code2) +{ + int faulted; + + safe_store_code(new_code1, ip, faulted); + if (unlikely(faulted)) + return -EFAULT; + ip += 4; + safe_store_code(new_code2, ip, faulted); + if (unlikely(faulted)) + return -EFAULT; + flush_icache_range(ip, ip + 8); /* original ip + 12 */ + return 0; +} +#endif + /* * The details about the calling site of mcount on MIPS * @@ -101,21 +125,21 @@ static int ftrace_modify_code(unsigned long ip, unsigned int new_code) * * 2.1 For KBUILD_MCOUNT_RA_ADDRESS and CONFIG_32BIT * - * lui v1, hi_16bit_of_mcount --> b 1f (0x10000005) + * lui v1, hi_16bit_of_mcount --> b 1f (0x10000005) * addiu v1, v1, low_16bit_of_mcount * move at, ra * move $12, ra_address * jalr v1 * sub sp, sp, 8 - * 1: offset = 5 instructions + * 1: offset = 5 instructions * 2.2 For the Other situations * - * lui v1, hi_16bit_of_mcount --> b 1f (0x10000004) + * lui v1, hi_16bit_of_mcount --> b 1f (0x10000004) * addiu v1, v1, low_16bit_of_mcount * move at, ra * jalr v1 * nop | move $12, ra_address | sub sp, sp, 8 - * 1: offset = 4 instructions + * 1: offset = 4 instructions */ #define INSN_B_1F (0x10000000 | MCOUNT_OFFSET_INSNS) @@ -131,8 +155,18 @@ int ftrace_make_nop(struct module *mod, * needed. */ new = in_kernel_space(ip) ? INSN_NOP : INSN_B_1F; - +#ifdef CONFIG_64BIT return ftrace_modify_code(ip, new); +#else + /* + * On 32 bit MIPS platforms, gcc adds a stack adjust + * instruction in the delay slot after the branch to + * mcount and expects mcount to restore the sp on return. + * This is based on a legacy API and does nothing but + * waste instructions so it's being removed at runtime. + */ + return ftrace_modify_code_2(ip, new, INSN_NOP); +#endif } int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) @@ -194,8 +228,8 @@ int ftrace_disable_ftrace_graph_caller(void) #ifndef KBUILD_MCOUNT_RA_ADDRESS -#define S_RA_SP (0xafbf << 16) /* s{d,w} ra, offset(sp) */ -#define S_R_SP (0xafb0 << 16) /* s{d,w} R, offset(sp) */ +#define S_RA_SP (0xafbf << 16) /* s{d,w} ra, offset(sp) */ +#define S_R_SP (0xafb0 << 16) /* s{d,w} R, offset(sp) */ #define OFFSET_MASK 0xffff /* stack offset range: 0 ~ PT_SIZE */ unsigned long ftrace_get_parent_ra_addr(unsigned long self_ra, unsigned long |