diff options
Diffstat (limited to 'arch/mips/kernel/ftrace.c')
| -rw-r--r-- | arch/mips/kernel/ftrace.c | 137 |
1 files changed, 105 insertions, 32 deletions
diff --git a/arch/mips/kernel/ftrace.c b/arch/mips/kernel/ftrace.c index 94ca2b018af..60e7e5e45af 100644 --- a/arch/mips/kernel/ftrace.c +++ b/arch/mips/kernel/ftrace.c @@ -11,18 +11,52 @@ #include <linux/uaccess.h> #include <linux/init.h> #include <linux/ftrace.h> +#include <linux/syscalls.h> #include <asm/asm.h> #include <asm/asm-offsets.h> #include <asm/cacheflush.h> +#include <asm/syscall.h> #include <asm/uasm.h> +#include <asm/unistd.h> #include <asm-generic/sections.h> +#if defined(KBUILD_MCOUNT_RA_ADDRESS) && defined(CONFIG_32BIT) +#define MCOUNT_OFFSET_INSNS 5 +#else +#define MCOUNT_OFFSET_INSNS 4 +#endif + +#ifdef CONFIG_DYNAMIC_FTRACE + +/* 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); +} + +#endif + +/* + * Check if the address is in kernel space + * + * Clone core_kernel_text() from kernel/extable.c, but doesn't call + * init_kernel_text() for Ftrace doesn't trace functions in init sections. + */ +static inline int in_kernel_space(unsigned long ip) +{ + if (ip >= (unsigned long)_stext && + ip <= (unsigned long)_etext) + return 1; + return 0; +} + #ifdef CONFIG_DYNAMIC_FTRACE #define JAL 0x0c000000 /* jump & link: ip --> ra, jump to target */ #define ADDR_MASK 0x03ffffff /* op_code|addr : 31...26|25 ....0 */ +#define JUMP_RANGE_MASK ((1UL << 28) - 1) #define INSN_NOP 0x00000000 /* nop */ #define INSN_JAL(addr) \ @@ -44,32 +78,19 @@ static inline void ftrace_dyn_arch_init_insns(void) /* jal (ftrace_caller + 8), jump over the first two instruction */ buf = (u32 *)&insn_jal_ftrace_caller; - uasm_i_jal(&buf, (FTRACE_ADDR + 8)); + uasm_i_jal(&buf, (FTRACE_ADDR + 8) & JUMP_RANGE_MASK); #ifdef CONFIG_FUNCTION_GRAPH_TRACER /* j ftrace_graph_caller */ buf = (u32 *)&insn_j_ftrace_graph_caller; - uasm_i_j(&buf, (unsigned long)ftrace_graph_caller); + uasm_i_j(&buf, (unsigned long)ftrace_graph_caller & JUMP_RANGE_MASK); #endif } -/* - * Check if the address is in kernel space - * - * Clone core_kernel_text() from kernel/extable.c, but doesn't call - * init_kernel_text() for Ftrace doesn't trace functions in init sections. - */ -static inline int in_kernel_space(unsigned long ip) -{ - if (ip >= (unsigned long)_stext && - ip <= (unsigned long)_etext) - return 1; - return 0; -} - static int ftrace_modify_code(unsigned long ip, unsigned int new_code) { int faulted; + mm_segment_t old_fs; /* *(unsigned int *)ip = new_code; */ safe_store_code(new_code, ip, faulted); @@ -77,10 +98,30 @@ static int ftrace_modify_code(unsigned long ip, unsigned int new_code) if (unlikely(faulted)) return -EFAULT; + old_fs = get_fs(); + set_fs(get_ds()); flush_icache_range(ip, ip + 8); + set_fs(old_fs); + + 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; + safe_store_code(new_code2, ip + 4, faulted); + if (unlikely(faulted)) + return -EFAULT; + flush_icache_range(ip, ip + 8); return 0; } +#endif /* * The details about the calling site of mcount on MIPS @@ -94,28 +135,23 @@ 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 */ -#if defined(KBUILD_MCOUNT_RA_ADDRESS) && defined(CONFIG_32BIT) -#define MCOUNT_OFFSET_INSNS 5 -#else -#define MCOUNT_OFFSET_INSNS 4 -#endif #define INSN_B_1F (0x10000000 | MCOUNT_OFFSET_INSNS) int ftrace_make_nop(struct module *mod, @@ -129,8 +165,18 @@ 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) @@ -155,7 +201,7 @@ int ftrace_update_ftrace_func(ftrace_func_t func) return ftrace_modify_code(FTRACE_CALL_IP, new); } -int __init ftrace_dyn_arch_init(void *data) +int __init ftrace_dyn_arch_init(void) { /* Encode the instructions when booting */ ftrace_dyn_arch_init_insns(); @@ -163,9 +209,6 @@ int __init ftrace_dyn_arch_init(void *data) /* Remove "b ftrace_stub" to ensure ftrace_caller() is executed */ ftrace_modify_code(MCOUNT_ADDR, INSN_NOP); - /* The return code is retured via data */ - *(unsigned long *)data = 0; - return 0; } #endif /* CONFIG_DYNAMIC_FTRACE */ @@ -192,8 +235,8 @@ 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 @@ -324,3 +367,33 @@ out: WARN_ON(1); } #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ + +#ifdef CONFIG_FTRACE_SYSCALLS + +#ifdef CONFIG_32BIT +unsigned long __init arch_syscall_addr(int nr) +{ + return (unsigned long)sys_call_table[nr - __NR_O32_Linux]; +} +#endif + +#ifdef CONFIG_64BIT + +unsigned long __init arch_syscall_addr(int nr) +{ +#ifdef CONFIG_MIPS32_N32 + if (nr >= __NR_N32_Linux && nr <= __NR_N32_Linux + __NR_N32_Linux_syscalls) + return (unsigned long)sysn32_call_table[nr - __NR_N32_Linux]; +#endif + if (nr >= __NR_64_Linux && nr <= __NR_64_Linux + __NR_64_Linux_syscalls) + return (unsigned long)sys_call_table[nr - __NR_64_Linux]; +#ifdef CONFIG_MIPS32_O32 + if (nr >= __NR_O32_Linux && nr <= __NR_O32_Linux + __NR_O32_Linux_syscalls) + return (unsigned long)sys32_call_table[nr - __NR_O32_Linux]; +#endif + + return (unsigned long) &sys_ni_syscall; +} +#endif + +#endif /* CONFIG_FTRACE_SYSCALLS */ |