Messages in this thread Patch in this message | | | From | "Naveen N. Rao" <> | Subject | [PATCH 2/5] kprobes: convert kprobe_lookup_name() to a function | Date | Thu, 16 Feb 2017 16:22:40 +0530 |
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The macro is now pretty long and ugly on powerpc. In the light of further changes needed here, convert it to a __weak variant to be over-ridden with a nicer looking function.
Suggested-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> --- arch/powerpc/include/asm/kprobes.h | 53 ---------------------------------- arch/powerpc/kernel/kprobes.c | 58 ++++++++++++++++++++++++++++++++++++++ include/linux/kprobes.h | 1 + kernel/kprobes.c | 20 ++++++------- 4 files changed, 67 insertions(+), 65 deletions(-)
diff --git a/arch/powerpc/include/asm/kprobes.h b/arch/powerpc/include/asm/kprobes.h index d821835ade86..ab5bd200bb48 100644 --- a/arch/powerpc/include/asm/kprobes.h +++ b/arch/powerpc/include/asm/kprobes.h @@ -58,59 +58,6 @@ extern kprobe_opcode_t optprobe_template_end[]; #define MAX_OPTINSN_SIZE (optprobe_template_end - optprobe_template_entry) #define RELATIVEJUMP_SIZE sizeof(kprobe_opcode_t) /* 4 bytes */ -#ifdef PPC64_ELF_ABI_v2 -/* PPC64 ABIv2 needs local entry point */ -#define kprobe_lookup_name(name, addr) \ -{ \ - addr = (kprobe_opcode_t *)kallsyms_lookup_name(name); \ - if (addr) \ - addr = (kprobe_opcode_t *)ppc_function_entry(addr); \ -} -#elif defined(PPC64_ELF_ABI_v1) -/* - * 64bit powerpc ABIv1 uses function descriptors: - * - Check for the dot variant of the symbol first. - * - If that fails, try looking up the symbol provided. - * - * This ensures we always get to the actual symbol and not the descriptor. - * Also handle <module:symbol> format. - */ -#define kprobe_lookup_name(name, addr) \ -{ \ - char dot_name[MODULE_NAME_LEN + 1 + KSYM_NAME_LEN]; \ - const char *modsym; \ - bool dot_appended = false; \ - if ((modsym = strchr(name, ':')) != NULL) { \ - modsym++; \ - if (*modsym != '\0' && *modsym != '.') { \ - /* Convert to <module:.symbol> */ \ - strncpy(dot_name, name, modsym - name); \ - dot_name[modsym - name] = '.'; \ - dot_name[modsym - name + 1] = '\0'; \ - strncat(dot_name, modsym, \ - sizeof(dot_name) - (modsym - name) - 2);\ - dot_appended = true; \ - } else { \ - dot_name[0] = '\0'; \ - strncat(dot_name, name, sizeof(dot_name) - 1); \ - } \ - } else if (name[0] != '.') { \ - dot_name[0] = '.'; \ - dot_name[1] = '\0'; \ - strncat(dot_name, name, KSYM_NAME_LEN - 2); \ - dot_appended = true; \ - } else { \ - dot_name[0] = '\0'; \ - strncat(dot_name, name, KSYM_NAME_LEN - 1); \ - } \ - addr = (kprobe_opcode_t *)kallsyms_lookup_name(dot_name); \ - if (!addr && dot_appended) { \ - /* Let's try the original non-dot symbol lookup */ \ - addr = (kprobe_opcode_t *)kallsyms_lookup_name(name); \ - } \ -} -#endif - #define flush_insn_slot(p) do { } while (0) #define kretprobe_blacklist_size 0 diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c index 331751701fed..a7aa7394954d 100644 --- a/arch/powerpc/kernel/kprobes.c +++ b/arch/powerpc/kernel/kprobes.c @@ -42,6 +42,64 @@ DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk); struct kretprobe_blackpoint kretprobe_blacklist[] = {{NULL, NULL}}; +kprobe_opcode_t *kprobe_lookup_name(const char *name) +{ + kprobe_opcode_t *addr; + +#ifdef PPC64_ELF_ABI_v2 + /* PPC64 ABIv2 needs local entry point */ + addr = (kprobe_opcode_t *)kallsyms_lookup_name(name); + if (addr) + addr = (kprobe_opcode_t *)ppc_function_entry(addr); +#elif defined(PPC64_ELF_ABI_v1) + /* + * 64bit powerpc ABIv1 uses function descriptors: + * - Check for the dot variant of the symbol first. + * - If that fails, try looking up the symbol provided. + * + * This ensures we always get to the actual symbol and not + * the descriptor. + * + * Also handle <module:symbol> format. + */ + char dot_name[MODULE_NAME_LEN + 1 + KSYM_NAME_LEN]; + const char *modsym; + bool dot_appended = false; + if ((modsym = strchr(name, ':')) != NULL) { + modsym++; + if (*modsym != '\0' && *modsym != '.') { + /* Convert to <module:.symbol> */ + strncpy(dot_name, name, modsym - name); + dot_name[modsym - name] = '.'; + dot_name[modsym - name + 1] = '\0'; + strncat(dot_name, modsym, + sizeof(dot_name) - (modsym - name) - 2); + dot_appended = true; + } else { + dot_name[0] = '\0'; + strncat(dot_name, name, sizeof(dot_name) - 1); + } + } else if (name[0] != '.') { + dot_name[0] = '.'; + dot_name[1] = '\0'; + strncat(dot_name, name, KSYM_NAME_LEN - 2); + dot_appended = true; + } else { + dot_name[0] = '\0'; + strncat(dot_name, name, KSYM_NAME_LEN - 1); + } + addr = (kprobe_opcode_t *)kallsyms_lookup_name(dot_name); + if (!addr && dot_appended) { + /* Let's try the original non-dot symbol lookup */ + addr = (kprobe_opcode_t *)kallsyms_lookup_name(name); + } +#else + addr = (kprobe_opcode_t *)kallsyms_lookup_name(dot_name); +#endif + + return addr; +} + int __kprobes arch_prepare_kprobe(struct kprobe *p) { int ret = 0; diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h index 0c2489435117..34b7d00765d2 100644 --- a/include/linux/kprobes.h +++ b/include/linux/kprobes.h @@ -364,6 +364,7 @@ static inline struct kprobe_ctlblk *get_kprobe_ctlblk(void) return this_cpu_ptr(&kprobe_ctlblk); } +kprobe_opcode_t *kprobe_lookup_name(const char *name); int register_kprobe(struct kprobe *p); void unregister_kprobe(struct kprobe *p); int register_kprobes(struct kprobe **kps, int num); diff --git a/kernel/kprobes.c b/kernel/kprobes.c index ab35ed802389..30f1d732dd74 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -58,15 +58,6 @@ #define KPROBE_TABLE_SIZE (1 << KPROBE_HASH_BITS) -/* - * Some oddball architectures like 64bit powerpc have function descriptors - * so this must be overridable. - */ -#ifndef kprobe_lookup_name -#define kprobe_lookup_name(name, addr) \ - addr = ((kprobe_opcode_t *)(kallsyms_lookup_name(name))) -#endif - static int kprobes_initialized; static struct hlist_head kprobe_table[KPROBE_TABLE_SIZE]; static struct hlist_head kretprobe_inst_table[KPROBE_TABLE_SIZE]; @@ -81,6 +72,11 @@ static struct { raw_spinlock_t lock ____cacheline_aligned_in_smp; } kretprobe_table_locks[KPROBE_TABLE_SIZE]; +kprobe_opcode_t * __weak kprobe_lookup_name(const char *name) +{ + return ((kprobe_opcode_t *)(kallsyms_lookup_name(name))); +} + static raw_spinlock_t *kretprobe_table_lock_ptr(unsigned long hash) { return &(kretprobe_table_locks[hash].lock); @@ -1365,7 +1361,7 @@ static kprobe_opcode_t *kprobe_addr(struct kprobe *p) goto invalid; if (p->symbol_name) { - kprobe_lookup_name(p->symbol_name, addr); + addr = kprobe_lookup_name(p->symbol_name); if (!addr) return ERR_PTR(-ENOENT); } @@ -2170,8 +2166,8 @@ static int __init init_kprobes(void) if (kretprobe_blacklist_size) { /* lookup the function address from its name */ for (i = 0; kretprobe_blacklist[i].name != NULL; i++) { - kprobe_lookup_name(kretprobe_blacklist[i].name, - kretprobe_blacklist[i].addr); + kretprobe_blacklist[i].addr = + kprobe_lookup_name(kretprobe_blacklist[i].name); if (!kretprobe_blacklist[i].addr) printk("kretprobe: lookup failed: %s\n", kretprobe_blacklist[i].name); -- 2.11.0
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