diff options
| -rw-r--r-- | arch/powerpc/include/asm/module.h | 3 | ||||
| -rw-r--r-- | arch/powerpc/kernel/ftrace.c | 14 | ||||
| -rw-r--r-- | arch/powerpc/kernel/module_64.c | 78 |
3 files changed, 31 insertions, 64 deletions
diff --git a/arch/powerpc/include/asm/module.h b/arch/powerpc/include/asm/module.h index 74d25a749018..5b6b5a427b54 100644 --- a/arch/powerpc/include/asm/module.h +++ b/arch/powerpc/include/asm/module.h @@ -78,8 +78,7 @@ struct mod_arch_specific { # endif /* MODULE */ #endif -bool is_module_trampoline(u32 *insns); -int module_trampoline_target(struct module *mod, u32 *trampoline, +int module_trampoline_target(struct module *mod, unsigned long trampoline, unsigned long *target); #ifdef CONFIG_DYNAMIC_FTRACE diff --git a/arch/powerpc/kernel/ftrace.c b/arch/powerpc/kernel/ftrace.c index 44d4d8eb3c85..4505cbfd0e13 100644 --- a/arch/powerpc/kernel/ftrace.c +++ b/arch/powerpc/kernel/ftrace.c @@ -106,10 +106,9 @@ static int __ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec, unsigned long addr) { - unsigned int op; - unsigned long entry, ptr; + unsigned long entry, ptr, tramp; unsigned long ip = rec->ip; - void *tramp; + unsigned int op; /* read where this goes */ if (probe_kernel_read(&op, (void *)ip, sizeof(int))) @@ -122,14 +121,9 @@ __ftrace_make_nop(struct module *mod, } /* lets find where the pointer goes */ - tramp = (void *)find_bl_target(ip, op); - - pr_devel("ip:%lx jumps to %p", ip, tramp); + tramp = find_bl_target(ip, op); - if (!is_module_trampoline(tramp)) { - pr_err("Not a trampoline\n"); - return -EINVAL; - } + pr_devel("ip:%lx jumps to %lx", ip, tramp); if (module_trampoline_target(mod, tramp, &ptr)) { pr_err("Failed to get trampoline target\n"); diff --git a/arch/powerpc/kernel/module_64.c b/arch/powerpc/kernel/module_64.c index 599c753c7960..9629966e614b 100644 --- a/arch/powerpc/kernel/module_64.c +++ b/arch/powerpc/kernel/module_64.c @@ -96,6 +96,8 @@ static unsigned int local_entry_offset(const Elf64_Sym *sym) } #endif +#define STUB_MAGIC 0x73747562 /* stub */ + /* Like PPC32, we need little trampolines to do > 24-bit jumps (into the kernel itself). But on PPC64, these need to be used for every jump, actually, to reset r2 (TOC+0x8000). */ @@ -105,7 +107,8 @@ struct ppc64_stub_entry * need 6 instructions on ABIv2 but we always allocate 7 so * so we don't have to modify the trampoline load instruction. */ u32 jump[7]; - u32 unused; + /* Used by ftrace to identify stubs */ + u32 magic; /* Data for the above code */ func_desc_t funcdata; }; @@ -139,70 +142,39 @@ static u32 ppc64_stub_insns[] = { }; #ifdef CONFIG_DYNAMIC_FTRACE - -static u32 ppc64_stub_mask[] = { - 0xffff0000, - 0xffff0000, - 0xffffffff, - 0xffffffff, -#if !defined(_CALL_ELF) || _CALL_ELF != 2 - 0xffffffff, -#endif - 0xffffffff, - 0xffffffff -}; - -bool is_module_trampoline(u32 *p) +int module_trampoline_target(struct module *mod, unsigned long addr, + unsigned long *target) { - unsigned int i; - u32 insns[ARRAY_SIZE(ppc64_stub_insns)]; - - BUILD_BUG_ON(sizeof(ppc64_stub_insns) != sizeof(ppc64_stub_mask)); + struct ppc64_stub_entry *stub; + func_desc_t funcdata; + u32 magic; - if (probe_kernel_read(insns, p, sizeof(insns))) + if (!within_module_core(addr, mod)) { + pr_err("%s: stub %lx not in module %s\n", __func__, addr, mod->name); return -EFAULT; - - for (i = 0; i < ARRAY_SIZE(ppc64_stub_insns); i++) { - u32 insna = insns[i]; - u32 insnb = ppc64_stub_insns[i]; - u32 mask = ppc64_stub_mask[i]; - - if ((insna & mask) != (insnb & mask)) - return false; } - return true; -} + stub = (struct ppc64_stub_entry *)addr; -int module_trampoline_target(struct module *mod, u32 *trampoline, - unsigned long *target) -{ - u32 buf[2]; - u16 upper, lower; - long offset; - void *toc_entry; - - if (probe_kernel_read(buf, trampoline, sizeof(buf))) + if (probe_kernel_read(&magic, &stub->magic, sizeof(magic))) { + pr_err("%s: fault reading magic for stub %lx for %s\n", __func__, addr, mod->name); return -EFAULT; + } - upper = buf[0] & 0xffff; - lower = buf[1] & 0xffff; - - /* perform the addis/addi, both signed */ - offset = ((short)upper << 16) + (short)lower; + if (magic != STUB_MAGIC) { + pr_err("%s: bad magic for stub %lx for %s\n", __func__, addr, mod->name); + return -EFAULT; + } - /* - * Now get the address this trampoline jumps to. This - * is always 32 bytes into our trampoline stub. - */ - toc_entry = (void *)mod->arch.toc + offset + 32; + if (probe_kernel_read(&funcdata, &stub->funcdata, sizeof(funcdata))) { + pr_err("%s: fault reading funcdata for stub %lx for %s\n", __func__, addr, mod->name); + return -EFAULT; + } - if (probe_kernel_read(target, toc_entry, sizeof(*target))) - return -EFAULT; + *target = stub_func_addr(funcdata); return 0; } - #endif /* Count how many different 24-bit relocations (different symbol, @@ -447,6 +419,8 @@ static inline int create_stub(const Elf64_Shdr *sechdrs, entry->jump[0] |= PPC_HA(reladdr); entry->jump[1] |= PPC_LO(reladdr); entry->funcdata = func_desc(addr); + entry->magic = STUB_MAGIC; + return 1; } |