diff options
| -rw-r--r-- | arch/arm64/Makefile | 3 | ||||
| -rw-r--r-- | arch/arm64/include/asm/module.h | 2 | ||||
| -rw-r--r-- | arch/arm64/kernel/Makefile | 3 | ||||
| -rw-r--r-- | arch/arm64/kernel/ftrace-mod.S | 18 | ||||
| -rw-r--r-- | arch/arm64/kernel/ftrace.c | 14 | ||||
| -rw-r--r-- | arch/arm64/kernel/module-plts.c | 12 | ||||
| -rw-r--r-- | arch/arm64/kernel/module.lds | 1 |
7 files changed, 22 insertions, 31 deletions
diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile index b35788c909f1ce..b481b4a7c01114 100644 --- a/arch/arm64/Makefile +++ b/arch/arm64/Makefile @@ -83,9 +83,6 @@ endif ifeq ($(CONFIG_ARM64_MODULE_PLTS),y) KBUILD_LDFLAGS_MODULE += -T $(srctree)/arch/arm64/kernel/module.lds -ifeq ($(CONFIG_DYNAMIC_FTRACE),y) -KBUILD_LDFLAGS_MODULE += $(objtree)/arch/arm64/kernel/ftrace-mod.o -endif endif # Default value diff --git a/arch/arm64/include/asm/module.h b/arch/arm64/include/asm/module.h index 11d4aaee82e11e..4f766178fa6ff3 100644 --- a/arch/arm64/include/asm/module.h +++ b/arch/arm64/include/asm/module.h @@ -32,7 +32,7 @@ struct mod_arch_specific { struct mod_plt_sec init; /* for CONFIG_DYNAMIC_FTRACE */ - void *ftrace_trampoline; + struct plt_entry *ftrace_trampoline; }; #endif diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile index 8265dd79089522..067baace74a09b 100644 --- a/arch/arm64/kernel/Makefile +++ b/arch/arm64/kernel/Makefile @@ -61,6 +61,3 @@ extra-y += $(head-y) vmlinux.lds ifeq ($(CONFIG_DEBUG_EFI),y) AFLAGS_head.o += -DVMLINUX_PATH="\"$(realpath $(objtree)/vmlinux)\"" endif - -# will be included by each individual module but not by the core kernel itself -extra-$(CONFIG_DYNAMIC_FTRACE) += ftrace-mod.o diff --git a/arch/arm64/kernel/ftrace-mod.S b/arch/arm64/kernel/ftrace-mod.S deleted file mode 100644 index 00c4025be4ff83..00000000000000 --- a/arch/arm64/kernel/ftrace-mod.S +++ /dev/null @@ -1,18 +0,0 @@ -/* - * Copyright (C) 2017 Linaro Ltd <ard.biesheuvel@linaro.org> - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 as - * published by the Free Software Foundation. - */ - -#include <linux/linkage.h> -#include <asm/assembler.h> - - .section ".text.ftrace_trampoline", "ax" - .align 3 -0: .quad 0 -__ftrace_trampoline: - ldr x16, 0b - br x16 -ENDPROC(__ftrace_trampoline) diff --git a/arch/arm64/kernel/ftrace.c b/arch/arm64/kernel/ftrace.c index c13b1fca0e5baf..50986e388d2b27 100644 --- a/arch/arm64/kernel/ftrace.c +++ b/arch/arm64/kernel/ftrace.c @@ -76,7 +76,7 @@ int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) if (offset < -SZ_128M || offset >= SZ_128M) { #ifdef CONFIG_ARM64_MODULE_PLTS - unsigned long *trampoline; + struct plt_entry trampoline; struct module *mod; /* @@ -104,22 +104,24 @@ int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) * is added in the future, but for now, the pr_err() below * deals with a theoretical issue only. */ - trampoline = (unsigned long *)mod->arch.ftrace_trampoline; - if (trampoline[0] != addr) { - if (trampoline[0] != 0) { + trampoline = get_plt_entry(addr); + if (!plt_entries_equal(mod->arch.ftrace_trampoline, + &trampoline)) { + if (!plt_entries_equal(mod->arch.ftrace_trampoline, + &(struct plt_entry){})) { pr_err("ftrace: far branches to multiple entry points unsupported inside a single module\n"); return -EINVAL; } /* point the trampoline to our ftrace entry point */ module_disable_ro(mod); - trampoline[0] = addr; + *mod->arch.ftrace_trampoline = trampoline; module_enable_ro(mod, true); /* update trampoline before patching in the branch */ smp_wmb(); } - addr = (unsigned long)&trampoline[1]; + addr = (unsigned long)(void *)mod->arch.ftrace_trampoline; #else /* CONFIG_ARM64_MODULE_PLTS */ return -EINVAL; #endif /* CONFIG_ARM64_MODULE_PLTS */ diff --git a/arch/arm64/kernel/module-plts.c b/arch/arm64/kernel/module-plts.c index ebff6c155cac29..ea640f92fe5ada 100644 --- a/arch/arm64/kernel/module-plts.c +++ b/arch/arm64/kernel/module-plts.c @@ -120,6 +120,7 @@ int module_frob_arch_sections(Elf_Ehdr *ehdr, Elf_Shdr *sechdrs, unsigned long core_plts = 0; unsigned long init_plts = 0; Elf64_Sym *syms = NULL; + Elf_Shdr *tramp = NULL; int i; /* @@ -131,6 +132,10 @@ int module_frob_arch_sections(Elf_Ehdr *ehdr, Elf_Shdr *sechdrs, mod->arch.core.plt = sechdrs + i; else if (!strcmp(secstrings + sechdrs[i].sh_name, ".init.plt")) mod->arch.init.plt = sechdrs + i; + else if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE) && + !strcmp(secstrings + sechdrs[i].sh_name, + ".text.ftrace_trampoline")) + tramp = sechdrs + i; else if (sechdrs[i].sh_type == SHT_SYMTAB) syms = (Elf64_Sym *)sechdrs[i].sh_addr; } @@ -181,5 +186,12 @@ int module_frob_arch_sections(Elf_Ehdr *ehdr, Elf_Shdr *sechdrs, mod->arch.init.plt_num_entries = 0; mod->arch.init.plt_max_entries = init_plts; + if (tramp) { + tramp->sh_type = SHT_NOBITS; + tramp->sh_flags = SHF_EXECINSTR | SHF_ALLOC; + tramp->sh_addralign = __alignof__(struct plt_entry); + tramp->sh_size = sizeof(struct plt_entry); + } + return 0; } diff --git a/arch/arm64/kernel/module.lds b/arch/arm64/kernel/module.lds index f7c9781a9d48b4..22e36a21c11345 100644 --- a/arch/arm64/kernel/module.lds +++ b/arch/arm64/kernel/module.lds @@ -1,4 +1,5 @@ SECTIONS { .plt (NOLOAD) : { BYTE(0) } .init.plt (NOLOAD) : { BYTE(0) } + .text.ftrace_trampoline (NOLOAD) : { BYTE(0) } } |