From: Ard Biesheuvel <[email protected]> Instead of emitting the ftrace trampoline PLT into a separate ELF section, allocate them at the start of the ordinary PLT array, so that no special sections are needed.
Signed-off-by: Ard Biesheuvel <[email protected]> --- arch/arm64/include/asm/module.lds.h | 1 - arch/arm64/kernel/module-plts.c | 18 +++++------------- arch/arm64/kernel/module.c | 9 +-------- 3 files changed, 6 insertions(+), 22 deletions(-) diff --git a/arch/arm64/include/asm/module.lds.h b/arch/arm64/include/asm/module.lds.h index 24fc9401c514..95540e956b41 100644 --- a/arch/arm64/include/asm/module.lds.h +++ b/arch/arm64/include/asm/module.lds.h @@ -1,6 +1,5 @@ SECTIONS { .plt 0 : { BYTE(0) } - .text.ftrace_trampoline 0 : { BYTE(0) } #ifdef CONFIG_KASAN_SW_TAGS /* diff --git a/arch/arm64/kernel/module-plts.c b/arch/arm64/kernel/module-plts.c index e30876b90e30..6900d2242f1b 100644 --- a/arch/arm64/kernel/module-plts.c +++ b/arch/arm64/kernel/module-plts.c @@ -275,12 +275,14 @@ static int partition_branch_plt_relas(Elf64_Sym *syms, Elf64_Rela *rela, return i; } +static const int ftrace_plts = IS_ENABLED(CONFIG_DYNAMIC_FTRACE) ? NR_FTRACE_PLTS : 0; + int module_frob_arch_sections(Elf_Ehdr *ehdr, Elf_Shdr *sechdrs, char *secstrings, struct module *mod) { - unsigned long core_plts = 0; + unsigned long core_plts = ftrace_plts; Elf64_Sym *syms = NULL; - Elf_Shdr *pltsec, *tramp = NULL; + Elf_Shdr *pltsec; int i; /* @@ -290,9 +292,6 @@ int module_frob_arch_sections(Elf_Ehdr *ehdr, Elf_Shdr *sechdrs, for (i = 0; i < ehdr->e_shnum; i++) { if (!strcmp(secstrings + sechdrs[i].sh_name, ".plt")) mod->arch.core.plt_shndx = i; - else if (!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; } @@ -336,15 +335,8 @@ int module_frob_arch_sections(Elf_Ehdr *ehdr, Elf_Shdr *sechdrs, pltsec->sh_flags = SHF_EXECINSTR | SHF_ALLOC; pltsec->sh_addralign = L1_CACHE_BYTES; pltsec->sh_size = (core_plts + 1) * sizeof(struct plt_entry); - mod->arch.core.plt_num_entries = 0; + mod->arch.core.plt_num_entries = ftrace_plts; mod->arch.core.plt_max_entries = core_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 = NR_FTRACE_PLTS * sizeof(struct plt_entry); - } - return 0; } diff --git a/arch/arm64/kernel/module.c b/arch/arm64/kernel/module.c index 6e5b488a219e..620c2b70115e 100644 --- a/arch/arm64/kernel/module.c +++ b/arch/arm64/kernel/module.c @@ -454,14 +454,7 @@ static int module_init_ftrace_plt(const Elf_Ehdr *hdr, struct module *mod) { #if defined(CONFIG_DYNAMIC_FTRACE) - const Elf_Shdr *s; - struct plt_entry *plts; - - s = find_section(hdr, sechdrs, ".text.ftrace_trampoline"); - if (!s) - return -ENOEXEC; - - plts = (void *)s->sh_addr; + struct plt_entry *plts = (void *)sechdrs[mod->arch.core.plt_shndx].sh_addr; __init_plt(&plts[FTRACE_PLT_IDX], FTRACE_ADDR); -- 2.55.0.860.g4b6b3295ed-goog
