diff options
Diffstat (limited to 'arch/arm64/kernel/module-plts.c')
| -rw-r--r-- | arch/arm64/kernel/module-plts.c | 50 |
1 files changed, 14 insertions, 36 deletions
diff --git a/arch/arm64/kernel/module-plts.c b/arch/arm64/kernel/module-plts.c index d05dbe658409..ea640f92fe5a 100644 --- a/arch/arm64/kernel/module-plts.c +++ b/arch/arm64/kernel/module-plts.c @@ -11,21 +11,6 @@ #include <linux/module.h> #include <linux/sort.h> -struct plt_entry { - /* - * A program that conforms to the AArch64 Procedure Call Standard - * (AAPCS64) must assume that a veneer that alters IP0 (x16) and/or - * IP1 (x17) may be inserted at any branch instruction that is - * exposed to a relocation that supports long branches. Since that - * is exactly what we are dealing with here, we are free to use x16 - * as a scratch register in the PLT veneers. - */ - __le32 mov0; /* movn x16, #0x.... */ - __le32 mov1; /* movk x16, #0x...., lsl #16 */ - __le32 mov2; /* movk x16, #0x...., lsl #32 */ - __le32 br; /* br x16 */ -}; - static bool in_init(const struct module *mod, void *loc) { return (u64)loc - (u64)mod->init_layout.base < mod->init_layout.size; @@ -40,33 +25,14 @@ u64 module_emit_plt_entry(struct module *mod, void *loc, const Elf64_Rela *rela, int i = pltsec->plt_num_entries; u64 val = sym->st_value + rela->r_addend; - /* - * MOVK/MOVN/MOVZ opcode: - * +--------+------------+--------+-----------+-------------+---------+ - * | sf[31] | opc[30:29] | 100101 | hw[22:21] | imm16[20:5] | Rd[4:0] | - * +--------+------------+--------+-----------+-------------+---------+ - * - * Rd := 0x10 (x16) - * hw := 0b00 (no shift), 0b01 (lsl #16), 0b10 (lsl #32) - * opc := 0b11 (MOVK), 0b00 (MOVN), 0b10 (MOVZ) - * sf := 1 (64-bit variant) - */ - plt[i] = (struct plt_entry){ - cpu_to_le32(0x92800010 | (((~val ) & 0xffff)) << 5), - cpu_to_le32(0xf2a00010 | ((( val >> 16) & 0xffff)) << 5), - cpu_to_le32(0xf2c00010 | ((( val >> 32) & 0xffff)) << 5), - cpu_to_le32(0xd61f0200) - }; + plt[i] = get_plt_entry(val); /* * Check if the entry we just created is a duplicate. Given that the * relocations are sorted, this will be the last entry we allocated. * (if one exists). */ - if (i > 0 && - plt[i].mov0 == plt[i - 1].mov0 && - plt[i].mov1 == plt[i - 1].mov1 && - plt[i].mov2 == plt[i - 1].mov2) + if (i > 0 && plt_entries_equal(plt + i, plt + i - 1)) return (u64)&plt[i - 1]; pltsec->plt_num_entries++; @@ -154,6 +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; /* @@ -165,6 +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; } @@ -215,5 +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; } |