diff options
Diffstat (limited to 'arch/mips/kernel/elf.c')
| -rw-r--r-- | arch/mips/kernel/elf.c | 191 |
1 files changed, 191 insertions, 0 deletions
diff --git a/arch/mips/kernel/elf.c b/arch/mips/kernel/elf.c new file mode 100644 index 000000000000..c92b15df6893 --- /dev/null +++ b/arch/mips/kernel/elf.c @@ -0,0 +1,191 @@ +/* + * Copyright (C) 2014 Imagination Technologies + * Author: Paul Burton <paul.burton@imgtec.com> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2 of the License, or (at your + * option) any later version. + */ + +#include <linux/elf.h> +#include <linux/sched.h> + +enum { + FP_ERROR = -1, + FP_DOUBLE_64A = -2, +}; + +int arch_elf_pt_proc(void *_ehdr, void *_phdr, struct file *elf, + bool is_interp, struct arch_elf_state *state) +{ + struct elfhdr *ehdr = _ehdr; + struct elf_phdr *phdr = _phdr; + struct mips_elf_abiflags_v0 abiflags; + int ret; + + if (config_enabled(CONFIG_64BIT) && + (ehdr->e_ident[EI_CLASS] != ELFCLASS32)) + return 0; + if (phdr->p_type != PT_MIPS_ABIFLAGS) + return 0; + if (phdr->p_filesz < sizeof(abiflags)) + return -EINVAL; + + ret = kernel_read(elf, phdr->p_offset, (char *)&abiflags, + sizeof(abiflags)); + if (ret < 0) + return ret; + if (ret != sizeof(abiflags)) + return -EIO; + + /* Record the required FP ABIs for use by mips_check_elf */ + if (is_interp) + state->interp_fp_abi = abiflags.fp_abi; + else + state->fp_abi = abiflags.fp_abi; + + return 0; +} + +static inline unsigned get_fp_abi(struct elfhdr *ehdr, int in_abi) +{ + /* If the ABI requirement is provided, simply return that */ + if (in_abi != -1) + return in_abi; + + /* If the EF_MIPS_FP64 flag was set, return MIPS_ABI_FP_64 */ + if (ehdr->e_flags & EF_MIPS_FP64) + return MIPS_ABI_FP_64; + + /* Default to MIPS_ABI_FP_DOUBLE */ + return MIPS_ABI_FP_DOUBLE; +} + +int arch_check_elf(void *_ehdr, bool has_interpreter, + struct arch_elf_state *state) +{ + struct elfhdr *ehdr = _ehdr; + unsigned fp_abi, interp_fp_abi, abi0, abi1; + + /* Ignore non-O32 binaries */ + if (config_enabled(CONFIG_64BIT) && + (ehdr->e_ident[EI_CLASS] != ELFCLASS32)) + return 0; + + fp_abi = get_fp_abi(ehdr, state->fp_abi); + + if (has_interpreter) { + interp_fp_abi = get_fp_abi(ehdr, state->interp_fp_abi); + + abi0 = min(fp_abi, interp_fp_abi); + abi1 = max(fp_abi, interp_fp_abi); + } else { + abi0 = abi1 = fp_abi; + } + + state->overall_abi = FP_ERROR; + + if (abi0 == abi1) { + state->overall_abi = abi0; + } else if (abi0 == MIPS_ABI_FP_ANY) { + state->overall_abi = abi1; + } else if (abi0 == MIPS_ABI_FP_DOUBLE) { + switch (abi1) { + case MIPS_ABI_FP_XX: + state->overall_abi = MIPS_ABI_FP_DOUBLE; + break; + + case MIPS_ABI_FP_64A: + state->overall_abi = FP_DOUBLE_64A; + break; + } + } else if (abi0 == MIPS_ABI_FP_SINGLE || + abi0 == MIPS_ABI_FP_SOFT) { + /* Cannot link with other ABIs */ + } else if (abi0 == MIPS_ABI_FP_OLD_64) { + switch (abi1) { + case MIPS_ABI_FP_XX: + case MIPS_ABI_FP_64: + case MIPS_ABI_FP_64A: + state->overall_abi = MIPS_ABI_FP_64; + break; + } + } else if (abi0 == MIPS_ABI_FP_XX || + abi0 == MIPS_ABI_FP_64 || + abi0 == MIPS_ABI_FP_64A) { + state->overall_abi = MIPS_ABI_FP_64; + } + + switch (state->overall_abi) { + case MIPS_ABI_FP_64: + case MIPS_ABI_FP_64A: + case FP_DOUBLE_64A: + if (!config_enabled(CONFIG_MIPS_O32_FP64_SUPPORT)) + return -ELIBBAD; + break; + + case FP_ERROR: + return -ELIBBAD; + } + + return 0; +} + +void mips_set_personality_fp(struct arch_elf_state *state) +{ + if (config_enabled(CONFIG_FP32XX_HYBRID_FPRS)) { + /* + * Use hybrid FPRs for all code which can correctly execute + * with that mode. + */ + switch (state->overall_abi) { + case MIPS_ABI_FP_DOUBLE: + case MIPS_ABI_FP_SINGLE: + case MIPS_ABI_FP_SOFT: + case MIPS_ABI_FP_XX: + case MIPS_ABI_FP_ANY: + /* FR=1, FRE=1 */ + clear_thread_flag(TIF_32BIT_FPREGS); + set_thread_flag(TIF_HYBRID_FPREGS); + return; + } + } + + switch (state->overall_abi) { + case MIPS_ABI_FP_DOUBLE: + case MIPS_ABI_FP_SINGLE: + case MIPS_ABI_FP_SOFT: + /* FR=0 */ + set_thread_flag(TIF_32BIT_FPREGS); + clear_thread_flag(TIF_HYBRID_FPREGS); + break; + + case FP_DOUBLE_64A: + /* FR=1, FRE=1 */ + clear_thread_flag(TIF_32BIT_FPREGS); + set_thread_flag(TIF_HYBRID_FPREGS); + break; + + case MIPS_ABI_FP_64: + case MIPS_ABI_FP_64A: + /* FR=1, FRE=0 */ + clear_thread_flag(TIF_32BIT_FPREGS); + clear_thread_flag(TIF_HYBRID_FPREGS); + break; + + case MIPS_ABI_FP_XX: + case MIPS_ABI_FP_ANY: + if (!config_enabled(CONFIG_MIPS_O32_FP64_SUPPORT)) + set_thread_flag(TIF_32BIT_FPREGS); + else + clear_thread_flag(TIF_32BIT_FPREGS); + + clear_thread_flag(TIF_HYBRID_FPREGS); + break; + + default: + case FP_ERROR: + BUG(); + } +} |