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-rw-r--r--arch/mips/kernel/elf.c191
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();
+ }
+}