Commit 2ed02dd4 authored by Maciej W. Rozycki's avatar Maciej W. Rozycki Committed by Ralf Baechle
Browse files

MIPS: Use a union to access the ELF file header 



Rewrite `arch_elf_pt_proc' and `arch_check_elf' using a union to access
the ELF file header.

Signed-off-by: default avatarMaciej W. Rozycki <macro@imgtec.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Matthew Fortune <Matthew.Fortune@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11474/


Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
parent a0fd81a9

arch/mips/kernel/elf.c

+26 −14
Original line number Diff line number Diff line
@@ -68,15 +68,23 @@ static struct mode_req none_req = { true, true, false, true, true }; 
int arch_elf_pt_proc(void *_ehdr, void *_phdr, struct file *elf,

		     bool is_interp, struct arch_elf_state *state)

{

	struct elf32_hdr *ehdr32 = _ehdr;

	union {

		struct elf32_hdr e32;

		struct elf64_hdr e64;

	} *ehdr = _ehdr;

	struct elf32_phdr *phdr32 = _phdr;

	struct elf64_phdr *phdr64 = _phdr;

	struct mips_elf_abiflags_v0 abiflags;

	bool elf32;

	u32 flags;

	int ret;



	elf32 = ehdr->e32.e_ident[EI_CLASS] == ELFCLASS32;

	flags = elf32 ? ehdr->e32.e_flags : ehdr->e64.e_flags;



	/* Lets see if this is an O32 ELF */

	if (ehdr32->e_ident[EI_CLASS] == ELFCLASS32) {

		if (ehdr32->e_flags & EF_MIPS_FP64) {

	if (elf32) {

		if (flags & EF_MIPS_FP64) {

			/*

			 * Set MIPS_ABI_FP_OLD_64 for EF_MIPS_FP64. We will override it

			 * later if needed
@@ -123,10 +131,17 @@ int arch_elf_pt_proc(void *_ehdr, void *_phdr, struct file *elf, 
int arch_check_elf(void *_ehdr, bool has_interpreter,

		   struct arch_elf_state *state)

{

	struct elf32_hdr *ehdr = _ehdr;

	union {

		struct elf32_hdr e32;

		struct elf64_hdr e64;

	} *ehdr = _ehdr;

	struct mode_req prog_req, interp_req;

	int fp_abi, interp_fp_abi, abi0, abi1, max_abi;

	bool is_mips64;

	bool elf32;

	u32 flags;



	elf32 = ehdr->e32.e_ident[EI_CLASS] == ELFCLASS32;

	flags = elf32 ? ehdr->e32.e_flags : ehdr->e64.e_flags;



	if (!config_enabled(CONFIG_MIPS_O32_FP64_SUPPORT))

		return 0;
@@ -142,21 +157,18 @@ int arch_check_elf(void *_ehdr, bool has_interpreter, 
		abi0 = abi1 = fp_abi;

	}



	is_mips64 = (ehdr->e_ident[EI_CLASS] == ELFCLASS64) ||

		    (ehdr->e_flags & EF_MIPS_ABI2);

	if (elf32 && !(flags & EF_MIPS_ABI2)) {

		/* Default to a mode capable of running code expecting FR=0 */

		state->overall_fp_mode = cpu_has_mips_r6 ? FP_FRE : FP_FR0;



	if (is_mips64) {

		/* Allow all ABIs we know about */

		max_abi = MIPS_ABI_FP_64A;

	} else {

		/* MIPS64 code always uses FR=1, thus the default is easy */

		state->overall_fp_mode = FP_FR1;



		/* Disallow access to the various FPXX & FP64 ABIs */

		max_abi = MIPS_ABI_FP_SOFT;

	} else {

		/* Default to a mode capable of running code expecting FR=0 */

		state->overall_fp_mode = cpu_has_mips_r6 ? FP_FRE : FP_FR0;



		/* Allow all ABIs we know about */

		max_abi = MIPS_ABI_FP_64A;

	}



	if ((abi0 > max_abi && abi0 != MIPS_ABI_FP_UNKNOWN) ||

CRA Git | Maintained and supported by SUSTech CRA and CCSE