Unverified Commit ea6a3737 authored by Paul Burton's avatar Paul Burton
Browse files

MIPS: Avoid FP ELF checks when CONFIG_MIPS_FP_SUPPORT=n 



When CONFIG_MIPS_FP_SUPPORT=n we don't support floating point, so we can
avoid needless checks of ELF headers specifying the FP ABI or NaN
encoding to use. Deselect CONFIG_ARCH_BINFMT_ELF_STATE in this case to
avoid the need for our arch_elf_pt_proc() & arch_check_elf() functions,
and stub out the mips_set_personality_nan() & mips_set_personality_fp()
functions such that SET_PERSONALITY() doesn't need to worry about any of
this.

Signed-off-by: default avatarPaul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/21011/
Cc: linux-mips@linux-mips.org
parent 4eec81d7

arch/mips/Kconfig

+1 −1
Original line number Diff line number Diff line
@@ -2,7 +2,7 @@ 
config MIPS

	bool

	default y

	select ARCH_BINFMT_ELF_STATE

	select ARCH_BINFMT_ELF_STATE if MIPS_FP_SUPPORT

	select ARCH_CLOCKSOURCE_DATA

	select ARCH_DISCARD_MEMBLOCK

	select ARCH_HAS_ELF_RANDOMIZE

arch/mips/include/asm/elf.h

+22 −4
Original line number Diff line number Diff line
@@ -481,6 +481,8 @@ struct linux_binprm; 
extern int arch_setup_additional_pages(struct linux_binprm *bprm,

				       int uses_interp);



#ifdef CONFIG_MIPS_FP_SUPPORT



struct arch_elf_state {

	int nan_2008;

	int fp_abi;
@@ -497,19 +499,35 @@ struct arch_elf_state { 
	.overall_fp_mode = -1,			\

}



/* Whether to accept legacy-NaN and 2008-NaN user binaries.  */

extern bool mips_use_nan_legacy;

extern bool mips_use_nan_2008;



extern int arch_elf_pt_proc(void *ehdr, void *phdr, struct file *elf,

			    bool is_interp, struct arch_elf_state *state);



extern int arch_check_elf(void *ehdr, bool has_interpreter, void *interp_ehdr,

			  struct arch_elf_state *state);



/* Whether to accept legacy-NaN and 2008-NaN user binaries.  */

extern bool mips_use_nan_legacy;

extern bool mips_use_nan_2008;



extern void mips_set_personality_nan(struct arch_elf_state *state);

extern void mips_set_personality_fp(struct arch_elf_state *state);



#else /* !CONFIG_MIPS_FP_SUPPORT */



struct arch_elf_state;



static inline void mips_set_personality_nan(struct arch_elf_state *state)

{

	/* no-op */

}



static inline void mips_set_personality_fp(struct arch_elf_state *state)

{

	/* no-op */

}



#endif /* !CONFIG_MIPS_FP_SUPPORT */



#define elf_read_implies_exec(ex, stk) mips_elf_read_implies_exec(&(ex), stk)

extern int mips_elf_read_implies_exec(void *elf_ex, int exstack);

arch/mips/kernel/elf.c

+4 −0
Original line number Diff line number Diff line
@@ -16,6 +16,8 @@ 
#include <asm/cpu-features.h>

#include <asm/cpu-info.h>



#ifdef CONFIG_MIPS_FP_SUPPORT



/* Whether to accept legacy-NaN and 2008-NaN user binaries.  */

bool mips_use_nan_legacy;

bool mips_use_nan_2008;
@@ -326,6 +328,8 @@ void mips_set_personality_nan(struct arch_elf_state *state) 
	}

}



#endif /* CONFIG_MIPS_FP_SUPPORT */



int mips_elf_read_implies_exec(void *elf_ex, int exstack)

{

	if (exstack != EXSTACK_DISABLE_X) {

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