Commit e3ddb8bb authored by Max Filippov's avatar Max Filippov
Browse files

xtensa: add FDPIC and static PIE support for noMMU 



Define ELFOSABI_XTENSA_FDPIC and use it as an OSABI tag in the ELF
header to distinguish FDPIC ELF files from regular ELF files.
Define ELF_FDPIC_PLAT_INIT and put executable map, interpreter map and
executable dynamic section addresses into registers a4..a6.
Update start_thread macro to preserve register values in the current
register window.
Add definitions for PTRACE_GETFDPIC, PTRACE_GETFDPIC_EXEC and
PTRACE_GETFDPIC_INTERP.

Signed-off-by: default avatarMax Filippov <jcmvbkbc@gmail.com>
parent ccd2d9df

arch/xtensa/include/asm/elf.h

+11 −0
Original line number Diff line number Diff line
@@ -93,6 +93,10 @@ typedef elf_fpreg_t elf_fpregset_t[ELF_NFPREG]; 
#define elf_check_arch(x) ( ( (x)->e_machine == EM_XTENSA )  || \

			    ( (x)->e_machine == EM_XTENSA_OLD ) )



#define ELFOSABI_XTENSA_FDPIC 65

#define elf_check_fdpic(x) ((x)->e_ident[EI_OSABI] == ELFOSABI_XTENSA_FDPIC)

#define ELF_FDPIC_CORE_EFLAGS 0



/*

 * These are used to set parameters in the core dumps.

 */
@@ -164,6 +168,13 @@ typedef elf_fpreg_t elf_fpregset_t[ELF_NFPREG]; 
		(_r)->areg[14] = 0; (_r)->areg[15] = 0; \

	} while (0)



#define ELF_FDPIC_PLAT_INIT(_r, _exec_map_addr, _interp_map_addr, dynamic_addr) \

	do { \

		(_r)->areg[4] = _exec_map_addr; \

		(_r)->areg[5] = _interp_map_addr; \

		(_r)->areg[6] = dynamic_addr; \

	} while (0)



typedef struct {

	xtregs_opt_t	opt;

	xtregs_user_t	user;

arch/xtensa/include/asm/processor.h

+3 −0
Original line number Diff line number Diff line
@@ -205,9 +205,12 @@ struct thread_struct { 
#define start_thread(regs, new_pc, new_sp) \

	do { \

		unsigned long syscall = (regs)->syscall; \

		unsigned long current_aregs[16]; \

		memcpy(current_aregs, (regs)->areg, sizeof(current_aregs)); \

		memset((regs), 0, sizeof(*(regs))); \

		(regs)->pc = (new_pc); \

		(regs)->ps = USER_PS_VALUE; \

		memcpy((regs)->areg, current_aregs, sizeof(current_aregs)); \

		(regs)->areg[1] = (new_sp); \

		(regs)->areg[0] = 0; \

		(regs)->wmask = 1; \

arch/xtensa/include/uapi/asm/ptrace.h

+4 −0
Original line number Diff line number Diff line
@@ -37,6 +37,10 @@ 
#define PTRACE_SETXTREGS	19

#define PTRACE_GETHBPREGS	20

#define PTRACE_SETHBPREGS	21

#define PTRACE_GETFDPIC		22



#define PTRACE_GETFDPIC_EXEC	0

#define PTRACE_GETFDPIC_INTERP	1



#ifndef __ASSEMBLY__

fs/Kconfig.binfmt

+1 −1
Original line number Diff line number Diff line
@@ -58,7 +58,7 @@ config ARCH_USE_GNU_PROPERTY 
config BINFMT_ELF_FDPIC

	bool "Kernel support for FDPIC ELF binaries"

	default y if !BINFMT_ELF

	depends on ARM || ((M68K || SUPERH) && !MMU)

	depends on ARM || ((M68K || SUPERH || XTENSA) && !MMU)

	select ELFCORE

	help

	  ELF FDPIC binaries are based on ELF, but allow the individual load