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Commit eb608fb3 authored by Heiko Carstens's avatar Heiko Carstens Committed by Martin Schwidefsky
Browse files

s390/exceptions: switch to relative exception table entries 



This is the s390 port of 70627654 "x86, extable: Switch to relative
exception table entries".
Reduces the size of our exception tables by 50% on 64 bit builds.

Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 24996edc

arch/s390/include/asm/processor.h

+24 −18
Original line number Diff line number Diff line
@@ -11,6 +11,8 @@ 
#ifndef __ASM_S390_PROCESSOR_H

#define __ASM_S390_PROCESSOR_H



#ifndef __ASSEMBLY__



#include <linux/linkage.h>

#include <linux/irqflags.h>

#include <asm/cpu.h>
@@ -348,23 +350,6 @@ extern void (*s390_base_ext_handler_fn)(void); 


#define ARCH_LOW_ADDRESS_LIMIT	0x7fffffffUL



/*

 * Helper macro for exception table entries

 */

#ifndef CONFIG_64BIT

#define EX_TABLE(_fault,_target)			\

	".section __ex_table,\"a\"\n"			\

	"	.align 4\n"				\

	"	.long  " #_fault "," #_target "\n"	\

	".previous\n"

#else

#define EX_TABLE(_fault,_target)			\

	".section __ex_table,\"a\"\n"			\

	"	.align 8\n"				\

	"	.quad  " #_fault "," #_target "\n"	\

	".previous\n"

#endif



extern int memcpy_real(void *, void *, size_t);

extern void memcpy_absolute(void *, void *, size_t);
@@ -375,4 +360,25 @@ extern void memcpy_absolute(void *, void *, size_t); 
	memcpy_absolute(&(dest), &__tmp, sizeof(__tmp));	\

}



/*

 * Helper macro for exception table entries

 */

#define EX_TABLE(_fault, _target)	\

	".section __ex_table,\"a\"\n"	\

	".align	4\n"			\

	".long	(" #_fault ") - .\n"	\

	".long	(" #_target ") - .\n"	\

	".previous\n"



#else /* __ASSEMBLY__ */



#define EX_TABLE(_fault, _target)	\

	.section __ex_table,"a"	;	\

	.align	4 ;			\

	.long	(_fault) - . ;		\

	.long	(_target) - . ;		\

	.previous



#endif /* __ASSEMBLY__ */



#endif /* __ASM_S390_PROCESSOR_H */

arch/s390/include/asm/uaccess.h

+14 −1
Original line number Diff line number Diff line
@@ -76,9 +76,22 @@ static inline int __range_ok(unsigned long addr, unsigned long size) 


struct exception_table_entry

{

        unsigned long insn, fixup;

	int insn, fixup;

};



static inline unsigned long extable_insn(const struct exception_table_entry *x)

{

	return (unsigned long)&x->insn + x->insn;

}



static inline unsigned long extable_fixup(const struct exception_table_entry *x)

{

	return (unsigned long)&x->fixup + x->fixup;

}



#define ARCH_HAS_SORT_EXTABLE

#define ARCH_HAS_SEARCH_EXTABLE



struct uaccess_ops {

	size_t (*copy_from_user)(size_t, const void __user *, void *);

	size_t (*copy_from_user_small)(size_t, const void __user *, void *);

arch/s390/kernel/early.c

+2 −2
Original line number Diff line number Diff line
@@ -255,14 +255,14 @@ static __init void setup_topology(void) 


static void early_pgm_check_handler(void)

{

	unsigned long addr;

	const struct exception_table_entry *fixup;

	unsigned long addr;



	addr = S390_lowcore.program_old_psw.addr;

	fixup = search_exception_tables(addr & PSW_ADDR_INSN);

	if (!fixup)

		disabled_wait(0);

	S390_lowcore.program_old_psw.addr = fixup->fixup | PSW_ADDR_AMODE;

	S390_lowcore.program_old_psw.addr = extable_fixup(fixup)|PSW_ADDR_AMODE;

}



static noinline __init void setup_lowcore_early(void)

arch/s390/kernel/entry64.S

+2 −3
Original line number Diff line number Diff line
@@ -10,6 +10,7 @@ 


#include <linux/init.h>

#include <linux/linkage.h>

#include <asm/processor.h>

#include <asm/cache.h>

#include <asm/errno.h>

#include <asm/ptrace.h>
@@ -1008,9 +1009,7 @@ sie_fault: 
.Lhost_id:

	.quad	0



	.section __ex_table,"a"

	.quad	sie_loop,sie_fault

	.previous

	EX_TABLE(sie_loop,sie_fault)

#endif



		.section .rodata, "a"

arch/s390/kernel/kprobes.c

+1 −1
Original line number Diff line number Diff line
@@ -547,7 +547,7 @@ static int __kprobes kprobe_trap_handler(struct pt_regs *regs, int trapnr) 
		 */

		entry = search_exception_tables(regs->psw.addr & PSW_ADDR_INSN);

		if (entry) {

			regs->psw.addr = entry->fixup | PSW_ADDR_AMODE;

			regs->psw.addr = extable_fixup(entry) | PSW_ADDR_AMODE;

			return 1;

		}