Commit 17a363dc authored by Heiko Carstens's avatar Heiko Carstens
Browse files

s390/traps,mm: add conditional trap handlers 



Add conditional trap handlers similar to conditional system calls
(COND_SYSCALL), to reduce the number of ifdefs.

Trap handlers which may or may not exist depending on config options
are supposed to have a COND_TRAP entry, which redirects to
default_trap_handler() for non-existent trap handlers during link
time.

This allows to get rid of the secure execution trap handlers for the
!PGSTE case.

Reviewed-by: default avatarVasily Gorbik <gor@linux.ibm.com>
Signed-off-by: default avatarHeiko Carstens <hca@linux.ibm.com>
parent 61311e32

arch/s390/kernel/entry.h

+0 −1
Original line number Diff line number Diff line
@@ -26,7 +26,6 @@ void do_dat_exception(struct pt_regs *regs); 
void do_secure_storage_access(struct pt_regs *regs);

void do_non_secure_storage_access(struct pt_regs *regs);

void do_secure_storage_violation(struct pt_regs *regs);

void default_trap_handler(struct pt_regs *regs);

void do_report_trap(struct pt_regs *regs, int si_signo, int si_code, char *str);

void kernel_stack_overflow(struct pt_regs * regs);

void do_signal(struct pt_regs *regs);

arch/s390/kernel/traps.c

+10 −1
Original line number Diff line number Diff line
@@ -79,7 +79,7 @@ void do_per_trap(struct pt_regs *regs) 
}

NOKPROBE_SYMBOL(do_per_trap);



void default_trap_handler(struct pt_regs *regs)

static void default_trap_handler(struct pt_regs *regs)

{

	if (user_mode(regs)) {

		report_user_fault(regs, SIGSEGV, 0);
@@ -404,3 +404,12 @@ static void (*pgm_check_table[128])(struct pt_regs *regs) = { 
	[0x40]		= monitor_event_exception,

	[0x41 ... 0x7f] = default_trap_handler,

};



#define COND_TRAP(x) asm(			\

	".weak " __stringify(x) "\n\t"		\

	".set  " __stringify(x) ","		\

	__stringify(default_trap_handler))



COND_TRAP(do_secure_storage_access);

COND_TRAP(do_non_secure_storage_access);

COND_TRAP(do_secure_storage_violation);

arch/s390/mm/fault.c

+2 −16
Original line number Diff line number Diff line
@@ -783,6 +783,7 @@ early_initcall(pfault_irq_init); 
#endif /* CONFIG_PFAULT */



#if IS_ENABLED(CONFIG_PGSTE)



void do_secure_storage_access(struct pt_regs *regs)

{

	unsigned long addr = regs->int_parm_long & __FAIL_ADDR_MASK;
@@ -859,19 +860,4 @@ void do_secure_storage_violation(struct pt_regs *regs) 
	send_sig(SIGSEGV, current, 0);

}



#else

void do_secure_storage_access(struct pt_regs *regs)

{

	default_trap_handler(regs);

}



void do_non_secure_storage_access(struct pt_regs *regs)

{

	default_trap_handler(regs);

}



void do_secure_storage_violation(struct pt_regs *regs)

{

	default_trap_handler(regs);

}

#endif
 
#endif /* CONFIG_PGSTE */