Commit fbf50f47 authored by Sven Schnelle's avatar Sven Schnelle Committed by Vasily Gorbik
Browse files

s390/signal: remove sigreturn on stack 



{rt_}sigreturn is now called from the vdso, so we no longer
need the svc on the stack, and therefore no hack to support that
mechanism on machines with non-executable stack.

Signed-off-by: default avatarSven Schnelle <svens@linux.ibm.com>
Reviewed-by: default avatarHeiko Carstens <hca@linux.ibm.com>
Signed-off-by: default avatarVasily Gorbik <gor@linux.ibm.com>
parent df29a744

arch/s390/include/asm/entry-common.h

+0 −1
Original line number Diff line number Diff line
@@ -14,7 +14,6 @@ 
#define ARCH_EXIT_TO_USER_MODE_WORK (_TIF_GUARDED_STORAGE | _TIF_PER_TRAP)



void do_per_trap(struct pt_regs *regs);

void do_syscall(struct pt_regs *regs);



#ifdef CONFIG_DEBUG_ENTRY

static __always_inline void arch_check_user_regs(struct pt_regs *regs)

arch/s390/kernel/syscall.c

+1 −1
Original line number Diff line number Diff line
@@ -108,7 +108,7 @@ SYSCALL_DEFINE0(ni_syscall) 
	return -ENOSYS;

}



void do_syscall(struct pt_regs *regs)

static void do_syscall(struct pt_regs *regs)

{

	unsigned long nr;

arch/s390/kernel/traps.c

+1 −11
Original line number Diff line number Diff line
@@ -301,10 +301,9 @@ static void (*pgm_check_table[128])(struct pt_regs *regs); 
void noinstr __do_pgm_check(struct pt_regs *regs)

{

	unsigned long last_break = S390_lowcore.breaking_event_addr;

	unsigned int trapnr, syscall_redirect = 0;

	unsigned int trapnr;

	irqentry_state_t state;



	add_random_kstack_offset();

	regs->int_code = *(u32 *)&S390_lowcore.pgm_ilc;

	regs->int_parm_long = S390_lowcore.trans_exc_code;
@@ -346,18 +345,9 @@ void noinstr __do_pgm_check(struct pt_regs *regs) 
	trapnr = regs->int_code & PGM_INT_CODE_MASK;

	if (trapnr)

		pgm_check_table[trapnr](regs);

	syscall_redirect = user_mode(regs) && test_pt_regs_flag(regs, PIF_SYSCALL);

out:

	local_irq_disable();

	irqentry_exit(regs, state);



	if (syscall_redirect) {

		enter_from_user_mode(regs);

		local_irq_enable();

		regs->orig_gpr2 = regs->gprs[2];

		do_syscall(regs);

		exit_to_user_mode();

	}

}



/*

arch/s390/mm/fault.c

+0 −23
Original line number Diff line number Diff line
@@ -285,26 +285,6 @@ static noinline void do_sigbus(struct pt_regs *regs) 
			(void __user *)(regs->int_parm_long & __FAIL_ADDR_MASK));

}



static noinline int signal_return(struct pt_regs *regs)

{

	u16 instruction;

	int rc;



	rc = __get_user(instruction, (u16 __user *) regs->psw.addr);

	if (rc)

		return rc;

	if (instruction == 0x0a77) {

		set_pt_regs_flag(regs, PIF_SYSCALL);

		regs->int_code = 0x00040077;

		return 0;

	} else if (instruction == 0x0aad) {

		set_pt_regs_flag(regs, PIF_SYSCALL);

		regs->int_code = 0x000400ad;

		return 0;

	}

	return -EACCES;

}



static noinline void do_fault_error(struct pt_regs *regs, int access,

					vm_fault_t fault)

{
@@ -312,9 +292,6 @@ static noinline void do_fault_error(struct pt_regs *regs, int access, 


	switch (fault) {

	case VM_FAULT_BADACCESS:

		if (access == VM_EXEC && signal_return(regs) == 0)

			break;

		fallthrough;

	case VM_FAULT_BADMAP:

		/* Bad memory access. Check if it is kernel or user space. */

		if (user_mode(regs)) {