Commit 985e00fe authored by Mao Minkai's avatar Mao Minkai Committed by guzitao
Browse files

sw64: expand struct pt_regs 

Sunway inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I8CCP8



--------------------------------

Add three new members to pt_regs
  - orig_r0: stores the r0 before syscall
  - orig_r19: stores the r19 before syscall

Since the syscall_nr is stored in r0, orig_r0 will be set to -1 in
non-syscall context or when syscall is complete.

Modify syscall process accordingly.

Signed-off-by: default avatarMao Minkai <maominkai@wxiat.com>
Reviewed-by: default avatarHe Sheng <hesheng@wxiat.com>
Signed-off-by: default avatarGu Zitao <guzitao@wxiat.com>
parent 1ecccb6a

arch/sw_64/include/asm/ptrace.h

+14 −3
Original line number Diff line number Diff line
@@ -6,6 +6,11 @@ 
#include <asm/hmcall.h>

#include <asm/page.h>



#define NO_SYSCALL	(-1)



#ifdef __KERNEL__

#ifndef __ASSEMBLY__



/*

 * This struct defines the way the registers are stored on the

 * kernel stack during a system call or other kernel entry
@@ -20,6 +25,8 @@ struct pt_regs { 
			unsigned long ps;

		};

	};

	unsigned long orig_r0;

	unsigned long orig_r19;

	/* These are saved by HMcode: */

	unsigned long hm_ps;

	unsigned long hm_pc;
@@ -37,9 +44,9 @@ struct pt_regs { 
#define kernel_stack_pointer(regs) ((unsigned long)((regs) + 1))

#define instruction_pointer_set(regs, val) ((regs)->pc = val)



#define force_successful_syscall_return() (current_pt_regs()->regs[0] = 0)

#define force_successful_syscall_return() (current_pt_regs()->orig_r0 = NO_SYSCALL)



#define MAX_REG_OFFSET (offsetof(struct pt_regs, ps))

#define MAX_REG_OFFSET (offsetof(struct pt_regs, orig_r0))



extern short regoffsets[];
@@ -70,9 +77,13 @@ static inline int is_syscall_success(struct pt_regs *regs) 


static inline long regs_return_value(struct pt_regs *regs)

{

	if (is_syscall_success(regs) || !user_mode(regs))

	if ((regs->orig_r0 == NO_SYSCALL) || is_syscall_success(regs))

		return regs->regs[0];

	else

		return -regs->regs[0];

}



#endif /* !__ASSEMBLY__ */

#endif /* __KERNEL__ */



#endif /* _ASM_SW64_PTRACE_H */

arch/sw_64/include/asm/syscall.h

+3 −3
Original line number Diff line number Diff line
@@ -29,18 +29,18 @@ static inline void syscall_set_return_value(struct task_struct *task, 
{

	if (error) {

		regs->regs[0]  = -error;

		regs->regs[19] = -1;

		regs->regs[19] = 1;

	} else {

		regs->regs[0] = val;

		regs->regs[19] = 0;

	}

}





static inline void syscall_rollback(struct task_struct *task,

				    struct pt_regs *regs)

{

	/* Do nothing */

	regs->regs[0] = regs->orig_r0;

	regs->regs[19] = regs->orig_r19;

}



static inline void syscall_get_arguments(struct task_struct *task,

arch/sw_64/kernel/asm-offsets.c

+2 −0
Original line number Diff line number Diff line
@@ -101,6 +101,8 @@ void foo(void) 
	DEFINE(PT_REGS_SP, offsetof(struct pt_regs, regs[30]));

	DEFINE(PT_REGS_PC, offsetof(struct pt_regs, pc));

	DEFINE(PT_REGS_PS, offsetof(struct pt_regs, ps));

	DEFINE(PT_REGS_ORIG_R0, offsetof(struct pt_regs, orig_r0));

	DEFINE(PT_REGS_ORIG_R19, offsetof(struct pt_regs, orig_r19));

	DEFINE(PT_REGS_HM_PS, offsetof(struct pt_regs, hm_ps));

	DEFINE(PT_REGS_HM_PC, offsetof(struct pt_regs, hm_pc));

	DEFINE(PT_REGS_HM_GP, offsetof(struct pt_regs, hm_gp));

arch/sw_64/kernel/entry.S

+24 −71
Original line number Diff line number Diff line
@@ -8,6 +8,7 @@ 
#include <asm/hmcall.h>

#include <asm/errno.h>

#include <asm/unistd.h>

#include <asm/ptrace.h>



	.text

	.set noat
@@ -63,9 +64,11 @@ 
	and	$6, 0x8, $7

	beq	$7, 1f

	sys_call HMC_rdusp

	br	$31, 2f

	br	2f

1:	ldi	$0, PT_REGS_SIZE($sp)

2:	stl	$0, PT_REGS_SP($sp)

	ldi	$1, NO_SYSCALL

	stl	$1, PT_REGS_ORIG_R0($sp)

	sys_call HMC_rdktp

	.endm
@@ -202,6 +205,8 @@ entSys: 


	SAVE_ALL

	ldl	$0, PT_REGS_R0($sp)

	stl	$0, PT_REGS_ORIG_R0($sp)

	stl	$19, PT_REGS_ORIG_R19($sp)

	ldi	$4, NR_SYSCALLS($31)

	stl	$16, PT_REGS_R16($sp)

	ldi	$5, sys_call_table
@@ -220,6 +225,10 @@ entSys: 
1:	call	$26, ($27), ni_syscall

	ldgp	$gp, 0($26)

	blt	$0, $syscall_error	/* the call failed */



	ldi	$1, NO_SYSCALL

	stl	$1, PT_REGS_ORIG_R0($sp)

$syscall_success:

	stl	$0, PT_REGS_R0($sp)

	stl	$31, PT_REGS_R19($sp)	/* a3=0 => no error */
@@ -231,7 +240,6 @@ ret_from_sys_call: 
#endif

	br	$27, 1f

1:	ldgp	$29, 0($27)

	selne	$26, 0, $18, $18		/* $18 = 0 => non-restartable */

	ldl	$0, PT_REGS_PS($sp)

	and	$0, 8, $0

	beq	$0, ret_to_kernel
@@ -246,7 +254,9 @@ ret_to_user: 
	sys_call HMC_swpipl

	ldw	$17, TI_FLAGS($8)

	and	$17, _TIF_WORK_MASK, $2

	bne	$2, work_pending

	beq	$2, restore_all

	mov	$sp, $16

	call	$26, do_notify_resume

restore_all:

	RESTORE_ALL

	sys_call HMC_rti
@@ -256,7 +266,6 @@ ret_to_kernel: 
	sys_call HMC_swpipl

	br restore_all





	.align 3

$syscall_error:

	/*
@@ -266,59 +275,16 @@ $syscall_error: 
	 * frame to indicate that a negative return value wasn't an

	 * error number..

	 */

	ldl	$18, PT_REGS_R0($sp)	/* old syscall nr (zero if success) */

	beq	$18, $ret_success

	ldl	$1, PT_REGS_ORIG_R0($sp)	/* old syscall nr (-1 if success) */

	blt	$1, $syscall_success



	ldl	$19, PT_REGS_R19($sp)	/* .. and this a3 */

	subl	$31, $0, $0	/* with error in v0 */

	addl	$31, 1, $1	/* set a3 for errno return */

	stl	$0, PT_REGS_R0($sp)

	mov	$31, $26	/* tell "ret_from_sys_call" we can restart */

	stl	$1, PT_REGS_R19($sp)	/* a3 for return */

	br	ret_from_sys_call





$ret_success:

	stl	$0, PT_REGS_R0($sp)

	stl	$31, PT_REGS_R19($sp)	/* a3=0 => no error */

	br	ret_from_sys_call

	.end entSys



/*

 * Do all cleanup when returning from all interrupts and system calls.

 *

 * Arguments:

 *	$8: current.

 *	$17: TI_FLAGS.

 *	$18: The old syscall number, or zero if this is not a return

 *		from a syscall that errored and is possibly restartable.

 *	$19: The old a3 value

 */



	.align 4

	.ent work_pending

work_pending:

	and	$17, _TIF_NOTIFY_RESUME | _TIF_SIGPENDING | _TIF_UPROBE | _TIF_PATCH_PENDING, $2

	bne	$2, $work_notifysig



$work_resched:

	/*

	 * We can get here only if we returned from syscall without SIGPENDING

	 * or got through work_notifysig already.  Either case means no syscall

	 * restarts for us, so let $18 and $19 burn.

	 */

	call	$26, schedule

	mov	0, $18

	br	ret_to_user



$work_notifysig:

	mov	$sp, $16

	call	$26, do_work_pending

	br	restore_all

	.end work_pending







/*

 * PTRACE syscall handler

 */
@@ -327,12 +293,11 @@ $work_notifysig: 
	.ent strace

strace:

	/* set up signal stack, call syscall_trace */

	mov	$0, $9

	mov	$19, $10

	call	$26, syscall_trace_enter

	blt	$0, $syscall_trace_failed



	/* get the system call number and the arguments back.. */

	stl	$0, PT_REGS_ORIG_R0($sp)

	ldl	$16, PT_REGS_R16($sp)

	ldl	$17, PT_REGS_R17($sp)

	ldl	$18, PT_REGS_R18($sp)
@@ -355,38 +320,27 @@ ret_from_straced: 


	/* check return.. */

	blt	$0, $strace_error	/* the call failed */

	stl	$31, PT_REGS_R19($sp)	/* a3=0 => no error */



	ldi	$1, NO_SYSCALL

	stl	$1, PT_REGS_ORIG_R0($sp)

$strace_success:

	stl	$0, PT_REGS_R0($sp)	/* save return value */

	stl	$31, PT_REGS_R19($sp)	/* a3=0 => no error */

	call	$26, syscall_trace_leave

	br	$31, ret_from_sys_call

	br	ret_from_sys_call



	.align 3

$strace_error:

	ldl	$18, PT_REGS_R0($sp)	/* old syscall nr (zero if success) */



	beq	$18, $strace_success

	ldl	$19, PT_REGS_R19($sp)	/* .. and this a3 */

	ldl	$1, PT_REGS_ORIG_R0($sp)	/* old syscall nr (-1 if success) */

	blt	$1, $strace_success



	subl	$31, $0, $0	/* with error in v0 */

	addl	$31, 1, $1	/* set a3 for errno return */

	stl	$0, PT_REGS_R0($sp)

	stl	$1, PT_REGS_R19($sp)	/* a3 for return */



	mov	$18, $9		/* save old syscall number */

	mov	$19, $10	/* save old a3 */

	call	$26, syscall_trace_leave

	mov	$9, $18

	mov	$10, $19



	mov	$31, $26	/* tell "ret_from_sys_call" we can restart */

	br	ret_from_sys_call



$syscall_trace_failed:

	call	$26, syscall_trace_leave

	mov	$9, $18

	mov	$10, $19

	mov	$31, $26	/* tell "ret_from_sys_call" we can restart */

	br	ret_from_sys_call

	.end strace
@@ -454,8 +408,7 @@ ret_from_kernel_thread: 
	mov	$9, $27

	mov	$10, $16

	call	$26, ($9)

	mov	$31, $19		/* to disable syscall restarts */

	br	$31, ret_to_user

	br	ret_to_user

	.end ret_from_kernel_thread



	.align 4

arch/sw_64/kernel/ptrace.c

+6 −6
Original line number Diff line number Diff line
@@ -374,19 +374,19 @@ asmlinkage unsigned long syscall_trace_enter(void) 
	struct pt_regs *regs = current_pt_regs();



	if (test_thread_flag(TIF_SYSCALL_TRACE) &&

		tracehook_report_syscall_entry(current_pt_regs()))

		ret = -1UL;

		tracehook_report_syscall_entry(regs))

		return NO_SYSCALL;



#ifdef CONFIG_SECCOMP

	/* Do seccomp after ptrace, to catch any tracer changes. */

	if (secure_computing() == -1)

		return -1;

		return NO_SYSCALL;

#endif



	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))

		trace_sys_enter(regs, regs->regs[0]);

	audit_syscall_entry(regs->regs[0], regs->regs[16], regs->regs[17], regs->regs[18], regs->regs[19]);

	return ret ?: current_pt_regs()->regs[0];

	return ret ?: regs->regs[0];

}



asmlinkage void
@@ -394,9 +394,9 @@ syscall_trace_leave(void) 
{

	struct pt_regs *regs = current_pt_regs();



	audit_syscall_exit(current_pt_regs());

	audit_syscall_exit(regs);

	if (test_thread_flag(TIF_SYSCALL_TRACE))

		tracehook_report_syscall_exit(current_pt_regs(), 0);

		tracehook_report_syscall_exit(regs, 0);

	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))

		trace_sys_exit(regs, regs_return_value(regs));

}