openkylin
/
linux
mirror of https://gitee.com/openkylin/linux.git
9
0
Fork 0
Code Issues Projects Releases Wiki Activity

MIPS: Add is_jr_ra_ins() to end the loop early 

For those leaf functions, they are likely to have no stack operations.
Add is_jr_ra_ins() to determine whether jr ra has been touched before
the frame_size is found. Without this patch, the get frame_size operation
may be out of range and get the frame_size from the next nested function.

There is no POOL32A format in uapi/asm/inst.h, so some bits here use the
format of r_format instead.
e.g.
---------------------------------------------------------------------
|    format      |  31:26  | 25:21 | 20:16 |    15:6    |    5:0    |
-----------------+---------+-------+-------+------------+------------
| pool32a_format | pool32a |  rt   |  rs   |   jalrc    | pool32axf |
-----------------+---------+-------+-------+------------+------------
|    r_format    |  opcode |  rs   |  rt   | rd:5, re:5 |    func   |
---------------------------------------------------------------------

Signed-off-by: Jinyang He <hejinyang@loongson.cn>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
This commit is contained in:
Jinyang He 2021-01-21 13:31:38 +08:00 committed by Thomas Bogendoerfer
parent 2d62f64bcc
commit 50886234e8
1 changed files with 33 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

34
arch/mips/kernel/process.c
View File

@ -188,6 +188,36 @@ struct mips_frame_info {
#define J_TARGET(pc,target) \
(((unsigned long)(pc) & 0xf0000000) | ((target) << 2))
static inline int is_jr_ra_ins(union mips_instruction *ip)
{
#ifdef CONFIG_CPU_MICROMIPS
/*
* jr16 ra
* jr ra
*/
if (mm_insn_16bit(ip->word >> 16)) {
if (ip->mm16_r5_format.opcode == mm_pool16c_op &&
ip->mm16_r5_format.rt == mm_jr16_op &&
ip->mm16_r5_format.imm == 31)
return 1;
return 0;
}
if (ip->r_format.opcode == mm_pool32a_op &&
ip->r_format.func == mm_pool32axf_op &&
((ip->u_format.uimmediate >> 6) & GENMASK(9, 0)) == mm_jalr_op &&
ip->r_format.rt == 31)
return 1;
return 0;
#else
if (ip->r_format.opcode == spec_op &&
ip->r_format.func == jr_op &&
ip->r_format.rs == 31)
return 1;
return 0;
#endif
}
static inline int is_ra_save_ins(union mips_instruction *ip, int *poff)
{
#ifdef CONFIG_CPU_MICROMIPS
@ -400,7 +430,9 @@ static int get_frame_info(struct mips_frame_info *info)
last_insn_size = 4;
}
if (!info->frame_size) {
if (is_jr_ra_ins(ip)) {
break;
} else if (!info->frame_size) {
is_sp_move_ins(&insn, &info->frame_size);
continue;
} else if (!saw_jump && is_jump_ins(ip)) {