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i386: simplify flow control in irettraps

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It is enough to have only one 'call calltrap' locally.

Reviewed by:	jhb
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D36302
This commit is contained in:
Konstantin Belousov 2022-08-22 08:56:45 +03:00
parent e8b2980e4a
commit 54e1546e09
1 changed files with 7 additions and 9 deletions
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16
sys/i386/i386/exception.s
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@ -231,26 +231,23 @@ irettraps:
jne 2f
/* -8 because exception did not switch ring */
movl $(2 * TF_SZ - TF_EIP - 8), %ecx
jmp 6f
jmp 5f
2: leal (doreti_popl_ds - 1b)(%ebx), %edx
cmpl %edx, TF_EIP(%esp)
jne 3f
movl $(2 * TF_SZ - TF_DS - 8), %ecx
jmp 6f
jmp 5f
3: leal (doreti_popl_es - 1b)(%ebx), %edx
cmpl %edx, TF_EIP(%esp)
jne 4f
movl $(2 * TF_SZ - TF_ES - 8), %ecx
jmp 6f
jmp 5f
4: leal (doreti_popl_fs - 1b)(%ebx), %edx
cmpl %edx, TF_EIP(%esp)
jne 5f
jne calltrap
movl $(2 * TF_SZ - TF_FS - 8), %ecx
jmp 6f
/* kernel mode, normal */
5: jmp calltrap
6: cmpl $PMAP_TRM_MIN_ADDRESS, %esp /* trampoline stack ? */
jb 5b /* if not, no need to change stacks */
5: cmpl $PMAP_TRM_MIN_ADDRESS, %esp /* trampoline stack ? */
jb calltrap /* if not, no need to change stacks */
movl (tramp_idleptd - 1b)(%ebx), %eax
movl %eax, %cr3
movl PCPU(KESP0), %edx
@ -259,6 +256,7 @@ irettraps:
movl %esp, %esi
rep; movsb
movl %edx, %esp
/* kernel mode, normal */
jmp calltrap
/*