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kolibrios/programs/develop/libraries/newlib/crt/chkstk.S
Sergey Semyonov (Serge) 27ddc31f12 newlib: crtdll
git-svn-id: svn://kolibrios.org@3805 a494cfbc-eb01-0410-851d-a64ba20cac60
2013-07-10 19:26:24 +00:00

62 lines
1.7 KiB
ArmAsm

.global ___chkstk
.global ___chkstk_ms
.global __alloca
.section .text
#.def ___chkstk; .scl 2; .type 32; .endef
#.def ___chkstk_ms; .scl 2; .type 32; .endef
#.def __alloca; .scl 2; .type 32; .endef
___chkstk:
__alloca:
pushl %ecx /* save temp */
leal 8(%esp), %ecx /* point past return addr */
subl %eax, %ecx
cmpl %fs:8, %ecx # check low stack limit
jb 1f
movl %esp, %eax /* save old stack pointer */
movl %ecx, %esp /* decrement stack */
movl (%eax), %ecx /* recover saved temp */
movl 4(%eax), %eax /* recover return address */
/* Push the return value back. Doing this instead of just
jumping to %eax preserves the cached call-return stack
used by most modern processors. */
pushl %eax
ret
1:
int3 #trap to debugger
.ascii "Stack overflow"
___chkstk_ms:
pushl %ecx /* save temp */
pushl %eax
cmpl $0x1000, %eax /* > 4k ?*/
leal 12(%esp), %ecx /* point past return addr */
jb 2f
1:
subl $0x1000, %ecx /* yes, move pointer down 4k*/
cmpl %fs:8, %ecx /* check low stack limit */
jb 3f
orl $0x0, (%ecx) /* probe there */
subl $0x1000, %eax /* decrement count */
cmpl $0x1000, %eax
ja 1b /* and do it again */
2:
subl %eax, %ecx
orl $0x0, (%ecx) /* less than 4k, just peek here */
popl %eax
popl %ecx
ret
3:
int3 #trap to debugger
.ascii "Stack overflow"