resolve.s

来自「ucLinux is a very good embeded sytem. Mo」· S 代码 · 共 50 行

/*
 * This function is _not_ called directly.  It is jumped to from PLT when
 * attempting to use a symbol that has not yet been resolved.  The first time a
 * jump symbol (such as a function call inside a shared library) is used
 * (before it gets resolved) it will jump here.  When we get called the stack
 * contains reloc_offset and tpnt is in MOF.
 *
 * We save all the registers, setup R10 and R11 with the right arguments then
 * call _dl_linux_resolver(tpnt, reloc_offset). _dl_linux_resolver() figures
 * out where the jump symbol is _really_ supposed to have jumped to and returns
 * that to us.  Once we have that, we overwrite tpnt with this fixed up
 * address. We then clean up after ourselves, put all the registers back how we
 * found them, then we jump to where the fixed up address, which is where the
 * jump symbol that got us here really wanted to jump to in the first place.
 */

.globl _dl_linux_resolve
.type _dl_linux_resolve,@function

_dl_linux_resolve:
	push $r13
	push $r12
	push $r11
	push $r10
	push $r9
	push $r0
	push $srp
	move.d [$sp+7*4],$r11
	move $mof,$r10
#ifdef __PIC__
	move.d $pc,$r0
	sub.d .:GOTOFF,$r0
	move.d _dl_linux_resolver:PLTG,$r9
	add.d $r0,$r9
	jsr $r9
#else
	jsr _dl_linux_resolver
#endif
	move.d $r10,[$sp+7*4]
	pop $srp
	pop $r0
	pop $r9
	pop $r10
	pop $r11
	pop $r12
	pop $r13
	jump [$sp+]

	.size _dl_linux_resolve, . - _dl_linux_resolve