From 3f72cdac73030761120cf32aeef44e7d03e2f1fa Mon Sep 17 00:00:00 2001 From: Rich Felker Date: Sun, 18 Sep 2011 10:14:37 -0400 Subject: overhaul clone syscall wrapping several things are changed. first, i have removed the old __uniclone function signature and replaced it with the "standard" linux __clone/clone signature. this was necessary to expose clone to applications anyway, and it makes it easier to port __clone to new archs, since it's now testable independently of pthread_create. secondly, i have removed all references to the ugly ldt descriptor structure (i386 only) from the c code and pthread structure. in places where it is needed, it is now created on the stack just when it's needed, in assembly code. thus, the i386 __clone function takes the desired thread pointer as its argument, rather than an ldt descriptor pointer, just like on all other sane archs. this should not affect applications since there is really no way an application can use clone with threads/tls in a way that doesn't horribly conflict with and clobber the underlying implementation's use. applications are expected to use clone only for creating actual processes, possibly with new namespace features and whatnot. --- src/thread/i386/clone.s | 73 +++++++++++++++++++++++++++++++++---------------- 1 file changed, 49 insertions(+), 24 deletions(-) (limited to 'src/thread/i386/clone.s') diff --git a/src/thread/i386/clone.s b/src/thread/i386/clone.s index 7af5f5db..bebf01a3 100644 --- a/src/thread/i386/clone.s +++ b/src/thread/i386/clone.s @@ -1,26 +1,51 @@ .text -.global __uniclone -.type __uniclone,@function -__uniclone: - movl 4(%esp),%ecx - subl $24,%ecx - movl 8(%esp),%eax - movl %eax,16(%ecx) - movl 12(%esp),%eax - movl %eax,24(%ecx) - pushl %ebx - pushl %esi - pushl %edi - pushl %ebp - movl %eax,8(%eax) - leal 20(%eax),%edx - leal 4(%eax),%esi - movl %edx,%edi - movl $0x7d0f00,%ebx - movl $120,%eax - int $128 - popl %ebp - popl %edi - popl %esi - popl %ebx +.global __clone +.weak clone +.type __clone,@function +.type clone,@function +__clone: +clone: + push %ebp + mov %esp,%ebp + push %ebx + push %esi + push %edi + + xor %eax,%eax + push $0x51 + mov %gs,%ax + push $0xfffff + shr $3,%eax + push 28(%ebp) + push %eax + mov $120,%al + + mov 12(%ebp),%ecx + mov 16(%ebp),%ebx + and $-16,%ecx + sub $16,%ecx + mov 20(%ebp),%edi + mov %edi,(%ecx) + mov 24(%ebp),%edx + mov %esp,%esi + mov 32(%ebp),%edi + mov 8(%ebp),%ebp + int $128 + test %eax,%eax + jnz 1f + + mov %ebp,%eax + xor %ebp,%ebp + call *%eax + mov %eax,%ebx + xor %eax,%eax + inc %eax + int $128 + hlt + +1: add $16,%esp + pop %edi + pop %esi + pop %ebx + pop %ebp ret -- cgit v1.2.1