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linux/arch/um/sys-x86_64/stub_segv.c
Ulrich Drepper 51018b0a31 [PATCH] make UML compile (FC6/x86-64)
I need this patch to get a UML kernel to compile.  This is with the
kernel headers in FC6 which are automatically generated from the kernel
tree.  Some headers are missing but those files don't need them.  At
least it appears so since the resuling kernel works fine.

Tested on x86-64.

Signed-off-by: Ulrich Drepper <drepper@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-15 14:18:39 -07:00

51 lines
1.5 KiB
C

/*
* Copyright (C) 2004 Jeff Dike (jdike@addtoit.com)
* Licensed under the GPL
*/
#include <stddef.h>
#include <signal.h>
#include <asm/unistd.h>
#include "uml-config.h"
#include "sysdep/sigcontext.h"
#include "sysdep/faultinfo.h"
#include "sysdep/stub.h"
/* Copied from sys-x86_64/signal.c - Can't find an equivalent definition
* in the libc headers anywhere.
*/
struct rt_sigframe
{
char *pretcode;
struct ucontext uc;
struct siginfo info;
};
/* Copied here from <linux/kernel.h> - we're userspace. */
#define container_of(ptr, type, member) ({ \
const typeof( ((type *)0)->member ) *__mptr = (ptr); \
(type *)( (char *)__mptr - offsetof(type,member) );})
void __attribute__ ((__section__ (".__syscall_stub")))
stub_segv_handler(int sig)
{
struct ucontext *uc;
int pid;
__asm__ __volatile__("movq %%rdx, %0" : "=g" (uc) :);
GET_FAULTINFO_FROM_SC(*((struct faultinfo *) UML_CONFIG_STUB_DATA),
&uc->uc_mcontext);
pid = stub_syscall0(__NR_getpid);
stub_syscall2(__NR_kill, pid, SIGUSR1);
/* sys_sigreturn expects that the stack pointer will be 8 bytes into
* the signal frame. So, we use the ucontext pointer, which we know
* already, to get the signal frame pointer, and add 8 to that.
*/
__asm__ __volatile__("movq %0, %%rsp; movq %1, %%rax ; syscall": :
"g" ((unsigned long)
container_of(uc, struct rt_sigframe, uc) + 8),
"g" (__NR_rt_sigreturn));
}