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linux/arch/um/kernel/exec_kern.c
Paolo 'Blaisorblade' Giarrusso aa6758d486 [PATCH] uml: implement {get,set}_thread_area for i386
Implement sys_[gs]et_thread_area and the corresponding ptrace operations for
UML.  This is the main chunk, additional parts follow.  This implementation is
now well tested and has run reliably for some time, and we've understood all
the previously existing problems.

Their implementation saves the new GDT content and then forwards the call to
the host when appropriate, i.e.  immediately when the target process is
running or on context switch otherwise (i.e.  on fork and on ptrace() calls).

In SKAS mode, we must switch registers on each context switch (because SKAS
does not switches tls_array together with current->mm).

Also, added get_cpu() locking; this has been done for SKAS mode, since TT does
not need it (it does not use smp_processor_id()).

Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Acked-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-31 12:18:52 -08:00

78 lines
1.7 KiB
C

/*
* Copyright (C) 2000, 2001 Jeff Dike (jdike@karaya.com)
* Licensed under the GPL
*/
#include "linux/slab.h"
#include "linux/smp_lock.h"
#include "linux/ptrace.h"
#include "asm/ptrace.h"
#include "asm/pgtable.h"
#include "asm/tlbflush.h"
#include "asm/uaccess.h"
#include "user_util.h"
#include "kern_util.h"
#include "mem_user.h"
#include "kern.h"
#include "irq_user.h"
#include "tlb.h"
#include "os.h"
#include "choose-mode.h"
#include "mode_kern.h"
void flush_thread(void)
{
arch_flush_thread(&current->thread.arch);
CHOOSE_MODE(flush_thread_tt(), flush_thread_skas());
}
void start_thread(struct pt_regs *regs, unsigned long eip, unsigned long esp)
{
CHOOSE_MODE_PROC(start_thread_tt, start_thread_skas, regs, eip, esp);
}
static long execve1(char *file, char __user * __user *argv,
char __user *__user *env)
{
long error;
#ifdef CONFIG_TTY_LOG
log_exec(argv, current->tty);
#endif
error = do_execve(file, argv, env, &current->thread.regs);
if (error == 0){
task_lock(current);
current->ptrace &= ~PT_DTRACE;
task_unlock(current);
set_cmdline(current_cmd());
}
return(error);
}
long um_execve(char *file, char __user *__user *argv, char __user *__user *env)
{
long err;
err = execve1(file, argv, env);
if(!err)
do_longjmp(current->thread.exec_buf, 1);
return(err);
}
long sys_execve(char __user *file, char __user *__user *argv,
char __user *__user *env)
{
long error;
char *filename;
lock_kernel();
filename = getname(file);
error = PTR_ERR(filename);
if (IS_ERR(filename)) goto out;
error = execve1(filename, argv, env);
putname(filename);
out:
unlock_kernel();
return(error);
}