Messages in this thread |  | | | Date | Sat, 26 Apr 2008 18:01:12 +0800 (CST) | | Subject | Re: [PATCH 2/19] UML - Tidy stub management code | | From | WANG Cong <> | |
From: Jeff Dike <jdike@addtoit.com>
Date: Fri, 25 Apr 2008 13:56:06 -0400
> Restructure the stub management code to make it simpler.
> > syscall_stub_done is extracted from do_syscall_stub.
> > The counters are gone since I never looked at them.
> > The common code in run_syscall_stub and syscall_stub_data is extracted
> into flush_syscalls.> > Signed-off-by: Jeff Dike <jdike@linux.intel.com>
> ---
> arch/um/os-Linux/skas/mem.c | 162 +++++++++++++++++++++++---------------------
> 1 file changed, 85 insertions(+), 77 deletions(-)
>
> Index: linux-2.6-git/arch/um/os-Linux/skas/mem.c
> ===================================================================
> --- linux-2.6-git.orig/arch/um/os-Linux/skas/mem.c 2008-04-25 11:36:59.000000000 -0400
> +++ linux-2.6-git/arch/um/os-Linux/skas/mem.c 2008-04-25 11:39:07.000000000 -0400
> @@ -40,35 +40,69 @@ static unsigned long syscall_regs[MAX_RE
>
> static int __init init_syscall_regs(void)
> {
> + unsigned long *stub_entry;
> +
> get_safe_registers(syscall_regs);
> + stub_entry = &batch_syscall_stub;
> +
> syscall_regs[REGS_IP_INDEX] = STUB_CODE +
> - ((unsigned long) &batch_syscall_stub -
> + ((unsigned long) stub_entry -
> (unsigned long) &__syscall_stub_start);
> return 0;
> }
>
> __initcall(init_syscall_regs);
>
> -extern int proc_mm;
> +static int syscall_stub_done(unsigned long stack)
> +{
> + unsigned long *syscall, *data, offset;
> + int ret, n;
> +
> + /*
> + * When the stub stops, we find the following values on the
> + * beginning of the stack:
> + * (long) return_value
> + * (long) offset to failed sycall data (0 if no error)
> + */
> + ret = *((unsigned long *) stack);
I am afraid the value will be truncated on 64bit machine, since
'ret' is 'int' while 'stack' points to an 'unsigned long'.
Is this expected?
Thanks.
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