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 <> |
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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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