linux/arch/x86/vdso
Jiri Slaby d7a0380dc3 x86-64, mm: Initialize VDSO earlier on 64 bits
When initrd is in use and a driver does request_module() in its
module_init (i.e. __initcall or device_initcall), a modprobe process
is created with VDSO mapping. But VDSO is inited even in __initcall,
i.e. on the same level (at the same time), so it may not be inited
yet (link order matters).

Move the VDSO initialization code earlier by switching to something
before rootfs_initcall where initrd is loaded as rootfs. Specifically
to subsys_initcall. Do it for standard 64-bit path (init_vdso_vars)
and for compat (sysenter_setup), just in case people have 32-bit
initrd and ia32 emulation built-in.

i386 (pure 32-bit) is not affected, since sysenter_setup() is called
from check_bugs()->identify_boot_cpu() in start_kernel() before
rest_init()->kernel_thread(kernel_init) where even kernel_init() calls
do_basic_setup()->do_initcalls().

What this patch fixes are early modprobe crashes such as:
Unpacking initramfs...
Freeing initrd memory: 9324k freed
modprobe[368]: segfault at 7fff4429c020 ip 00007fef397e160c \
    sp 00007fff442795c0 error 4 in ld-2.11.2.so[7fef397df000+1f000]

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
LKML-Reference: <1276720242-13365-1-git-send-email-jslaby@suse.cz>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2010-06-18 13:48:14 -07:00
..
vdso32 x86: gitignore arch/x86/vdso files 2008-01-30 13:32:32 +01:00
.gitignore x86: add vdso32-int80-syms.lds to .gitignore 2008-01-30 13:33:24 +01:00
Makefile kbuild: rename ld-option to cc-ldoption 2009-09-20 12:27:42 +02:00
vclock_gettime.c time: Introduce CLOCK_REALTIME_COARSE 2009-08-21 21:43:46 +02:00
vdso-layout.lds.S x86 vDSO: new layout 2008-01-30 13:30:41 +01:00
vdso-note.S
vdso.lds.S x86 vDSO: new layout 2008-01-30 13:30:41 +01:00
vdso.S x86_64 vDSO: use initdata 2008-04-28 13:49:35 -07:00
vdso32-setup.c x86-64, mm: Initialize VDSO earlier on 64 bits 2010-06-18 13:48:14 -07:00
vdso32.S x86_64: further cleanup of 32-bit compat syscall mechanisms 2008-07-16 11:08:27 +02:00
vextern.h
vgetcpu.c x86: add notrace annotations to vsyscall. 2008-05-23 20:31:39 +02:00
vma.c x86-64, mm: Initialize VDSO earlier on 64 bits 2010-06-18 13:48:14 -07:00
vvar.c