diff options
| author | Dmitry Safonov <dima@arista.com> | 2019-11-12 04:27:10 +0300 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2020-01-14 14:20:57 +0300 |
| commit | 64b302ab66c5965702693e79690823ca120288b9 (patch) | |
| tree | c25dbd01ca0bf17e1e9ca9a0e0c53b80849f02c3 /arch/x86/include/asm/vvar.h | |
| parent | 660fd04f9317172ae90f414c68b18a26ae88a829 (diff) | |
| download | linux-64b302ab66c5965702693e79690823ca120288b9.tar.xz | |
x86/vdso: Provide vdso_data offset on vvar_page
VDSO support for time namespaces needs to set up a page with the same
layout as VVAR. That timens page will be placed on position of VVAR page
inside namespace. That page has vdso_data->seq set to 1 to enforce
the slow path and vdso_data->clock_mode set to VCLOCK_TIMENS to enforce
the time namespace handling path.
To prepare the time namespace page the kernel needs to know the vdso_data
offset. Provide arch_get_vdso_data() helper for locating vdso_data on VVAR
page.
Co-developed-by: Andrei Vagin <avagin@openvz.org>
Signed-off-by: Andrei Vagin <avagin@openvz.org>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20191112012724.250792-22-dima@arista.com
Diffstat (limited to 'arch/x86/include/asm/vvar.h')
| -rw-r--r-- | arch/x86/include/asm/vvar.h | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/arch/x86/include/asm/vvar.h b/arch/x86/include/asm/vvar.h index 32f5d9a0b90e..ff2de3025388 100644 --- a/arch/x86/include/asm/vvar.h +++ b/arch/x86/include/asm/vvar.h @@ -19,10 +19,10 @@ #ifndef _ASM_X86_VVAR_H #define _ASM_X86_VVAR_H -#if defined(__VVAR_KERNEL_LDS) - -/* The kernel linker script defines its own magic to put vvars in the - * right place. +#ifdef EMIT_VVAR +/* + * EMIT_VVAR() is used by the kernel linker script to put vvars in the + * right place. Also, it's used by kernel code to import offsets values. */ #define DECLARE_VVAR(offset, type, name) \ EMIT_VVAR(name, offset) |