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| author |   Dmitry Safonov <dima@arista.com> | 2019-11-12 01:27:10 +0000 |
|---|---|---|
| committer |   Thomas Gleixner <tglx@linutronix.de> | 2020-01-14 12:20:57 +0100 |
| commit | 64b302ab66c5965702693e79690823ca120288b9 (patch) | |
| tree | c25dbd01ca0bf17e1e9ca9a0e0c53b80849f02c3 /arch/x86/entry/vdso | |
| parent | lib/vdso: Prepare for time namespace support (diff) | |
| download | wireguard-linux-64b302ab66c5965702693e79690823ca120288b9.tar.xz wireguard-linux-64b302ab66c5965702693e79690823ca120288b9.zip | |
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/entry/vdso')
| -rw-r--r-- | arch/x86/entry/vdso/vdso-layout.lds.S | 2 | ||||
| -rw-r--r-- | arch/x86/entry/vdso/vma.c | 11 |
2 files changed, 11 insertions, 2 deletions
diff --git a/arch/x86/entry/vdso/vdso-layout.lds.S b/arch/x86/entry/vdso/vdso-layout.lds.S index 93c6dc7812d0..2330daad67c3 100644 --- a/arch/x86/entry/vdso/vdso-layout.lds.S +++ b/arch/x86/entry/vdso/vdso-layout.lds.S @@ -21,9 +21,7 @@ SECTIONS /* Place all vvars at the offsets in asm/vvar.h. */ #define EMIT_VVAR(name, offset) vvar_ ## name = vvar_page + offset; -#define __VVAR_KERNEL_LDS #include <asm/vvar.h> -#undef __VVAR_KERNEL_LDS #undef EMIT_VVAR pvclock_page = vvar_start + PAGE_SIZE; diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c index 76cbe54e0c39..04e3498c6c41 100644 --- a/arch/x86/entry/vdso/vma.c +++ b/arch/x86/entry/vdso/vma.c @@ -24,6 +24,17 @@ #include <asm/cpufeature.h> #include <clocksource/hyperv_timer.h> +#undef _ASM_X86_VVAR_H +#define EMIT_VVAR(name, offset) \ + const size_t name ## _offset = offset; +#include <asm/vvar.h> + +struct vdso_data *arch_get_vdso_data(void *vvar_page) +{ + return (struct vdso_data *)(vvar_page + _vdso_data_offset); +} +#undef EMIT_VVAR + #if defined(CONFIG_X86_64) unsigned int __read_mostly vdso64_enabled = 1; #endif |