Currently vdso data is one page. Next patches will add per-cpu data to
vdso, which requires several pages if CPU number is big. This makes VDSO
data support multiple pages.
Cc: Andy Lutomirski <l...@amacapital.net>
Cc: H. Peter Anvin <h...@zytor.com>
Cc: Ingo Molnar <mi...@redhat.com>
Signed-off-by: Shaohua Li <s...@fb.com>
---
arch/x86/include/asm/vdso.h | 2 +-
arch/x86/include/asm/vvar.h | 8 ++++++--
arch/x86/kernel/asm-offsets.c | 5 +++++
arch/x86/kernel/vmlinux.lds.S | 6 +++---
arch/x86/tools/relocs.c | 2 +-
arch/x86/vdso/vdso-layout.lds.S | 9 +++++----
arch/x86/vdso/vdso2c.c | 6 +++---
arch/x86/vdso/vma.c | 9 +++++----
8 files changed, 29 insertions(+), 18 deletions(-)
diff --git a/arch/x86/include/asm/vdso.h b/arch/x86/include/asm/vdso.h
index 8021bd2..35ca749 100644
--- a/arch/x86/include/asm/vdso.h
+++ b/arch/x86/include/asm/vdso.h
@@ -20,7 +20,7 @@ struct vdso_image {
long sym_vvar_start; /* Negative offset to the vvar area */
- long sym_vvar_page;
+ long sym_vvar_pages;
long sym_hpet_page;
long sym_VDSO32_NOTE_MASK;
long sym___kernel_sigreturn;
diff --git a/arch/x86/include/asm/vvar.h b/arch/x86/include/asm/vvar.h
index 3f32dfc..62bc6f8 100644
--- a/arch/x86/include/asm/vvar.h
+++ b/arch/x86/include/asm/vvar.h
@@ -29,7 +29,7 @@
#else
-extern char __vvar_page;
+extern char __vvar_pages;
#define DECLARE_VVAR(offset, type, name) \
extern type vvar_ ## name __attribute__((visibility("hidden")));
@@ -45,7 +45,11 @@ extern char __vvar_page;
/* DECLARE_VVAR(offset, type, name) */
DECLARE_VVAR(128, struct vsyscall_gtod_data, vsyscall_gtod_data)
-
+/*
+ * you must update VVAR_TOTAL_SIZE to reflect all of the variables we're
+ * stuffing into the vvar area. Don't change any of the above without
+ * also changing this math of VVAR_TOTAL_SIZE
+ */
#undef DECLARE_VVAR
#endif
diff --git a/arch/x86/kernel/asm-offsets.c b/arch/x86/kernel/asm-offsets.c
index 9f6b934..0ab31a9 100644
--- a/arch/x86/kernel/asm-offsets.c
+++ b/arch/x86/kernel/asm-offsets.c
@@ -16,6 +16,7 @@
#include <asm/sigframe.h>
#include <asm/bootparam.h>
#include <asm/suspend.h>
+#include <asm/vgtod.h>
#ifdef CONFIG_XEN
#include <xen/interface/xen.h>
@@ -71,4 +72,8 @@ void common(void) {
BLANK();
DEFINE(PTREGS_SIZE, sizeof(struct pt_regs));
+
+ BLANK();
+ DEFINE(VVAR_TOTAL_SIZE,
+ ALIGN(128 + sizeof(struct vsyscall_gtod_data), PAGE_SIZE));
}
diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
index 00bf300..2efeee9 100644
--- a/arch/x86/kernel/vmlinux.lds.S
+++ b/arch/x86/kernel/vmlinux.lds.S
@@ -149,7 +149,7 @@ SECTIONS
. = ALIGN(PAGE_SIZE);
- __vvar_page = .;
+ __vvar_pages = .;
.vvar : AT(ADDR(.vvar) - LOAD_OFFSET) {
/* work around gold bug 13023 */
@@ -168,10 +168,10 @@ SECTIONS
* Pad the rest of the page with zeros. Otherwise the loader
* can leave garbage here.
*/
- . = __vvar_beginning_hack + PAGE_SIZE;
+ . = __vvar_beginning_hack + VVAR_TOTAL_SIZE;
} :data
- . = ALIGN(__vvar_page + PAGE_SIZE, PAGE_SIZE);
+ . = ALIGN(__vvar_pages + VVAR_TOTAL_SIZE, PAGE_SIZE);
/* Init code and data - will be freed after init */
. = ALIGN(PAGE_SIZE);
diff --git a/arch/x86/tools/relocs.c b/arch/x86/tools/relocs.c
index 0c2fae8..ea01c48 100644
--- a/arch/x86/tools/relocs.c
+++ b/arch/x86/tools/relocs.c
@@ -73,7 +73,7 @@ static const char * const sym_regex_kernel[S_NSYMTYPES] = {
"init_per_cpu__.*|"
"__end_rodata_hpage_align|"
#endif
- "__vvar_page|"
+ "__vvar_pages|"
"_end)$"
};
diff --git a/arch/x86/vdso/vdso-layout.lds.S b/arch/x86/vdso/vdso-layout.lds.S
index de2c921..413c739 100644
--- a/arch/x86/vdso/vdso-layout.lds.S
+++ b/arch/x86/vdso/vdso-layout.lds.S
@@ -1,4 +1,5 @@
#include <asm/vdso.h>
+#include <asm/asm-offsets.h>
/*
* Linker script for vDSO. This is an ELF shared object prelinked to
@@ -25,17 +26,17 @@ SECTIONS
* segment.
*/
- vvar_start = . - 2 * PAGE_SIZE;
- vvar_page = vvar_start;
+ vvar_start = . - (VVAR_TOTAL_SIZE + PAGE_SIZE);
+ vvar_pages = vvar_start;
/* Place all vvars at the offsets in asm/vvar.h. */
-#define EMIT_VVAR(name, offset) vvar_ ## name = vvar_page + offset;
+#define EMIT_VVAR(name, offset) vvar_ ## name = vvar_pages + offset;
#define __VVAR_KERNEL_LDS
#include <asm/vvar.h>
#undef __VVAR_KERNEL_LDS
#undef EMIT_VVAR
- hpet_page = vvar_start + PAGE_SIZE;
+ hpet_page = vvar_start + VVAR_TOTAL_SIZE;
. = SIZEOF_HEADERS;
diff --git a/arch/x86/vdso/vdso2c.c b/arch/x86/vdso/vdso2c.c
index 8627db2..95eda74 100644
--- a/arch/x86/vdso/vdso2c.c
+++ b/arch/x86/vdso/vdso2c.c
@@ -71,14 +71,14 @@ const char *outfilename;
/* Symbols that we need in vdso2c. */
enum {
sym_vvar_start,
- sym_vvar_page,
+ sym_vvar_pages,
sym_hpet_page,
sym_VDSO_FAKE_SECTION_TABLE_START,
sym_VDSO_FAKE_SECTION_TABLE_END,
};
const int special_pages[] = {
- sym_vvar_page,
+ sym_vvar_pages,
sym_hpet_page,
};
@@ -89,7 +89,7 @@ struct vdso_sym {
struct vdso_sym required_syms[] = {
[sym_vvar_start] = {"vvar_start", true},
- [sym_vvar_page] = {"vvar_page", true},
+ [sym_vvar_pages] = {"vvar_pages", true},
[sym_hpet_page] = {"hpet_page", true},
[sym_VDSO_FAKE_SECTION_TABLE_START] = {
"VDSO_FAKE_SECTION_TABLE_START", false
diff --git a/arch/x86/vdso/vma.c b/arch/x86/vdso/vma.c
index 009495b..6496c65 100644
--- a/arch/x86/vdso/vma.c
+++ b/arch/x86/vdso/vma.c
@@ -19,6 +19,7 @@
#include <asm/page.h>
#include <asm/hpet.h>
#include <asm/desc.h>
+#include <asm/asm-offsets.h>
#if defined(CONFIG_X86_64)
unsigned int __read_mostly vdso64_enabled = 1;
@@ -133,11 +134,11 @@ static int map_vdso(const struct vdso_image *image, bool
calculate_addr)
goto up_fail;
}
- if (image->sym_vvar_page)
+ if (image->sym_vvar_pages)
ret = remap_pfn_range(vma,
- text_start + image->sym_vvar_page,
- __pa_symbol(&__vvar_page) >> PAGE_SHIFT,
- PAGE_SIZE,
+ text_start + image->sym_vvar_pages,
+ __pa_symbol(&__vvar_pages) >> PAGE_SHIFT,
+ VVAR_TOTAL_SIZE,
PAGE_READONLY);
if (ret)
--
1.8.1
--
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