[PATCH 14/28] x86: vdso: Allocate vvar page from C code
Thomas Weißschuh
thomas.weissschuh at linutronix.de
Thu Oct 10 00:01:16 PDT 2024
Allocate the vvar page through the standard union vdso_data_store
and remove the custom linker script logic.
Signed-off-by: Thomas Weißschuh <thomas.weissschuh at linutronix.de>
---
arch/x86/entry/vdso/vma.c | 16 +++++-----------
arch/x86/include/asm/vdso/vsyscall.h | 6 ++++--
arch/x86/kernel/vmlinux.lds.S | 23 -----------------------
arch/x86/tools/relocs.c | 1 -
4 files changed, 9 insertions(+), 37 deletions(-)
diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c
index 8437906fd4b353ad0fe208d811817a1b6f8f8dcb..5731dc35d1d2c0b81c37adf133fc6fa35c41cba1 100644
--- a/arch/x86/entry/vdso/vma.c
+++ b/arch/x86/entry/vdso/vma.c
@@ -20,25 +20,19 @@
#include <asm/vgtod.h>
#include <asm/proto.h>
#include <asm/vdso.h>
-#include <asm/vvar.h>
#include <asm/tlb.h>
#include <asm/page.h>
#include <asm/desc.h>
#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);
+ return (struct vdso_data *)vvar_page;
}
-#undef EMIT_VVAR
-DEFINE_VVAR(struct vdso_data, _vdso_data);
+static union vdso_data_store vdso_data_store __page_aligned_data;
+struct vdso_data *vdso_data = vdso_data_store.data;
unsigned int vclocks_used __read_mostly;
@@ -153,7 +147,7 @@ static vm_fault_t vvar_fault(const struct vm_special_mapping *sm,
if (sym_offset == image->sym_vvar_page) {
struct page *timens_page = find_timens_vvar_page(vma);
- pfn = __pa_symbol(&__vvar_page) >> PAGE_SHIFT;
+ pfn = __pa_symbol(vdso_data) >> PAGE_SHIFT;
/*
* If a task belongs to a time namespace then a namespace
@@ -200,7 +194,7 @@ static vm_fault_t vvar_fault(const struct vm_special_mapping *sm,
if (!timens_page)
return VM_FAULT_SIGBUS;
- pfn = __pa_symbol(&__vvar_page) >> PAGE_SHIFT;
+ pfn = __pa_symbol(vdso_data) >> PAGE_SHIFT;
return vmf_insert_pfn(vma, vmf->address, pfn);
}
diff --git a/arch/x86/include/asm/vdso/vsyscall.h b/arch/x86/include/asm/vdso/vsyscall.h
index 2cbb32a8a45e2f5c7bc02172af0fa09173f33924..5d6760746d15b0e12c7bf0eb727241e7576ca9c7 100644
--- a/arch/x86/include/asm/vdso/vsyscall.h
+++ b/arch/x86/include/asm/vdso/vsyscall.h
@@ -9,20 +9,22 @@
#include <asm/vgtod.h>
#include <asm/vvar.h>
+extern struct vdso_data *vdso_data;
+
/*
* Update the vDSO data page to keep in sync with kernel timekeeping.
*/
static __always_inline
struct vdso_data *__x86_get_k_vdso_data(void)
{
- return _vdso_data;
+ return vdso_data;
}
#define __arch_get_k_vdso_data __x86_get_k_vdso_data
static __always_inline
struct vdso_rng_data *__x86_get_k_vdso_rng_data(void)
{
- return (void *)&__vvar_page + __VDSO_RND_DATA_OFFSET;
+ return (void *)vdso_data + __VDSO_RND_DATA_OFFSET;
}
#define __arch_get_k_vdso_rng_data __x86_get_k_vdso_rng_data
diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
index 6726be89b7a663a1554f8f4b297bba65b4ebdf61..e7e19842736a774191142b6ce43bf5567540cb80 100644
--- a/arch/x86/kernel/vmlinux.lds.S
+++ b/arch/x86/kernel/vmlinux.lds.S
@@ -193,29 +193,6 @@ SECTIONS
ORC_UNWIND_TABLE
- . = ALIGN(PAGE_SIZE);
- __vvar_page = .;
-
- .vvar : AT(ADDR(.vvar) - LOAD_OFFSET) {
- /* work around gold bug 13023 */
- __vvar_beginning_hack = .;
-
- /* Place all vvars at the offsets in asm/vvar.h. */
-#define EMIT_VVAR(name, offset) \
- . = __vvar_beginning_hack + offset; \
- *(.vvar_ ## name)
-#include <asm/vvar.h>
-#undef EMIT_VVAR
-
- /*
- * Pad the rest of the page with zeros. Otherwise the loader
- * can leave garbage here.
- */
- . = __vvar_beginning_hack + PAGE_SIZE;
- } :data
-
- . = ALIGN(__vvar_page + PAGE_SIZE, PAGE_SIZE);
-
/* Init code and data - will be freed after init */
. = ALIGN(PAGE_SIZE);
.init.begin : AT(ADDR(.init.begin) - LOAD_OFFSET) {
diff --git a/arch/x86/tools/relocs.c b/arch/x86/tools/relocs.c
index c101bed6194000004bd84e1679259cce9977d290..6afe2e5e9102873634c6ad9a3a0b9c66bba5da50 100644
--- a/arch/x86/tools/relocs.c
+++ b/arch/x86/tools/relocs.c
@@ -89,7 +89,6 @@ static const char * const sym_regex_kernel[S_NSYMTYPES] = {
"init_per_cpu__.*|"
"__end_rodata_hpage_align|"
#endif
- "__vvar_page|"
"_end)$"
};
--
2.47.0
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