@@ -1576,6 +1576,10 @@ config HAVE_SPARSE_SYSCALL_NR
entries at 4000, 5000 and 6000 locations. This option turns on syscall
related optimizations for a given architecture.
+config ARCH_HAS_VDSO_ARCH_DATA
+ depends on GENERIC_VDSO_DATA_STORE
+ bool
+
config ARCH_HAS_VDSO_TIME_DATA
bool
@@ -9,11 +9,13 @@
#include <uapi/linux/types.h>
#include <uapi/asm-generic/errno-base.h>
+#include <vdso/align.h>
#include <vdso/bits.h>
#include <vdso/clocksource.h>
#include <vdso/ktime.h>
#include <vdso/limits.h>
#include <vdso/math64.h>
+#include <vdso/page.h>
#include <vdso/processor.h>
#include <vdso/time.h>
#include <vdso/time32.h>
@@ -25,6 +27,15 @@
struct arch_vdso_time_data {};
#endif
+#if defined(CONFIG_ARCH_HAS_VDSO_ARCH_DATA)
+#include <asm/vdso/arch_data.h>
+#elif defined(CONFIG_GENERIC_VDSO_DATA_STORE)
+struct vdso_arch_data {
+ /* Needed for the generic code, never actually used at runtime */
+ char __unused;
+};
+#endif
+
#define VDSO_BASES (CLOCK_TAI + 1)
#define VDSO_HRES (BIT(CLOCK_REALTIME) | \
BIT(CLOCK_MONOTONIC) | \
@@ -146,9 +157,11 @@ extern struct vdso_rng_data _vdso_rng_data __attribute__((visibility("hidden")))
extern const struct vdso_time_data vdso_u_time_data[CS_BASES] __attribute__((visibility("hidden")));
extern const struct vdso_time_data vdso_u_timens_data[CS_BASES] __attribute__((visibility("hidden")));
extern const struct vdso_rng_data vdso_u_rng_data __attribute__((visibility("hidden")));
+extern const struct vdso_arch_data vdso_u_arch_data __attribute__((visibility("hidden")));
extern struct vdso_time_data *vdso_k_time_data;
extern struct vdso_rng_data *vdso_k_rng_data;
+extern struct vdso_arch_data *vdso_k_arch_data;
#endif
/**
@@ -161,10 +174,15 @@ union vdso_data_store {
#ifdef CONFIG_GENERIC_VDSO_DATA_STORE
+#define VDSO_ARCH_DATA_SIZE ALIGN(sizeof(struct vdso_arch_data), PAGE_SIZE)
+#define VDSO_ARCH_DATA_PAGES (VDSO_ARCH_DATA_SIZE >> PAGE_SHIFT)
+
enum vdso_pages {
VDSO_TIME_PAGE_OFFSET,
VDSO_TIMENS_PAGE_OFFSET,
VDSO_RNG_PAGE_OFFSET,
+ VDSO_ARCH_PAGES_START,
+ VDSO_ARCH_PAGES_END = VDSO_ARCH_PAGES_START + VDSO_ARCH_DATA_PAGES - 1,
VDSO_NR_PAGES
};
@@ -204,6 +222,13 @@ static __always_inline struct vdso_rng_data *__arch_get_vdso_k_rng_data(void)
#endif /* CONFIG_GENERIC_VDSO_DATA_STORE */
+#ifdef CONFIG_ARCH_HAS_VDSO_ARCH_DATA
+static __always_inline const struct vdso_arch_data *__arch_get_vdso_u_arch_data(void)
+{
+ return &vdso_u_arch_data;
+}
+#endif /* CONFIG_ARCH_HAS_VDSO_ARCH_DATA */
+
/*
* The generic vDSO implementation requires that gettimeofday.h
* provides:
@@ -234,11 +259,18 @@ static __always_inline struct vdso_rng_data *__arch_get_vdso_k_rng_data(void)
#define __vdso_u_rng_data
#endif
+#ifdef CONFIG_ARCH_HAS_VDSO_ARCH_DATA
+#define __vdso_u_arch_data PROVIDE(vdso_u_arch_data = vdso_u_data + 3 * PAGE_SIZE);
+#else
+#define __vdso_u_arch_data
+#endif
+
#define VDSO_VVAR_SYMS \
PROVIDE(vdso_u_data = . - __VDSO_PAGES * PAGE_SIZE); \
PROVIDE(vdso_u_time_data = vdso_u_data); \
__vdso_u_timens_data \
__vdso_u_rng_data \
+ __vdso_u_arch_data \
#endif /* !__ASSEMBLY__ */
@@ -24,6 +24,14 @@ struct vdso_rng_data *vdso_k_rng_data = &vdso_rng_data_store.data;
static_assert(sizeof(vdso_rng_data_store) == PAGE_SIZE);
#endif /* CONFIG_VDSO_GETRANDOM */
+#ifdef CONFIG_ARCH_HAS_VDSO_ARCH_DATA
+static union {
+ struct vdso_arch_data data;
+ u8 page[VDSO_ARCH_DATA_SIZE];
+} vdso_arch_data_store __page_aligned_data;
+struct vdso_arch_data *vdso_k_arch_data = &vdso_arch_data_store.data;
+#endif
+
static vm_fault_t vvar_fault(const struct vm_special_mapping *sm,
struct vm_area_struct *vma, struct vm_fault *vmf)
{
@@ -63,6 +71,12 @@ static vm_fault_t vvar_fault(const struct vm_special_mapping *sm,
return VM_FAULT_SIGBUS;
pfn = __phys_to_pfn(__pa_symbol(vdso_k_rng_data));
break;
+ case VDSO_ARCH_PAGES_START ... VDSO_ARCH_PAGES_END:
+ if (!IS_ENABLED(CONFIG_ARCH_HAS_VDSO_ARCH_DATA))
+ return VM_FAULT_SIGBUS;
+ pfn = __phys_to_pfn(__pa_symbol(vdso_k_arch_data)) +
+ vmf->pgoff - VDSO_ARCH_PAGES_START;
+ break;
default:
return VM_FAULT_SIGBUS;
}
Some architectures need to architecture-specific data to the vDSO. Enable the generic vDSO storage mechanism to both store and map this data. Some architectures require more than a single page, like LoongArch, so prepare for that usecase, too. Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> --- arch/Kconfig | 4 ++++ include/vdso/datapage.h | 32 ++++++++++++++++++++++++++++++++ lib/vdso_kernel/datastore.c | 14 ++++++++++++++ 3 files changed, 50 insertions(+)