x86/vdso: Get pvclock data from the vvar VMA instead of the fixmap
Signed-off-by: Andy Lutomirski <luto@kernel.org> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/9d37826fdc7e2d2809efe31d5345f97186859284.1449702533.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
parent
6b078f5de7
commit
dac16fba6f
|
@ -36,6 +36,11 @@ static notrace cycle_t vread_hpet(void)
|
|||
}
|
||||
#endif
|
||||
|
||||
#ifdef CONFIG_PARAVIRT_CLOCK
|
||||
extern u8 pvclock_page
|
||||
__attribute__((visibility("hidden")));
|
||||
#endif
|
||||
|
||||
#ifndef BUILD_VDSO32
|
||||
|
||||
#include <linux/kernel.h>
|
||||
|
@ -62,23 +67,14 @@ notrace static long vdso_fallback_gtod(struct timeval *tv, struct timezone *tz)
|
|||
|
||||
#ifdef CONFIG_PARAVIRT_CLOCK
|
||||
|
||||
static notrace const struct pvclock_vsyscall_time_info *get_pvti(int cpu)
|
||||
static notrace const struct pvclock_vsyscall_time_info *get_pvti0(void)
|
||||
{
|
||||
const struct pvclock_vsyscall_time_info *pvti_base;
|
||||
int idx = cpu / (PAGE_SIZE/PVTI_SIZE);
|
||||
int offset = cpu % (PAGE_SIZE/PVTI_SIZE);
|
||||
|
||||
BUG_ON(PVCLOCK_FIXMAP_BEGIN + idx > PVCLOCK_FIXMAP_END);
|
||||
|
||||
pvti_base = (struct pvclock_vsyscall_time_info *)
|
||||
__fix_to_virt(PVCLOCK_FIXMAP_BEGIN+idx);
|
||||
|
||||
return &pvti_base[offset];
|
||||
return (const struct pvclock_vsyscall_time_info *)&pvclock_page;
|
||||
}
|
||||
|
||||
static notrace cycle_t vread_pvclock(int *mode)
|
||||
{
|
||||
const struct pvclock_vcpu_time_info *pvti = &get_pvti(0)->pvti;
|
||||
const struct pvclock_vcpu_time_info *pvti = &get_pvti0()->pvti;
|
||||
cycle_t ret;
|
||||
u64 tsc, pvti_tsc;
|
||||
u64 last, delta, pvti_system_time;
|
||||
|
|
|
@ -25,7 +25,7 @@ SECTIONS
|
|||
* segment.
|
||||
*/
|
||||
|
||||
vvar_start = . - 2 * PAGE_SIZE;
|
||||
vvar_start = . - 3 * PAGE_SIZE;
|
||||
vvar_page = vvar_start;
|
||||
|
||||
/* Place all vvars at the offsets in asm/vvar.h. */
|
||||
|
@ -36,6 +36,7 @@ SECTIONS
|
|||
#undef EMIT_VVAR
|
||||
|
||||
hpet_page = vvar_start + PAGE_SIZE;
|
||||
pvclock_page = vvar_start + 2 * PAGE_SIZE;
|
||||
|
||||
. = SIZEOF_HEADERS;
|
||||
|
||||
|
|
|
@ -73,6 +73,7 @@ enum {
|
|||
sym_vvar_start,
|
||||
sym_vvar_page,
|
||||
sym_hpet_page,
|
||||
sym_pvclock_page,
|
||||
sym_VDSO_FAKE_SECTION_TABLE_START,
|
||||
sym_VDSO_FAKE_SECTION_TABLE_END,
|
||||
};
|
||||
|
@ -80,6 +81,7 @@ enum {
|
|||
const int special_pages[] = {
|
||||
sym_vvar_page,
|
||||
sym_hpet_page,
|
||||
sym_pvclock_page,
|
||||
};
|
||||
|
||||
struct vdso_sym {
|
||||
|
@ -91,6 +93,7 @@ struct vdso_sym required_syms[] = {
|
|||
[sym_vvar_start] = {"vvar_start", true},
|
||||
[sym_vvar_page] = {"vvar_page", true},
|
||||
[sym_hpet_page] = {"hpet_page", true},
|
||||
[sym_pvclock_page] = {"pvclock_page", true},
|
||||
[sym_VDSO_FAKE_SECTION_TABLE_START] = {
|
||||
"VDSO_FAKE_SECTION_TABLE_START", false
|
||||
},
|
||||
|
|
|
@ -100,6 +100,7 @@ static int map_vdso(const struct vdso_image *image, bool calculate_addr)
|
|||
.name = "[vvar]",
|
||||
.pages = no_pages,
|
||||
};
|
||||
struct pvclock_vsyscall_time_info *pvti;
|
||||
|
||||
if (calculate_addr) {
|
||||
addr = vdso_addr(current->mm->start_stack,
|
||||
|
@ -169,6 +170,18 @@ static int map_vdso(const struct vdso_image *image, bool calculate_addr)
|
|||
}
|
||||
#endif
|
||||
|
||||
pvti = pvclock_pvti_cpu0_va();
|
||||
if (pvti && image->sym_pvclock_page) {
|
||||
ret = remap_pfn_range(vma,
|
||||
text_start + image->sym_pvclock_page,
|
||||
__pa(pvti) >> PAGE_SHIFT,
|
||||
PAGE_SIZE,
|
||||
PAGE_READONLY);
|
||||
|
||||
if (ret)
|
||||
goto up_fail;
|
||||
}
|
||||
|
||||
up_fail:
|
||||
if (ret)
|
||||
current->mm->context.vdso = NULL;
|
||||
|
|
|
@ -4,6 +4,15 @@
|
|||
#include <linux/clocksource.h>
|
||||
#include <asm/pvclock-abi.h>
|
||||
|
||||
#ifdef CONFIG_PARAVIRT_CLOCK
|
||||
extern struct pvclock_vsyscall_time_info *pvclock_pvti_cpu0_va(void);
|
||||
#else
|
||||
static inline struct pvclock_vsyscall_time_info *pvclock_pvti_cpu0_va(void)
|
||||
{
|
||||
return NULL;
|
||||
}
|
||||
#endif
|
||||
|
||||
/* some helper functions for xen and kvm pv clock sources */
|
||||
cycle_t pvclock_clocksource_read(struct pvclock_vcpu_time_info *src);
|
||||
u8 pvclock_read_flags(struct pvclock_vcpu_time_info *src);
|
||||
|
|
|
@ -22,6 +22,7 @@ struct vdso_image {
|
|||
|
||||
long sym_vvar_page;
|
||||
long sym_hpet_page;
|
||||
long sym_pvclock_page;
|
||||
long sym_VDSO32_NOTE_MASK;
|
||||
long sym___kernel_sigreturn;
|
||||
long sym___kernel_rt_sigreturn;
|
||||
|
|
|
@ -45,6 +45,11 @@ early_param("no-kvmclock", parse_no_kvmclock);
|
|||
static struct pvclock_vsyscall_time_info *hv_clock;
|
||||
static struct pvclock_wall_clock wall_clock;
|
||||
|
||||
struct pvclock_vsyscall_time_info *pvclock_pvti_cpu0_va(void)
|
||||
{
|
||||
return hv_clock;
|
||||
}
|
||||
|
||||
/*
|
||||
* The wallclock is the time of day when we booted. Since then, some time may
|
||||
* have elapsed since the hypervisor wrote the data. So we try to account for
|
||||
|
|
Loading…
Reference in a new issue