On 10/12/2015 00:12, Andy Lutomirski wrote: > Signed-off-by: Andy Lutomirski <l...@kernel.org> > --- > arch/x86/entry/vdso/vclock_gettime.c | 20 ++++++++------------ > arch/x86/entry/vdso/vdso-layout.lds.S | 3 ++- > arch/x86/entry/vdso/vdso2c.c | 3 +++ > arch/x86/entry/vdso/vma.c | 13 +++++++++++++ > arch/x86/include/asm/pvclock.h | 9 +++++++++ > arch/x86/include/asm/vdso.h | 1 + > arch/x86/kernel/kvmclock.c | 5 +++++ > 7 files changed, 41 insertions(+), 13 deletions(-) > > diff --git a/arch/x86/entry/vdso/vclock_gettime.c > b/arch/x86/entry/vdso/vclock_gettime.c > index c325ba1bdddf..5dd363d54348 100644 > --- a/arch/x86/entry/vdso/vclock_gettime.c > +++ b/arch/x86/entry/vdso/vclock_gettime.c > @@ -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; > diff --git a/arch/x86/entry/vdso/vdso-layout.lds.S > b/arch/x86/entry/vdso/vdso-layout.lds.S > index de2c921025f5..4158acc17df0 100644 > --- a/arch/x86/entry/vdso/vdso-layout.lds.S > +++ b/arch/x86/entry/vdso/vdso-layout.lds.S > @@ -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; > > diff --git a/arch/x86/entry/vdso/vdso2c.c b/arch/x86/entry/vdso/vdso2c.c > index 785d9922b106..491020b2826d 100644 > --- a/arch/x86/entry/vdso/vdso2c.c > +++ b/arch/x86/entry/vdso/vdso2c.c > @@ -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 > }, > diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c > index 64df47148160..aa828191c654 100644 > --- a/arch/x86/entry/vdso/vma.c > +++ b/arch/x86/entry/vdso/vma.c > @@ -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; > diff --git a/arch/x86/include/asm/pvclock.h b/arch/x86/include/asm/pvclock.h > index 7a6bed5c08bc..3864398c7cb2 100644 > --- a/arch/x86/include/asm/pvclock.h > +++ b/arch/x86/include/asm/pvclock.h > @@ -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); > diff --git a/arch/x86/include/asm/vdso.h b/arch/x86/include/asm/vdso.h > index 756de9190aec..deabaf9759b6 100644 > --- a/arch/x86/include/asm/vdso.h > +++ b/arch/x86/include/asm/vdso.h > @@ -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; > diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c > index 2bd81e302427..ec1b06dc82d2 100644 > --- a/arch/x86/kernel/kvmclock.c > +++ b/arch/x86/kernel/kvmclock.c > @@ -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 >
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