x86/vdso: Get pvclock data from the vvar VMA instead of the fixmap (dac16fba) · Commits · e / devices / android_kernel_teracube_2e

arch/x86/entry/vdso/vclock_gettime.c

+8 −12

Original line number	Original line	Diff line number	Diff line
	@@ -36,6 +36,11 @@ static notrace cycle_t vread_hpet(void)
	}		}
	#endif		#endif

			#ifdef CONFIG_PARAVIRT_CLOCK
			extern u8 pvclock_page
			__attribute__((visibility("hidden")));
			#endif

	#ifndef BUILD_VDSO32		#ifndef BUILD_VDSO32

	#include <linux/kernel.h>		#include <linux/kernel.h>
	@@ -62,23 +67,14 @@ notrace static long vdso_fallback_gtod(struct timeval tv, struct timezone tz)

	#ifdef CONFIG_PARAVIRT_CLOCK		#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;		return (const struct pvclock_vsyscall_time_info *)&pvclock_page;
	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];
	}		}

	static notrace cycle_t vread_pvclock(int *mode)		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;		cycle_t ret;
	u64 tsc, pvti_tsc;		u64 tsc, pvti_tsc;
	u64 last, delta, pvti_system_time;		u64 last, delta, pvti_system_time;

+2 −1

Original line number	Original line	Diff line number	Diff line
	@@ -25,7 +25,7 @@ SECTIONS
	* segment.		* segment.
	*/		*/

	vvar_start = . - 2 * PAGE_SIZE;		vvar_start = . - 3 * PAGE_SIZE;
	vvar_page = vvar_start;		vvar_page = vvar_start;

	/* Place all vvars at the offsets in asm/vvar.h. */		/* Place all vvars at the offsets in asm/vvar.h. */
	@@ -36,6 +36,7 @@ SECTIONS
	#undef EMIT_VVAR		#undef EMIT_VVAR

	hpet_page = vvar_start + PAGE_SIZE;		hpet_page = vvar_start + PAGE_SIZE;
			pvclock_page = vvar_start + 2 * PAGE_SIZE;

	. = SIZEOF_HEADERS;		. = SIZEOF_HEADERS;

+3 −0

Original line number	Original line	Diff line number	Diff line
	@@ -73,6 +73,7 @@ enum {
	sym_vvar_start,		sym_vvar_start,
	sym_vvar_page,		sym_vvar_page,
	sym_hpet_page,		sym_hpet_page,
			sym_pvclock_page,
	sym_VDSO_FAKE_SECTION_TABLE_START,		sym_VDSO_FAKE_SECTION_TABLE_START,
	sym_VDSO_FAKE_SECTION_TABLE_END,		sym_VDSO_FAKE_SECTION_TABLE_END,
	};		};
	@@ -80,6 +81,7 @@ enum {
	const int special_pages[] = {		const int special_pages[] = {
	sym_vvar_page,		sym_vvar_page,
	sym_hpet_page,		sym_hpet_page,
			sym_pvclock_page,
	};		};

	struct vdso_sym {		struct vdso_sym {
	@@ -91,6 +93,7 @@ struct vdso_sym required_syms[] = {
	[sym_vvar_start] = {"vvar_start", true},		[sym_vvar_start] = {"vvar_start", true},
	[sym_vvar_page] = {"vvar_page", true},		[sym_vvar_page] = {"vvar_page", true},
	[sym_hpet_page] = {"hpet_page", true},		[sym_hpet_page] = {"hpet_page", true},
			[sym_pvclock_page] = {"pvclock_page", true},
	[sym_VDSO_FAKE_SECTION_TABLE_START] = {		[sym_VDSO_FAKE_SECTION_TABLE_START] = {
	"VDSO_FAKE_SECTION_TABLE_START", false		"VDSO_FAKE_SECTION_TABLE_START", false
	},		},

+13 −0

Original line number	Original line	Diff line number	Diff line
	@@ -100,6 +100,7 @@ static int map_vdso(const struct vdso_image *image, bool calculate_addr)
	.name = "[vvar]",		.name = "[vvar]",
	.pages = no_pages,		.pages = no_pages,
	};		};
			struct pvclock_vsyscall_time_info *pvti;

	if (calculate_addr) {		if (calculate_addr) {
	addr = vdso_addr(current->mm->start_stack,		addr = vdso_addr(current->mm->start_stack,
	@@ -169,6 +170,18 @@ static int map_vdso(const struct vdso_image *image, bool calculate_addr)
	}		}
	#endif		#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:		up_fail:
	if (ret)		if (ret)
	current->mm->context.vdso = NULL;		current->mm->context.vdso = NULL;

+9 −0

Original line number	Original line	Diff line number	Diff line
	@@ -4,6 +4,15 @@
	#include <linux/clocksource.h>		#include <linux/clocksource.h>
	#include <asm/pvclock-abi.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 */		/* some helper functions for xen and kvm pv clock sources */
	cycle_t pvclock_clocksource_read(struct pvclock_vcpu_time_info *src);		cycle_t pvclock_clocksource_read(struct pvclock_vcpu_time_info *src);
	u8 pvclock_read_flags(struct pvclock_vcpu_time_info *src);		u8 pvclock_read_flags(struct pvclock_vcpu_time_info *src);