x86/cpu_entry_area: Move it out of the fixmap

Put the cpu_entry_area into a separate P4D entry. The fixmap gets too big
and 0-day already hit a case where the fixmap PTEs were cleared by
cleanup_highmap().

Aside of that the fixmap API is a pain as it's all backwards.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Thomas Gleixner
2017-12-20 18:51:31 +01:00
committed by Ingo Molnar
parent ed1bbc40a0
commit 92a0f81d89
14 changed files with 148 additions and 93 deletions

View File

@@ -25,7 +25,6 @@
#else
#include <uapi/asm/vsyscall.h>
#endif
#include <asm/cpu_entry_area.h>
/*
* We can't declare FIXADDR_TOP as variable for x86_64 because vsyscall
@@ -84,7 +83,6 @@ enum fixed_addresses {
FIX_IO_APIC_BASE_0,
FIX_IO_APIC_BASE_END = FIX_IO_APIC_BASE_0 + MAX_IO_APICS - 1,
#endif
FIX_RO_IDT, /* Virtual mapping for read-only IDT */
#ifdef CONFIG_X86_32
FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */
FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1,
@@ -100,9 +98,6 @@ enum fixed_addresses {
#ifdef CONFIG_X86_INTEL_MID
FIX_LNW_VRTC,
#endif
/* Fixmap entries to remap the GDTs, one per processor. */
FIX_CPU_ENTRY_AREA_TOP,
FIX_CPU_ENTRY_AREA_BOTTOM = FIX_CPU_ENTRY_AREA_TOP + (CPU_ENTRY_AREA_PAGES * NR_CPUS) - 1,
#ifdef CONFIG_ACPI_APEI_GHES
/* Used for GHES mapping from assorted contexts */
@@ -143,7 +138,7 @@ enum fixed_addresses {
extern void reserve_top_address(unsigned long reserve);
#define FIXADDR_SIZE (__end_of_permanent_fixed_addresses << PAGE_SHIFT)
#define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE)
#define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE)
extern int fixmaps_set;
@@ -191,30 +186,5 @@ void __init *early_memremap_decrypted_wp(resource_size_t phys_addr,
void __early_set_fixmap(enum fixed_addresses idx,
phys_addr_t phys, pgprot_t flags);
static inline unsigned int __get_cpu_entry_area_page_index(int cpu, int page)
{
BUILD_BUG_ON(sizeof(struct cpu_entry_area) % PAGE_SIZE != 0);
return FIX_CPU_ENTRY_AREA_BOTTOM - cpu*CPU_ENTRY_AREA_PAGES - page;
}
#define __get_cpu_entry_area_offset_index(cpu, offset) ({ \
BUILD_BUG_ON(offset % PAGE_SIZE != 0); \
__get_cpu_entry_area_page_index(cpu, offset / PAGE_SIZE); \
})
#define get_cpu_entry_area_index(cpu, field) \
__get_cpu_entry_area_offset_index((cpu), offsetof(struct cpu_entry_area, field))
static inline struct cpu_entry_area *get_cpu_entry_area(int cpu)
{
return (struct cpu_entry_area *)__fix_to_virt(__get_cpu_entry_area_page_index(cpu, 0));
}
static inline struct entry_stack *cpu_entry_stack(int cpu)
{
return &get_cpu_entry_area(cpu)->entry_stack_page.stack;
}
#endif /* !__ASSEMBLY__ */
#endif /* _ASM_X86_FIXMAP_H */