x86: move PAGE_OFFSET, TASK_SIZE & friends to page_{32,64}_types.h (999c83e8) · Commits · 戴 / test

arch/x86/include/asm/page_32_types.h

+11 −0

Original line number	Diff line number	Diff line
		@@ -41,6 +41,17 @@
		#define __VIRTUAL_MASK_SHIFT 32
		#endif /* CONFIG_X86_PAE */

		/*
		* User space process size: 3GB (default).
		*/
		#define IA32_PAGE_OFFSET PAGE_OFFSET
		#define TASK_SIZE PAGE_OFFSET
		#define TASK_SIZE_LOW TASK_SIZE
		#define TASK_SIZE_MAX TASK_SIZE
		#define DEFAULT_MAP_WINDOW TASK_SIZE
		#define STACK_TOP TASK_SIZE
		#define STACK_TOP_MAX STACK_TOP

		/*
		* Kernel image size is limited to 512 MB (see in arch/x86/kernel/head_32.S)
		*/

arch/x86/include/asm/page_64_types.h

+38 −0

Original line number	Diff line number	Diff line
		@@ -58,6 +58,44 @@
		#define __VIRTUAL_MASK_SHIFT 47
		#endif

		/*
		* User space process size. This is the first address outside the user range.
		* There are a few constraints that determine this:
		*
		* On Intel CPUs, if a SYSCALL instruction is at the highest canonical
		* address, then that syscall will enter the kernel with a
		* non-canonical return address, and SYSRET will explode dangerously.
		* We avoid this particular problem by preventing anything executable
		* from being mapped at the maximum canonical address.
		*
		* On AMD CPUs in the Ryzen family, there's a nasty bug in which the
		* CPUs malfunction if they execute code from the highest canonical page.
		* They'll speculate right off the end of the canonical space, and
		* bad things happen. This is worked around in the same way as the
		* Intel problem.
		*
		* With page table isolation enabled, we map the LDT in ... [stay tuned]
		*/
		#define TASK_SIZE_MAX ((1UL << __VIRTUAL_MASK_SHIFT) - PAGE_SIZE)

		#define DEFAULT_MAP_WINDOW ((1UL << 47) - PAGE_SIZE)

		/* This decides where the kernel will search for a free chunk of vm
		* space during mmap's.
		*/
		#define IA32_PAGE_OFFSET ((current->personality & ADDR_LIMIT_3GB) ? \
		0xc0000000 : 0xFFFFe000)

		#define TASK_SIZE_LOW (test_thread_flag(TIF_ADDR32) ? \
		IA32_PAGE_OFFSET : DEFAULT_MAP_WINDOW)
		#define TASK_SIZE (test_thread_flag(TIF_ADDR32) ? \
		IA32_PAGE_OFFSET : TASK_SIZE_MAX)
		#define TASK_SIZE_OF(child) ((test_tsk_thread_flag(child, TIF_ADDR32)) ? \
		IA32_PAGE_OFFSET : TASK_SIZE_MAX)

		#define STACK_TOP TASK_SIZE_LOW
		#define STACK_TOP_MAX TASK_SIZE_MAX

		/*
		* Maximum kernel image size is limited to 1 GiB, due to the fixmap living
		* in the next 1 GiB (see level2_kernel_pgt in arch/x86/kernel/head_64.S).

arch/x86/include/asm/processor.h

+0 −49

Original line number	Diff line number	Diff line
		@@ -782,17 +782,6 @@ static inline void spin_lock_prefetch(const void *x)
		})

		#ifdef CONFIG_X86_32
		/*
		* User space process size: 3GB (default).
		*/
		#define IA32_PAGE_OFFSET PAGE_OFFSET
		#define TASK_SIZE PAGE_OFFSET
		#define TASK_SIZE_LOW TASK_SIZE
		#define TASK_SIZE_MAX TASK_SIZE
		#define DEFAULT_MAP_WINDOW TASK_SIZE
		#define STACK_TOP TASK_SIZE
		#define STACK_TOP_MAX STACK_TOP

		#define INIT_THREAD { \
		.sp0 = TOP_OF_INIT_STACK, \
		.sysenter_cs = __KERNEL_CS, \
		@@ -802,44 +791,6 @@ static inline void spin_lock_prefetch(const void *x)
		#define KSTK_ESP(task) (task_pt_regs(task)->sp)

		#else
		/*
		* User space process size. This is the first address outside the user range.
		* There are a few constraints that determine this:
		*
		* On Intel CPUs, if a SYSCALL instruction is at the highest canonical
		* address, then that syscall will enter the kernel with a
		* non-canonical return address, and SYSRET will explode dangerously.
		* We avoid this particular problem by preventing anything executable
		* from being mapped at the maximum canonical address.
		*
		* On AMD CPUs in the Ryzen family, there's a nasty bug in which the
		* CPUs malfunction if they execute code from the highest canonical page.
		* They'll speculate right off the end of the canonical space, and
		* bad things happen. This is worked around in the same way as the
		* Intel problem.
		*
		* With page table isolation enabled, we map the LDT in ... [stay tuned]
		*/
		#define TASK_SIZE_MAX ((1UL << __VIRTUAL_MASK_SHIFT) - PAGE_SIZE)

		#define DEFAULT_MAP_WINDOW ((1UL << 47) - PAGE_SIZE)

		/* This decides where the kernel will search for a free chunk of vm
		* space during mmap's.
		*/
		#define IA32_PAGE_OFFSET ((current->personality & ADDR_LIMIT_3GB) ? \
		0xc0000000 : 0xFFFFe000)

		#define TASK_SIZE_LOW (test_thread_flag(TIF_ADDR32) ? \
		IA32_PAGE_OFFSET : DEFAULT_MAP_WINDOW)
		#define TASK_SIZE (test_thread_flag(TIF_ADDR32) ? \
		IA32_PAGE_OFFSET : TASK_SIZE_MAX)
		#define TASK_SIZE_OF(child) ((test_tsk_thread_flag(child, TIF_ADDR32)) ? \
		IA32_PAGE_OFFSET : TASK_SIZE_MAX)

		#define STACK_TOP TASK_SIZE_LOW
		#define STACK_TOP_MAX TASK_SIZE_MAX

		#define INIT_THREAD { \
		.addr_limit = KERNEL_DS, \
		}

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