From 999c83e8ffd90caa00ee6caf054e037cf8a27d0e Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 3 Sep 2020 16:22:38 +0200 Subject: [PATCH] x86: move PAGE_OFFSET, TASK_SIZE & friends to page_{32,64}_types.h At least for 64-bit this moves them closer to some of the defines they are based on, and it prepares for using the TASK_SIZE_MAX definition from assembly. Signed-off-by: Christoph Hellwig Reviewed-by: Kees Cook Signed-off-by: Al Viro --- arch/x86/include/asm/page_32_types.h | 11 ++++++++ arch/x86/include/asm/page_64_types.h | 38 ++++++++++++++++++++++++++++ arch/x86/include/asm/processor.h | 49 ------------------------------------ 3 files changed, 49 insertions(+), 49 deletions(-) diff --git a/arch/x86/include/asm/page_32_types.h b/arch/x86/include/asm/page_32_types.h index 565ad75..2623692 100644 --- a/arch/x86/include/asm/page_32_types.h +++ b/arch/x86/include/asm/page_32_types.h @@ -42,6 +42,17 @@ #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) */ #define KERNEL_IMAGE_SIZE (512 * 1024 * 1024) diff --git a/arch/x86/include/asm/page_64_types.h b/arch/x86/include/asm/page_64_types.h index 288b065..996595c 100644 --- a/arch/x86/include/asm/page_64_types.h +++ b/arch/x86/include/asm/page_64_types.h @@ -59,6 +59,44 @@ #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). * diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index 97143d8..1618eeb0 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -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, \ } -- 2.7.4