diff options
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/ia32/ia32_aout.c | 1 | ||||
| -rw-r--r-- | arch/x86/include/asm/page_32_types.h | 11 | ||||
| -rw-r--r-- | arch/x86/include/asm/page_64_types.h | 38 | ||||
| -rw-r--r-- | arch/x86/include/asm/processor.h | 60 | ||||
| -rw-r--r-- | arch/x86/include/asm/thread_info.h | 2 | ||||
| -rw-r--r-- | arch/x86/include/asm/uaccess.h | 26 | ||||
| -rw-r--r-- | arch/x86/kernel/asm-offsets.c | 3 | ||||
| -rw-r--r-- | arch/x86/lib/getuser.S | 47 | ||||
| -rw-r--r-- | arch/x86/lib/putuser.S | 25 |
9 files changed, 88 insertions, 125 deletions
diff --git a/arch/x86/ia32/ia32_aout.c b/arch/x86/ia32/ia32_aout.c index ca8a657edf59..a09fc37ead9d 100644 --- a/arch/x86/ia32/ia32_aout.c +++ b/arch/x86/ia32/ia32_aout.c @@ -239,7 +239,6 @@ beyond_if: (regs)->ss = __USER32_DS; regs->r8 = regs->r9 = regs->r10 = regs->r11 = regs->r12 = regs->r13 = regs->r14 = regs->r15 = 0; - set_fs(USER_DS); return 0; } diff --git a/arch/x86/include/asm/page_32_types.h b/arch/x86/include/asm/page_32_types.h index 565ad755c785..f462895a33e4 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 d0c6c10c18a0..3f49dac03617 100644 --- a/arch/x86/include/asm/page_64_types.h +++ b/arch/x86/include/asm/page_64_types.h @@ -60,6 +60,44 @@ #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 ((_AC(1,UL) << __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 5ac507586769..82a08b585818 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -482,10 +482,6 @@ extern unsigned int fpu_user_xstate_size; struct perf_event; -typedef struct { - unsigned long seg; -} mm_segment_t; - struct thread_struct { /* Cached TLS descriptors: */ struct desc_struct tls_array[GDT_ENTRY_TLS_ENTRIES]; @@ -538,8 +534,6 @@ struct thread_struct { */ unsigned long iopl_emul; - mm_segment_t addr_limit; - unsigned int sig_on_uaccess_err:1; /* Floating point and extended processor state */ @@ -783,67 +777,15 @@ 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, \ - .addr_limit = KERNEL_DS, \ } #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, \ -} +#define INIT_THREAD { } extern unsigned long KSTK_ESP(struct task_struct *task); diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h index 267701ae3d86..44733a4bfc42 100644 --- a/arch/x86/include/asm/thread_info.h +++ b/arch/x86/include/asm/thread_info.h @@ -102,7 +102,6 @@ struct thread_info { #define TIF_SYSCALL_TRACEPOINT 28 /* syscall tracepoint instrumentation */ #define TIF_ADDR32 29 /* 32-bit address space on 64 bits */ #define TIF_X32 30 /* 32-bit native x86-64 binary */ -#define TIF_FSCHECK 31 /* Check FS is USER_DS on return */ #define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE) #define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME) @@ -131,7 +130,6 @@ struct thread_info { #define _TIF_SYSCALL_TRACEPOINT (1 << TIF_SYSCALL_TRACEPOINT) #define _TIF_ADDR32 (1 << TIF_ADDR32) #define _TIF_X32 (1 << TIF_X32) -#define _TIF_FSCHECK (1 << TIF_FSCHECK) /* flags to check in __switch_to() */ #define _TIF_WORK_CTXSW_BASE \ diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h index 477c503f2753..f13659523108 100644 --- a/arch/x86/include/asm/uaccess.h +++ b/arch/x86/include/asm/uaccess.h @@ -13,30 +13,6 @@ #include <asm/extable.h> /* - * The fs value determines whether argument validity checking should be - * performed or not. If get_fs() == USER_DS, checking is performed, with - * get_fs() == KERNEL_DS, checking is bypassed. - * - * For historical reasons, these macros are grossly misnamed. - */ - -#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) }) - -#define KERNEL_DS MAKE_MM_SEG(-1UL) -#define USER_DS MAKE_MM_SEG(TASK_SIZE_MAX) - -#define get_fs() (current->thread.addr_limit) -static inline void set_fs(mm_segment_t fs) -{ - current->thread.addr_limit = fs; - /* On user-mode return, check fs is correct */ - set_thread_flag(TIF_FSCHECK); -} - -#define uaccess_kernel() (get_fs().seg == KERNEL_DS.seg) -#define user_addr_max() (current->thread.addr_limit.seg) - -/* * Test whether a block of memory is a valid user space address. * Returns 0 if the range is valid, nonzero otherwise. */ @@ -93,7 +69,7 @@ static inline bool pagefault_disabled(void); #define access_ok(addr, size) \ ({ \ WARN_ON_IN_IRQ(); \ - likely(!__range_not_ok(addr, size, user_addr_max())); \ + likely(!__range_not_ok(addr, size, TASK_SIZE_MAX)); \ }) extern int __get_user_1(void); diff --git a/arch/x86/kernel/asm-offsets.c b/arch/x86/kernel/asm-offsets.c index 3ca07ad552ae..70b7154f4bdd 100644 --- a/arch/x86/kernel/asm-offsets.c +++ b/arch/x86/kernel/asm-offsets.c @@ -38,9 +38,6 @@ static void __used common(void) #endif BLANK(); - OFFSET(TASK_addr_limit, task_struct, thread.addr_limit); - - BLANK(); OFFSET(crypto_tfm_ctx_offset, crypto_tfm, __crt_ctx); BLANK(); diff --git a/arch/x86/lib/getuser.S b/arch/x86/lib/getuser.S index 2cd902e06062..fa1bc2104b32 100644 --- a/arch/x86/lib/getuser.S +++ b/arch/x86/lib/getuser.S @@ -37,10 +37,19 @@ #define ASM_BARRIER_NOSPEC ALTERNATIVE "", "lfence", X86_FEATURE_LFENCE_RDTSC +#ifdef CONFIG_X86_5LEVEL +#define LOAD_TASK_SIZE_MINUS_N(n) \ + ALTERNATIVE __stringify(mov $((1 << 47) - 4096 - (n)),%rdx), \ + __stringify(mov $((1 << 56) - 4096 - (n)),%rdx), X86_FEATURE_LA57 +#else +#define LOAD_TASK_SIZE_MINUS_N(n) \ + mov $(TASK_SIZE_MAX - (n)),%_ASM_DX +#endif + .text SYM_FUNC_START(__get_user_1) - mov PER_CPU_VAR(current_task), %_ASM_DX - cmp TASK_addr_limit(%_ASM_DX),%_ASM_AX + LOAD_TASK_SIZE_MINUS_N(0) + cmp %_ASM_DX,%_ASM_AX jae bad_get_user sbb %_ASM_DX, %_ASM_DX /* array_index_mask_nospec() */ and %_ASM_DX, %_ASM_AX @@ -53,15 +62,13 @@ SYM_FUNC_END(__get_user_1) EXPORT_SYMBOL(__get_user_1) SYM_FUNC_START(__get_user_2) - add $1,%_ASM_AX - jc bad_get_user - mov PER_CPU_VAR(current_task), %_ASM_DX - cmp TASK_addr_limit(%_ASM_DX),%_ASM_AX + LOAD_TASK_SIZE_MINUS_N(1) + cmp %_ASM_DX,%_ASM_AX jae bad_get_user sbb %_ASM_DX, %_ASM_DX /* array_index_mask_nospec() */ and %_ASM_DX, %_ASM_AX ASM_STAC -2: movzwl -1(%_ASM_AX),%edx +2: movzwl (%_ASM_AX),%edx xor %eax,%eax ASM_CLAC ret @@ -69,15 +76,13 @@ SYM_FUNC_END(__get_user_2) EXPORT_SYMBOL(__get_user_2) SYM_FUNC_START(__get_user_4) - add $3,%_ASM_AX - jc bad_get_user - mov PER_CPU_VAR(current_task), %_ASM_DX - cmp TASK_addr_limit(%_ASM_DX),%_ASM_AX + LOAD_TASK_SIZE_MINUS_N(3) + cmp %_ASM_DX,%_ASM_AX jae bad_get_user sbb %_ASM_DX, %_ASM_DX /* array_index_mask_nospec() */ and %_ASM_DX, %_ASM_AX ASM_STAC -3: movl -3(%_ASM_AX),%edx +3: movl (%_ASM_AX),%edx xor %eax,%eax ASM_CLAC ret @@ -86,29 +91,25 @@ EXPORT_SYMBOL(__get_user_4) SYM_FUNC_START(__get_user_8) #ifdef CONFIG_X86_64 - add $7,%_ASM_AX - jc bad_get_user - mov PER_CPU_VAR(current_task), %_ASM_DX - cmp TASK_addr_limit(%_ASM_DX),%_ASM_AX + LOAD_TASK_SIZE_MINUS_N(7) + cmp %_ASM_DX,%_ASM_AX jae bad_get_user sbb %_ASM_DX, %_ASM_DX /* array_index_mask_nospec() */ and %_ASM_DX, %_ASM_AX ASM_STAC -4: movq -7(%_ASM_AX),%rdx +4: movq (%_ASM_AX),%rdx xor %eax,%eax ASM_CLAC ret #else - add $7,%_ASM_AX - jc bad_get_user_8 - mov PER_CPU_VAR(current_task), %_ASM_DX - cmp TASK_addr_limit(%_ASM_DX),%_ASM_AX + LOAD_TASK_SIZE_MINUS_N(7) + cmp %_ASM_DX,%_ASM_AX jae bad_get_user_8 sbb %_ASM_DX, %_ASM_DX /* array_index_mask_nospec() */ and %_ASM_DX, %_ASM_AX ASM_STAC -4: movl -7(%_ASM_AX),%edx -5: movl -3(%_ASM_AX),%ecx +4: movl (%_ASM_AX),%edx +5: movl 4(%_ASM_AX),%ecx xor %eax,%eax ASM_CLAC ret diff --git a/arch/x86/lib/putuser.S b/arch/x86/lib/putuser.S index b34a17763f28..0ea344c5ea43 100644 --- a/arch/x86/lib/putuser.S +++ b/arch/x86/lib/putuser.S @@ -33,12 +33,19 @@ * as they get called from within inline assembly. */ -#define ENTER mov PER_CPU_VAR(current_task), %_ASM_BX +#ifdef CONFIG_X86_5LEVEL +#define LOAD_TASK_SIZE_MINUS_N(n) \ + ALTERNATIVE __stringify(mov $((1 << 47) - 4096 - (n)),%rbx), \ + __stringify(mov $((1 << 56) - 4096 - (n)),%rbx), X86_FEATURE_LA57 +#else +#define LOAD_TASK_SIZE_MINUS_N(n) \ + mov $(TASK_SIZE_MAX - (n)),%_ASM_BX +#endif .text SYM_FUNC_START(__put_user_1) - ENTER - cmp TASK_addr_limit(%_ASM_BX),%_ASM_CX + LOAD_TASK_SIZE_MINUS_N(0) + cmp %_ASM_BX,%_ASM_CX jae .Lbad_put_user SYM_INNER_LABEL(__put_user_nocheck_1, SYM_L_GLOBAL) ASM_STAC @@ -51,9 +58,7 @@ EXPORT_SYMBOL(__put_user_1) EXPORT_SYMBOL(__put_user_nocheck_1) SYM_FUNC_START(__put_user_2) - ENTER - mov TASK_addr_limit(%_ASM_BX),%_ASM_BX - sub $1,%_ASM_BX + LOAD_TASK_SIZE_MINUS_N(1) cmp %_ASM_BX,%_ASM_CX jae .Lbad_put_user SYM_INNER_LABEL(__put_user_nocheck_2, SYM_L_GLOBAL) @@ -67,9 +72,7 @@ EXPORT_SYMBOL(__put_user_2) EXPORT_SYMBOL(__put_user_nocheck_2) SYM_FUNC_START(__put_user_4) - ENTER - mov TASK_addr_limit(%_ASM_BX),%_ASM_BX - sub $3,%_ASM_BX + LOAD_TASK_SIZE_MINUS_N(3) cmp %_ASM_BX,%_ASM_CX jae .Lbad_put_user SYM_INNER_LABEL(__put_user_nocheck_4, SYM_L_GLOBAL) @@ -83,9 +86,7 @@ EXPORT_SYMBOL(__put_user_4) EXPORT_SYMBOL(__put_user_nocheck_4) SYM_FUNC_START(__put_user_8) - ENTER - mov TASK_addr_limit(%_ASM_BX),%_ASM_BX - sub $7,%_ASM_BX + LOAD_TASK_SIZE_MINUS_N(7) cmp %_ASM_BX,%_ASM_CX jae .Lbad_put_user SYM_INNER_LABEL(__put_user_nocheck_8, SYM_L_GLOBAL) |