diff options
Diffstat (limited to 'arch/x86/lib/putuser.S')
| -rw-r--r-- | arch/x86/lib/putuser.S | 122 |
1 files changed, 122 insertions, 0 deletions
diff --git a/arch/x86/lib/putuser.S b/arch/x86/lib/putuser.S new file mode 100644 index 000000000..b7dfd6024 --- /dev/null +++ b/arch/x86/lib/putuser.S @@ -0,0 +1,122 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * __put_user functions. + * + * (C) Copyright 2005 Linus Torvalds + * (C) Copyright 2005 Andi Kleen + * (C) Copyright 2008 Glauber Costa + * + * These functions have a non-standard call interface + * to make them more efficient, especially as they + * return an error value in addition to the "real" + * return value. + */ +#include <linux/linkage.h> +#include <asm/thread_info.h> +#include <asm/errno.h> +#include <asm/asm.h> +#include <asm/smap.h> +#include <asm/export.h> + + +/* + * __put_user_X + * + * Inputs: %eax[:%edx] contains the data + * %ecx contains the address + * + * Outputs: %ecx is error code (0 or -EFAULT) + * + * Clobbers: %ebx needed for task pointer + * + * These functions should not modify any other registers, + * as they get called from within inline assembly. + */ + +#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) + 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) + ENDBR + ASM_STAC +1: movb %al,(%_ASM_CX) + xor %ecx,%ecx + ASM_CLAC + RET +SYM_FUNC_END(__put_user_1) +EXPORT_SYMBOL(__put_user_1) +EXPORT_SYMBOL(__put_user_nocheck_1) + +SYM_FUNC_START(__put_user_2) + 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) + ENDBR + ASM_STAC +2: movw %ax,(%_ASM_CX) + xor %ecx,%ecx + ASM_CLAC + RET +SYM_FUNC_END(__put_user_2) +EXPORT_SYMBOL(__put_user_2) +EXPORT_SYMBOL(__put_user_nocheck_2) + +SYM_FUNC_START(__put_user_4) + 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) + ENDBR + ASM_STAC +3: movl %eax,(%_ASM_CX) + xor %ecx,%ecx + ASM_CLAC + RET +SYM_FUNC_END(__put_user_4) +EXPORT_SYMBOL(__put_user_4) +EXPORT_SYMBOL(__put_user_nocheck_4) + +SYM_FUNC_START(__put_user_8) + 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) + ENDBR + ASM_STAC +4: mov %_ASM_AX,(%_ASM_CX) +#ifdef CONFIG_X86_32 +5: movl %edx,4(%_ASM_CX) +#endif + xor %ecx,%ecx + ASM_CLAC + RET +SYM_FUNC_END(__put_user_8) +EXPORT_SYMBOL(__put_user_8) +EXPORT_SYMBOL(__put_user_nocheck_8) + +SYM_CODE_START_LOCAL(.Lbad_put_user_clac) + ASM_CLAC +.Lbad_put_user: + movl $-EFAULT,%ecx + RET +SYM_CODE_END(.Lbad_put_user_clac) + + _ASM_EXTABLE_UA(1b, .Lbad_put_user_clac) + _ASM_EXTABLE_UA(2b, .Lbad_put_user_clac) + _ASM_EXTABLE_UA(3b, .Lbad_put_user_clac) + _ASM_EXTABLE_UA(4b, .Lbad_put_user_clac) +#ifdef CONFIG_X86_32 + _ASM_EXTABLE_UA(5b, .Lbad_put_user_clac) +#endif |