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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:02:30 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:02:30 +0000 |
commit | 76cb841cb886eef6b3bee341a2266c76578724ad (patch) | |
tree | f5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /arch/x86/lib/putuser.S | |
parent | Initial commit. (diff) | |
download | linux-76cb841cb886eef6b3bee341a2266c76578724ad.tar.xz linux-76cb841cb886eef6b3bee341a2266c76578724ad.zip |
Adding upstream version 4.19.249.upstream/4.19.249
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/x86/lib/putuser.S')
-rw-r--r-- | arch/x86/lib/putuser.S | 103 |
1 files changed, 103 insertions, 0 deletions
diff --git a/arch/x86/lib/putuser.S b/arch/x86/lib/putuser.S new file mode 100644 index 000000000..96dce5fe2 --- /dev/null +++ b/arch/x86/lib/putuser.S @@ -0,0 +1,103 @@ +/* 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: %eax is error code (0 or -EFAULT) + * + * These functions should not modify any other registers, + * as they get called from within inline assembly. + */ + +#define ENTER mov PER_CPU_VAR(current_task), %_ASM_BX +#define EXIT ASM_CLAC ; \ + ret + +.text +ENTRY(__put_user_1) + ENTER + cmp TASK_addr_limit(%_ASM_BX),%_ASM_CX + jae bad_put_user + ASM_STAC +1: movb %al,(%_ASM_CX) + xor %eax,%eax + EXIT +ENDPROC(__put_user_1) +EXPORT_SYMBOL(__put_user_1) + +ENTRY(__put_user_2) + ENTER + mov TASK_addr_limit(%_ASM_BX),%_ASM_BX + sub $1,%_ASM_BX + cmp %_ASM_BX,%_ASM_CX + jae bad_put_user + ASM_STAC +2: movw %ax,(%_ASM_CX) + xor %eax,%eax + EXIT +ENDPROC(__put_user_2) +EXPORT_SYMBOL(__put_user_2) + +ENTRY(__put_user_4) + ENTER + mov TASK_addr_limit(%_ASM_BX),%_ASM_BX + sub $3,%_ASM_BX + cmp %_ASM_BX,%_ASM_CX + jae bad_put_user + ASM_STAC +3: movl %eax,(%_ASM_CX) + xor %eax,%eax + EXIT +ENDPROC(__put_user_4) +EXPORT_SYMBOL(__put_user_4) + +ENTRY(__put_user_8) + ENTER + mov TASK_addr_limit(%_ASM_BX),%_ASM_BX + sub $7,%_ASM_BX + cmp %_ASM_BX,%_ASM_CX + jae bad_put_user + ASM_STAC +4: mov %_ASM_AX,(%_ASM_CX) +#ifdef CONFIG_X86_32 +5: movl %edx,4(%_ASM_CX) +#endif + xor %eax,%eax + EXIT +ENDPROC(__put_user_8) +EXPORT_SYMBOL(__put_user_8) + +bad_put_user: + movl $-EFAULT,%eax + EXIT +END(bad_put_user) + + _ASM_EXTABLE(1b,bad_put_user) + _ASM_EXTABLE(2b,bad_put_user) + _ASM_EXTABLE(3b,bad_put_user) + _ASM_EXTABLE(4b,bad_put_user) +#ifdef CONFIG_X86_32 + _ASM_EXTABLE(5b,bad_put_user) +#endif |