diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2008-07-14 13:43:24 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-07-14 13:43:24 -0700 |
commit | a3da5bf84a97d48cfaf66c6842470fc403da5121 (patch) | |
tree | cdf66c0cff8c61eedd60601fc9dffdd1ed39b880 /arch/x86/lib/getuser.S | |
parent | 3b23e665b68387f5ee7b21f7b75ceea4d9acae4a (diff) | |
parent | d59fdcf2ac501de99c3dfb452af5e254d4342886 (diff) |
Merge branch 'x86/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (821 commits)
x86: make 64bit hpet_set_mapping to use ioremap too, v2
x86: get x86_phys_bits early
x86: max_low_pfn_mapped fix #4
x86: change _node_to_cpumask_ptr to return const ptr
x86: I/O APIC: remove an IRQ2-mask hack
x86: fix numaq_tsc_disable calling
x86, e820: remove end_user_pfn
x86: max_low_pfn_mapped fix, #3
x86: max_low_pfn_mapped fix, #2
x86: max_low_pfn_mapped fix, #1
x86_64: fix delayed signals
x86: remove conflicting nx6325 and nx6125 quirks
x86: Recover timer_ack lost in the merge of the NMI watchdog
x86: I/O APIC: Never configure IRQ2
x86: L-APIC: Always fully configure IRQ0
x86: L-APIC: Set IRQ0 as edge-triggered
x86: merge dwarf2 headers
x86: use AS_CFI instead of UNWIND_INFO
x86: use ignore macro instead of hash comment
x86: use matching CFI_ENDPROC
...
Diffstat (limited to 'arch/x86/lib/getuser.S')
-rw-r--r-- | arch/x86/lib/getuser.S | 104 |
1 files changed, 104 insertions, 0 deletions
diff --git a/arch/x86/lib/getuser.S b/arch/x86/lib/getuser.S new file mode 100644 index 000000000000..ad374003742f --- /dev/null +++ b/arch/x86/lib/getuser.S @@ -0,0 +1,104 @@ +/* + * __get_user functions. + * + * (C) Copyright 1998 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. + */ + +/* + * __get_user_X + * + * Inputs: %[r|e]ax contains the address. + * The register is modified, but all changes are undone + * before returning because the C code doesn't know about it. + * + * Outputs: %[r|e]ax is error code (0 or -EFAULT) + * %[r|e]dx contains zero-extended value + * + * + * These functions should not modify any other registers, + * as they get called from within inline assembly. + */ + +#include <linux/linkage.h> +#include <asm/dwarf2.h> +#include <asm/page.h> +#include <asm/errno.h> +#include <asm/asm-offsets.h> +#include <asm/thread_info.h> +#include <asm/asm.h> + + .text +ENTRY(__get_user_1) + CFI_STARTPROC + GET_THREAD_INFO(%_ASM_DX) + cmp TI_addr_limit(%_ASM_DX),%_ASM_AX + jae bad_get_user +1: movzb (%_ASM_AX),%edx + xor %eax,%eax + ret + CFI_ENDPROC +ENDPROC(__get_user_1) + +ENTRY(__get_user_2) + CFI_STARTPROC + add $1,%_ASM_AX + jc bad_get_user + GET_THREAD_INFO(%_ASM_DX) + cmp TI_addr_limit(%_ASM_DX),%_ASM_AX + jae bad_get_user +2: movzwl -1(%_ASM_AX),%edx + xor %eax,%eax + ret + CFI_ENDPROC +ENDPROC(__get_user_2) + +ENTRY(__get_user_4) + CFI_STARTPROC + add $3,%_ASM_AX + jc bad_get_user + GET_THREAD_INFO(%_ASM_DX) + cmp TI_addr_limit(%_ASM_DX),%_ASM_AX + jae bad_get_user +3: mov -3(%_ASM_AX),%edx + xor %eax,%eax + ret + CFI_ENDPROC +ENDPROC(__get_user_4) + +#ifdef CONFIG_X86_64 +ENTRY(__get_user_8) + CFI_STARTPROC + add $7,%_ASM_AX + jc bad_get_user + GET_THREAD_INFO(%_ASM_DX) + cmp TI_addr_limit(%_ASM_DX),%_ASM_AX + jae bad_get_user +4: movq -7(%_ASM_AX),%_ASM_DX + xor %eax,%eax + ret + CFI_ENDPROC +ENDPROC(__get_user_8) +#endif + +bad_get_user: + CFI_STARTPROC + xor %edx,%edx + mov $(-EFAULT),%_ASM_AX + ret + CFI_ENDPROC +END(bad_get_user) + +.section __ex_table,"a" + _ASM_PTR 1b,bad_get_user + _ASM_PTR 2b,bad_get_user + _ASM_PTR 3b,bad_get_user +#ifdef CONFIG_X86_64 + _ASM_PTR 4b,bad_get_user +#endif |