diff options
Diffstat (limited to 'arch/x86/lib')
| -rw-r--r-- | arch/x86/lib/copy_mc.c | 4 | ||||
| -rw-r--r-- | arch/x86/lib/copy_mc_64.S | 10 | ||||
| -rw-r--r-- | arch/x86/lib/usercopy.c | 22 |
3 files changed, 18 insertions, 18 deletions
diff --git a/arch/x86/lib/copy_mc.c b/arch/x86/lib/copy_mc.c index c13e8c9ee926..80efd45a7761 100644 --- a/arch/x86/lib/copy_mc.c +++ b/arch/x86/lib/copy_mc.c @@ -10,10 +10,6 @@ #include <asm/mce.h> #ifdef CONFIG_X86_MCE -/* - * See COPY_MC_TEST for self-test of the copy_mc_fragile() - * implementation. - */ static DEFINE_STATIC_KEY_FALSE(copy_mc_fragile_key); void enable_copy_mc_fragile(void) diff --git a/arch/x86/lib/copy_mc_64.S b/arch/x86/lib/copy_mc_64.S index 892d8915f609..e5f77e293034 100644 --- a/arch/x86/lib/copy_mc_64.S +++ b/arch/x86/lib/copy_mc_64.S @@ -2,14 +2,11 @@ /* Copyright(c) 2016-2020 Intel Corporation. All rights reserved. */ #include <linux/linkage.h> -#include <asm/copy_mc_test.h> -#include <asm/export.h> #include <asm/asm.h> #ifndef CONFIG_UML #ifdef CONFIG_X86_MCE -COPY_MC_TEST_CTL /* * copy_mc_fragile - copy memory with indication if an exception / fault happened @@ -38,8 +35,6 @@ SYM_FUNC_START(copy_mc_fragile) subl %ecx, %edx .L_read_leading_bytes: movb (%rsi), %al - COPY_MC_TEST_SRC %rsi 1 .E_leading_bytes - COPY_MC_TEST_DST %rdi 1 .E_leading_bytes .L_write_leading_bytes: movb %al, (%rdi) incq %rsi @@ -55,8 +50,6 @@ SYM_FUNC_START(copy_mc_fragile) .L_read_words: movq (%rsi), %r8 - COPY_MC_TEST_SRC %rsi 8 .E_read_words - COPY_MC_TEST_DST %rdi 8 .E_write_words .L_write_words: movq %r8, (%rdi) addq $8, %rsi @@ -73,8 +66,6 @@ SYM_FUNC_START(copy_mc_fragile) movl %edx, %ecx .L_read_trailing_bytes: movb (%rsi), %al - COPY_MC_TEST_SRC %rsi 1 .E_trailing_bytes - COPY_MC_TEST_DST %rdi 1 .E_trailing_bytes .L_write_trailing_bytes: movb %al, (%rdi) incq %rsi @@ -88,7 +79,6 @@ SYM_FUNC_START(copy_mc_fragile) .L_done: ret SYM_FUNC_END(copy_mc_fragile) -EXPORT_SYMBOL_GPL(copy_mc_fragile) .section .fixup, "ax" /* diff --git a/arch/x86/lib/usercopy.c b/arch/x86/lib/usercopy.c index 3f435d7fca5e..c3e8a62ca561 100644 --- a/arch/x86/lib/usercopy.c +++ b/arch/x86/lib/usercopy.c @@ -9,9 +9,23 @@ #include <asm/tlbflush.h> -/* - * We rely on the nested NMI work to allow atomic faults from the NMI path; the - * nested NMI paths are careful to preserve CR2. +/** + * copy_from_user_nmi - NMI safe copy from user + * @to: Pointer to the destination buffer + * @from: Pointer to a user space address of the current task + * @n: Number of bytes to copy + * + * Returns: The number of not copied bytes. 0 is success, i.e. all bytes copied + * + * Contrary to other copy_from_user() variants this function can be called + * from NMI context. Despite the name it is not restricted to be called + * from NMI context. It is safe to be called from any other context as + * well. It disables pagefaults across the copy which means a fault will + * abort the copy. + * + * For NMI context invocations this relies on the nested NMI work to allow + * atomic faults from the NMI path; the nested NMI paths are careful to + * preserve CR2. */ unsigned long copy_from_user_nmi(void *to, const void __user *from, unsigned long n) @@ -27,7 +41,7 @@ copy_from_user_nmi(void *to, const void __user *from, unsigned long n) /* * Even though this function is typically called from NMI/IRQ context * disable pagefaults so that its behaviour is consistent even when - * called form other contexts. + * called from other contexts. */ pagefault_disable(); ret = __copy_from_user_inatomic(to, from, n); |