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authorLinus Torvalds <torvalds@linux-foundation.org>2021-09-09 22:25:49 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2021-09-09 22:25:49 +0200
commit35776f10513c0d523c5dd2f1b415f642497779e2 (patch)
treea99b60499d587d9b2e9ecc68d6159dd3550aa874 /mm
parentMerge tag 'trace-v5.15-2' of git://git.kernel.org/pub/scm/linux/kernel/git/ro... (diff)
parentARM: 9118/1: div64: Remove always-true __div64_const32_is_OK() duplicate (diff)
downloadlinux-35776f10513c0d523c5dd2f1b415f642497779e2.tar.xz
linux-35776f10513c0d523c5dd2f1b415f642497779e2.zip
Merge tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm
Pull ARM development updates from Russell King: - Rename "mod_init" and "mod_exit" so that initcall debug output is actually useful (Randy Dunlap) - Update maintainers entries for linux-arm-kernel to indicate it is moderated for non-subscribers (Randy Dunlap) - Move install rules to arch/arm/Makefile (Masahiro Yamada) - Drop unnecessary ARCH_NR_GPIOS definition (Linus Walleij) - Don't warn about atags_to_fdt() stack size (David Heidelberg) - Speed up unaligned copy_{from,to}_kernel_nofault (Arnd Bergmann) - Get rid of set_fs() usage (Arnd Bergmann) - Remove checks for GCC prior to v4.6 (Geert Uytterhoeven) * tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm: ARM: 9118/1: div64: Remove always-true __div64_const32_is_OK() duplicate ARM: 9117/1: asm-generic: div64: Remove always-true __div64_const32_is_OK() ARM: 9116/1: unified: Remove check for gcc < 4 ARM: 9110/1: oabi-compat: fix oabi epoll sparse warning ARM: 9113/1: uaccess: remove set_fs() implementation ARM: 9112/1: uaccess: add __{get,put}_kernel_nofault ARM: 9111/1: oabi-compat: rework fcntl64() emulation ARM: 9114/1: oabi-compat: rework sys_semtimedop emulation ARM: 9108/1: oabi-compat: rework epoll_wait/epoll_pwait emulation ARM: 9107/1: syscall: always store thread_info->abi_syscall ARM: 9109/1: oabi-compat: add epoll_pwait handler ARM: 9106/1: traps: use get_kernel_nofault instead of set_fs() ARM: 9115/1: mm/maccess: fix unaligned copy_{from,to}_kernel_nofault ARM: 9105/1: atags_to_fdt: don't warn about stack size ARM: 9103/1: Drop ARCH_NR_GPIOS definition ARM: 9102/1: move theinstall rules to arch/arm/Makefile ARM: 9100/1: MAINTAINERS: mark all linux-arm-kernel@infradead list as moderated ARM: 9099/1: crypto: rename 'mod_init' & 'mod_exit' functions to be module-specific
Diffstat (limited to 'mm')
-rw-r--r--mm/maccess.c28
1 files changed, 22 insertions, 6 deletions
diff --git a/mm/maccess.c b/mm/maccess.c
index 3bd70405f2d8..d3f1a1f0b1c1 100644
--- a/mm/maccess.c
+++ b/mm/maccess.c
@@ -24,13 +24,21 @@ bool __weak copy_from_kernel_nofault_allowed(const void *unsafe_src,
long copy_from_kernel_nofault(void *dst, const void *src, size_t size)
{
+ unsigned long align = 0;
+
+ if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS))
+ align = (unsigned long)dst | (unsigned long)src;
+
if (!copy_from_kernel_nofault_allowed(src, size))
return -ERANGE;
pagefault_disable();
- copy_from_kernel_nofault_loop(dst, src, size, u64, Efault);
- copy_from_kernel_nofault_loop(dst, src, size, u32, Efault);
- copy_from_kernel_nofault_loop(dst, src, size, u16, Efault);
+ if (!(align & 7))
+ copy_from_kernel_nofault_loop(dst, src, size, u64, Efault);
+ if (!(align & 3))
+ copy_from_kernel_nofault_loop(dst, src, size, u32, Efault);
+ if (!(align & 1))
+ copy_from_kernel_nofault_loop(dst, src, size, u16, Efault);
copy_from_kernel_nofault_loop(dst, src, size, u8, Efault);
pagefault_enable();
return 0;
@@ -50,10 +58,18 @@ EXPORT_SYMBOL_GPL(copy_from_kernel_nofault);
long copy_to_kernel_nofault(void *dst, const void *src, size_t size)
{
+ unsigned long align = 0;
+
+ if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS))
+ align = (unsigned long)dst | (unsigned long)src;
+
pagefault_disable();
- copy_to_kernel_nofault_loop(dst, src, size, u64, Efault);
- copy_to_kernel_nofault_loop(dst, src, size, u32, Efault);
- copy_to_kernel_nofault_loop(dst, src, size, u16, Efault);
+ if (!(align & 7))
+ copy_to_kernel_nofault_loop(dst, src, size, u64, Efault);
+ if (!(align & 3))
+ copy_to_kernel_nofault_loop(dst, src, size, u32, Efault);
+ if (!(align & 1))
+ copy_to_kernel_nofault_loop(dst, src, size, u16, Efault);
copy_to_kernel_nofault_loop(dst, src, size, u8, Efault);
pagefault_enable();
return 0;