From 12700c17fc286149324f92d6d380bc48e43f253d Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Tue, 15 Feb 2022 17:55:04 +0100 Subject: uaccess: generalize access_ok() There are many different ways that access_ok() is defined across architectures, but in the end, they all just compare against the user_addr_max() value or they accept anything. Provide one definition that works for most architectures, checking against TASK_SIZE_MAX for user processes or skipping the check inside of uaccess_kernel() sections. For architectures without CONFIG_SET_FS(), this should be the fastest check, as it comes down to a single comparison of a pointer against a compile-time constant, while the architecture specific versions tend to do something more complex for historic reasons or get something wrong. Type checking for __user annotations is handled inconsistently across architectures, but this is easily simplified as well by using an inline function that takes a 'const void __user *' argument. A handful of callers need an extra __user annotation for this. Some architectures had trick to use 33-bit or 65-bit arithmetic on the addresses to calculate the overflow, however this simpler version uses fewer registers, which means it can produce better object code in the end despite needing a second (statically predicted) branch. Reviewed-by: Christoph Hellwig Acked-by: Mark Rutland [arm64, asm-generic] Acked-by: Geert Uytterhoeven Acked-by: Stafford Horne Acked-by: Dinh Nguyen Signed-off-by: Arnd Bergmann --- arch/microblaze/include/asm/uaccess.h | 8 +------- 1 file changed, 1 insertion(+), 7 deletions(-) (limited to 'arch/microblaze') diff --git a/arch/microblaze/include/asm/uaccess.h b/arch/microblaze/include/asm/uaccess.h index 3fe96979d2c6..bf9b7657a65a 100644 --- a/arch/microblaze/include/asm/uaccess.h +++ b/arch/microblaze/include/asm/uaccess.h @@ -39,13 +39,7 @@ # define uaccess_kernel() (get_fs().seg == KERNEL_DS.seg) -static inline int __access_ok(unsigned long addr, unsigned long size) -{ - unsigned long limit = user_addr_max(); - - return (size <= limit) && (addr <= (limit - size)); -} -#define access_ok(addr, size) __access_ok((unsigned long)addr, size) +#include # define __FIXUP_SECTION ".section .fixup,\"ax\"\n" # define __EX_TABLE_SECTION ".section __ex_table,\"a\"\n" -- cgit v1.2.3