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authorArnd Bergmann <arnd@arndb.de>2022-02-15 17:55:04 +0100
committerArnd Bergmann <arnd@arndb.de>2022-02-25 09:36:05 +0100
commit12700c17fc286149324f92d6d380bc48e43f253d (patch)
tree63157067b99d0adec5db4058ab9235b4802d1e49 /arch/nds32/include/asm/uaccess.h
parentuaccess: fix type mismatch warnings from access_ok() (diff)
downloadlinux-dev-12700c17fc286149324f92d6d380bc48e43f253d.tar.xz
linux-dev-12700c17fc286149324f92d6d380bc48e43f253d.zip
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 <hch@lst.de> Acked-by: Mark Rutland <mark.rutland@arm.com> [arm64, asm-generic] Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Stafford Horne <shorne@gmail.com> Acked-by: Dinh Nguyen <dinguyen@kernel.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'arch/nds32/include/asm/uaccess.h')
-rw-r--r--arch/nds32/include/asm/uaccess.h7
1 files changed, 2 insertions, 5 deletions
diff --git a/arch/nds32/include/asm/uaccess.h b/arch/nds32/include/asm/uaccess.h
index 37a40981deb3..832d642a4068 100644
--- a/arch/nds32/include/asm/uaccess.h
+++ b/arch/nds32/include/asm/uaccess.h
@@ -38,18 +38,15 @@ extern int fixup_exception(struct pt_regs *regs);
#define get_fs() (current_thread_info()->addr_limit)
#define user_addr_max get_fs
+#define uaccess_kernel() (get_fs() == KERNEL_DS)
static inline void set_fs(mm_segment_t fs)
{
current_thread_info()->addr_limit = fs;
}
-#define uaccess_kernel() (get_fs() == KERNEL_DS)
+#include <asm-generic/access_ok.h>
-#define __range_ok(addr, size) (size <= get_fs() && addr <= (get_fs() -size))
-
-#define access_ok(addr, size) \
- __range_ok((unsigned long)addr, (unsigned long)size)
/*
* Single-value transfer routines. They automatically use the right
* size if we just have the right pointer type. Note that the functions