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authorAndrew Morton <akpm@linux-foundation.org>2015-11-06 05:46:03 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2015-11-06 06:34:48 +0300
commit0ab32b6f1b88444524e52429fab334ff96683a3f (patch)
tree421de8da078f1ca72131097fdee0b9d4d1ef7c59 /arch/arm/mm/alignment.c
parent86d2adccfbe7d5a1f050fa08db9638c9168736d9 (diff)
downloadlinux-0ab32b6f1b88444524e52429fab334ff96683a3f.tar.xz
uaccess: reimplement probe_kernel_address() using probe_kernel_read()
probe_kernel_address() is basically the same as the (later added) probe_kernel_read(). The return value on EFAULT is a bit different: probe_kernel_address() returns number-of-bytes-not-copied whereas probe_kernel_read() returns -EFAULT. All callers have been checked, none cared. probe_kernel_read() can be overridden by the architecture whereas probe_kernel_address() cannot. parisc, blackfin and um do this, to insert additional checking. Hence this patch possibly fixes obscure bugs, although there are only two probe_kernel_address() callsites outside arch/. My first attempt involved removing probe_kernel_address() entirely and converting all callsites to use probe_kernel_read() directly, but that got tiresome. This patch shrinks mm/slab_common.o by 218 bytes. For a single probe_kernel_address() callsite. Cc: Steven Miao <realmz6@gmail.com> Cc: Jeff Dike <jdike@addtoit.com> Cc: Richard Weinberger <richard@nod.at> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/arm/mm/alignment.c')
-rw-r--r--arch/arm/mm/alignment.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/arm/mm/alignment.c b/arch/arm/mm/alignment.c
index 00b7f7de28a1..7d5f4c736a16 100644
--- a/arch/arm/mm/alignment.c
+++ b/arch/arm/mm/alignment.c
@@ -803,7 +803,7 @@ do_alignment(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
}
}
} else {
- fault = probe_kernel_address(instrptr, instr);
+ fault = probe_kernel_address((void *)instrptr, instr);
instr = __mem_to_opcode_arm(instr);
}