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| author | Andrew Morton <akpm@linux-foundation.org> | 2015-11-05 18:46:03 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-11-05 19:34:48 -0800 |
| commit | 0ab32b6f1b88444524e52429fab334ff96683a3f (patch) | |
| tree | 421de8da078f1ca72131097fdee0b9d4d1ef7c59 /arch | |
| parent | 86d2adccfbe7d5a1f050fa08db9638c9168736d9 (diff) | |
| download | linux-0ab32b6f1b88444524e52429fab334ff96683a3f.tar.gz | |
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')
| -rw-r--r-- | arch/arm/mm/alignment.c | 2 | ||||
| -rw-r--r-- | arch/powerpc/sysdev/fsl_pci.c | 2 |
2 files changed, 2 insertions, 2 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); } diff --git a/arch/powerpc/sysdev/fsl_pci.c b/arch/powerpc/sysdev/fsl_pci.c index ebc1f412cf49..13b9bcf5485e 100644 --- a/arch/powerpc/sysdev/fsl_pci.c +++ b/arch/powerpc/sysdev/fsl_pci.c @@ -999,7 +999,7 @@ int fsl_pci_mcheck_exception(struct pt_regs *regs) ret = get_user(regs->nip, &inst); pagefault_enable(); } else { - ret = probe_kernel_address(regs->nip, inst); + ret = probe_kernel_address((void *)regs->nip, inst); } if (mcheck_handle_load(regs, inst)) { |