diff options
author | Christoph Hellwig <hch@lst.de> | 2020-06-08 21:34:27 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-06-09 09:39:15 -0700 |
commit | eab0c6089b68974ebc6a9a7eab68456eeb6a99c7 (patch) | |
tree | 6b03656fac37fc4c4e43c74e33a5fd5b9f3d2b68 /arch | |
parent | cd0309058f849257f08d1a3dd0c384d1fd20c1e8 (diff) | |
download | linux-eab0c6089b68974ebc6a9a7eab68456eeb6a99c7.tar.bz2 |
maccess: unify the probe kernel arch hooks
Currently architectures have to override every routine that probes
kernel memory, which includes a pure read and strcpy, both in strict
and not strict variants. Just provide a single arch hooks instead to
make sure all architectures cover all the cases.
[akpm@linux-foundation.org: fix !CONFIG_X86_64 build]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20200521152301.2587579-11-hch@lst.de
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch')
-rw-r--r-- | arch/parisc/lib/memcpy.c | 12 | ||||
-rw-r--r-- | arch/um/kernel/maccess.c | 10 | ||||
-rw-r--r-- | arch/x86/mm/maccess.c | 33 |
3 files changed, 20 insertions, 35 deletions
diff --git a/arch/parisc/lib/memcpy.c b/arch/parisc/lib/memcpy.c index beceaab34ecb..5b75c35d1da0 100644 --- a/arch/parisc/lib/memcpy.c +++ b/arch/parisc/lib/memcpy.c @@ -57,14 +57,10 @@ void * memcpy(void * dst,const void *src, size_t count) EXPORT_SYMBOL(raw_copy_in_user); EXPORT_SYMBOL(memcpy); -long probe_kernel_read(void *dst, const void *src, size_t size) +bool probe_kernel_read_allowed(const void *unsafe_src, size_t size, bool strict) { - unsigned long addr = (unsigned long)src; - - if (addr < PAGE_SIZE) - return -EFAULT; - + if ((unsigned long)unsafe_src < PAGE_SIZE) + return false; /* check for I/O space F_EXTEND(0xfff00000) access as well? */ - - return __probe_kernel_read(dst, src, size); + return true; } diff --git a/arch/um/kernel/maccess.c b/arch/um/kernel/maccess.c index 67b2e0fa92bb..ad2c538ce497 100644 --- a/arch/um/kernel/maccess.c +++ b/arch/um/kernel/maccess.c @@ -7,15 +7,13 @@ #include <linux/kernel.h> #include <os.h> -long probe_kernel_read(void *dst, const void *src, size_t size) +bool probe_kernel_read_allowed(const void *src, size_t size, bool strict) { void *psrc = (void *)rounddown((unsigned long)src, PAGE_SIZE); if ((unsigned long)src < PAGE_SIZE || size <= 0) - return -EFAULT; - + return false; if (os_mincore(psrc, size + src - psrc) <= 0) - return -EFAULT; - - return __probe_kernel_read(dst, src, size); + return false; + return true; } diff --git a/arch/x86/mm/maccess.c b/arch/x86/mm/maccess.c index 62c4017a2473..86000c1150e8 100644 --- a/arch/x86/mm/maccess.c +++ b/arch/x86/mm/maccess.c @@ -9,35 +9,26 @@ static __always_inline u64 canonical_address(u64 vaddr, u8 vaddr_bits) return ((s64)vaddr << (64 - vaddr_bits)) >> (64 - vaddr_bits); } -static __always_inline bool invalid_probe_range(u64 vaddr) +bool probe_kernel_read_allowed(const void *unsafe_src, size_t size, bool strict) { + unsigned long vaddr = (unsigned long)unsafe_src; + + if (!strict) + return true; + /* * Range covering the highest possible canonical userspace address * as well as non-canonical address range. For the canonical range * we also need to include the userspace guard page. */ - return vaddr < TASK_SIZE_MAX + PAGE_SIZE || - canonical_address(vaddr, boot_cpu_data.x86_virt_bits) != vaddr; + return vaddr >= TASK_SIZE_MAX + PAGE_SIZE && + canonical_address(vaddr, boot_cpu_data.x86_virt_bits) == vaddr; } #else -static __always_inline bool invalid_probe_range(u64 vaddr) +bool probe_kernel_read_allowed(const void *unsafe_src, size_t size, bool strict) { - return vaddr < TASK_SIZE_MAX; + if (!strict) + return true; + return (unsigned long)unsafe_src >= TASK_SIZE_MAX; } #endif - -long probe_kernel_read_strict(void *dst, const void *src, size_t size) -{ - if (unlikely(invalid_probe_range((unsigned long)src))) - return -EFAULT; - - return __probe_kernel_read(dst, src, size); -} - -long strncpy_from_kernel_nofault(char *dst, const void *unsafe_addr, long count) -{ - if (unlikely(invalid_probe_range((unsigned long)unsafe_addr))) - return -EFAULT; - - return __strncpy_from_unsafe(dst, unsafe_addr, count); -} |