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author | Linus Torvalds <torvalds@linux-foundation.org> | 2020-06-09 09:54:46 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-06-09 09:54:46 -0700 |
commit | a5ad5742f671de906adbf29fbedf0a04705cebad (patch) | |
tree | 88d1a4c18e2025a5a8335dbbc9dea8bebeba5789 /arch/x86/mm/maccess.c | |
parent | 013b2deba9a6b80ca02f4fafd7dedf875e9b4450 (diff) | |
parent | 4fa7252338a56fbc90220e6330f136a379175a7a (diff) | |
download | linux-a5ad5742f671de906adbf29fbedf0a04705cebad.tar.gz linux-a5ad5742f671de906adbf29fbedf0a04705cebad.tar.bz2 linux-a5ad5742f671de906adbf29fbedf0a04705cebad.zip |
Merge branch 'akpm' (patches from Andrew)
Merge even more updates from Andrew Morton:
- a kernel-wide sweep of show_stack()
- pagetable cleanups
- abstract out accesses to mmap_sem - prep for mmap_sem scalability work
- hch's user acess work
Subsystems affected by this patch series: debug, mm/pagemap, mm/maccess,
mm/documentation.
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (93 commits)
include/linux/cache.h: expand documentation over __read_mostly
maccess: return -ERANGE when probe_kernel_read() fails
x86: use non-set_fs based maccess routines
maccess: allow architectures to provide kernel probing directly
maccess: move user access routines together
maccess: always use strict semantics for probe_kernel_read
maccess: remove strncpy_from_unsafe
tracing/kprobes: handle mixed kernel/userspace probes better
bpf: rework the compat kernel probe handling
bpf:bpf_seq_printf(): handle potentially unsafe format string better
bpf: handle the compat string in bpf_trace_copy_string better
bpf: factor out a bpf_trace_copy_string helper
maccess: unify the probe kernel arch hooks
maccess: remove probe_read_common and probe_write_common
maccess: rename strnlen_unsafe_user to strnlen_user_nofault
maccess: rename strncpy_from_unsafe_strict to strncpy_from_kernel_nofault
maccess: rename strncpy_from_unsafe_user to strncpy_from_user_nofault
maccess: update the top of file comment
maccess: clarify kerneldoc comments
maccess: remove duplicate kerneldoc comments
...
Diffstat (limited to 'arch/x86/mm/maccess.c')
-rw-r--r-- | arch/x86/mm/maccess.c | 28 |
1 files changed, 7 insertions, 21 deletions
diff --git a/arch/x86/mm/maccess.c b/arch/x86/mm/maccess.c index f5b85bdc0535..e1d7d7477c22 100644 --- a/arch/x86/mm/maccess.c +++ b/arch/x86/mm/maccess.c @@ -9,35 +9,21 @@ 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) { + unsigned long vaddr = (unsigned long)unsafe_src; + /* * 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) { - return vaddr < TASK_SIZE_MAX; + 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_unsafe_strict(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); -} |