diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2018-04-14 08:50:50 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-04-14 08:50:50 -0700 |
commit | 18b7fd1c93e5204355ddbf2608a097d64df81b88 (patch) | |
tree | 28f21a1c0fd621ef4fe3bd257adb970ca9039d88 /mm/gup.c | |
parent | 48023102b7078a6674516b1fe0d639669336049d (diff) | |
parent | df6f2801f511b07c08c110fe9f047a34cb40286f (diff) |
Merge branch 'akpm' (patches from Andrew)
Merge yet more updates from Andrew Morton:
- various hotfixes
- kexec_file updates and feature work
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (27 commits)
kernel/kexec_file.c: move purgatories sha256 to common code
kernel/kexec_file.c: allow archs to set purgatory load address
kernel/kexec_file.c: remove mis-use of sh_offset field during purgatory load
kernel/kexec_file.c: remove unneeded variables in kexec_purgatory_setup_sechdrs
kernel/kexec_file.c: remove unneeded for-loop in kexec_purgatory_setup_sechdrs
kernel/kexec_file.c: split up __kexec_load_puragory
kernel/kexec_file.c: use read-only sections in arch_kexec_apply_relocations*
kernel/kexec_file.c: search symbols in read-only kexec_purgatory
kernel/kexec_file.c: make purgatory_info->ehdr const
kernel/kexec_file.c: remove checks in kexec_purgatory_load
include/linux/kexec.h: silence compile warnings
kexec_file, x86: move re-factored code to generic side
x86: kexec_file: clean up prepare_elf64_headers()
x86: kexec_file: lift CRASH_MAX_RANGES limit on crash_mem buffer
x86: kexec_file: remove X86_64 dependency from prepare_elf64_headers()
x86: kexec_file: purge system-ram walking from prepare_elf64_headers()
kexec_file,x86,powerpc: factor out kexec_file_ops functions
kexec_file: make use of purgatory optional
proc: revalidate misc dentries
mm, slab: reschedule cache_reap() on the same CPU
...
Diffstat (limited to 'mm/gup.c')
-rw-r--r-- | mm/gup.c | 9 |
1 files changed, 7 insertions, 2 deletions
@@ -1740,7 +1740,9 @@ bool gup_fast_permitted(unsigned long start, int nr_pages, int write) /* * Like get_user_pages_fast() except it's IRQ-safe in that it won't fall back to - * the regular GUP. It will only return non-negative values. + * the regular GUP. + * Note a difference with get_user_pages_fast: this always returns the + * number of pages pinned, 0 if no pages were pinned. */ int __get_user_pages_fast(unsigned long start, int nr_pages, int write, struct page **pages) @@ -1806,9 +1808,12 @@ int get_user_pages_fast(unsigned long start, int nr_pages, int write, len = (unsigned long) nr_pages << PAGE_SHIFT; end = start + len; + if (nr_pages <= 0) + return 0; + if (unlikely(!access_ok(write ? VERIFY_WRITE : VERIFY_READ, (void __user *)start, len))) - return 0; + return -EFAULT; if (gup_fast_permitted(start, nr_pages, write)) { local_irq_disable(); |