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author | Olof Johansson <olof@lixom.net> | 2013-11-15 15:17:59 -0800 |
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committer | Olof Johansson <olof@lixom.net> | 2013-11-15 15:17:59 -0800 |
commit | 6886059f2ef5d62c73e87a905e84fa4f87d56074 (patch) | |
tree | dfe6e1611d7c50057df52db7b55eafbfb8e33a93 /arch/x86/lib/usercopy.c | |
parent | ca439c9b983ffa14e9eae6030e3ee80ad039388f (diff) | |
parent | 26273e02a0cf18eb72416559310d3294390a9024 (diff) |
Merge tag 'omap-for-v3.13/fixes-for-merge-window-take2' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap into fixes
Few clock fixes, a runtime PM fix, and pinctrl-single fix along
with few other fixes that popped up during the merge window.
* tag 'omap-for-v3.13/fixes-for-merge-window-take2' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap:
ARM: OMAP2+: Fix build for dra7xx without omap4 and 5
ARM: OMAP2+: omap_device: maintain sane runtime pm status around suspend/resume
doc: devicetree: Add bindings documentation for omap-des driver
ARM: dts: doc: Document missing compatible property for omap-sham driver
ARM: OMAP3: Beagle: fix return value check in beagle_opp_init()
ARM: OMAP: devicetree: fix SPI node compatible property syntax items
pinctrl: single: call pcs_soc->rearm() whenever IRQ mask is changed
ARM: OMAP2+: smsc911x: fix return value check in gpmc_smsc911x_init()
+ sync with newer trunk
Diffstat (limited to 'arch/x86/lib/usercopy.c')
-rw-r--r-- | arch/x86/lib/usercopy.c | 43 |
1 files changed, 15 insertions, 28 deletions
diff --git a/arch/x86/lib/usercopy.c b/arch/x86/lib/usercopy.c index 4f74d94c8d97..ddf9ecb53cc3 100644 --- a/arch/x86/lib/usercopy.c +++ b/arch/x86/lib/usercopy.c @@ -11,39 +11,26 @@ #include <linux/sched.h> /* - * best effort, GUP based copy_from_user() that is NMI-safe + * We rely on the nested NMI work to allow atomic faults from the NMI path; the + * nested NMI paths are careful to preserve CR2. */ unsigned long copy_from_user_nmi(void *to, const void __user *from, unsigned long n) { - unsigned long offset, addr = (unsigned long)from; - unsigned long size, len = 0; - struct page *page; - void *map; - int ret; + unsigned long ret; if (__range_not_ok(from, n, TASK_SIZE)) - return len; - - do { - ret = __get_user_pages_fast(addr, 1, 0, &page); - if (!ret) - break; - - offset = addr & (PAGE_SIZE - 1); - size = min(PAGE_SIZE - offset, n - len); - - map = kmap_atomic(page); - memcpy(to, map+offset, size); - kunmap_atomic(map); - put_page(page); - - len += size; - to += size; - addr += size; - - } while (len < n); - - return len; + return 0; + + /* + * Even though this function is typically called from NMI/IRQ context + * disable pagefaults so that its behaviour is consistent even when + * called form other contexts. + */ + pagefault_disable(); + ret = __copy_from_user_inatomic(to, from, n); + pagefault_enable(); + + return ret; } EXPORT_SYMBOL_GPL(copy_from_user_nmi); |