Messages in this thread | | | Date | Tue, 27 Feb 2018 09:16:09 -0800 | From | Davidlohr Bueso <> | Subject | Re: [PATCH] ia64/err-inject: Use get_user_pages_fast() |
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Andrew, if you're ok with the patch below, could it be routed your way?
Thanks, Davidlohr
On Mon, 22 Jan 2018, Davidlohr Bueso wrote:
>At the point of sysfs callback, the call to gup is >done without mmap_sem (or any lock for that matter). >This is racy. As such, use the get_user_pages_fast() >alternative and safely avoid taking the lock, if possible. > >Signed-off-by: Davidlohr Bueso <dbueso@suse.de> >--- > arch/ia64/kernel/err_inject.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > >diff --git a/arch/ia64/kernel/err_inject.c b/arch/ia64/kernel/err_inject.c >index 85bba43e7d5d..658a8e06a69b 100644 >--- a/arch/ia64/kernel/err_inject.c >+++ b/arch/ia64/kernel/err_inject.c >@@ -142,7 +142,7 @@ store_virtual_to_phys(struct device *dev, struct device_attribute *attr, > u64 virt_addr=simple_strtoull(buf, NULL, 16); > int ret; > >- ret = get_user_pages(virt_addr, 1, FOLL_WRITE, NULL, NULL); >+ ret = get_user_pages_fast(virt_addr, 1, FOLL_WRITE, NULL); > if (ret<=0) { > #ifdef ERR_INJ_DEBUG > printk("Virtual address %lx is not existing.\n",virt_addr); >-- >2.13.6 >
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