From: Anshuman Khandual Date: Mon, 4 Dec 2017 05:49:22 +0000 (+0530) Subject: powerpc/mm: Invalidate subpage_prot() system call on radix platforms X-Git-Tag: Ubuntu-5.2.0-15.16~5062^2~68 X-Git-Url: https://git.proxmox.com/?a=commitdiff_plain;h=5b2b80714796073ec9e196c7aeec59b7489fe676;p=mirror_ubuntu-eoan-kernel.git powerpc/mm: Invalidate subpage_prot() system call on radix platforms Radix enabled platforms don't support subpage_prot() system calls. But at present the system call goes through without an error and fails later on while validating expected subpage accesses. Lets not allow the system call on powerpc radix platforms to begin with to prevent this confusion in user space. Signed-off-by: Anshuman Khandual Signed-off-by: Michael Ellerman --- diff --git a/arch/powerpc/mm/subpage-prot.c b/arch/powerpc/mm/subpage-prot.c index 781532d7bc4d..f14a07c2fb90 100644 --- a/arch/powerpc/mm/subpage-prot.c +++ b/arch/powerpc/mm/subpage-prot.c @@ -195,6 +195,9 @@ long sys_subpage_prot(unsigned long addr, unsigned long len, u32 __user *map) unsigned long next, limit; int err; + if (radix_enabled()) + return -ENOENT; + /* Check parameters */ if ((addr & ~PAGE_MASK) || (len & ~PAGE_MASK) || addr >= mm->task_size || len >= mm->task_size ||