From mboxrd@z Thu Jan 1 00:00:00 1970 From: labbott@fedoraproject.org (Laura Abbott) Date: Tue, 12 Jan 2016 13:46:27 -0800 Subject: [PATCH] arm64: Allow vmalloc regions to be set with set_memory_* Message-ID: <1452635187-8057-1-git-send-email-labbott@fedoraproject.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org The range of set_memory_* is currently restricted to the module address range because of difficulties in breaking down larger block sizes. vmalloc maps PAGE_SIZE pages so it is safe to use as well. Update the function ranges and add a comment explaining why the range is restricted the way it is. Signed-off-by: Laura Abbott --- This should let the protections for the eBPF work as expected, I don't know if there is some sort of self test for thatL. --- arch/arm64/mm/pageattr.c | 25 +++++++++++++++++++++---- 1 file changed, 21 insertions(+), 4 deletions(-) diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c index 3571c73..274208e 100644 --- a/arch/arm64/mm/pageattr.c +++ b/arch/arm64/mm/pageattr.c @@ -36,6 +36,26 @@ static int change_page_range(pte_t *ptep, pgtable_t token, unsigned long addr, return 0; } +static bool validate_addr(unsigned long start, unsigned long end) +{ + /* + * This check explicitly excludes most kernel memory. Most kernel + * memory is mapped with a larger page size and breaking down the + * larger page size without causing TLB conflicts is very difficult. + * + * If you need to call set_memory_* on a range, the recommendation is + * to use vmalloc since that range is mapped with pages. + */ + if (start >= MODULES_VADDR && start < MODULES_END && + end >= MODULES_VADDR && end < MODULES_END) + return true; + + if (is_vmalloc_addr(start) && is_vmalloc_addr(end)) + return true; + + return false; +} + static int change_memory_common(unsigned long addr, int numpages, pgprot_t set_mask, pgprot_t clear_mask) { @@ -51,10 +71,7 @@ static int change_memory_common(unsigned long addr, int numpages, WARN_ON_ONCE(1); } - if (start < MODULES_VADDR || start >= MODULES_END) - return -EINVAL; - - if (end < MODULES_VADDR || end >= MODULES_END) + if (!validate_addr(start, end)) return -EINVAL; data.set_mask = set_mask; -- 2.5.0