[PATCH 5/9] x86/mm/pat: don't warn about W^X violations before mark_rodata_ro()

["Mike Rapoport (Microsoft)" <rppt@kernel.org>]

The kernel text is mapped RWX until mark_rodata_ro(), so W^X violations
that verify_rwx() detects before that can be false positives.

CHECK_WX is enabled by default with STRICT_KERNEL_RWX and it reports
mappings that remain W+X after mark_rodata_ro().

Drop the warning about W^X violations before mark_rodata_ro().

Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
---
 arch/x86/mm/pat/set_memory.c | 18 ++++++------------
 1 file changed, 6 insertions(+), 12 deletions(-)

diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c
index a1bea16a3c3bb..a674433850dc9 100644
--- a/arch/x86/mm/pat/set_memory.c
+++ b/arch/x86/mm/pat/set_memory.c
@@ -718,21 +718,15 @@ static inline pgprot_t verify_rwx(pgprot_t old, pgprot_t new, unsigned long star
 	if (!rw || nx)
 		return new;
 
-	end = start + npg * PAGE_SIZE - 1;
-
 	/*
-	 * If the kernel text is still RWX, gently complain, this could be a
-	 * false positive.
-	 * Once debug_checkwx() becomes mandatory for CONFIG_STRICT_KERNEL_RWX,
-	 * the warning can be removed completely.
+	 * The kernel text is RWX until mark_rodata_ro() and the entire kernel
+	 * page table is verified after the text is protected, so there is no
+	 * need to warn.
 	 */
-	if (!kernel_set_to_readonly) {
-		pr_warn_once("CPA detected W^X violation: %016llx -> %016llx range: 0x%016lx - 0x%016lx PFN %lx\n",
-		  (unsigned long long)pgprot_val(old),
-		  (unsigned long long)pgprot_val(new),
-		  start, end, pfn);
+	if (!kernel_set_to_readonly)
 		return new;
-	}
+
+	end = start + npg * PAGE_SIZE - 1;
 
 	WARN_ONCE(1, "CPA detected W^X violation: %016llx -> %016llx range: 0x%016lx - 0x%016lx PFN %lx\n",
 		  (unsigned long long)pgprot_val(old),

-- 
2.53.0