linux-kernel - [PATCH] powerpc/mm/32s: only use MMU to mark initmem NX if STRICT_KERNEL

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Sat, 15 Jun 2019 14:47:29 +0200
From:   Andreas Schwab <schwab@...ux-m68k.org>
To:     Christophe Leroy <christophe.leroy@....fr>
Cc:     Benjamin Herrenschmidt <benh@...nel.crashing.org>,
        Paul Mackerras <paulus@...ba.org>,
        Michael Ellerman <mpe@...erman.id.au>, j.neuschaefer@....net,
        linux-kernel@...r.kernel.org, linuxppc-dev@...ts.ozlabs.org
Subject: [PATCH] powerpc/mm/32s: only use MMU to mark initmem NX if STRICT_KERNEL_RWX

If STRICT_KERNEL_RWX is disabled, never use the MMU to mark initmen
nonexecutable.

Also move a misplaced paren that makes the condition always true.

Fixes: 63b2bc619565 ("powerpc/mm/32s: Use BATs for STRICT_KERNEL_RWX")
Signed-off-by: Andreas Schwab <schwab@...ux-m68k.org>
---
 arch/powerpc/mm/pgtable_32.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/mm/pgtable_32.c b/arch/powerpc/mm/pgtable_32.c
index d53188dee18f..3935dc263d65 100644
--- a/arch/powerpc/mm/pgtable_32.c
+++ b/arch/powerpc/mm/pgtable_32.c
@@ -360,9 +360,11 @@ void mark_initmem_nx(void)
 	unsigned long numpages = PFN_UP((unsigned long)_einittext) -
 				 PFN_DOWN((unsigned long)_sinittext);
 
-	if (v_block_mapped((unsigned long)_stext) + 1)
+#ifdef CONFIG_STRICT_KERNEL_RWX
+	if (v_block_mapped((unsigned long)_stext + 1))
 		mmu_mark_initmem_nx();
 	else
+#endif
 		change_page_attr(page, numpages, PAGE_KERNEL);
 }
 
-- 
2.22.0

-- 
Andreas Schwab, schwab@...ux-m68k.org
GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510  2552 DF73 E780 A9DA AEC1
"And now for something completely different."