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From: Jordan Niethe <jniethe5@gmail.com>
To: linuxppc-dev@lists.ozlabs.org
Cc: ajd@linux.ibm.com, cmr@codefail.de, npiggin@gmail.com,
	aneesh.kumar@linux.ibm.com, naveen.n.rao@linux.ibm.com,
	Jordan Niethe <jniethe5@gmail.com>,
	dja@axtens.net
Subject: [PATCH v14 7/9] powerpc: Set ARCH_HAS_STRICT_MODULE_RWX
Date: Mon, 17 May 2021 13:28:08 +1000	[thread overview]
Message-ID: <20210517032810.129949-8-jniethe5@gmail.com> (raw)
In-Reply-To: <20210517032810.129949-1-jniethe5@gmail.com>

From: Russell Currey <ruscur@russell.cc>

To enable strict module RWX on powerpc, set:

    CONFIG_STRICT_MODULE_RWX=y

You should also have CONFIG_STRICT_KERNEL_RWX=y set to have any real
security benefit.

ARCH_HAS_STRICT_MODULE_RWX is set to require ARCH_HAS_STRICT_KERNEL_RWX.
This is due to a quirk in arch/Kconfig and arch/powerpc/Kconfig that
makes STRICT_MODULE_RWX *on by default* in configurations where
STRICT_KERNEL_RWX is *unavailable*.

Since this doesn't make much sense, and module RWX without kernel RWX
doesn't make much sense, having the same dependencies as kernel RWX
works around this problem.

Book32s/32 processors with a hash mmu (i.e. 604 core) can not set memory
protection on a page by page basis so do not enable.

Signed-off-by: Russell Currey <ruscur@russell.cc>
[jpn: - predicate on !PPC_BOOK3S_604
      - make module_alloc() use PAGE_KERNEL protection]
Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
---
v10: - Predicate on !PPC_BOOK3S_604
     - Make module_alloc() use PAGE_KERNEL protection
v11: - Neaten up
v13: Use strict_kernel_rwx_enabled()
v14: Make changes to module_alloc() its own commit
---
 arch/powerpc/Kconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index cce0a137b046..cb5d9d862c35 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -140,6 +140,7 @@ config PPC
 	select ARCH_HAS_SCALED_CPUTIME		if VIRT_CPU_ACCOUNTING_NATIVE && PPC_BOOK3S_64
 	select ARCH_HAS_SET_MEMORY
 	select ARCH_HAS_STRICT_KERNEL_RWX	if ((PPC_BOOK3S_64 || PPC32) && !HIBERNATION)
+	select ARCH_HAS_STRICT_MODULE_RWX	if ARCH_HAS_STRICT_KERNEL_RWX && !PPC_BOOK3S_604
 	select ARCH_HAS_TICK_BROADCAST		if GENERIC_CLOCKEVENTS_BROADCAST
 	select ARCH_HAS_UACCESS_FLUSHCACHE
 	select ARCH_HAS_COPY_MC			if PPC64
-- 
2.25.1


  parent reply	other threads:[~2021-05-17  3:37 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-17  3:28 [PATCH v14 0/9] powerpc: Further Strict RWX support Jordan Niethe
2021-05-17  3:28 ` [PATCH v14 1/9] powerpc/mm: Implement set_memory() routines Jordan Niethe
2021-05-17  3:28 ` [PATCH v14 2/9] powerpc/lib/code-patching: Set up Strict RWX patching earlier Jordan Niethe
2021-05-17  3:28 ` [PATCH v14 3/9] powerpc/modules: Make module_alloc() Strict Module RWX aware Jordan Niethe
2021-05-17  6:36   ` Christophe Leroy
2021-05-17  6:48     ` Jordan Niethe
2021-05-17 11:01       ` Michael Ellerman
2021-05-17 11:05         ` Christophe Leroy
2021-05-18  1:43           ` Michael Ellerman
2021-05-17  3:28 ` [PATCH v14 4/9] powerpc/kprobes: Mark newly allocated probes as ROX Jordan Niethe
2021-05-17  3:28 ` [PATCH v14 5/9] powerpc/bpf: Remove bpf_jit_free() Jordan Niethe
2021-05-17  3:28 ` [PATCH v14 6/9] powerpc/bpf: Write protect JIT code Jordan Niethe
2021-05-17  6:39   ` Christophe Leroy
2021-05-20  4:02     ` Jordan Niethe
2021-05-17  3:28 ` Jordan Niethe [this message]
2021-05-17  6:48   ` [PATCH v14 7/9] powerpc: Set ARCH_HAS_STRICT_MODULE_RWX Christophe Leroy
2021-05-20  3:50     ` Jordan Niethe
2021-05-17  3:28 ` [PATCH v14 8/9] powerpc/mm: implement set_memory_attr() Jordan Niethe
2021-05-17  3:28 ` [PATCH v14 9/9] powerpc/32: use set_memory_attr() Jordan Niethe

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