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 v12 6/8] powerpc: Set ARCH_HAS_STRICT_MODULE_RWX
Date: Thu, 6 May 2021 12:34:47 +1000 [thread overview]
Message-ID: <20210506023449.3568630-7-jniethe5@gmail.com> (raw)
In-Reply-To: <20210506023449.3568630-1-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.
With STRICT_MODULE_RWX, now make module_alloc() allocate pages with
KERNEL_PAGE protection rather than KERNEL_PAGE_EXEC.
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
---
arch/powerpc/Kconfig | 1 +
arch/powerpc/kernel/module.c | 4 +++-
2 files changed, 4 insertions(+), 1 deletion(-)
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
diff --git a/arch/powerpc/kernel/module.c b/arch/powerpc/kernel/module.c
index 3f35c8d20be7..33e4011228b0 100644
--- a/arch/powerpc/kernel/module.c
+++ b/arch/powerpc/kernel/module.c
@@ -92,12 +92,14 @@ int module_finalize(const Elf_Ehdr *hdr,
static __always_inline void *
__module_alloc(unsigned long size, unsigned long start, unsigned long end)
{
+ pgprot_t prot = IS_ENABLED(CONFIG_STRICT_MODULE_RWX) ? PAGE_KERNEL :
+ PAGE_KERNEL_EXEC;
/*
* Don't do huge page allocations for modules yet until more testing
* is done. STRICT_MODULE_RWX may require extra work to support this
* too.
*/
- return __vmalloc_node_range(size, 1, start, end, GFP_KERNEL, PAGE_KERNEL_EXEC,
+ return __vmalloc_node_range(size, 1, start, end, GFP_KERNEL, prot,
VM_FLUSH_RESET_PERMS | VM_NO_HUGE_VMAP,
NUMA_NO_NODE, __builtin_return_address(0));
}
--
2.25.1
next prev parent reply other threads:[~2021-05-06 2:41 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-06 2:34 [PATCH v12 0/8] powerpc: Further Strict RWX support Jordan Niethe
2021-05-06 2:34 ` [PATCH v12 1/8] powerpc/mm: Implement set_memory() routines Jordan Niethe
2021-05-06 2:34 ` [PATCH v12 2/8] powerpc/lib/code-patching: Set up Strict RWX patching earlier Jordan Niethe
2021-05-07 5:51 ` Christophe Leroy
2021-05-06 2:34 ` [PATCH v12 3/8] powerpc/kprobes: Mark newly allocated probes as ROX Jordan Niethe
2021-05-07 5:34 ` Christophe Leroy
2021-05-06 2:34 ` [PATCH v12 4/8] powerpc/bpf: Remove bpf_jit_free() Jordan Niethe
2021-05-07 5:51 ` Christophe Leroy
2021-05-06 2:34 ` [PATCH v12 5/8] powerpc/bpf: Write protect JIT code Jordan Niethe
2021-05-07 5:53 ` Christophe Leroy
2021-05-06 2:34 ` Jordan Niethe [this message]
2021-05-07 5:35 ` [PATCH v12 6/8] powerpc: Set ARCH_HAS_STRICT_MODULE_RWX Christophe Leroy
2021-05-10 0:52 ` Jordan Niethe
2021-05-06 2:34 ` [PATCH v12 7/8] powerpc/mm: implement set_memory_attr() Jordan Niethe
2021-05-06 2:34 ` [PATCH v12 8/8] powerpc/32: use set_memory_attr() Jordan Niethe
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