From: Zong Li <zong.li@sifive.com>
To: paul.walmsley@sifive.com, palmer@dabbelt.com,
aou@eecs.berkeley.edu, linux-riscv@lists.infradead.org,
linux-kernel@vger.kernel.org
Cc: Zong Li <zong.li@sifive.com>
Subject: [PATCH 6/8] riscv: add STRICT_KERNEL_RWX support
Date: Mon, 17 Feb 2020 16:32:21 +0800 [thread overview]
Message-ID: <20200217083223.2011-7-zong.li@sifive.com> (raw)
In-Reply-To: <20200217083223.2011-1-zong.li@sifive.com>
The commit contains that make text section as non-writable, rodata
section as read-only, and data section as non-executable.
The init section should be changed to non-executable.
Signed-off-by: Zong Li <zong.li@sifive.com>
---
arch/riscv/Kconfig | 1 +
arch/riscv/include/asm/set_memory.h | 8 +++++
arch/riscv/mm/init.c | 45 +++++++++++++++++++++++++++++
3 files changed, 54 insertions(+)
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index f524d7e60648..308a4dbc0b39 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -62,6 +62,7 @@ config RISCV
select ARCH_HAS_GIGANTIC_PAGE
select ARCH_HAS_SET_DIRECT_MAP
select ARCH_HAS_SET_MEMORY
+ select ARCH_HAS_STRICT_KERNEL_RWX
select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
select SPARSEMEM_STATIC if 32BIT
select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
diff --git a/arch/riscv/include/asm/set_memory.h b/arch/riscv/include/asm/set_memory.h
index a91f192063c2..d3076087cb34 100644
--- a/arch/riscv/include/asm/set_memory.h
+++ b/arch/riscv/include/asm/set_memory.h
@@ -15,6 +15,14 @@ int set_memory_rw(unsigned long addr, int numpages);
int set_memory_x(unsigned long addr, int numpages);
int set_memory_nx(unsigned long addr, int numpages);
+#ifdef CONFIG_STRICT_KERNEL_RWX
+void set_kernel_text_ro(void);
+void set_kernel_text_rw(void);
+#else
+static inline void set_kernel_text_ro(void) { }
+static inline void set_kernel_text_rw(void) { }
+#endif
+
int set_direct_map_invalid_noflush(struct page *page);
int set_direct_map_default_noflush(struct page *page);
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index 965a8cf4829c..09fa643e079c 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -12,11 +12,13 @@
#include <linux/sizes.h>
#include <linux/of_fdt.h>
#include <linux/libfdt.h>
+#include <linux/set_memory.h>
#include <asm/fixmap.h>
#include <asm/tlbflush.h>
#include <asm/sections.h>
#include <asm/pgtable.h>
+#include <asm/ptdump.h>
#include <asm/io.h>
#include "../kernel/head.h"
@@ -477,6 +479,49 @@ static void __init setup_vm_final(void)
csr_write(CSR_SATP, PFN_DOWN(__pa_symbol(swapper_pg_dir)) | SATP_MODE);
local_flush_tlb_all();
}
+
+#ifdef CONFIG_STRICT_KERNEL_RWX
+void set_kernel_text_rw(void)
+{
+ unsigned long text_start = (unsigned long)_text;
+ unsigned long text_end = (unsigned long)_etext;
+
+ set_memory_rw(text_start, (text_end - text_start) >> PAGE_SHIFT);
+}
+
+void set_kernel_text_ro(void)
+{
+ unsigned long text_start = (unsigned long)_text;
+ unsigned long text_end = (unsigned long)_etext;
+
+ set_memory_ro(text_start, (text_end - text_start) >> PAGE_SHIFT);
+}
+
+void mark_rodata_ro(void)
+{
+ unsigned long text_start = (unsigned long)_text;
+ unsigned long text_end = (unsigned long)_etext;
+ unsigned long rodata_start = (unsigned long)__start_rodata;
+ unsigned long data_start = (unsigned long)_sdata;
+ unsigned long max_low = (unsigned long)(__va(PFN_PHYS(max_low_pfn)));
+
+ set_memory_ro(text_start, (text_end - text_start) >> PAGE_SHIFT);
+ set_memory_ro(rodata_start, (data_start - rodata_start) >> PAGE_SHIFT);
+ set_memory_nx(rodata_start, (data_start - rodata_start) >> PAGE_SHIFT);
+ set_memory_nx(data_start, (max_low - data_start) >> PAGE_SHIFT);
+}
+#endif
+
+void free_initmem(void)
+{
+ unsigned long init_begin = (unsigned long)__init_begin;
+ unsigned long init_end = (unsigned long)__init_end;
+
+ /* Make the region as non-execuatble. */
+ set_memory_nx(init_begin, (init_end - init_begin) >> PAGE_SHIFT);
+ free_initmem_default(POISON_FREE_INITMEM);
+}
+
#else
asmlinkage void __init setup_vm(uintptr_t dtb_pa)
{
--
2.25.0
next prev parent reply other threads:[~2020-02-17 8:32 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-17 8:32 [PATCH 0/8] Support strict kernel memory permissions for security Zong Li
2020-02-17 8:32 ` [PATCH 1/8] riscv: add ARCH_HAS_SET_MEMORY support Zong Li
2020-03-05 0:57 ` Palmer Dabbelt
2020-02-17 8:32 ` [PATCH 2/8] riscv: add ARCH_HAS_SET_DIRECT_MAP support Zong Li
2020-03-05 0:57 ` Palmer Dabbelt
2020-02-17 8:32 ` [PATCH 3/8] riscv: add ARCH_SUPPORTS_DEBUG_PAGEALLOC support Zong Li
2020-03-05 0:57 ` Palmer Dabbelt
2020-02-17 8:32 ` [PATCH 4/8] riscv: move exception table immediately after RO_DATA Zong Li
2020-03-05 0:57 ` Palmer Dabbelt
2020-03-05 4:01 ` Zong Li
2020-02-17 8:32 ` [PATCH 5/8] riscv: add alignment for text, rodata and data sections Zong Li
2020-03-05 0:58 ` Palmer Dabbelt
2020-02-17 8:32 ` Zong Li [this message]
2020-03-05 1:21 ` [PATCH 6/8] riscv: add STRICT_KERNEL_RWX support Palmer Dabbelt
2020-03-05 4:08 ` Zong Li
2020-02-17 8:32 ` [PATCH 7/8] riscv: add DEBUG_WX support Zong Li
2020-03-05 1:44 ` Palmer Dabbelt
2020-03-05 5:53 ` Zong Li
2020-02-17 8:32 ` [PATCH 8/8] riscv: add two hook functions of ftrace Zong Li
2020-03-05 1:44 ` Palmer Dabbelt
2020-03-05 4:27 ` Zong Li
2020-03-05 15:55 ` [PATCH 0/8] Support strict kernel memory permissions for security Palmer Dabbelt
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