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 <[email protected]>
---
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
On Mon, 17 Feb 2020 00:32:21 PST (-0800), [email protected] wrote:
> 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 <[email protected]>
> ---
> 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);
Ya, this'll risk barfing because of srodata.
> + 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)
> {
Palmer Dabbelt <[email protected]> 於 2020年3月5日 週四 上午9:22寫道：
>
> On Mon, 17 Feb 2020 00:32:21 PST (-0800), [email protected] wrote:
> > 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 <[email protected]>
> > ---
> > 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);
>
> Ya, this'll risk barfing because of srodata.
It might be OK because the range includes .rodata, .srodata and
__ex_table sections, but I need another symbol instead of _sdata as
you mentioned in other patch.
>
> > + 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)
> > {
>