* [RESEND][PATCH] x86, relocs: move ELF relocation handling to C
@ 2013-07-02 18:22 Kees Cook
2013-07-03 3:22 ` Zhang Yanfei
0 siblings, 1 reply; 4+ messages in thread
From: Kees Cook @ 2013-07-02 18:22 UTC (permalink / raw)
To: linux-kernel
Cc: Thomas Gleixner, Ingo Molnar, H. Peter Anvin, x86, Yinghai Lu,
Matt Fleming, Borislav Petkov, Alexander Duyck, Jacob Shin,
Pekka Enberg
Moves the relocation handling into C, after decompression. This requires
that the decompressed size is passed to the decompression routine as
well so that relocations can be found. Only kernels that need relocation
support will use the code (currently just x86_32), but this is laying
the ground work for 64-bit support in support of KASLR.
Based on work by Neill Clift and Michael Davidson.
Signed-off-by: Kees Cook <keescook@chromium.org>
---
arch/x86/Kconfig | 4 +-
arch/x86/Makefile | 8 ++--
arch/x86/boot/compressed/head_32.S | 31 ++------------
arch/x86/boot/compressed/head_64.S | 1 +
arch/x86/boot/compressed/misc.c | 77 +++++++++++++++++++++++++++++++++-
arch/x86/include/asm/page_32_types.h | 2 +
arch/x86/include/asm/page_64_types.h | 5 ---
arch/x86/include/asm/page_types.h | 6 +++
8 files changed, 94 insertions(+), 40 deletions(-)
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index fe120da..f11ad6f 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1695,13 +1695,13 @@ config RELOCATABLE
it has been loaded at and the compile time physical address
(CONFIG_PHYSICAL_START) is ignored.
-# Relocation on x86-32 needs some additional build support
+# Relocation on x86 needs some additional build support
config X86_NEED_RELOCS
def_bool y
depends on X86_32 && RELOCATABLE
config PHYSICAL_ALIGN
- hex "Alignment value to which kernel should be aligned" if X86_32
+ hex "Alignment value to which kernel should be aligned"
default "0x1000000"
range 0x2000 0x1000000
---help---
diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index 5c47726..43f8cef 100644
--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile
@@ -16,6 +16,10 @@ endif
# e.g.: obj-y += foo_$(BITS).o
export BITS
+ifdef CONFIG_X86_NEED_RELOCS
+ LDFLAGS_vmlinux := --emit-relocs
+endif
+
ifeq ($(CONFIG_X86_32),y)
BITS := 32
UTS_MACHINE := i386
@@ -25,10 +29,6 @@ ifeq ($(CONFIG_X86_32),y)
KBUILD_AFLAGS += $(biarch)
KBUILD_CFLAGS += $(biarch)
- ifdef CONFIG_RELOCATABLE
- LDFLAGS_vmlinux := --emit-relocs
- endif
-
KBUILD_CFLAGS += -msoft-float -mregparm=3 -freg-struct-return
# Never want PIC in a 32-bit kernel, prevent breakage with GCC built
diff --git a/arch/x86/boot/compressed/head_32.S b/arch/x86/boot/compressed/head_32.S
index 1e3184f..5d6f689 100644
--- a/arch/x86/boot/compressed/head_32.S
+++ b/arch/x86/boot/compressed/head_32.S
@@ -181,8 +181,9 @@ relocated:
/*
* Do the decompression, and jump to the new kernel..
*/
- leal z_extract_offset_negative(%ebx), %ebp
/* push arguments for decompress_kernel: */
+ pushl $z_output_len /* decompressed length */
+ leal z_extract_offset_negative(%ebx), %ebp
pushl %ebp /* output address */
pushl $z_input_len /* input_len */
leal input_data(%ebx), %eax
@@ -191,33 +192,7 @@ relocated:
pushl %eax /* heap area */
pushl %esi /* real mode pointer */
call decompress_kernel
- addl $20, %esp
-
-#if CONFIG_RELOCATABLE
-/*
- * Find the address of the relocations.
- */
- leal z_output_len(%ebp), %edi
-
-/*
- * Calculate the delta between where vmlinux was compiled to run
- * and where it was actually loaded.
- */
- movl %ebp, %ebx
- subl $LOAD_PHYSICAL_ADDR, %ebx
- jz 2f /* Nothing to be done if loaded at compiled addr. */
-/*
- * Process relocations.
- */
-
-1: subl $4, %edi
- movl (%edi), %ecx
- testl %ecx, %ecx
- jz 2f
- addl %ebx, -__PAGE_OFFSET(%ebx, %ecx)
- jmp 1b
-2:
-#endif
+ addl $24, %esp
/*
* Jump to the decompressed kernel.
diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S
index 16f24e6..6632693 100644
--- a/arch/x86/boot/compressed/head_64.S
+++ b/arch/x86/boot/compressed/head_64.S
@@ -340,6 +340,7 @@ relocated:
leaq input_data(%rip), %rdx /* input_data */
movl $z_input_len, %ecx /* input_len */
movq %rbp, %r8 /* output target address */
+ movq $z_output_len, %r9 /* decompressed length */
call decompress_kernel
popq %rsi
diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c
index 7cb56c6..b756a04 100644
--- a/arch/x86/boot/compressed/misc.c
+++ b/arch/x86/boot/compressed/misc.c
@@ -267,6 +267,79 @@ static void error(char *x)
asm("hlt");
}
+#if CONFIG_X86_NEED_RELOCS
+static void handle_relocations(void *output, unsigned long output_len)
+{
+ int *reloc;
+ unsigned long delta, map, ptr;
+ unsigned long min_addr = (unsigned long)output;
+ unsigned long max_addr = min_addr + output_len;
+
+ /*
+ * Calculate the delta between where vmlinux was linked to load
+ * and where it was actually loaded.
+ */
+ delta = min_addr - LOAD_PHYSICAL_ADDR;
+ if (!delta) {
+ debug_putstr("No relocation needed... ");
+ return;
+ }
+ debug_putstr("Performing relocations... ");
+
+ /*
+ * The kernel contains a table of relocation addresses. Those
+ * addresses have the final load address of the kernel in virtual
+ * memory. We are currently working in the self map. So we need to
+ * create an adjustment for kernel memory addresses to the self map.
+ * This will involve subtracting out the base address of the kernel.
+ */
+ map = delta - __START_KERNEL_map;
+
+ /*
+ * Process relocations: 32 bit relocations first then 64 bit after.
+ * Two sets of binary relocations are added to the end of the kernel
+ * before compression. Each relocation table entry is the kernel
+ * address of the location which needs to be updated stored as a
+ * 32-bit value which is sign extended to 64 bits.
+ *
+ * Format is:
+ *
+ * kernel bits...
+ * 0 - zero terminator for 64 bit relocations
+ * 64 bit relocation repeated
+ * 0 - zero terminator for 32 bit relocations
+ * 32 bit relocation repeated
+ *
+ * So we work backwards from the end of the decompressed image.
+ */
+ for (reloc = output + output_len - sizeof(*reloc); *reloc; reloc--) {
+ int extended = *reloc;
+ extended += map;
+
+ ptr = (unsigned long)extended;
+ if (ptr < min_addr || ptr > max_addr)
+ error("32-bit relocation outside of kernel!\n");
+
+ *(uint32_t *)ptr += delta;
+ }
+#ifdef CONFIG_X86_64
+ for (reloc--; *reloc; reloc--) {
+ long extended = *reloc;
+ extended += map;
+
+ ptr = (unsigned long)extended;
+ if (ptr < min_addr || ptr > max_addr)
+ error("64-bit relocation outside of kernel!\n");
+
+ *(uint64_t *)ptr += delta;
+ }
+#endif
+}
+#else
+static inline void handle_relocations(void *output, unsigned long output_len)
+{ }
+#endif
+
static void parse_elf(void *output)
{
#ifdef CONFIG_X86_64
@@ -321,7 +394,8 @@ static void parse_elf(void *output)
asmlinkage void decompress_kernel(void *rmode, memptr heap,
unsigned char *input_data,
unsigned long input_len,
- unsigned char *output)
+ unsigned char *output,
+ unsigned long output_len)
{
real_mode = rmode;
@@ -361,6 +435,7 @@ asmlinkage void decompress_kernel(void *rmode, memptr heap,
debug_putstr("\nDecompressing Linux... ");
decompress(input_data, input_len, NULL, NULL, output, NULL, error);
parse_elf(output);
+ handle_relocations(output, output_len);
debug_putstr("done.\nBooting the kernel.\n");
return;
}
diff --git a/arch/x86/include/asm/page_32_types.h b/arch/x86/include/asm/page_32_types.h
index ef17af0..f48b17d 100644
--- a/arch/x86/include/asm/page_32_types.h
+++ b/arch/x86/include/asm/page_32_types.h
@@ -15,6 +15,8 @@
*/
#define __PAGE_OFFSET _AC(CONFIG_PAGE_OFFSET, UL)
+#define __START_KERNEL_map __PAGE_OFFSET
+
#define THREAD_SIZE_ORDER 1
#define THREAD_SIZE (PAGE_SIZE << THREAD_SIZE_ORDER)
diff --git a/arch/x86/include/asm/page_64_types.h b/arch/x86/include/asm/page_64_types.h
index 6c896fb..43dcd80 100644
--- a/arch/x86/include/asm/page_64_types.h
+++ b/arch/x86/include/asm/page_64_types.h
@@ -32,11 +32,6 @@
*/
#define __PAGE_OFFSET _AC(0xffff880000000000, UL)
-#define __PHYSICAL_START ((CONFIG_PHYSICAL_START + \
- (CONFIG_PHYSICAL_ALIGN - 1)) & \
- ~(CONFIG_PHYSICAL_ALIGN - 1))
-
-#define __START_KERNEL (__START_KERNEL_map + __PHYSICAL_START)
#define __START_KERNEL_map _AC(0xffffffff80000000, UL)
/* See Documentation/x86/x86_64/mm.txt for a description of the memory map. */
diff --git a/arch/x86/include/asm/page_types.h b/arch/x86/include/asm/page_types.h
index 54c9787..086c2fa 100644
--- a/arch/x86/include/asm/page_types.h
+++ b/arch/x86/include/asm/page_types.h
@@ -33,6 +33,12 @@
(((current->personality & READ_IMPLIES_EXEC) ? VM_EXEC : 0 ) | \
VM_READ | VM_WRITE | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
+#define __PHYSICAL_START ((CONFIG_PHYSICAL_START + \
+ (CONFIG_PHYSICAL_ALIGN - 1)) & \
+ ~(CONFIG_PHYSICAL_ALIGN - 1))
+
+#define __START_KERNEL (__START_KERNEL_map + __PHYSICAL_START)
+
#ifdef CONFIG_X86_64
#include <asm/page_64_types.h>
#else
--
1.7.9.5
--
Kees Cook
Chrome OS Security
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [RESEND][PATCH] x86, relocs: move ELF relocation handling to C
2013-07-02 18:22 [RESEND][PATCH] x86, relocs: move ELF relocation handling to C Kees Cook
@ 2013-07-03 3:22 ` Zhang Yanfei
2013-07-08 13:25 ` Kees Cook
0 siblings, 1 reply; 4+ messages in thread
From: Zhang Yanfei @ 2013-07-03 3:22 UTC (permalink / raw)
To: Kees Cook
Cc: linux-kernel, Thomas Gleixner, Ingo Molnar, H. Peter Anvin, x86,
Yinghai Lu, Matt Fleming, Borislav Petkov, Alexander Duyck,
Jacob Shin, Pekka Enberg
Hello Kees,
On 07/03/2013 02:22 AM, Kees Cook wrote:
> Moves the relocation handling into C, after decompression. This requires
> that the decompressed size is passed to the decompression routine as
> well so that relocations can be found. Only kernels that need relocation
> support will use the code (currently just x86_32), but this is laying
> the ground work for 64-bit support in support of KASLR.
>
> Based on work by Neill Clift and Michael Davidson.
>
> Signed-off-by: Kees Cook <keescook@chromium.org>
> ---
> arch/x86/Kconfig | 4 +-
> arch/x86/Makefile | 8 ++--
> arch/x86/boot/compressed/head_32.S | 31 ++------------
> arch/x86/boot/compressed/head_64.S | 1 +
> arch/x86/boot/compressed/misc.c | 77 +++++++++++++++++++++++++++++++++-
> arch/x86/include/asm/page_32_types.h | 2 +
> arch/x86/include/asm/page_64_types.h | 5 ---
> arch/x86/include/asm/page_types.h | 6 +++
> 8 files changed, 94 insertions(+), 40 deletions(-)
>
> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> index fe120da..f11ad6f 100644
> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -1695,13 +1695,13 @@ config RELOCATABLE
> it has been loaded at and the compile time physical address
> (CONFIG_PHYSICAL_START) is ignored.
>
> -# Relocation on x86-32 needs some additional build support
> +# Relocation on x86 needs some additional build support
> config X86_NEED_RELOCS
> def_bool y
> depends on X86_32 && RELOCATABLE
Here it still actually depends on x86_32, so why change the comment?
>
> config PHYSICAL_ALIGN
> - hex "Alignment value to which kernel should be aligned" if X86_32
> + hex "Alignment value to which kernel should be aligned"
> default "0x1000000"
> range 0x2000 0x1000000
If you open this option for x86_64, the range should be modified a bit
to indicate the fact that on x86_64, the alignment of the kernel should
be at least 2M and the alignment itself should be 2M aligned.
otherwise, someone specifies an incorrect value here, say 0x300000,
which will cause the error:
#error "Invalid value for CONFIG_PHYSICAL_ALIGN"
when compiling the kernel.
> ---help---
> diff --git a/arch/x86/Makefile b/arch/x86/Makefile
> index 5c47726..43f8cef 100644
> --- a/arch/x86/Makefile
> +++ b/arch/x86/Makefile
> @@ -16,6 +16,10 @@ endif
> # e.g.: obj-y += foo_$(BITS).o
> export BITS
>
> +ifdef CONFIG_X86_NEED_RELOCS
> + LDFLAGS_vmlinux := --emit-relocs
> +endif
> +
> ifeq ($(CONFIG_X86_32),y)
> BITS := 32
> UTS_MACHINE := i386
> @@ -25,10 +29,6 @@ ifeq ($(CONFIG_X86_32),y)
> KBUILD_AFLAGS += $(biarch)
> KBUILD_CFLAGS += $(biarch)
>
> - ifdef CONFIG_RELOCATABLE
> - LDFLAGS_vmlinux := --emit-relocs
> - endif
> -
> KBUILD_CFLAGS += -msoft-float -mregparm=3 -freg-struct-return
>
> # Never want PIC in a 32-bit kernel, prevent breakage with GCC built
> diff --git a/arch/x86/boot/compressed/head_32.S b/arch/x86/boot/compressed/head_32.S
> index 1e3184f..5d6f689 100644
> --- a/arch/x86/boot/compressed/head_32.S
> +++ b/arch/x86/boot/compressed/head_32.S
> @@ -181,8 +181,9 @@ relocated:
> /*
> * Do the decompression, and jump to the new kernel..
> */
> - leal z_extract_offset_negative(%ebx), %ebp
> /* push arguments for decompress_kernel: */
> + pushl $z_output_len /* decompressed length */
> + leal z_extract_offset_negative(%ebx), %ebp
> pushl %ebp /* output address */
> pushl $z_input_len /* input_len */
> leal input_data(%ebx), %eax
> @@ -191,33 +192,7 @@ relocated:
> pushl %eax /* heap area */
> pushl %esi /* real mode pointer */
> call decompress_kernel
> - addl $20, %esp
> -
> -#if CONFIG_RELOCATABLE
> -/*
> - * Find the address of the relocations.
> - */
> - leal z_output_len(%ebp), %edi
> -
> -/*
> - * Calculate the delta between where vmlinux was compiled to run
> - * and where it was actually loaded.
> - */
> - movl %ebp, %ebx
> - subl $LOAD_PHYSICAL_ADDR, %ebx
> - jz 2f /* Nothing to be done if loaded at compiled addr. */
> -/*
> - * Process relocations.
> - */
> -
> -1: subl $4, %edi
> - movl (%edi), %ecx
> - testl %ecx, %ecx
> - jz 2f
> - addl %ebx, -__PAGE_OFFSET(%ebx, %ecx)
> - jmp 1b
> -2:
> -#endif
> + addl $24, %esp
>
> /*
> * Jump to the decompressed kernel.
> diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S
> index 16f24e6..6632693 100644
> --- a/arch/x86/boot/compressed/head_64.S
> +++ b/arch/x86/boot/compressed/head_64.S
> @@ -340,6 +340,7 @@ relocated:
> leaq input_data(%rip), %rdx /* input_data */
> movl $z_input_len, %ecx /* input_len */
> movq %rbp, %r8 /* output target address */
> + movq $z_output_len, %r9 /* decompressed length */
> call decompress_kernel
> popq %rsi
>
> diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c
> index 7cb56c6..b756a04 100644
> --- a/arch/x86/boot/compressed/misc.c
> +++ b/arch/x86/boot/compressed/misc.c
> @@ -267,6 +267,79 @@ static void error(char *x)
> asm("hlt");
> }
>
> +#if CONFIG_X86_NEED_RELOCS
> +static void handle_relocations(void *output, unsigned long output_len)
> +{
> + int *reloc;
> + unsigned long delta, map, ptr;
> + unsigned long min_addr = (unsigned long)output;
> + unsigned long max_addr = min_addr + output_len;
> +
> + /*
> + * Calculate the delta between where vmlinux was linked to load
> + * and where it was actually loaded.
> + */
> + delta = min_addr - LOAD_PHYSICAL_ADDR;
> + if (!delta) {
> + debug_putstr("No relocation needed... ");
> + return;
> + }
> + debug_putstr("Performing relocations... ");
> +
> + /*
> + * The kernel contains a table of relocation addresses. Those
> + * addresses have the final load address of the kernel in virtual
> + * memory. We are currently working in the self map. So we need to
> + * create an adjustment for kernel memory addresses to the self map.
> + * This will involve subtracting out the base address of the kernel.
> + */
> + map = delta - __START_KERNEL_map;
> +
> + /*
> + * Process relocations: 32 bit relocations first then 64 bit after.
> + * Two sets of binary relocations are added to the end of the kernel
> + * before compression. Each relocation table entry is the kernel
> + * address of the location which needs to be updated stored as a
> + * 32-bit value which is sign extended to 64 bits.
> + *
> + * Format is:
> + *
> + * kernel bits...
> + * 0 - zero terminator for 64 bit relocations
> + * 64 bit relocation repeated
> + * 0 - zero terminator for 32 bit relocations
> + * 32 bit relocation repeated
> + *
> + * So we work backwards from the end of the decompressed image.
> + */
> + for (reloc = output + output_len - sizeof(*reloc); *reloc; reloc--) {
> + int extended = *reloc;
> + extended += map;
> +
> + ptr = (unsigned long)extended;
> + if (ptr < min_addr || ptr > max_addr)
> + error("32-bit relocation outside of kernel!\n");
> +
> + *(uint32_t *)ptr += delta;
> + }
> +#ifdef CONFIG_X86_64
> + for (reloc--; *reloc; reloc--) {
> + long extended = *reloc;
> + extended += map;
> +
> + ptr = (unsigned long)extended;
> + if (ptr < min_addr || ptr > max_addr)
> + error("64-bit relocation outside of kernel!\n");
> +
> + *(uint64_t *)ptr += delta;
> + }
> +#endif
> +}
> +#else
> +static inline void handle_relocations(void *output, unsigned long output_len)
> +{ }
> +#endif
> +
> static void parse_elf(void *output)
> {
> #ifdef CONFIG_X86_64
> @@ -321,7 +394,8 @@ static void parse_elf(void *output)
> asmlinkage void decompress_kernel(void *rmode, memptr heap,
> unsigned char *input_data,
> unsigned long input_len,
> - unsigned char *output)
> + unsigned char *output,
> + unsigned long output_len)
> {
> real_mode = rmode;
>
> @@ -361,6 +435,7 @@ asmlinkage void decompress_kernel(void *rmode, memptr heap,
> debug_putstr("\nDecompressing Linux... ");
> decompress(input_data, input_len, NULL, NULL, output, NULL, error);
> parse_elf(output);
> + handle_relocations(output, output_len);
> debug_putstr("done.\nBooting the kernel.\n");
> return;
> }
> diff --git a/arch/x86/include/asm/page_32_types.h b/arch/x86/include/asm/page_32_types.h
> index ef17af0..f48b17d 100644
> --- a/arch/x86/include/asm/page_32_types.h
> +++ b/arch/x86/include/asm/page_32_types.h
> @@ -15,6 +15,8 @@
> */
> #define __PAGE_OFFSET _AC(CONFIG_PAGE_OFFSET, UL)
>
> +#define __START_KERNEL_map __PAGE_OFFSET
> +
> #define THREAD_SIZE_ORDER 1
> #define THREAD_SIZE (PAGE_SIZE << THREAD_SIZE_ORDER)
>
> diff --git a/arch/x86/include/asm/page_64_types.h b/arch/x86/include/asm/page_64_types.h
> index 6c896fb..43dcd80 100644
> --- a/arch/x86/include/asm/page_64_types.h
> +++ b/arch/x86/include/asm/page_64_types.h
> @@ -32,11 +32,6 @@
> */
> #define __PAGE_OFFSET _AC(0xffff880000000000, UL)
>
> -#define __PHYSICAL_START ((CONFIG_PHYSICAL_START + \
> - (CONFIG_PHYSICAL_ALIGN - 1)) & \
> - ~(CONFIG_PHYSICAL_ALIGN - 1))
> -
> -#define __START_KERNEL (__START_KERNEL_map + __PHYSICAL_START)
> #define __START_KERNEL_map _AC(0xffffffff80000000, UL)
>
> /* See Documentation/x86/x86_64/mm.txt for a description of the memory map. */
> diff --git a/arch/x86/include/asm/page_types.h b/arch/x86/include/asm/page_types.h
> index 54c9787..086c2fa 100644
> --- a/arch/x86/include/asm/page_types.h
> +++ b/arch/x86/include/asm/page_types.h
> @@ -33,6 +33,12 @@
> (((current->personality & READ_IMPLIES_EXEC) ? VM_EXEC : 0 ) | \
> VM_READ | VM_WRITE | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
>
> +#define __PHYSICAL_START ((CONFIG_PHYSICAL_START + \
> + (CONFIG_PHYSICAL_ALIGN - 1)) & \
> + ~(CONFIG_PHYSICAL_ALIGN - 1))
I know you just moved the code. Could this macro be like this:
#define __PHYSICAL_START ALIGN(CONFIG_PHYSICAL_START, CONFIG_PHYSICAL_ALIGN)
> +
> +#define __START_KERNEL (__START_KERNEL_map + __PHYSICAL_START)
> +
> #ifdef CONFIG_X86_64
> #include <asm/page_64_types.h>
> #else
>
--
Thanks.
Zhang Yanfei
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [RESEND][PATCH] x86, relocs: move ELF relocation handling to C
2013-07-03 3:22 ` Zhang Yanfei
@ 2013-07-08 13:25 ` Kees Cook
2013-07-08 15:26 ` Zhang Yanfei
0 siblings, 1 reply; 4+ messages in thread
From: Kees Cook @ 2013-07-08 13:25 UTC (permalink / raw)
To: Zhang Yanfei
Cc: LKML, Thomas Gleixner, Ingo Molnar, H. Peter Anvin, x86,
Yinghai Lu, Matt Fleming, Borislav Petkov, Alexander Duyck,
Jacob Shin, Pekka Enberg
On Tue, Jul 2, 2013 at 8:22 PM, Zhang Yanfei <zhangyanfei@cn.fujitsu.com> wrote:
> Hello Kees,
>
> On 07/03/2013 02:22 AM, Kees Cook wrote:
>> Moves the relocation handling into C, after decompression. This requires
>> that the decompressed size is passed to the decompression routine as
>> well so that relocations can be found. Only kernels that need relocation
>> support will use the code (currently just x86_32), but this is laying
>> the ground work for 64-bit support in support of KASLR.
>>
>> Based on work by Neill Clift and Michael Davidson.
>>
>> Signed-off-by: Kees Cook <keescook@chromium.org>
>> ---
>> arch/x86/Kconfig | 4 +-
>> arch/x86/Makefile | 8 ++--
>> arch/x86/boot/compressed/head_32.S | 31 ++------------
>> arch/x86/boot/compressed/head_64.S | 1 +
>> arch/x86/boot/compressed/misc.c | 77 +++++++++++++++++++++++++++++++++-
>> arch/x86/include/asm/page_32_types.h | 2 +
>> arch/x86/include/asm/page_64_types.h | 5 ---
>> arch/x86/include/asm/page_types.h | 6 +++
>> 8 files changed, 94 insertions(+), 40 deletions(-)
>>
>> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
>> index fe120da..f11ad6f 100644
>> --- a/arch/x86/Kconfig
>> +++ b/arch/x86/Kconfig
>> @@ -1695,13 +1695,13 @@ config RELOCATABLE
>> it has been loaded at and the compile time physical address
>> (CONFIG_PHYSICAL_START) is ignored.
>>
>> -# Relocation on x86-32 needs some additional build support
>> +# Relocation on x86 needs some additional build support
>> config X86_NEED_RELOCS
>> def_bool y
>> depends on X86_32 && RELOCATABLE
>
> Here it still actually depends on x86_32, so why change the comment?
Yeah, I can leave this as-is.
>> config PHYSICAL_ALIGN
>> - hex "Alignment value to which kernel should be aligned" if X86_32
>> + hex "Alignment value to which kernel should be aligned"
>> default "0x1000000"
>> range 0x2000 0x1000000
>
> If you open this option for x86_64, the range should be modified a bit
> to indicate the fact that on x86_64, the alignment of the kernel should
> be at least 2M and the alignment itself should be 2M aligned.
>
> otherwise, someone specifies an incorrect value here, say 0x300000,
> which will cause the error:
>
> #error "Invalid value for CONFIG_PHYSICAL_ALIGN"
>
> when compiling the kernel.
Are you looking for this to be added to the Kconfig help text, or do
you mean there should be build-time sanity checks for the value?
>> ---help---
>> diff --git a/arch/x86/Makefile b/arch/x86/Makefile
>> index 5c47726..43f8cef 100644
>> --- a/arch/x86/Makefile
>> +++ b/arch/x86/Makefile
>> @@ -16,6 +16,10 @@ endif
>> # e.g.: obj-y += foo_$(BITS).o
>> export BITS
>>
>> +ifdef CONFIG_X86_NEED_RELOCS
>> + LDFLAGS_vmlinux := --emit-relocs
>> +endif
>> +
>> ifeq ($(CONFIG_X86_32),y)
>> BITS := 32
>> UTS_MACHINE := i386
>> @@ -25,10 +29,6 @@ ifeq ($(CONFIG_X86_32),y)
>> KBUILD_AFLAGS += $(biarch)
>> KBUILD_CFLAGS += $(biarch)
>>
>> - ifdef CONFIG_RELOCATABLE
>> - LDFLAGS_vmlinux := --emit-relocs
>> - endif
>> -
>> KBUILD_CFLAGS += -msoft-float -mregparm=3 -freg-struct-return
>>
>> # Never want PIC in a 32-bit kernel, prevent breakage with GCC built
>> diff --git a/arch/x86/boot/compressed/head_32.S b/arch/x86/boot/compressed/head_32.S
>> index 1e3184f..5d6f689 100644
>> --- a/arch/x86/boot/compressed/head_32.S
>> +++ b/arch/x86/boot/compressed/head_32.S
>> @@ -181,8 +181,9 @@ relocated:
>> /*
>> * Do the decompression, and jump to the new kernel..
>> */
>> - leal z_extract_offset_negative(%ebx), %ebp
>> /* push arguments for decompress_kernel: */
>> + pushl $z_output_len /* decompressed length */
>> + leal z_extract_offset_negative(%ebx), %ebp
>> pushl %ebp /* output address */
>> pushl $z_input_len /* input_len */
>> leal input_data(%ebx), %eax
>> @@ -191,33 +192,7 @@ relocated:
>> pushl %eax /* heap area */
>> pushl %esi /* real mode pointer */
>> call decompress_kernel
>> - addl $20, %esp
>> -
>> -#if CONFIG_RELOCATABLE
>> -/*
>> - * Find the address of the relocations.
>> - */
>> - leal z_output_len(%ebp), %edi
>> -
>> -/*
>> - * Calculate the delta between where vmlinux was compiled to run
>> - * and where it was actually loaded.
>> - */
>> - movl %ebp, %ebx
>> - subl $LOAD_PHYSICAL_ADDR, %ebx
>> - jz 2f /* Nothing to be done if loaded at compiled addr. */
>> -/*
>> - * Process relocations.
>> - */
>> -
>> -1: subl $4, %edi
>> - movl (%edi), %ecx
>> - testl %ecx, %ecx
>> - jz 2f
>> - addl %ebx, -__PAGE_OFFSET(%ebx, %ecx)
>> - jmp 1b
>> -2:
>> -#endif
>> + addl $24, %esp
>>
>> /*
>> * Jump to the decompressed kernel.
>> diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S
>> index 16f24e6..6632693 100644
>> --- a/arch/x86/boot/compressed/head_64.S
>> +++ b/arch/x86/boot/compressed/head_64.S
>> @@ -340,6 +340,7 @@ relocated:
>> leaq input_data(%rip), %rdx /* input_data */
>> movl $z_input_len, %ecx /* input_len */
>> movq %rbp, %r8 /* output target address */
>> + movq $z_output_len, %r9 /* decompressed length */
>> call decompress_kernel
>> popq %rsi
>>
>> diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c
>> index 7cb56c6..b756a04 100644
>> --- a/arch/x86/boot/compressed/misc.c
>> +++ b/arch/x86/boot/compressed/misc.c
>> @@ -267,6 +267,79 @@ static void error(char *x)
>> asm("hlt");
>> }
>>
>> +#if CONFIG_X86_NEED_RELOCS
>> +static void handle_relocations(void *output, unsigned long output_len)
>> +{
>> + int *reloc;
>> + unsigned long delta, map, ptr;
>> + unsigned long min_addr = (unsigned long)output;
>> + unsigned long max_addr = min_addr + output_len;
>> +
>> + /*
>> + * Calculate the delta between where vmlinux was linked to load
>> + * and where it was actually loaded.
>> + */
>> + delta = min_addr - LOAD_PHYSICAL_ADDR;
>> + if (!delta) {
>> + debug_putstr("No relocation needed... ");
>> + return;
>> + }
>> + debug_putstr("Performing relocations... ");
>> +
>> + /*
>> + * The kernel contains a table of relocation addresses. Those
>> + * addresses have the final load address of the kernel in virtual
>> + * memory. We are currently working in the self map. So we need to
>> + * create an adjustment for kernel memory addresses to the self map.
>> + * This will involve subtracting out the base address of the kernel.
>> + */
>> + map = delta - __START_KERNEL_map;
>> +
>> + /*
>> + * Process relocations: 32 bit relocations first then 64 bit after.
>> + * Two sets of binary relocations are added to the end of the kernel
>> + * before compression. Each relocation table entry is the kernel
>> + * address of the location which needs to be updated stored as a
>> + * 32-bit value which is sign extended to 64 bits.
>> + *
>> + * Format is:
>> + *
>> + * kernel bits...
>> + * 0 - zero terminator for 64 bit relocations
>> + * 64 bit relocation repeated
>> + * 0 - zero terminator for 32 bit relocations
>> + * 32 bit relocation repeated
>> + *
>> + * So we work backwards from the end of the decompressed image.
>> + */
>> + for (reloc = output + output_len - sizeof(*reloc); *reloc; reloc--) {
>> + int extended = *reloc;
>> + extended += map;
>> +
>> + ptr = (unsigned long)extended;
>> + if (ptr < min_addr || ptr > max_addr)
>> + error("32-bit relocation outside of kernel!\n");
>> +
>> + *(uint32_t *)ptr += delta;
>> + }
>> +#ifdef CONFIG_X86_64
>> + for (reloc--; *reloc; reloc--) {
>> + long extended = *reloc;
>> + extended += map;
>> +
>> + ptr = (unsigned long)extended;
>> + if (ptr < min_addr || ptr > max_addr)
>> + error("64-bit relocation outside of kernel!\n");
>> +
>> + *(uint64_t *)ptr += delta;
>> + }
>> +#endif
>> +}
>> +#else
>> +static inline void handle_relocations(void *output, unsigned long output_len)
>> +{ }
>> +#endif
>> +
>> static void parse_elf(void *output)
>> {
>> #ifdef CONFIG_X86_64
>> @@ -321,7 +394,8 @@ static void parse_elf(void *output)
>> asmlinkage void decompress_kernel(void *rmode, memptr heap,
>> unsigned char *input_data,
>> unsigned long input_len,
>> - unsigned char *output)
>> + unsigned char *output,
>> + unsigned long output_len)
>> {
>> real_mode = rmode;
>>
>> @@ -361,6 +435,7 @@ asmlinkage void decompress_kernel(void *rmode, memptr heap,
>> debug_putstr("\nDecompressing Linux... ");
>> decompress(input_data, input_len, NULL, NULL, output, NULL, error);
>> parse_elf(output);
>> + handle_relocations(output, output_len);
>> debug_putstr("done.\nBooting the kernel.\n");
>> return;
>> }
>> diff --git a/arch/x86/include/asm/page_32_types.h b/arch/x86/include/asm/page_32_types.h
>> index ef17af0..f48b17d 100644
>> --- a/arch/x86/include/asm/page_32_types.h
>> +++ b/arch/x86/include/asm/page_32_types.h
>> @@ -15,6 +15,8 @@
>> */
>> #define __PAGE_OFFSET _AC(CONFIG_PAGE_OFFSET, UL)
>>
>> +#define __START_KERNEL_map __PAGE_OFFSET
>> +
>> #define THREAD_SIZE_ORDER 1
>> #define THREAD_SIZE (PAGE_SIZE << THREAD_SIZE_ORDER)
>>
>> diff --git a/arch/x86/include/asm/page_64_types.h b/arch/x86/include/asm/page_64_types.h
>> index 6c896fb..43dcd80 100644
>> --- a/arch/x86/include/asm/page_64_types.h
>> +++ b/arch/x86/include/asm/page_64_types.h
>> @@ -32,11 +32,6 @@
>> */
>> #define __PAGE_OFFSET _AC(0xffff880000000000, UL)
>>
>> -#define __PHYSICAL_START ((CONFIG_PHYSICAL_START + \
>> - (CONFIG_PHYSICAL_ALIGN - 1)) & \
>> - ~(CONFIG_PHYSICAL_ALIGN - 1))
>> -
>> -#define __START_KERNEL (__START_KERNEL_map + __PHYSICAL_START)
>> #define __START_KERNEL_map _AC(0xffffffff80000000, UL)
>>
>> /* See Documentation/x86/x86_64/mm.txt for a description of the memory map. */
>> diff --git a/arch/x86/include/asm/page_types.h b/arch/x86/include/asm/page_types.h
>> index 54c9787..086c2fa 100644
>> --- a/arch/x86/include/asm/page_types.h
>> +++ b/arch/x86/include/asm/page_types.h
>> @@ -33,6 +33,12 @@
>> (((current->personality & READ_IMPLIES_EXEC) ? VM_EXEC : 0 ) | \
>> VM_READ | VM_WRITE | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
>>
>> +#define __PHYSICAL_START ((CONFIG_PHYSICAL_START + \
>> + (CONFIG_PHYSICAL_ALIGN - 1)) & \
>> + ~(CONFIG_PHYSICAL_ALIGN - 1))
>
> I know you just moved the code. Could this macro be like this:
>
> #define __PHYSICAL_START ALIGN(CONFIG_PHYSICAL_START, CONFIG_PHYSICAL_ALIGN)
Yeah, I'll fix that too.
Thanks!
-Kees
>
>> +
>> +#define __START_KERNEL (__START_KERNEL_map + __PHYSICAL_START)
>> +
>> #ifdef CONFIG_X86_64
>> #include <asm/page_64_types.h>
>> #else
>>
>
>
> --
> Thanks.
> Zhang Yanfei
--
Kees Cook
Chrome OS Security
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [RESEND][PATCH] x86, relocs: move ELF relocation handling to C
2013-07-08 13:25 ` Kees Cook
@ 2013-07-08 15:26 ` Zhang Yanfei
0 siblings, 0 replies; 4+ messages in thread
From: Zhang Yanfei @ 2013-07-08 15:26 UTC (permalink / raw)
To: Kees Cook, H. Peter Anvin
Cc: Zhang Yanfei, LKML, Thomas Gleixner, Ingo Molnar, x86,
Yinghai Lu, Matt Fleming, Borislav Petkov, Alexander Duyck,
Jacob Shin, Pekka Enberg
On 07/08/2013 09:25 PM, Kees Cook wrote:
> On Tue, Jul 2, 2013 at 8:22 PM, Zhang Yanfei <zhangyanfei@cn.fujitsu.com> wrote:
>> Hello Kees,
>>
>> On 07/03/2013 02:22 AM, Kees Cook wrote:
>>> Moves the relocation handling into C, after decompression. This requires
>>> that the decompressed size is passed to the decompression routine as
>>> well so that relocations can be found. Only kernels that need relocation
>>> support will use the code (currently just x86_32), but this is laying
>>> the ground work for 64-bit support in support of KASLR.
>>>
>>> Based on work by Neill Clift and Michael Davidson.
>>>
>>> Signed-off-by: Kees Cook <keescook@chromium.org>
>>> ---
>>> arch/x86/Kconfig | 4 +-
>>> arch/x86/Makefile | 8 ++--
>>> arch/x86/boot/compressed/head_32.S | 31 ++------------
>>> arch/x86/boot/compressed/head_64.S | 1 +
>>> arch/x86/boot/compressed/misc.c | 77 +++++++++++++++++++++++++++++++++-
>>> arch/x86/include/asm/page_32_types.h | 2 +
>>> arch/x86/include/asm/page_64_types.h | 5 ---
>>> arch/x86/include/asm/page_types.h | 6 +++
>>> 8 files changed, 94 insertions(+), 40 deletions(-)
>>>
>>> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
>>> index fe120da..f11ad6f 100644
>>> --- a/arch/x86/Kconfig
>>> +++ b/arch/x86/Kconfig
>>> @@ -1695,13 +1695,13 @@ config RELOCATABLE
>>> it has been loaded at and the compile time physical address
>>> (CONFIG_PHYSICAL_START) is ignored.
>>>
>>> -# Relocation on x86-32 needs some additional build support
>>> +# Relocation on x86 needs some additional build support
>>> config X86_NEED_RELOCS
>>> def_bool y
>>> depends on X86_32 && RELOCATABLE
>>
>> Here it still actually depends on x86_32, so why change the comment?
>
> Yeah, I can leave this as-is.
>
>>> config PHYSICAL_ALIGN
>>> - hex "Alignment value to which kernel should be aligned" if X86_32
>>> + hex "Alignment value to which kernel should be aligned"
>>> default "0x1000000"
>>> range 0x2000 0x1000000
>>
>> If you open this option for x86_64, the range should be modified a bit
>> to indicate the fact that on x86_64, the alignment of the kernel should
>> be at least 2M and the alignment itself should be 2M aligned.
>>
>> otherwise, someone specifies an incorrect value here, say 0x300000,
>> which will cause the error:
>>
>> #error "Invalid value for CONFIG_PHYSICAL_ALIGN"
>>
>> when compiling the kernel.
>
> Are you looking for this to be added to the Kconfig help text, or do
> you mean there should be build-time sanity checks for the value?
I don't know. The sanity check is already in arch/x86/include/asm/boot.h:
/* Minimum kernel alignment, as a power of two */
#ifdef CONFIG_X86_64
#define MIN_KERNEL_ALIGN_LG2 PMD_SHIFT
#else
#define MIN_KERNEL_ALIGN_LG2 (PAGE_SHIFT + THREAD_SIZE_ORDER)
#endif
#define MIN_KERNEL_ALIGN (_AC(1, UL) << MIN_KERNEL_ALIGN_LG2)
#if (CONFIG_PHYSICAL_ALIGN & (CONFIG_PHYSICAL_ALIGN-1)) || \
(CONFIG_PHYSICAL_ALIGN < MIN_KERNEL_ALIGN)
#error "Invalid value for CONFIG_PHYSICAL_ALIGN"
#endif
But just from the config:
range 0x2000 0x1000000
is just a align restriction for x86_32, not for x86_64. So we should
not emit this hint for x86_64, or change this hint to:
config PHYSICAL_ALIGN
hex "Alignment value to which kernel should be aligned"
default "0x1000000"
range 0x2000 0x1000000 if X86_32
range 0x200000 0x1000000 if X86_64
And add the description in the Kconfig help text?
Peter?
>
>>> ---help---
>>> diff --git a/arch/x86/Makefile b/arch/x86/Makefile
>>> index 5c47726..43f8cef 100644
>>> --- a/arch/x86/Makefile
>>> +++ b/arch/x86/Makefile
>>> @@ -16,6 +16,10 @@ endif
>>> # e.g.: obj-y += foo_$(BITS).o
>>> export BITS
>>>
>>> +ifdef CONFIG_X86_NEED_RELOCS
>>> + LDFLAGS_vmlinux := --emit-relocs
>>> +endif
>>> +
>>> ifeq ($(CONFIG_X86_32),y)
>>> BITS := 32
>>> UTS_MACHINE := i386
>>> @@ -25,10 +29,6 @@ ifeq ($(CONFIG_X86_32),y)
>>> KBUILD_AFLAGS += $(biarch)
>>> KBUILD_CFLAGS += $(biarch)
>>>
>>> - ifdef CONFIG_RELOCATABLE
>>> - LDFLAGS_vmlinux := --emit-relocs
>>> - endif
>>> -
>>> KBUILD_CFLAGS += -msoft-float -mregparm=3 -freg-struct-return
>>>
>>> # Never want PIC in a 32-bit kernel, prevent breakage with GCC built
>>> diff --git a/arch/x86/boot/compressed/head_32.S b/arch/x86/boot/compressed/head_32.S
>>> index 1e3184f..5d6f689 100644
>>> --- a/arch/x86/boot/compressed/head_32.S
>>> +++ b/arch/x86/boot/compressed/head_32.S
>>> @@ -181,8 +181,9 @@ relocated:
>>> /*
>>> * Do the decompression, and jump to the new kernel..
>>> */
>>> - leal z_extract_offset_negative(%ebx), %ebp
>>> /* push arguments for decompress_kernel: */
>>> + pushl $z_output_len /* decompressed length */
>>> + leal z_extract_offset_negative(%ebx), %ebp
>>> pushl %ebp /* output address */
>>> pushl $z_input_len /* input_len */
>>> leal input_data(%ebx), %eax
>>> @@ -191,33 +192,7 @@ relocated:
>>> pushl %eax /* heap area */
>>> pushl %esi /* real mode pointer */
>>> call decompress_kernel
>>> - addl $20, %esp
>>> -
>>> -#if CONFIG_RELOCATABLE
>>> -/*
>>> - * Find the address of the relocations.
>>> - */
>>> - leal z_output_len(%ebp), %edi
>>> -
>>> -/*
>>> - * Calculate the delta between where vmlinux was compiled to run
>>> - * and where it was actually loaded.
>>> - */
>>> - movl %ebp, %ebx
>>> - subl $LOAD_PHYSICAL_ADDR, %ebx
>>> - jz 2f /* Nothing to be done if loaded at compiled addr. */
>>> -/*
>>> - * Process relocations.
>>> - */
>>> -
>>> -1: subl $4, %edi
>>> - movl (%edi), %ecx
>>> - testl %ecx, %ecx
>>> - jz 2f
>>> - addl %ebx, -__PAGE_OFFSET(%ebx, %ecx)
>>> - jmp 1b
>>> -2:
>>> -#endif
>>> + addl $24, %esp
>>>
>>> /*
>>> * Jump to the decompressed kernel.
>>> diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S
>>> index 16f24e6..6632693 100644
>>> --- a/arch/x86/boot/compressed/head_64.S
>>> +++ b/arch/x86/boot/compressed/head_64.S
>>> @@ -340,6 +340,7 @@ relocated:
>>> leaq input_data(%rip), %rdx /* input_data */
>>> movl $z_input_len, %ecx /* input_len */
>>> movq %rbp, %r8 /* output target address */
>>> + movq $z_output_len, %r9 /* decompressed length */
>>> call decompress_kernel
>>> popq %rsi
>>>
>>> diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c
>>> index 7cb56c6..b756a04 100644
>>> --- a/arch/x86/boot/compressed/misc.c
>>> +++ b/arch/x86/boot/compressed/misc.c
>>> @@ -267,6 +267,79 @@ static void error(char *x)
>>> asm("hlt");
>>> }
>>>
>>> +#if CONFIG_X86_NEED_RELOCS
>>> +static void handle_relocations(void *output, unsigned long output_len)
>>> +{
>>> + int *reloc;
>>> + unsigned long delta, map, ptr;
>>> + unsigned long min_addr = (unsigned long)output;
>>> + unsigned long max_addr = min_addr + output_len;
>>> +
>>> + /*
>>> + * Calculate the delta between where vmlinux was linked to load
>>> + * and where it was actually loaded.
>>> + */
>>> + delta = min_addr - LOAD_PHYSICAL_ADDR;
>>> + if (!delta) {
>>> + debug_putstr("No relocation needed... ");
>>> + return;
>>> + }
>>> + debug_putstr("Performing relocations... ");
>>> +
>>> + /*
>>> + * The kernel contains a table of relocation addresses. Those
>>> + * addresses have the final load address of the kernel in virtual
>>> + * memory. We are currently working in the self map. So we need to
>>> + * create an adjustment for kernel memory addresses to the self map.
>>> + * This will involve subtracting out the base address of the kernel.
>>> + */
>>> + map = delta - __START_KERNEL_map;
>>> +
>>> + /*
>>> + * Process relocations: 32 bit relocations first then 64 bit after.
>>> + * Two sets of binary relocations are added to the end of the kernel
>>> + * before compression. Each relocation table entry is the kernel
>>> + * address of the location which needs to be updated stored as a
>>> + * 32-bit value which is sign extended to 64 bits.
>>> + *
>>> + * Format is:
>>> + *
>>> + * kernel bits...
>>> + * 0 - zero terminator for 64 bit relocations
>>> + * 64 bit relocation repeated
>>> + * 0 - zero terminator for 32 bit relocations
>>> + * 32 bit relocation repeated
>>> + *
>>> + * So we work backwards from the end of the decompressed image.
>>> + */
>>> + for (reloc = output + output_len - sizeof(*reloc); *reloc; reloc--) {
>>> + int extended = *reloc;
>>> + extended += map;
>>> +
>>> + ptr = (unsigned long)extended;
>>> + if (ptr < min_addr || ptr > max_addr)
>>> + error("32-bit relocation outside of kernel!\n");
>>> +
>>> + *(uint32_t *)ptr += delta;
>>> + }
>>> +#ifdef CONFIG_X86_64
>>> + for (reloc--; *reloc; reloc--) {
>>> + long extended = *reloc;
>>> + extended += map;
>>> +
>>> + ptr = (unsigned long)extended;
>>> + if (ptr < min_addr || ptr > max_addr)
>>> + error("64-bit relocation outside of kernel!\n");
>>> +
>>> + *(uint64_t *)ptr += delta;
>>> + }
>>> +#endif
>>> +}
>>> +#else
>>> +static inline void handle_relocations(void *output, unsigned long output_len)
>>> +{ }
>>> +#endif
>>> +
>>> static void parse_elf(void *output)
>>> {
>>> #ifdef CONFIG_X86_64
>>> @@ -321,7 +394,8 @@ static void parse_elf(void *output)
>>> asmlinkage void decompress_kernel(void *rmode, memptr heap,
>>> unsigned char *input_data,
>>> unsigned long input_len,
>>> - unsigned char *output)
>>> + unsigned char *output,
>>> + unsigned long output_len)
>>> {
>>> real_mode = rmode;
>>>
>>> @@ -361,6 +435,7 @@ asmlinkage void decompress_kernel(void *rmode, memptr heap,
>>> debug_putstr("\nDecompressing Linux... ");
>>> decompress(input_data, input_len, NULL, NULL, output, NULL, error);
>>> parse_elf(output);
>>> + handle_relocations(output, output_len);
>>> debug_putstr("done.\nBooting the kernel.\n");
>>> return;
>>> }
>>> diff --git a/arch/x86/include/asm/page_32_types.h b/arch/x86/include/asm/page_32_types.h
>>> index ef17af0..f48b17d 100644
>>> --- a/arch/x86/include/asm/page_32_types.h
>>> +++ b/arch/x86/include/asm/page_32_types.h
>>> @@ -15,6 +15,8 @@
>>> */
>>> #define __PAGE_OFFSET _AC(CONFIG_PAGE_OFFSET, UL)
>>>
>>> +#define __START_KERNEL_map __PAGE_OFFSET
>>> +
>>> #define THREAD_SIZE_ORDER 1
>>> #define THREAD_SIZE (PAGE_SIZE << THREAD_SIZE_ORDER)
>>>
>>> diff --git a/arch/x86/include/asm/page_64_types.h b/arch/x86/include/asm/page_64_types.h
>>> index 6c896fb..43dcd80 100644
>>> --- a/arch/x86/include/asm/page_64_types.h
>>> +++ b/arch/x86/include/asm/page_64_types.h
>>> @@ -32,11 +32,6 @@
>>> */
>>> #define __PAGE_OFFSET _AC(0xffff880000000000, UL)
>>>
>>> -#define __PHYSICAL_START ((CONFIG_PHYSICAL_START + \
>>> - (CONFIG_PHYSICAL_ALIGN - 1)) & \
>>> - ~(CONFIG_PHYSICAL_ALIGN - 1))
>>> -
>>> -#define __START_KERNEL (__START_KERNEL_map + __PHYSICAL_START)
>>> #define __START_KERNEL_map _AC(0xffffffff80000000, UL)
>>>
>>> /* See Documentation/x86/x86_64/mm.txt for a description of the memory map. */
>>> diff --git a/arch/x86/include/asm/page_types.h b/arch/x86/include/asm/page_types.h
>>> index 54c9787..086c2fa 100644
>>> --- a/arch/x86/include/asm/page_types.h
>>> +++ b/arch/x86/include/asm/page_types.h
>>> @@ -33,6 +33,12 @@
>>> (((current->personality & READ_IMPLIES_EXEC) ? VM_EXEC : 0 ) | \
>>> VM_READ | VM_WRITE | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
>>>
>>> +#define __PHYSICAL_START ((CONFIG_PHYSICAL_START + \
>>> + (CONFIG_PHYSICAL_ALIGN - 1)) & \
>>> + ~(CONFIG_PHYSICAL_ALIGN - 1))
>>
>> I know you just moved the code. Could this macro be like this:
>>
>> #define __PHYSICAL_START ALIGN(CONFIG_PHYSICAL_START, CONFIG_PHYSICAL_ALIGN)
>
> Yeah, I'll fix that too.
>
> Thanks!
>
> -Kees
>
>>
>>> +
>>> +#define __START_KERNEL (__START_KERNEL_map + __PHYSICAL_START)
>>> +
>>> #ifdef CONFIG_X86_64
>>> #include <asm/page_64_types.h>
>>> #else
>>>
>>
>>
>> --
>> Thanks.
>> Zhang Yanfei
>
>
>
> --
> Kees Cook
> Chrome OS Security
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
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> Please read the FAQ at http://www.tux.org/lkml/
--
Thanks.
Zhang Yanfei
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2013-07-08 15:26 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2013-07-02 18:22 [RESEND][PATCH] x86, relocs: move ELF relocation handling to C Kees Cook
2013-07-03 3:22 ` Zhang Yanfei
2013-07-08 13:25 ` Kees Cook
2013-07-08 15:26 ` Zhang Yanfei
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