Re: [x86/KASLR] ed9f007ee6: -- System halted

From: Yinghai Lu
Date: Mon Jun 27 2016 - 14:59:43 EST

output is:

early console in setup code
early console in extract_kernel
input_data: 0x0000000008fbb276
input_len: 0x00000000018c6e00
output: 0x0000000001000000
output_len: 0x0000000009867c98
kernel_total_size: 0x0000000008769000
booted via startup_32()
Physical KASLR using RDTSC...
Virtual KASLR using RDTSC...

Decompressing Linux...

XZ-compressed data is corrupt

-- System halted

Can you apply attached debug patch and send out dmesg?
---
arch/x86/boot/compressed/misc.c | 24 ------------------------
arch/x86/boot/compressed/misc.h | 10 ----------
arch/x86/boot/compressed/pagetable.c | 2 --
3 files changed, 36 deletions(-)

Index: linux-2.6/arch/x86/boot/compressed/misc.c
===================================================================
--- linux-2.6.orig/arch/x86/boot/compressed/misc.c
+++ linux-2.6/arch/x86/boot/compressed/misc.c
@@ -152,23 +152,6 @@ void __putstr(const char *s)
outb(0xff & (pos >> 1), vidport+1);
}

-void __puthex(unsigned long value)
-{
- char alpha[2] = "0";
- int bits;
-
- for (bits = sizeof(value) * 8 - 4; bits >= 0; bits -= 4) {
- unsigned long digit = (value >> bits) & 0xf;
-
- if (digit < 0xA)
- alpha[0] = '0' + digit;
- else
- alpha[0] = 'a' + (digit - 0xA);
-
- __putstr(alpha);
- }
-}
-
#if CONFIG_X86_NEED_RELOCS
static void handle_relocations(void *output, unsigned long output_len,
unsigned long virt_addr)
@@ -365,13 +348,6 @@ asmlinkage __visible void *extract_kerne
free_mem_ptr = heap; /* Heap */
free_mem_end_ptr = heap + BOOT_HEAP_SIZE;

- /* Report initial kernel position details. */
- debug_putaddr(input_data);
- debug_putaddr(input_len);
- debug_putaddr(output);
- debug_putaddr(output_len);
- debug_putaddr(kernel_total_size);
-
/*
* The memory hole needed for the kernel is the larger of either
* the entire decompressed kernel plus relocation table, or the
Index: linux-2.6/arch/x86/boot/compressed/misc.h
===================================================================
--- linux-2.6.orig/arch/x86/boot/compressed/misc.h
+++ linux-2.6/arch/x86/boot/compressed/misc.h
@@ -34,27 +34,17 @@ extern memptr free_mem_ptr;
extern memptr free_mem_end_ptr;
extern struct boot_params *boot_params;
void __putstr(const char *s);
-void __puthex(unsigned long value);
#define error_putstr(__x) __putstr(__x)
#define error_puthex(__x) __puthex(__x)

#ifdef CONFIG_X86_VERBOSE_BOOTUP

#define debug_putstr(__x) __putstr(__x)
-#define debug_puthex(__x) __puthex(__x)
-#define debug_putaddr(__x) { \
- debug_putstr(#__x ": 0x"); \
- debug_puthex((unsigned long)(__x)); \
- debug_putstr("\n"); \
- }

#else

static inline void debug_putstr(const char *s)
{ }
-static inline void debug_puthex(const char *s)
-{ }
-#define debug_putaddr(x) /* */

#endif

Index: linux-2.6/arch/x86/boot/compressed/pagetable.c
===================================================================
--- linux-2.6.orig/arch/x86/boot/compressed/pagetable.c
+++ linux-2.6/arch/x86/boot/compressed/pagetable.c
@@ -45,8 +45,6 @@ static void *alloc_pgt_page(void *contex
/* Validate there is space available for a new page. */
if (pages->pgt_buf_offset >= pages->pgt_buf_size) {
debug_putstr("out of pgt_buf in " __FILE__ "!?\n");
- debug_putaddr(pages->pgt_buf_offset);
- debug_putaddr(pages->pgt_buf_size);
return NULL;
}

Subject: [PATCH] x86, boot: Add printf support for early console in compressed/misc.c

Reuse printf.c in x86 setup code.

Later decompresser code could print out more info for debug info.

Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>

---
arch/x86/boot/compressed/Makefile | 1 +
arch/x86/boot/compressed/misc.h | 7 +++++++
arch/x86/boot/compressed/pagetable.c | 4 ++++
arch/x86/boot/compressed/printf.c | 5 +++++
4 files changed, 17 insertions(+)

Index: linux-2.6/arch/x86/boot/compressed/Makefile
===================================================================
--- linux-2.6.orig/arch/x86/boot/compressed/Makefile
+++ linux-2.6/arch/x86/boot/compressed/Makefile
@@ -73,6 +73,7 @@ vmlinux-objs-y := $(obj)/vmlinux.lds $(o
$(obj)/string.o $(obj)/cmdline.o $(obj)/error.o \
$(obj)/piggy.o $(obj)/cpuflags.o

+vmlinux-objs-$(CONFIG_X86_VERBOSE_BOOTUP) += $(obj)/printf.o
vmlinux-objs-$(CONFIG_EARLY_PRINTK) += $(obj)/early_serial_console.o
vmlinux-objs-$(CONFIG_RANDOMIZE_BASE) += $(obj)/kaslr.o
ifdef CONFIG_X86_64
Index: linux-2.6/arch/x86/boot/compressed/printf.c
===================================================================
--- /dev/null
+++ linux-2.6/arch/x86/boot/compressed/printf.c
@@ -0,0 +1,5 @@
+#include "misc.h"
+
+#define puts(__x) __putstr(__x)
+
+#include "../printf.c"
Index: linux-2.6/arch/x86/boot/compressed/misc.h
===================================================================
--- linux-2.6.orig/arch/x86/boot/compressed/misc.h
+++ linux-2.6/arch/x86/boot/compressed/misc.h
@@ -37,14 +37,21 @@ void __putstr(const char *s);
#define error_putstr(__x) __putstr(__x)
#define error_puthex(__x) __puthex(__x)

+/* printf.c */
+int sprintf(char *buf, const char *fmt, ...);
+int printf(const char *fmt, ...);
+
#ifdef CONFIG_X86_VERBOSE_BOOTUP

#define debug_putstr(__x) __putstr(__x)
+#define debug_printf printf

#else

static inline void debug_putstr(const char *s)
{ }
+static inline int debug_printf(const char *fmt, ...)
+{ }

#endif

Subject: [PATCH] x86, boot: Add print out for input/output info early console in compressed/misc.c

Use printf to print out decompress_kernel input and output info.

Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>

---
arch/x86/boot/compressed/misc.c | 42 ++++++++++++++++++++++++++++++++++++++--
1 file changed, 40 insertions(+), 2 deletions(-)

Index: linux-2.6/arch/x86/boot/compressed/misc.c
===================================================================
--- linux-2.6.orig/arch/x86/boot/compressed/misc.c
+++ linux-2.6/arch/x86/boot/compressed/misc.c
@@ -322,6 +322,8 @@ asmlinkage __visible void *extract_kerne
{
const unsigned long kernel_total_size = VO__end - VO__text;
unsigned long virt_addr = (unsigned long)output;
+ unsigned long output_run_size = max(output_len, kernel_total_size);
+ unsigned long init_size;

/* Retain x86 boot parameters pointer passed from startup_32/64. */
boot_params = rmode;
@@ -348,6 +350,37 @@ asmlinkage __visible void *extract_kerne
free_mem_ptr = heap; /* Heap */
free_mem_end_ptr = heap + BOOT_HEAP_SIZE;

+ init_size = boot_params->hdr.init_size;
+ debug_putstr("decompress_kernel:\n");
+ debug_printf(" input: [0x%010lx-0x%010lx]\n",
+ (unsigned long)input_data,
+ (unsigned long)input_data + input_len - 1);
+ debug_printf(" output: [0x%010lx-0x%010lx] 0x%08lx: output_len\n",
+ (unsigned long)output,
+ (unsigned long)output + output_len - 1,
+ (unsigned long)output_len);
+ debug_printf(" [0x%010lx-0x%010lx] 0x%08lx: run_size\n",
+ (unsigned long)output,
+ (unsigned long)output + kernel_total_size - 1,
+ (unsigned long)kernel_total_size);
+ debug_printf(" [0x%010lx-0x%010lx] 0x%08lx: output_run_size\n",
+ (unsigned long)output,
+ (unsigned long)output + output_run_size - 1,
+ (unsigned long)output_run_size);
+ debug_printf(" [0x%010lx-0x%010lx] 0x%08lx: init_size\n",
+ (unsigned long)output,
+ (unsigned long)output + init_size - 1,
+ (unsigned long)init_size);
+ debug_printf("ZO text/data: [0x%010lx-0x%010lx]\n",
+ (unsigned long)input_data + input_len,
+ (unsigned long)output + init_size - 1);
+ debug_printf(" ZO heap: [0x%010lx-0x%010lx]\n",
+ (unsigned long)heap,
+ (unsigned long)heap + BOOT_HEAP_SIZE - 1);
+ debug_printf(" VO bss/brk: [0x%010lx-0x%010lx]\n",
+ (unsigned long)output + (VO___bss_start - VO__text),
+ (unsigned long)output + kernel_total_size - 1);
+
/*
* The memory hole needed for the kernel is the larger of either
* the entire decompressed kernel plus relocation table, or the
@@ -355,8 +388,13 @@ asmlinkage __visible void *extract_kerne
*/
choose_random_location((unsigned long)input_data, input_len,
(unsigned long *)&output,
- max(output_len, kernel_total_size),
- &virt_addr);
+ output_run_size, &virt_addr);
+
+ if ((unsigned long)output != virt_addr)
+ debug_printf(" new output: [0x%010lx-0x%010lx] 0x%08lx: output_run_size\n",
+ virt_addr,
+ virt_addr + output_run_size - 1,
+ output_run_size);

/* Validate memory location choices. */
if ((unsigned long)output & (MIN_KERNEL_ALIGN - 1))
Subject: [PATCH] x86, boot: Add more debug printout in compressed/misc.c

with support that use printf.c in x86 setup code.
print out more info for debug info.

Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>


---
arch/x86/boot/compressed/misc.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)

Index: linux-2.6/arch/x86/boot/compressed/misc.c
===================================================================
--- linux-2.6.orig/arch/x86/boot/compressed/misc.c
+++ linux-2.6/arch/x86/boot/compressed/misc.c
@@ -287,7 +287,7 @@ static void parse_elf(void *output)
return;
}

- debug_putstr("Parsing ELF... ");
+ debug_putstr("Parsing ELF...\n");

phdrs = malloc(sizeof(*phdrs) * ehdr.e_phnum);
if (!phdrs)
@@ -307,6 +307,11 @@ static void parse_elf(void *output)
dest = (void *)(phdr->p_paddr);
#endif
memmove(dest, output + phdr->p_offset, phdr->p_filesz);
+ debug_printf(" parse_elf: [0x%010lx-0x%010lx] <=== [0x%010lx-0x%010lx]\n",
+ (unsigned long)dest,
+ (unsigned long)dest + phdr->p_filesz - 1,
+ (unsigned long)output + phdr->p_offset,
+ (unsigned long)output + phdr->p_offset + phdr->p_filesz - 1);
break;
default: /* Ignore other PT_* */ break;
}
@@ -431,6 +436,11 @@ asmlinkage __visible void *extract_kerne
error("Wrong destination address");
#endif

+ debug_printf(" decompress: [0x%010lx-0x%010lx] <=== [0x%010lx-0x%010lx]\n",
+ (unsigned long)output,
+ (unsigned long)output + output_len - 1,
+ (unsigned long)input_data,
+ (unsigned long)input_data + input_len - 1);
debug_putstr("\nDecompressing Linux... ");
__decompress(input_data, input_len, NULL, NULL, output, output_len,
NULL, error);