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

[Yinghai Lu]

On Tue, Jun 28, 2016 at 12:49 PM, Yinghai Lu <yinghai@xxxxxxxxxx> wrote:
> On Mon, Jun 27, 2016 at 10:43 PM, Ye Xiaolong <xiaolong.ye@xxxxxxxxx> wrote:
>> On Mon, Jun 27, 2016 at 11:59:37AM -0700, Yinghai Lu wrote:
>>>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?
>>
>> There are 4 patches you attached, do you mean to apply them all based on
>> commit ed9f007ee6? I tried and seemed they can't apply clearly on it.
>

Please check attached updated debug patches.

You should apply them after ed9f007ee6 in following sequence

revert_79063a7.patch
early_console_more_2_2x.patch
early_console_more_2_2x_add_0.patch
early_console_more_2_2x_add_1.patch

Thanks

Yinghai
---
 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 |   45 ++++++++++++++++++++++++++++++++++++++--
 1 file changed, 43 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 +322,9 @@ asmlinkage __visible void *extract_kerne
 {
 	const unsigned long kernel_total_size = VO__end - VO__text;
 	unsigned long virt_addr = (unsigned long)output;
+	unsigned char *output_orig = 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 +351,37 @@ 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 +389,15 @@ 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 (output != output_orig)
+		debug_printf("  new output: [0x%010lx-0x%010lx] 0x%08lx: output_run_size\n",
+			 (unsigned long)output,
+			 (unsigned long)output + output_run_size - 1,
+			 output_run_size);
+	if ((unsigned long)output != virt_addr)
+		debug_printf("   virt_addr: 0x%010lx\n", virt_addr);
 
 	/* 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
@@ -269,7 +269,7 @@ 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)
@@ -289,6 +289,11 @@ 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;
 		}
@@ -418,6 +423,11 @@ asmlinkage __visible void *extract_kerne
 		error("Destination virtual address changed when not relocatable");
 #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);