kexec-tools: x86_64 elf header generation

o This patch is to generate the elf-core headers for x86_64.
  Not sure whether to retain the options --elf32 and --elf64
  but as of now, we port them to x86_64 also.

o We conditionally fill up the vaddr in the phdr as we got
  two linearly memory mapped regions in x86_64 unlike i386.
  To get the virtual address, we make of use of __START_KERNEL_map
  for the frist 0 to 40MB and for others we make use of PAGE_OFFSET.

o Support for per cpu dynamic allocation of crash notes.

Signed-off-by: Murali M Chakravarthy <muralim@in.ibm.com>
Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: Maneesh Soni <maneesh@in.ibm.com>

5 files changed, 324 insertions, 2 deletions

diff --git a/kexec/arch/x86_64/Makefile b/kexec/arch/x86_64/Makefile
index 18e1690..799e2a4 100644
--- a/kexec/arch/x86_64/Makefile
+++ b/kexec/arch/x86_64/Makefile
@@ -1,13 +1,13 @@
 #
 # kexec x86_64 (linux booting linux)
 #
-KEXEC_C_SRCS+= kexec/arch/i386/crashdump-x86.c
 KEXEC_C_SRCS+= kexec/arch/i386/kexec-elf-x86.c 
 KEXEC_C_SRCS+= kexec/arch/i386/kexec-bzImage.c 
 KEXEC_C_SRCS+= kexec/arch/i386/kexec-multiboot-x86.c
 KEXEC_C_SRCS+= kexec/arch/i386/kexec-beoboot-x86.c
 KEXEC_C_SRCS+= kexec/arch/i386/kexec-nbi.c
 KEXEC_C_SRCS+= kexec/arch/i386/x86-linux-setup.c
+KEXEC_C_SRCS+= kexec/arch/x86_64/crashdump-x86_64.c
 KEXEC_C_SRCS+= kexec/arch/x86_64/kexec-x86_64.c 
 KEXEC_C_SRCS+= kexec/arch/x86_64/kexec-elf-x86_64.c 
 KEXEC_C_SRCS+= kexec/arch/x86_64/kexec-elf-rel-x86_64.c
diff --git a/kexec/arch/x86_64/crashdump-x86_64.c b/kexec/arch/x86_64/crashdump-x86_64.c
new file mode 100644
index 0000000..299d9d1
--- /dev/null
+++ b/kexec/arch/x86_64/crashdump-x86_64.c
@@ -0,0 +1,283 @@
+/*
+ * kexec: Linux boots Linux
+ *
+ * Created by: Murali M Chakravarthy (muralim@in.ibm.com)
+ * Copyright (C) IBM Corporation, 2005. All rights reserved
+ * Heavily borrowed from kexec/arch/i386/crashdump-x86.c
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation (version 2 of the License).
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <limits.h>
+#include <elf.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include "../../kexec.h"
+#include "../../kexec-elf.h"
+#include "../../kexec-syscall.h"
+#include "kexec-x86_64.h"
+#include "crashdump-x86_64.h"
+#include <x86/x86-linux.h>
+
+/* Returns the virtual address of start of crash notes buffer for a cpu. */
+static int get_crash_notes_section_addr(int cpu, unsigned long long *addr)
+{
+
+#define MAX_SYSFS_PATH_LEN	70
+	char crash_notes[MAX_SYSFS_PATH_LEN];
+	char line[MAX_LINE];
+	FILE *fp;
+	struct stat cpu_stat;
+
+	sprintf(crash_notes, "/sys/devices/system/cpu");
+	if (stat(crash_notes, &cpu_stat)) {
+		die("Cannot stat %s: %s\nTry mounting sysfs\n",
+				crash_notes, strerror(errno));
+	}
+
+	sprintf(crash_notes, "/sys/devices/system/cpu/cpu%d/crash_notes", cpu);
+	fp = fopen(crash_notes, "r");
+	if (!fp) {
+		/* CPU is not physically present.*/
+		*addr = 0;
+		return -1;
+	}
+
+	if (fgets(line, sizeof(line), fp) != 0) {
+		int count;
+		count = sscanf(line, "%Lx", addr);
+		if (count != 1) {
+			*addr = 0;
+			return -1;
+		}
+#if 0
+		printf("crash_notes addr = %Lx\n", *addr);
+#endif
+	}
+	return 0;
+}
+
+/* Prepares the crash memory elf64 headers and stores in supplied buffer. */
+static int prepare_crash_memory_elf64_headers(struct kexec_info *info,
+						void *buf, unsigned long size)
+{
+	Elf64_Ehdr *elf;
+	Elf64_Phdr *phdr;
+	int i;
+	char *bufp;
+	long int nr_cpus = 0;
+	unsigned long long notes_addr;
+
+	bufp = (char*) buf;
+
+	/* Setup ELF Header*/
+	elf = (Elf64_Ehdr *) bufp;
+	bufp += sizeof(Elf64_Ehdr);
+	memcpy(elf->e_ident, ELFMAG, SELFMAG);
+	elf->e_ident[EI_CLASS]  = ELFCLASS64;
+	elf->e_ident[EI_DATA]   = ELFDATA2LSB;
+	elf->e_ident[EI_VERSION]= EV_CURRENT;
+	elf->e_ident[EI_OSABI] = ELFOSABI_NONE;
+	memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
+	elf->e_type	= ET_CORE;
+	elf->e_machine	= EM_X86_64;
+	elf->e_version	= EV_CURRENT;
+	elf->e_entry	= 0;
+	elf->e_phoff	= sizeof(Elf64_Ehdr);
+	elf->e_shoff	= 0;
+	elf->e_flags	= 0;
+	elf->e_ehsize   = sizeof(Elf64_Ehdr);
+	elf->e_phentsize= sizeof(Elf64_Phdr);
+	elf->e_phnum    = 0;
+	elf->e_shentsize= 0;
+	elf->e_shnum    = 0;
+	elf->e_shstrndx = 0;
+
+	/* PT_NOTE program headers. One per cpu*/
+	nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
+	if (nr_cpus < 0) {
+		return -1;
+	}
+
+	/* Need to find a better way to determine per cpu notes section size. */
+#define MAX_NOTE_BYTES	1024
+	for (i = 0; i < nr_cpus; i++) {
+		if (get_crash_notes_section_addr (i, &notes_addr) < 0) {
+			/* This cpu is not present. Skip it. */
+			continue;
+		}
+
+		phdr = (Elf64_Phdr *) bufp;
+		bufp += sizeof(Elf64_Phdr);
+		phdr->p_type	= PT_NOTE;
+		phdr->p_flags	= 0;
+		phdr->p_offset  = phdr->p_paddr = notes_addr;
+		phdr->p_vaddr   = 0;
+		phdr->p_filesz	= phdr->p_memsz	= MAX_NOTE_BYTES;
+		/* Do we need any alignment of segments? */
+		phdr->p_align	= 0;
+
+		/* Increment number of program headers. */
+		(elf->e_phnum)++;
+	}
+
+	/* Setup PT_LOAD type program header for every system RAM chunk.
+	 * A seprate program header for Backup Region*/
+	for (i = 0; i < CRASH_MAX_MEMORY_RANGES; i++) {
+		unsigned long long mstart, mend;
+		mstart = crash_memory_range[i].start;
+		mend = crash_memory_range[i].end;
+		if (!mstart && !mend)
+			break;
+		phdr = (Elf64_Phdr *) bufp;
+		bufp += sizeof(Elf64_Phdr);
+		phdr->p_type	= PT_LOAD;
+		phdr->p_flags	= PF_R|PF_W|PF_X;
+		if (mstart == BACKUP_START && mend == BACKUP_END)
+			phdr->p_offset	= info->backup_start;
+		else
+			phdr->p_offset	= mstart;
+
+		/* Handle linearly mapped region.*/
+
+		/* Filling the vaddr conditionally as we have two linearly
+		 * mapped regions here. One is __START_KERNEL_map 0 to 40 MB
+		 * other one is PAGE_OFFSET */
+
+		if ((mend <= (MAXMEM - 1)) && mstart < KERNEL_TEXT_SIZE)
+			phdr->p_vaddr = mstart + __START_KERNEL_map;
+		else {
+			if (mend <= (MAXMEM - 1))
+				phdr->p_vaddr = mstart + PAGE_OFFSET;
+			else
+				phdr->p_vaddr = -1ULL;
+		}
+		phdr->p_paddr = mstart;
+		phdr->p_filesz	= phdr->p_memsz	= mend - mstart + 1;
+		/* Do we need any alignment of segments? */
+		phdr->p_align	= 0;
+
+		/* Increment number of program headers. */
+		(elf->e_phnum)++;
+	}
+	return 0;
+}
+
+/* Prepares the crash memory elf32 headers and stores in supplied buffer. */
+static int prepare_crash_memory_elf32_headers(struct kexec_info *info,
+						void *buf, unsigned long size)
+{
+	Elf32_Ehdr *elf;
+	Elf32_Phdr *phdr;
+	int i;
+	char *bufp;
+	long int nr_cpus = 0;
+	unsigned long long notes_addr;
+
+	bufp = (char*) buf;
+
+	/* Setup ELF Header*/
+	elf = (Elf32_Ehdr *) bufp;
+	bufp += sizeof(Elf32_Ehdr);
+	memcpy(elf->e_ident, ELFMAG, SELFMAG);
+	elf->e_ident[EI_CLASS]  = ELFCLASS32;
+	elf->e_ident[EI_DATA]   = ELFDATA2LSB;
+	elf->e_ident[EI_VERSION]= EV_CURRENT;
+	elf->e_ident[EI_OSABI] = ELFOSABI_NONE;
+	memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
+	elf->e_type	= ET_CORE;
+	elf->e_machine	= EM_X86_64;
+	elf->e_version	= EV_CURRENT;
+	elf->e_entry	= 0;
+	elf->e_phoff	= sizeof(Elf32_Ehdr);
+	elf->e_shoff	= 0;
+	elf->e_flags	= 0;
+	elf->e_ehsize   = sizeof(Elf32_Ehdr);
+	elf->e_phentsize= sizeof(Elf32_Phdr);
+	elf->e_phnum    = 0;
+	elf->e_shentsize= 0;
+	elf->e_shnum    = 0;
+	elf->e_shstrndx = 0;
+
+	/* PT_NOTE program headers. One per cpu*/
+	nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
+	if (nr_cpus < 0) {
+		return -1;
+	}
+
+	/* Need to find a better way to determine per cpu notes section size. */
+#define MAX_NOTE_BYTES	1024
+	for (i = 0; i < nr_cpus; i++) {
+		if (get_crash_notes_section_addr (i, &notes_addr) < 0) {
+			/* This cpu is not present. Skip it. */
+			return -1;
+		}
+		phdr = (Elf32_Phdr *) bufp;
+		bufp += sizeof(Elf32_Phdr);
+		phdr->p_type	= PT_NOTE;
+		phdr->p_flags	= 0;
+		phdr->p_offset  = phdr->p_paddr = notes_addr;
+		phdr->p_vaddr   = 0;
+		phdr->p_filesz	= phdr->p_memsz	= MAX_NOTE_BYTES;
+		/* Do we need any alignment of segments? */
+		phdr->p_align	= 0;
+
+		/* Increment number of program headers. */
+		(elf->e_phnum)++;
+	}
+
+	/* Setup PT_LOAD type program header for every system RAM chunk.
+	 * A seprate program header for Backup Region*/
+	for (i = 0; i < CRASH_MAX_MEMORY_RANGES; i++) {
+		unsigned long long mstart, mend;
+		mstart = crash_memory_range[i].start;
+		mend = crash_memory_range[i].end;
+		if (!mstart && !mend)
+			break;
+		phdr = (Elf32_Phdr *) bufp;
+		bufp += sizeof(Elf32_Phdr);
+		phdr->p_type	= PT_LOAD;
+		phdr->p_flags	= PF_R|PF_W|PF_X;
+		if (mstart == BACKUP_START && mend == BACKUP_END)
+			phdr->p_offset	= info->backup_start;
+		else
+			phdr->p_offset	= mstart;
+		/* Handle linearly mapped region.*/
+
+		/* Filling the vaddr conditionally as we have two linearly
+		 * mapped regions here. One is __START_KERNEL_map 0 to 40 MB
+		 * other one is PAGE_OFFSET */
+
+		if (mend <= (MAXMEM - 1) && mstart < KERNEL_TEXT_SIZE)
+			phdr->p_vaddr = mstart + __START_KERNEL_map;
+		else {
+			if (mend <= (MAXMEM - 1))
+				phdr->p_vaddr = mstart + PAGE_OFFSET;
+			else
+				phdr->p_vaddr = UINT_MAX;
+		}
+		phdr->p_paddr = mstart;
+		phdr->p_filesz	= phdr->p_memsz	= mend - mstart + 1;
+		/* Do we need any alignment of segments? */
+		phdr->p_align	= 0;
+		/* Increment number of program headers. */
+		(elf->e_phnum)++;
+	}
+	return 0;
+}
+
diff --git a/kexec/arch/x86_64/crashdump-x86_64.h b/kexec/arch/x86_64/crashdump-x86_64.h
new file mode 100644
index 0000000..2eb55db
--- /dev/null
+++ b/kexec/arch/x86_64/crashdump-x86_64.h
@@ -0,0 +1,24 @@
+#ifndef CRASHDUMP_X86_64_H
+#define CRASHDUMP_X86_64_H
+
+int load_crashdump_segments(struct kexec_info *info, char *mod_cmdline,
+				unsigned long max_addr, unsigned long min_base);
+
+#define __START_KERNEL_map      0xffffffff80000000UL
+#define PAGE_OFFSET		0xffff810000000000UL
+#define __pa(x)                 (((unsigned long)(x)>=__START_KERNEL_map)?(unsigned long)(x) - (unsigned long)__START_KERNEL_map:(unsigned long)(x) - PAGE_OFFSET)
+
+#define MAXMEM           0x3fffffffffffUL
+
+/* Kernel text size */
+#define KERNEL_TEXT_SIZE  (40UL*1024*1024)
+
+#define CRASH_MAX_MEMMAP_NR	(KEXEC_MAX_SEGMENTS + 1)
+#define CRASH_MAX_MEMORY_RANGES	(MAX_MEMORY_RANGES + 2)
+
+/* Backup Region, First 640K of System RAM. */
+#define BACKUP_START	0x00000000
+#define BACKUP_END	0x0009ffff
+#define BACKUP_SIZE	(BACKUP_END - BACKUP_START + 1)
+
+#endif /* CRASHDUMP_X86_64_H */
diff --git a/kexec/arch/x86_64/include/arch/options.h b/kexec/arch/x86_64/include/arch/options.h
index 75065b9..189ef46 100644
--- a/kexec/arch/x86_64/include/arch/options.h
+++ b/kexec/arch/x86_64/include/arch/options.h
@@ -6,7 +6,9 @@
 #define OPT_SERIAL_BAUD    (OPT_MAX+2)
 #define OPT_CONSOLE_VGA    (OPT_MAX+3)
 #define OPT_CONSOLE_SERIAL (OPT_MAX+4)
-#define OPT_ARCH_MAX       (OPT_MAX+5)
+#define OPT_ELF32_CORE     (OPT_MAX+5)
+#define OPT_ELF64_CORE     (OPT_MAX+6)
+#define OPT_ARCH_MAX       (OPT_MAX+7)
 
 #define KEXEC_ARCH_OPTIONS \
 	KEXEC_OPTIONS \
@@ -15,6 +17,8 @@
 	{ "serial-baud",    1, 0, OPT_SERIAL_BAUD }, \
 	{ "console-vga",    0, 0, OPT_CONSOLE_VGA }, \
 	{ "console-serial", 0, 0, OPT_CONSOLE_SERIAL }, \
+	{ "elf32-core-headers", 0, 0, OPT_ELF32_CORE }, \
+	{ "elf64-core-headers", 0, 0, OPT_ELF64_CORE }, \
 
 #define KEXEC_ARCH_OPT_STR KEXEC_OPT_STR ""
 
diff --git a/kexec/arch/x86_64/kexec-x86_64.c b/kexec/arch/x86_64/kexec-x86_64.c
index 5c3349f..530adcf 100644
--- a/kexec/arch/x86_64/kexec-x86_64.c
+++ b/kexec/arch/x86_64/kexec-x86_64.c
@@ -30,6 +30,7 @@
 #include "../../kexec-elf.h"
 #include "../../kexec-syscall.h"
 #include "kexec-x86_64.h"
+#include "crashdump-x86_64.h"
 #include <arch/options.h>
 
 #define MAX_MEMORY_RANGES 64
@@ -136,6 +137,8 @@ void arch_usage(void)
 		"     --serial-baud=<buad_rate> Specify the serial port baud rate\n"
 		"     --console-vga             Enable the vga console\n"
 		"     --console-serial          Enable the serial console\n"
+		"     --elf32-core-headers      Prepare core headers in ELF32 format\n"
+		"     --elf64-core-headers      Prepare core headers in ELF64 format\n"
 		);
 }
 
@@ -145,12 +148,14 @@ struct {
 	uint32_t serial_baud;
 	uint8_t  console_vga;
 	uint8_t  console_serial;
+	int core_header_type;
 } arch_options = {
 	.reset_vga   = 0,
 	.serial_base = 0x3f8,
 	.serial_baud = 0,
 	.console_vga = 0,
 	.console_serial = 0,
+	.core_header_type = CORE_TYPE_ELF64,
 };
 
 int arch_process_options(int argc, char **argv)
@@ -214,6 +219,12 @@ int arch_process_options(int argc, char **argv)
 			}
 			arch_options.serial_baud = value;
 			break;
+			case OPT_ELF32_CORE:
+				arch_options.core_header_type = CORE_TYPE_ELF32;
+				break;
+			case OPT_ELF64_CORE:
+				arch_options.core_header_type = CORE_TYPE_ELF64;
+				break;
 		}
 	}
 	/* Reset getopt for the next pass; called in other source modules */