i386 crashdump: pass acpi info, and generalize hack

- Pass the acpi memap to the kernel.
- Port the fix from x86_64 to not truncate the elf
  note segment to 16K, to keep large machines happy.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Simon Horman <horms@verge.net.au>

1 files changed, 58 insertions, 6 deletions

diff --git a/kexec/arch/i386/crashdump-x86.c b/kexec/arch/i386/crashdump-x86.c
index 4b45067..b3adbd0 100644
--- a/kexec/arch/i386/crashdump-x86.c
+++ b/kexec/arch/i386/crashdump-x86.c
@@ -519,6 +519,39 @@ static enum coretype get_core_type(struct kexec_info *info,
 	}
 }
 
+/* Appends memmap=X#Y commandline for ACPI to command line*/
+static int cmdline_add_memmap_acpi(char *cmdline, unsigned long start,
+					unsigned long end)
+{
+	int cmdlen, len, align = 1024;
+	unsigned long startk, endk;
+	char str_mmap[256], str_tmp[20];
+
+	if (!(end - start))
+		return 0;
+
+	startk = start/1024;
+	endk = (end + align - 1)/1024;
+	strcpy (str_mmap, " memmap=");
+	ultoa((endk - startk), str_tmp);
+	strcat (str_mmap, str_tmp);
+	strcat (str_mmap, "K#");
+	ultoa(startk, str_tmp);
+	strcat (str_mmap, str_tmp);
+	strcat (str_mmap, "K");
+	len = strlen(str_mmap);
+	cmdlen = strlen(cmdline) + len;
+	if (cmdlen > (COMMAND_LINE_SIZE - 1))
+		die("Command line overflow\n");
+	strcat(cmdline, str_mmap);
+
+#ifdef DEBUG
+		printf("Command line after adding acpi memmap\n");
+		printf("%s\n", cmdline);
+#endif
+	return 0;
+}
+
 /* Loads additional segments in case of a panic kernel is being loaded.
  * One segment for backup region, another segment for storing elf headers
  * for crash memory image.
@@ -527,8 +560,8 @@ int load_crashdump_segments(struct kexec_info *info, char* mod_cmdline,
 				unsigned long max_addr, unsigned long min_base)
 {
 	void *tmp;
-	unsigned long sz, elfcorehdr;
-	int nr_ranges, align = 1024;
+	unsigned long sz, bufsz, memsz, elfcorehdr;
+	int nr_ranges, align = 1024, i;
 	struct memory_range *mem_range, *memmap_p;
 	struct crash_elf_info elf_info;
 
@@ -591,17 +624,18 @@ int load_crashdump_segments(struct kexec_info *info, char* mod_cmdline,
 	if (arch_options.core_header_type == CORE_TYPE_ELF64) {
 		if (crash_create_elf64_headers(info, &elf_info,
 					       crash_memory_range, nr_ranges,
-					       &tmp, &sz,
+					       &tmp, &bufsz,
 					       ELF_CORE_HEADER_ALIGN) < 0)
 			return -1;
 	}
 	else {
 		if (crash_create_elf32_headers(info, &elf_info,
 					       crash_memory_range, nr_ranges,
-					       &tmp, &sz,
+					       &tmp, &bufsz,
 					       ELF_CORE_HEADER_ALIGN) < 0)
 			return -1;
 	}
+	/* the size of the elf headers allocated is returned in 'bufsz' */
 
 	/* Hack: With some ld versions (GNU ld version 2.14.90.0.4 20030523),
 	 * vmlinux program headers show a gap of two pages between bss segment
@@ -610,13 +644,31 @@ int load_crashdump_segments(struct kexec_info *info, char* mod_cmdline,
 	 * elf core header segment to 16K to avoid being placed in such gaps.
 	 * This is a makeshift solution until it is fixed in kernel.
 	 */
-	elfcorehdr = add_buffer(info, tmp, sz, 16*1024, align, min_base,
+	if (bufsz < (16*1024)) {
+		/* bufsize is big enough for all the PT_NOTE's and PT_LOAD's */
+		memsz = 16*1024;
+		/* memsz will be the size of the memory hole we look for */
+	} else {
+		memsz = bufsz;
+	}
+	elfcorehdr = add_buffer(info, tmp, bufsz, memsz, align, min_base,
 							max_addr, -1);
 	dbgprintf("Created elf header segment at 0x%lx\n", elfcorehdr);
-	if (delete_memmap(memmap_p, elfcorehdr, sz) < 0)
+	if (delete_memmap(memmap_p, elfcorehdr, memsz) < 0)
 		return -1;
 	cmdline_add_memmap(mod_cmdline, memmap_p);
 	cmdline_add_elfcorehdr(mod_cmdline, elfcorehdr);
+
+	/* Inform second kernel about the presence of ACPI tables. */
+	for (i = 0; i < CRASH_MAX_MEMORY_RANGES; i++) {
+		unsigned long start, end;
+		if ( !( mem_range[i].type == RANGE_ACPI
+			|| mem_range[i].type == RANGE_ACPI_NVS) )
+			continue;
+		start = mem_range[i].start;
+		end = mem_range[i].end;
+		cmdline_add_memmap_acpi(mod_cmdline, start, end);
+	}
 	return 0;
 }