The zImage* executable files on ppc64 use a special section called
".kernel:vmlinux.strip" which contains a compressed vmlinux executable
file.
This patch adds a service to detect and unzip such a section in a
malloc'ed buffer. The buffer is then used in elf_ppc64_load() to
load the new vmlinux.
Signed-off-by: C?dric Le Goater <clg at fr.ibm.com>
---
kexec/arch/ppc64/kexec-elf-ppc64.c | 15 ++++
kexec/arch/ppc64/kexec-ppc64.h | 2 +
kexec/arch/ppc64/kexec-zImage-ppc64.c | 123 +++++++++++++++++++++++++++++++++
3 files changed, 140 insertions(+)
diff --git a/kexec/arch/ppc64/kexec-elf-ppc64.c b/kexec/arch/ppc64/kexec-elf-ppc64.c
index ce1036762582..069d8ba6e690 100644
--- a/kexec/arch/ppc64/kexec-elf-ppc64.c
+++ b/kexec/arch/ppc64/kexec-elf-ppc64.c
@@ -116,6 +116,8 @@ int elf_ppc64_load(int argc, char **argv, const char *buf, off_t len,
uint64_t toc_addr;
uint32_t my_run_at_load;
unsigned int slave_code[256/sizeof (unsigned int)], master_entry;
+ void *vmlinux_addr;
+ int vmlinux_size;
/* See options.h -- add any more there, too. */
static const struct option options[] = {
@@ -184,6 +186,7 @@ int elf_ppc64_load(int argc, char **argv, const char *buf, off_t len,
modified_cmdline_len = strlen(modified_cmdline);
}
+retry:
/* Parse the Elf file */
result = build_elf_exec_info(buf, len, &ehdr, 0);
if (result < 0) {
@@ -191,6 +194,18 @@ int elf_ppc64_load(int argc, char **argv, const char *buf, off_t len,
return result;
}
+ /* If this is a zimage boot wrapper, rebuild the elf info on
+ * the new vmlinux which has been unzipped and go on with the
+ * kernel load.
+ */
+ if (!zImage_ppc64_unzip(&ehdr, &vmlinux_addr, &vmlinux_size)) {
+ free_elf_info(&ehdr);
+ free((void *) buf);
+ buf = vmlinux_addr;
+ len = vmlinux_size;
+ goto retry;
+ }
+
/* Load the Elf data. Physical load addresses in elf64 header do not
* show up correctly. Use user supplied address for now to patch the
* elf header
diff --git a/kexec/arch/ppc64/kexec-ppc64.h b/kexec/arch/ppc64/kexec-ppc64.h
index 9a0aecff7b33..e546d4737bfa 100644
--- a/kexec/arch/ppc64/kexec-ppc64.h
+++ b/kexec/arch/ppc64/kexec-ppc64.h
@@ -37,4 +37,6 @@ typedef struct mem_rgns {
extern mem_rgns_t usablemem_rgns;
+int zImage_ppc64_unzip(struct mem_ehdr *ehdr, void **buf, int *len);
+
#endif /* KEXEC_PPC64_H */
diff --git a/kexec/arch/ppc64/kexec-zImage-ppc64.c b/kexec/arch/ppc64/kexec-zImage-ppc64.c
index d084ee587be5..67d751f19d7d 100644
--- a/kexec/arch/ppc64/kexec-zImage-ppc64.c
+++ b/kexec/arch/ppc64/kexec-zImage-ppc64.c
@@ -30,6 +30,9 @@
#include <getopt.h>
#include <linux/elf.h>
#include "../../kexec.h"
+#include "kexec-ppc64.h"
+
+#include <zlib.h>
#define MAX_HEADERS 32
@@ -175,3 +178,123 @@ void zImage_ppc64_usage(void)
{
fprintf(stderr, "zImage support is still broken\n");
}
+
+#define HEAD_CRC 2
+#define EXTRA_FIELD 4
+#define ORIG_NAME 8
+#define COMMENT 0x10
+#define RESERVED 0xe0
+
+static int get_header_len(const char *header)
+{
+ int len = 10;
+ int flags = header[3];
+
+ /* check for gzip header */
+ if ((header[0] != 0x1f) || (header[1] != 0x8b) ||
+ (header[2] != Z_DEFLATED) || (flags & RESERVED) != 0) {
+ fprintf(stderr, "bad gzip header\n");
+ return -1;
+ }
+
+ if ((flags & EXTRA_FIELD) != 0)
+ len = 12 + header[10] + (header[11] << 8);
+
+ if ((flags & ORIG_NAME) != 0)
+ while (header[len++] != 0)
+ ;
+ if ((flags & COMMENT) != 0)
+ while (header[len++] != 0)
+ ;
+ if ((flags & HEAD_CRC) != 0)
+ len += 2;
+
+ return len;
+}
+
+static int gunzip(void *src, int srclen, void *dst, int dstlen)
+{
+ z_stream strm;
+ int hdrlen;
+ int len;
+ int ret;
+
+ strm.zalloc = Z_NULL;
+ strm.zfree = Z_NULL;
+ strm.opaque = Z_NULL;
+ strm.avail_in = 0;
+ strm.next_in = Z_NULL;
+
+ hdrlen = get_header_len(src);
+ if (hdrlen == -1)
+ return -1;
+
+ if (hdrlen >= srclen) {
+ fprintf(stderr, "gzip header too large : %d\n", hdrlen);
+ return -1;
+ }
+
+ ret = inflateInit2(&strm, -MAX_WBITS);
+ if (ret != Z_OK) {
+ fprintf(stderr, "inflateInit2 failed : %d\n", ret);
+ return -1;
+ }
+
+ /* skip gzip header */
+ strm.total_in = hdrlen;
+ strm.next_in = src + hdrlen;
+ strm.avail_in = srclen - hdrlen;
+
+ strm.next_out = dst;
+ strm.avail_out = dstlen;
+
+ ret = inflate(&strm, Z_FULL_FLUSH);
+ if (ret != Z_OK && ret != Z_STREAM_END) {
+ fprintf(stderr, "inflate failed: %d %s\n", ret, strm.msg);
+ return -1;
+ }
+
+ len = strm.next_out - (unsigned char *) dst;
+
+ inflateEnd(&strm);
+
+ return len;
+}
+
+int zImage_ppc64_unzip(struct mem_ehdr *ehdr, void **buf, int *len)
+{
+ struct mem_shdr *shdr;
+ void *vmlinuz_addr;
+ unsigned long vmlinuz_size;
+ unsigned int *vmlinux_sizep;
+
+ void *vmlinux_addr;
+ int vmlinux_size;
+
+ shdr = elf_rel_find_section(ehdr, ".kernel:vmlinux.strip");
+ if (!shdr)
+ return -1;
+
+ vmlinuz_addr = (void *) shdr->sh_data;
+ vmlinuz_size = shdr->sh_size;
+
+ /* The size of the uncompressed file is stored in the last 4
+ * bytes. The vmlinux size should be less than 4G ... */
+ vmlinux_sizep = (vmlinuz_addr + vmlinuz_size) - 4;
+
+ fprintf(stderr, "Found vmlinuz at %p, unzipping %d bytes\n",
+ vmlinuz_addr, *vmlinux_sizep);
+ vmlinux_addr = xmalloc(*vmlinux_sizep);
+
+ vmlinux_size = gunzip(vmlinuz_addr, vmlinuz_size,
+ vmlinux_addr, *vmlinux_sizep);
+ if (vmlinux_size != *vmlinux_sizep) {
+ fprintf(stderr, "gunzip failed : only got %d of %d bytes.\n",
+ vmlinux_size, *vmlinux_sizep);
+ return -1;
+ }
+
+ *buf = vmlinux_addr;
+ *len = vmlinux_size;
+ return 0;
+}
--
1.7.10.4
