arm64: Use default kernel offset when the image file can't be seeked
While introducing new code to extract the kernel offset from the
image, commit fd0a05b ("arm64: Obtain text offset from kernel image")
introduced a regression where something such as:
./lkvm run -c 8 -p earlycon <(zcat /boot/vmlinuz-5.8.0-rc5-00172-ga161216e31ba)
now fails to load the kernel, as the file descriptor cannot be
seeked.
Let's assume the good old 0x80000 offset when the seek syscall fails,
with a warning for a good measure.
Fixes: fd0a05b ("arm64: Obtain text offset from kernel image")
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200716120801.2996-1-maz@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
diff --git a/arm/aarch64/kvm.c b/arm/aarch64/kvm.c
index a46d438..49e1dd3 100644
--- a/arm/aarch64/kvm.c
+++ b/arm/aarch64/kvm.c
@@ -15,6 +15,7 @@
struct arm64_image_header header;
off_t cur_offset;
ssize_t size;
+ const char *warn_str;
/* the 32bit kernel offset is a well known value */
if (kvm->cfg.arch.aarch32_guest)
@@ -22,8 +23,10 @@
cur_offset = lseek(fd, 0, SEEK_CUR);
if (cur_offset == (off_t)-1 ||
- lseek(fd, 0, SEEK_SET) == (off_t)-1)
- die("Failed to seek in image file");
+ lseek(fd, 0, SEEK_SET) == (off_t)-1) {
+ warn_str = "Failed to seek in kernel image file";
+ goto fail;
+ }
size = xread(fd, &header, sizeof(header));
if (size < 0 || (size_t)size < sizeof(header))
@@ -37,7 +40,9 @@
if (le64_to_cpu(header.image_size))
return le64_to_cpu(header.text_offset);
- pr_warning("Image size is 0, assuming TEXT_OFFSET to be 0x80000");
+ warn_str = "Image size is 0";
+fail:
+ pr_warning("%s, assuming TEXT_OFFSET to be 0x80000", warn_str);
return 0x80000;
}
