commit 4a90cb11140a6bb3712228861a32e4035013ad85

Author: Mark Wielaard <mark@klomp.org>

Date:   Thu Dec 5 15:03:54 2019 +0100

    libdwfl: Find and handle compressed vmlinuz image.

    Both the dwfl_linux_kernel_find_elf callback and the

    dwfl_linux_kernel_report_offline reporting function only handled

    vmlinix images possibly compressed with .gz, .bz2 or .xz extension.

    They did not find or handle the much more common vmlinuz compressed

    images.

    It is not completely clear why we didn't up to now. Support for

    compressed ELF files was added in 2009 and the code was updated to

    to try to find the .gz, .bz2 or .xz extension variants in 2011.

    But not the vmlinuz named variant.

    Reported-by: Aaron Merey <amerey@redhat.com>

    Tested-by: Frank Ch. Eigler <fche@redhat.com>

    Signed-off-by: Mark Wielaard <mark@klomp.org>

diff --git a/libdwfl/linux-kernel-modules.c b/libdwfl/linux-kernel-modules.c

index d46ab5aa..48fb1ff0 100644

--- a/libdwfl/linux-kernel-modules.c

+++ b/libdwfl/linux-kernel-modules.c

@@ -174,6 +174,8 @@ kernel_release (void)

 static int

 find_kernel_elf (Dwfl *dwfl, const char *release, char **fname)

 {

+  /* First try to find an uncompressed vmlinux image.  Possibly

+     including debuginfo.  */

   if ((release[0] == '/'

        ? asprintf (fname, "%s/vmlinux", release)

        : asprintf (fname, "/boot/vmlinux-%s", release)) < 0)

@@ -188,6 +190,27 @@ find_kernel_elf (Dwfl *dwfl, const char *release, char **fname)

       fd = try_kernel_name (dwfl, fname, true);

     }

+  /* There might be a compressed vmlinuz image.  Probably without

+     debuginfo, but try to find it under the debug path also, just in

+     case.  */

+  if (fd < 0)

+    {

+      free (*fname);

+      if ((release[0] == '/'

+           ? asprintf (fname, "%s/vmlinuz", release)

+           : asprintf (fname, "/boot/vmlinuz-%s", release)) < 0)

+        return -1;

+

+      fd = try_kernel_name (dwfl, fname, true);

+      if (fd < 0 && release[0] != '/')

+	{

+	  free (*fname);

+	  if (asprintf (fname, MODULEDIRFMT "/vmlinuz", release) < 0)

+	    return -1;

+	  fd = try_kernel_name (dwfl, fname, true);

+	}

+    }

+

   return fd;

 }