x86/build: make linking work again with ld incapable of generating build ID

The retaining of .note.* in a PT_NOTE segment requires a matching
program header to be present in the first place. Drop the respective
conditional and adjust mkelf32 to deal with (ignore) the potentially
present but empty extra segment (but have the new code be generic by
dropping any excess trailing entirely empty segments).

Fixes: dedb0aa42c6d ("x86/build: use --orphan-handling linker option if available")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>

diff --git a/xen/arch/x86/boot/mkelf32.c b/xen/arch/x86/boot/mkelf32.c
index bcbde1a056129877fd86fabcfba29ddfea5d022d..3d639c2e08a2d1a4743a67386234314fc353945f 100644 (file)
--- a/xen/arch/x86/boot/mkelf32.c
+++ b/xen/arch/x86/boot/mkelf32.c
@@ -320,6 +320,19 @@ int main(int argc, char **argv)
                 (int)in64_ehdr.e_phentsize, (int)sizeof(in64_phdr));
         return 1;
     }
+
+    /* Ignore entirely empty trailing program headers. */
+    while ( in64_ehdr.e_phnum > num_phdrs )
+    {
+        (void)lseek(infd,
+                    in64_ehdr.e_phoff + in64_ehdr.e_phnum * sizeof(in64_phdr),
+                    SEEK_SET);
+        do_read(infd, &in64_phdr, sizeof(in64_phdr));
+        endianadjust_phdr64(&in64_phdr);
+        if ( in64_phdr.p_memsz )
+            break;
+        --in64_ehdr.e_phnum;
+    }
     if ( in64_ehdr.e_phnum != num_phdrs )
     {
         fprintf(stderr, "Expect precisly %d program header; found %d.\n",

diff --git a/xen/arch/x86/xen.lds.S b/xen/arch/x86/xen.lds.S
index 68501c71863ae51b9037018ebba71ce7bdd409a8..6e4abbc1ce9d2571295186d64876500c9bf2da9b 100644 (file)
--- a/xen/arch/x86/xen.lds.S
+++ b/xen/arch/x86/xen.lds.S
@@ -40,9 +40,7 @@ OUTPUT_ARCH(i386:x86-64)
 PHDRS
 {
   text PT_LOAD ;
-#if defined(BUILD_ID) || defined(CONFIG_PVH_GUEST)
   note PT_NOTE ;
-#endif
 }
 #define PHDR(x) :x
 #else