git: cad6775d969e - stable/13 - kldxref: Workaround incorrect PT_DYNAMIC in existing powerpc kernels

The branch stable/13 has been updated by jhb:

URL: https://cgit.FreeBSD.org/src/commit/?id=cad6775d969e66bfff46669f55f3b0def8efc0ca

commit cad6775d969e66bfff46669f55f3b0def8efc0ca
Author:     John Baldwin <jhb@FreeBSD.org>
AuthorDate: 2024-01-09 18:57:48 +0000
Commit:     John Baldwin <jhb@FreeBSD.org>
CommitDate: 2024-01-18 21:32:10 +0000

    kldxref: Workaround incorrect PT_DYNAMIC in existing powerpc kernels
    
    Existing powerpc kernels include additional sections beyond .dynamic
    in the PT_DYNAMIC segment.  Relax the requirement for an exact size
    match of the section and segment for PowerPC files as a workaround.
    
    Reported by:    jrtc27
    Sponsored by:   DARPA
    Differential Revision:  https://reviews.freebsd.org/D43123
    
    (cherry picked from commit 6631e2f9b49e08f53c7beb560ee8509c343b3927)
---
 usr.sbin/kldxref/ef.c | 11 ++++++++++-
 usr.sbin/kldxref/ef.h |  1 +
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/usr.sbin/kldxref/ef.c b/usr.sbin/kldxref/ef.c
index fd0782ff1dd0..1ef27f2bc54a 100644
--- a/usr.sbin/kldxref/ef.c
+++ b/usr.sbin/kldxref/ef.c
@@ -248,8 +248,17 @@ ef_parse_dynamic(elf_file_t ef, const GElf_Phdr *phdyn)
 	dynamic_idx = -1;
 	for (i = 0; i < nshdr; i++) {
 		if (shdr[i].sh_type == SHT_DYNAMIC) {
+			/*
+			 * PowerPC kernels contain additional sections
+			 * beyond .dynamic in PT_DYNAMIC due to a linker
+			 * script bug.  Permit a section with a smaller
+			 * size as a workaround.
+			 */
 			if (shdr[i].sh_offset != phdyn->p_offset ||
-			    shdr[i].sh_size != phdyn->p_filesz) {
+			    ((elf_machine(ef->ef_efile) == EM_PPC ||
+			    elf_machine(ef->ef_efile) == EM_PPC64) ?
+			    shdr[i].sh_size > phdyn->p_filesz :
+			    shdr[i].sh_size != phdyn->p_filesz)) {
 				warnx(".dynamic section doesn't match phdr");
 				error = EFTYPE;
 				goto out;
diff --git a/usr.sbin/kldxref/ef.h b/usr.sbin/kldxref/ef.h
index 2909704bf2d1..25dc5216b169 100644
--- a/usr.sbin/kldxref/ef.h
+++ b/usr.sbin/kldxref/ef.h
@@ -100,6 +100,7 @@ struct elf_file {
 	int ef_fd;
 };
 
+#define	elf_machine(ef)		((ef)->ef_hdr.e_machine)
 #define	elf_class(ef)		((ef)->ef_hdr.e_ident[EI_CLASS])
 #define	elf_encoding(ef)	((ef)->ef_hdr.e_ident[EI_DATA])