Patch "objtool: Support Clang non-section symbols in ORC dump" has been added to the 4.19-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    objtool: Support Clang non-section symbols in ORC dump

to the 4.19-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     objtool-support-clang-non-section-symbols-in-orc-dum.patch
and it can be found in the queue-4.19 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit b6fa7c0d37efea6d69497bc4447a69465e7ea437
Author: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Date:   Wed Apr 1 13:23:26 2020 -0500

    objtool: Support Clang non-section symbols in ORC dump
    
    [ Upstream commit 8782e7cab51b6bf01a5a86471dd82228af1ac185 ]
    
    Historically, the relocation symbols for ORC entries have only been
    section symbols:
    
      .text+0: sp:sp+8 bp:(und) type:call end:0
    
    However, the Clang assembler is aggressive about stripping section
    symbols.  In that case we will need to use function symbols:
    
      freezing_slow_path+0: sp:sp+8 bp:(und) type:call end:0
    
    In preparation for the generation of such entries in "objtool orc
    generate", add support for reading them in "objtool orc dump".
    
    Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
    Signed-off-by: Borislav Petkov <bp@xxxxxxx>
    Reviewed-by: Miroslav Benes <mbenes@xxxxxxx>
    Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
    Link: https://lkml.kernel.org/r/b811b5eb1a42602c3b523576dc5efab9ad1c174d.1585761021.git.jpoimboe@xxxxxxxxxx
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/tools/objtool/orc_dump.c b/tools/objtool/orc_dump.c
index faa444270ee3a..1a3e774941f8e 100644
--- a/tools/objtool/orc_dump.c
+++ b/tools/objtool/orc_dump.c
@@ -78,7 +78,7 @@ int orc_dump(const char *_objname)
 	char *name;
 	size_t nr_sections;
 	Elf64_Addr orc_ip_addr = 0;
-	size_t shstrtab_idx;
+	size_t shstrtab_idx, strtab_idx = 0;
 	Elf *elf;
 	Elf_Scn *scn;
 	GElf_Shdr sh;
@@ -139,6 +139,8 @@ int orc_dump(const char *_objname)
 
 		if (!strcmp(name, ".symtab")) {
 			symtab = data;
+		} else if (!strcmp(name, ".strtab")) {
+			strtab_idx = i;
 		} else if (!strcmp(name, ".orc_unwind")) {
 			orc = data->d_buf;
 			orc_size = sh.sh_size;
@@ -150,7 +152,7 @@ int orc_dump(const char *_objname)
 		}
 	}
 
-	if (!symtab || !orc || !orc_ip)
+	if (!symtab || !strtab_idx || !orc || !orc_ip)
 		return 0;
 
 	if (orc_size % sizeof(*orc) != 0) {
@@ -171,21 +173,29 @@ int orc_dump(const char *_objname)
 				return -1;
 			}
 
-			scn = elf_getscn(elf, sym.st_shndx);
-			if (!scn) {
-				WARN_ELF("elf_getscn");
-				return -1;
-			}
-
-			if (!gelf_getshdr(scn, &sh)) {
-				WARN_ELF("gelf_getshdr");
-				return -1;
-			}
-
-			name = elf_strptr(elf, shstrtab_idx, sh.sh_name);
-			if (!name || !*name) {
-				WARN_ELF("elf_strptr");
-				return -1;
+			if (GELF_ST_TYPE(sym.st_info) == STT_SECTION) {
+				scn = elf_getscn(elf, sym.st_shndx);
+				if (!scn) {
+					WARN_ELF("elf_getscn");
+					return -1;
+				}
+
+				if (!gelf_getshdr(scn, &sh)) {
+					WARN_ELF("gelf_getshdr");
+					return -1;
+				}
+
+				name = elf_strptr(elf, shstrtab_idx, sh.sh_name);
+				if (!name) {
+					WARN_ELF("elf_strptr");
+					return -1;
+				}
+			} else {
+				name = elf_strptr(elf, strtab_idx, sym.st_name);
+				if (!name) {
+					WARN_ELF("elf_strptr");
+					return -1;
+				}
 			}
 
 			printf("%s+%llx:", name, (unsigned long long)rela.r_addend);