recordmcount: Correct st_shndx handling

One should only use st_shndx when >SHN_UNDEF and <SHN_LORESERVE. When SHN_XINDEX, then use .symtab_shndx. Otherwise use 0. This handles the case: st_shndx >= SHN_LORESERVE && st_shndx != SHN_XINDEX. Link: https://lore.kernel.org/lkml/[email protected]/ Link: https://lkml.kernel.org/r/[email protected] Reported-by: Mark-PK Tsai <[email protected]> Tested-by: Mark-PK Tsai <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> [handle endianness of sym->st_shndx] Signed-off-by: Mark-PK Tsai <[email protected]> Signed-off-by: Steven Rostedt (VMware) <[email protected]>
d0u9 · Jun 18, 2021 · fb78076 · fb78076
1 parent 3e08a9f
commit fb78076
Showing 1 changed file with 10 additions and 5 deletions.
diff --git a/scripts/recordmcount.h b/scripts/recordmcount.h
@@ -192,15 +192,20 @@ static unsigned int get_symindex(Elf_Sym const *sym, Elf32_Word const *symtab,
 				 Elf32_Word const *symtab_shndx)
 {
 	unsigned long offset;
+	unsigned short shndx = w2(sym->st_shndx);
 	int index;
 
-	if (sym->st_shndx != SHN_XINDEX)
-		return w2(sym->st_shndx);
+	if (shndx > SHN_UNDEF && shndx < SHN_LORESERVE)
+		return shndx;
 
-	offset = (unsigned long)sym - (unsigned long)symtab;
-	index = offset / sizeof(*sym);
+	if (shndx == SHN_XINDEX) {
+		offset = (unsigned long)sym - (unsigned long)symtab;
+		index = offset / sizeof(*sym);
 
-	return w(symtab_shndx[index]);
+		return w(symtab_shndx[index]);
+	}
+
+	return 0;
 }
 
 static unsigned int get_shnum(Elf_Ehdr const *ehdr, Elf_Shdr const *shdr0)