[PATCH 3/5] elflint: Fix invalid type of relocation info and other issues on mips

["Ying Huang" <ying.huang@oss.cipunited.com>]

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From: Ying Huang <ying.huang@oss.cipunited.com>

add some check related functions
---
 backends/mips_init.c      |  3 +++
 backends/mips_symbol.c    | 33 +++++++++++++++++++++++++++++++++
 libebl/eblrelocvaliduse.c |  8 ++++++--
 src/elflint.c             | 23 ++++++++++++++++++++---
 4 files changed, 62 insertions(+), 5 deletions(-)

diff --git a/backends/mips_init.c b/backends/mips_init.c
index 5bba822b..4c2f21b9 100644
--- a/backends/mips_init.c
+++ b/backends/mips_init.c
@@ -51,6 +51,9 @@ mips_init (Elf *elf __attribute__ ((unused)),
   HOOK (eh, segment_type_name);
   HOOK (eh, dynamic_tag_check);
   HOOK (eh, dynamic_tag_name);
+  HOOK (eh, machine_section_flag_check);
   HOOK (eh, check_object_attribute);
+  HOOK (eh, check_special_symbol);
+  HOOK (eh, check_reloc_target_type);
   return eh;
 }
diff --git a/backends/mips_symbol.c b/backends/mips_symbol.c
index e760d58d..8787fcee 100644
--- a/backends/mips_symbol.c
+++ b/backends/mips_symbol.c
@@ -158,6 +158,39 @@ mips_section_type_name (int type,
   return NULL;
 }
 
+bool
+mips_check_reloc_target_type (Ebl *ebl __attribute__ ((unused)), Elf64_Word sh_type)
+{
+  return (sh_type == SHT_MIPS_DWARF);
+}
+
+/* Check whether given symbol's st_value and st_size are OK despite failing
+   normal checks.  */
+bool
+mips_check_special_symbol (Elf *elf,
+			    const GElf_Sym *sym __attribute__ ((unused)),
+			    const char *name __attribute__ ((unused)),
+			    const GElf_Shdr *destshdr)
+{
+  size_t shstrndx;
+  if (elf_getshdrstrndx (elf, &shstrndx) != 0)
+    return false;
+  const char *sname = elf_strptr (elf, shstrndx, destshdr->sh_name);
+  if (sname == NULL)
+    return false;
+  return (strcmp (sname, ".got") == 0 || strcmp (sname, ".bss") == 0);
+}
+
+/* Check whether SHF_MASKPROC flags are valid.  */
+bool
+mips_machine_section_flag_check (GElf_Xword sh_flags)
+{
+  return ((sh_flags &~ (SHF_MIPS_GPREL |
+		        SHF_MIPS_MERGE |
+			SHF_MIPS_ADDR |
+			SHF_MIPS_STRINGS)) == 0);
+}
+
 /* Check whether machine flags are valid.  */
 bool
 mips_machine_flag_check (GElf_Word flags)
diff --git a/libebl/eblrelocvaliduse.c b/libebl/eblrelocvaliduse.c
index f0bed345..44b8d300 100644
--- a/libebl/eblrelocvaliduse.c
+++ b/libebl/eblrelocvaliduse.c
@@ -32,10 +32,14 @@
 #endif
 
 #include <libeblP.h>
-
+#include <libelfP.h>
 
 bool
 ebl_reloc_valid_use (Ebl *ebl, int reloc)
 {
-  return ebl != NULL ? ebl->reloc_valid_use (ebl->elf, reloc) : false;
+  int relocNew = reloc;
+  GElf_Ehdr ehdr;
+  if(ebl->elf->class == ELFCLASS64 && gelf_getehdr(ebl->elf, &ehdr) != NULL && ehdr.e_machine == EM_MIPS)
+    relocNew = ELF64_MIPS_R_TYPE(reloc);
+  return ebl != NULL ? ebl->reloc_valid_use (ebl->elf, relocNew) : false;
 }
diff --git a/src/elflint.c b/src/elflint.c
index dd42dcb4..04f1ee92 100644
--- a/src/elflint.c
+++ b/src/elflint.c
@@ -935,7 +935,10 @@ section [%2d] '%s': symbol %zu (%s): non-local symbol outside range described in
 	}
 
       if (GELF_ST_TYPE (sym->st_info) == STT_SECTION
-	  && GELF_ST_BIND (sym->st_info) != STB_LOCAL)
+	  && GELF_ST_BIND (sym->st_info) != STB_LOCAL
+	  && ehdr->e_machine != EM_MIPS
+	  && strcmp (name, "_DYNAMIC_LINK") != 0
+	  && strcmp (name, "_DYNAMIC_LINKING") != 0)
 	ERROR (_("\
 section [%2d] '%s': symbol %zu (%s): non-local section symbol\n"),
 	       idx, section_name (ebl, idx), cnt, name);
@@ -3789,6 +3792,12 @@ cannot get section header for section [%2zu] '%s': %s\n"),
 		    && ebl_bss_plt_p (ebl))
 		  good_type = SHT_NOBITS;
 
+	        if (ehdr->e_machine == EM_MIPS
+	            && (strstr(special_sections[s].name, ".debug") != NULL))
+		  {
+	            good_type = SHT_MIPS_DWARF;
+		  }
+
 		/* In a debuginfo file, any normal section can be SHT_NOBITS.
 		   This is only invalid for DWARF sections and .shstrtab.  */
 		if (shdr->sh_type != good_type
@@ -3953,8 +3962,16 @@ section [%2zu] '%s': size not multiple of entry size\n"),
 	      sh_flags &= ~(GElf_Xword) SHF_MASKPROC;
 	    }
 	  if (sh_flags & SHF_MASKOS)
-	    if (gnuld)
-	      sh_flags &= ~(GElf_Xword) SHF_GNU_RETAIN;
+	    {
+	      if (gnuld)
+	        sh_flags &= ~(GElf_Xword) SHF_GNU_RETAIN;
+	      if (ehdr->e_machine == EM_MIPS)
+	        {
+	          if(sh_flags == SHF_MIPS_NOSTRIP || sh_flags == SHF_MIPS_LOCAL
+		   || sh_flags == SHF_MIPS_NAMES || sh_flags == SHF_MIPS_NODUPE)
+	            sh_flags &= ~shdr->sh_flags;
+	        }
+	    }
 	  if (sh_flags != 0)
 	    ERROR (_("section [%2zu] '%s' contains unknown flag(s)"
 			    " %#" PRIx64 "\n"),
-- 
2.30.2