From: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Date: Fri, 4 Feb 2022 18:54:59 +0000 (-0300)
Subject: hppa: Fix bind-now audit (BZ #28857)
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=4dca2d3a7b43bf99bd6a567870a3144af4e763ef;p=thirdparty%2Fglibc.git

hppa: Fix bind-now audit (BZ #28857)

On hppa, a function pointer returned by la_symbind is actually a function
descriptor has the plabel bit set (bit 30).  This must be cleared to get
the actual address of the descriptor.  If the descriptor has been bound,
the first word of the descriptor is the physical address of theA function,
otherwise, the first word of the descriptor points to a trampoline in the
PLT.

This patch also adds a workaround on tests because on hppa (and it seems
to be the only ABI I have see it), some shared library adds a dynamic PLT
relocation to am empty symbol name:

$ readelf -r elf/tst-audit25mod1.so
[...]
Relocation section '.rela.plt' at offset 0x464 contains 6 entries:
 Offset     Info    Type            Sym.Value  Sym. Name + Addend
00002008  00000081 R_PARISC_IPLT                508
[...]

It breaks some assumptions on the test, where a symbol with an empty
name ("") is passed on la_symbind.

Checked on x86_64-linux-gnu and hppa-linux-gnu.

(cherry picked from commit 9e94f57484a2aba0fe67ea2059b5843f651887c2)
---

diff --git a/elf/Makefile b/elf/Makefile
index 38e5793f35b..fe954374c97 100644
--- a/elf/Makefile
+++ b/elf/Makefile
@@ -2072,7 +2072,7 @@ $(objpfx)tst-audit24c.out: $(objpfx)tst-auditmod24c.so
 $(objpfx)tst-audit24c: $(objpfx)tst-audit24amod1.so \
 		       $(objpfx)tst-audit24amod2.so
 tst-audit24c-ENV = LD_BIND_NOW=1 LD_AUDIT=$(objpfx)tst-auditmod24c.so
-LDFLAGS-tst-audit24b = -Wl,-z,lazy
+LDFLAGS-tst-audit24c = -Wl,-z,lazy
 
 $(objpfx)tst-audit24d.out: $(objpfx)tst-auditmod24d.so
 $(objpfx)tst-audit24d: $(objpfx)tst-audit24dmod1.so \
diff --git a/elf/dl-audit.c b/elf/dl-audit.c
index 72a50717ef6..ec9b032eae3 100644
--- a/elf/dl-audit.c
+++ b/elf/dl-audit.c
@@ -257,7 +257,8 @@ _dl_audit_symbind (struct link_map *l, struct reloc_result *reloc_result,
       reloc_result->flags = flags;
     }
 
-  DL_FIXUP_BINDNOW_RELOC (value, new_value, sym.st_value);
+  if (flags & LA_SYMB_ALTVALUE)
+    DL_FIXUP_BINDNOW_RELOC (value, new_value, sym.st_value);
 }
 
 void
diff --git a/elf/tst-auditmod24a.c b/elf/tst-auditmod24a.c
index d8e88f3984a..3075dfae2fd 100644
--- a/elf/tst-auditmod24a.c
+++ b/elf/tst-auditmod24a.c
@@ -110,5 +110,7 @@ la_symbind32 (Elf32_Sym *sym, unsigned int ndx,
       return sym->st_value;
     }
 
-  abort ();
+  if (symname[0] != '\0')
+    abort ();
+  return sym->st_value;
 }
diff --git a/elf/tst-auditmod24d.c b/elf/tst-auditmod24d.c
index 8c803ecc0a4..badc6be451e 100644
--- a/elf/tst-auditmod24d.c
+++ b/elf/tst-auditmod24d.c
@@ -116,5 +116,7 @@ la_symbind32 (Elf32_Sym *sym, unsigned int ndx,
 	}
     }
 
-  abort ();
+  if (symname[0] != '\0')
+    abort ();
+  return sym->st_value;
 }
diff --git a/elf/tst-auditmod25.c b/elf/tst-auditmod25.c
index 526f5c54bc2..20640a8daf3 100644
--- a/elf/tst-auditmod25.c
+++ b/elf/tst-auditmod25.c
@@ -72,7 +72,7 @@ la_symbind32 (Elf32_Sym *sym, unsigned int ndx,
 	      unsigned int *flags, const char *symname)
 #endif
 {
-  if (*refcook != -1 && *defcook != -1)
+  if (*refcook != -1 && *defcook != -1 && symname[0] != '\0')
     fprintf (stderr, "la_symbind: %s %u\n", symname,
 	     *flags & (LA_SYMB_NOPLTENTER | LA_SYMB_NOPLTEXIT) ? 1 : 0);
   return sym->st_value;
diff --git a/sysdeps/hppa/dl-lookupcfg.h b/sysdeps/hppa/dl-lookupcfg.h
index f4f00714fa1..92fd0b7c844 100644
--- a/sysdeps/hppa/dl-lookupcfg.h
+++ b/sysdeps/hppa/dl-lookupcfg.h
@@ -80,7 +80,9 @@ void attribute_hidden _dl_unmap (struct link_map *map);
 /* Extract the code address from a fixup value */
 #define DL_FIXUP_VALUE_CODE_ADDR(value) ((value).ip)
 #define DL_FIXUP_VALUE_ADDR(value) ((uintptr_t) &(value))
-#define DL_FIXUP_ADDR_VALUE(addr) (*(struct fdesc *) (addr))
+/* Clear the plabel bit to get the actual address of the descriptor.  */
+#define DL_FIXUP_ADDR_VALUE(addr) \
+  (*(DL_FIXUP_VALUE_TYPE *) ((uintptr_t) (addr) & ~2))
 #define DL_FIXUP_BINDNOW_ADDR_VALUE(addr) (addr)
-#define DL_FIXUP_BINDNOW_RELOC(value, new_value, st_value) \
-  (*value) = *(struct fdesc *) (st_value)
+#define DL_FIXUP_BINDNOW_RELOC(value, new_value, st_value)	\
+  *(value) = *(DL_FIXUP_VALUE_TYPE *) ((uintptr_t) (new_value) & ~2)