commit 4dca2d3a7b43bf99bd6a567870a3144af4e763ef

Author: Adhemerval Zanella <adhemerval.zanella@linaro.org>

Date:   Fri Feb 4 15:54:59 2022 -0300

    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 57059293d0bc86cb..3e17a0706f5ec2df 100644

--- a/elf/Makefile

+++ b/elf/Makefile

@@ -2116,7 +2116,7 @@ $(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 72a50717ef60a357..ec9b032eae37c103 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 d8e88f3984af1707..3075dfae2fd3d288 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 8c803ecc0a48f21b..badc6be451ee0357 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 526f5c54bc2c3b8c..20640a8daf346b5f 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 f4f00714fa158e18..92fd0b7c844713ce 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)