[glibc/release/2.35/master] hppa: Fix bind-now audit (BZ #28857)

[glibc/release/2.35/master] hppa: Fix bind-now audit (BZ #28857)

[Adhemerval Zanella]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=c60e6a458b8e2efc39c81d372a88d258009eb1b7

commit c60e6a458b8e2efc39c81d372a88d258009eb1b7
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-pick picked from 9e94f57484a2aba0fe67ea2059b5843f651887c2)

Diff:
---
 NEWS                        | 1 +
 elf/Makefile                | 2 +-
 elf/dl-audit.c              | 3 ++-
 elf/tst-auditmod24a.c       | 4 +++-
 elf/tst-auditmod24d.c       | 4 +++-
 elf/tst-auditmod25.c        | 2 +-
 sysdeps/hppa/dl-lookupcfg.h | 8 +++++---
 7 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/NEWS b/NEWS
index 094a979afb..d11e2d9d31 100644
--- a/NEWS
+++ b/NEWS
@@ -13,6 +13,7 @@ The following bugs are resolved with this release:
   [28850] linux: __get_nprocs_sched reads uninitialized memory from the stack
   [28853] libc: tst-spawn6 changes current foreground process group
     (breaks test isolation)
+  [28857] libc: FAIL: elf/tst-audit24a
   [28860] build: --enable-kernel=5.1.0 build fails because of missing
     __convert_scm_timestamps
   [28865] linux: _SC_NPROCESSORS_CONF and _SC_NPROCESSORS_ONLN are inaccurate
diff --git a/elf/Makefile b/elf/Makefile
index ac37159b89..b2bd03a9f6 100644
--- a/elf/Makefile
+++ b/elf/Makefile
@@ -2210,7 +2210,7 @@ $(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 794bfd45cd..efc0492474 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 d8e88f3984..3075dfae2f 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 8c803ecc0a..badc6be451 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 526f5c54bc..20640a8daf 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 8da2412fea..27d2cd5e0e 100644
--- a/sysdeps/hppa/dl-lookupcfg.h
+++ b/sysdeps/hppa/dl-lookupcfg.h
@@ -79,7 +79,9 @@ 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)