Also mark ELF solib trampoline minimal symbols special

In installing minimal symbols for ELF shared library trampolines
we "forget" to make individual symbols special where required.  This
leads to problems on the MIPS target using microMIPS SVR4 lazy stubs.
Lacking the special annotation these stubs are treated as standard
MIPS code and this makes GDB insert the wrong software breakpoint
instruction, breaking e.g. single-stepping through these stubs.  This
is not a very frequent scenario as microMIPS SVR4 lazy stubs are
typically only used in shared libraries with the main executable
using PLT, handled elsewhere.  Still it triggers e.g. when a software
watchpoint has been installed.  The symptom is SIGILL or the program
going astray, depending on the endianness.  Disassembly of these stubs
is also wrong.

	* elfread.c (elf_symtab_read): Also mark solib trampoline minimal
	symbols special.

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 757cc69..6387550 100644 (file)
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,10 @@
 2014-10-03  Maciej W. Rozycki  <macro@codesourcery.com>
 
+       * elfread.c (elf_symtab_read): Also mark solib trampoline minimal
+       symbols special.
+
+2014-10-03  Maciej W. Rozycki  <macro@codesourcery.com>
+
        * breakpoint.h (bp_target_info): Add `reqstd_address' member,
        update comments.
        * breakpoint.c (one_breakpoint_xfer_memory): Use `reqstd_address'

diff --git a/gdb/elfread.c b/gdb/elfread.c
index 9b8233c..19aaed3 100644 (file)
--- a/gdb/elfread.c
+++ b/gdb/elfread.c
@@ -328,7 +328,10 @@ elf_symtab_read (struct objfile *objfile, int type,
            (sym->name, strlen (sym->name), copy_names,
             symaddr, mst_solib_trampoline, sect, objfile);
          if (msym != NULL)
-           msym->filename = filesymname;
+           {
+             msym->filename = filesymname;
+             gdbarch_elf_make_msymbol_special (gdbarch, sym, msym);
+           }
          continue;
        }