diff options
| -rw-r--r-- | gdb/ChangeLog | 10 | ||||
| -rw-r--r-- | gdb/arm-linux-tdep.c | 90 | ||||
| -rw-r--r-- | gdb/config/arm/tm-linux.h | 4 |
3 files changed, 100 insertions, 4 deletions
diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 9db2aa5..6257d90 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,13 @@ +2000-05-25 Scott Bambrough <scottb@netwinder.org> + + * arm-linux-tdep.c (find_minsym_and_objfile): New. + (skip_hurd_resolver): New. + (arm_linux_skip_solib_resolver): New. + (arm_skip_solib_resolver): Removed. + + * config/arm/tm-linux.h (SKIP_SOLIB_RESOLVER): Changed to use + arm_linux_skip_solib_resolver. + 2000-05-25 Mark Kettenis <kettenis@gnu.org> * acconfig.h (HAVE_R_FS, HAVE_R_GS): Add. diff --git a/gdb/arm-linux-tdep.c b/gdb/arm-linux-tdep.c index 667fd0b..cbe8c18 100644 --- a/gdb/arm-linux-tdep.c +++ b/gdb/arm-linux-tdep.c @@ -24,6 +24,11 @@ #include "gdbtypes.h" #include "floatformat.h" +/* For arm_linux_skip_solib_resolver. */ +#include "symtab.h" +#include "symfile.h" +#include "objfiles.h" + #ifdef GET_LONGJMP_TARGET /* Figure out where the longjmp will land. We expect that we have @@ -340,10 +345,91 @@ arm_linux_push_arguments (int nargs, value_ptr * args, CORE_ADDR sp, with. Before the fixup/resolver code returns, it actually calls the requested function and repairs &GOT[n+3]. */ +/* Find the minimal symbol named NAME, and return both the minsym + struct and its objfile. This probably ought to be in minsym.c, but + everything there is trying to deal with things like C++ and + SOFUN_ADDRESS_MAYBE_TURQUOISE, ... Since this is so simple, it may + be considered too special-purpose for general consumption. */ + +static struct minimal_symbol * +find_minsym_and_objfile (char *name, struct objfile **objfile_p) +{ + struct objfile *objfile; + + ALL_OBJFILES (objfile) + { + struct minimal_symbol *msym; + + ALL_OBJFILE_MSYMBOLS (objfile, msym) + { + if (SYMBOL_NAME (msym) + && STREQ (SYMBOL_NAME (msym), name)) + { + *objfile_p = objfile; + return msym; + } + } + } + + return 0; +} + + +static CORE_ADDR +skip_hurd_resolver (CORE_ADDR pc) +{ + /* The HURD dynamic linker is part of the GNU C library, so many + GNU/Linux distributions use it. (All ELF versions, as far as I + know.) An unresolved PLT entry points to "_dl_runtime_resolve", + which calls "fixup" to patch the PLT, and then passes control to + the function. + + We look for the symbol `_dl_runtime_resolve', and find `fixup' in + the same objfile. If we are at the entry point of `fixup', then + we set a breakpoint at the return address (at the top of the + stack), and continue. + + It's kind of gross to do all these checks every time we're + called, since they don't change once the executable has gotten + started. But this is only a temporary hack --- upcoming versions + of Linux will provide a portable, efficient interface for + debugging programs that use shared libraries. */ + + struct objfile *objfile; + struct minimal_symbol *resolver + = find_minsym_and_objfile ("_dl_runtime_resolve", &objfile); + + if (resolver) + { + struct minimal_symbol *fixup + = lookup_minimal_symbol ("fixup", 0, objfile); + + if (fixup && SYMBOL_VALUE_ADDRESS (fixup) == pc) + return (SAVED_PC_AFTER_CALL (get_current_frame ())); + } + + return 0; +} + +/* See the comments for SKIP_SOLIB_RESOLVER at the top of infrun.c. + This function: + 1) decides whether a PLT has sent us into the linker to resolve + a function reference, and + 2) if so, tells us where to set a temporary breakpoint that will + trigger when the dynamic linker is done. */ + CORE_ADDR -arm_skip_solib_resolver (CORE_ADDR pc) +arm_linux_skip_solib_resolver (CORE_ADDR pc) { - /* FIXME */ + CORE_ADDR result; + + /* Plug in functions for other kinds of resolvers here. */ + result = skip_hurd_resolver (pc); + printf ("Result = 0x%08x\n"); + if (result) + return result; + + return 0; } diff --git a/gdb/config/arm/tm-linux.h b/gdb/config/arm/tm-linux.h index af2e809..9dcd666 100644 --- a/gdb/config/arm/tm-linux.h +++ b/gdb/config/arm/tm-linux.h @@ -118,8 +118,8 @@ extern CORE_ADDR find_solib_trampoline_target (CORE_ADDR pc); need to skip over the dynamic linker call. This function decides when to skip, and where to skip to. See the comments for SKIP_SOLIB_RESOLVER at the top of infrun.c. */ -extern CORE_ADDR arm_skip_solib_resolver (CORE_ADDR pc); -#define SKIP_SOLIB_RESOLVER arm_skip_solib_resolver +extern CORE_ADDR arm_linux_skip_solib_resolver (CORE_ADDR pc); +#define SKIP_SOLIB_RESOLVER arm_linux_skip_solib_resolver /* When we call a function in a shared library, and the PLT sends us into the dynamic linker to find the function's real address, we |