From 5a16cfaeb6a845fff113b9d8e1027a033abb50a6 Mon Sep 17 00:00:00 2001 From: Ed Maste Date: Tue, 20 Feb 2007 18:10:13 +0000 Subject: Avoid writing uninitialized stack data into a thread's MMX/SSE state by first getting the current state with td_thr_getxmmregs_p. Without this, debugging a threaded app that uses libthr resulted in kernel panics or spurious SIGFPEs for me. (As of revision 1.6, sys/i386/i386/ptrace_machdep.c masks off the reserved bits in the mxcsr register, which prevents the kernel panics.) Architectures without PT_GETXMMREGS are not affected. MFC after: 1 week --- gnu/usr.bin/gdb/libgdb/fbsd-threads.c | 19 ++++++++++++------- 1 file changed, 12 insertions(+), 7 deletions(-) (limited to 'gnu/usr.bin') diff --git a/gnu/usr.bin/gdb/libgdb/fbsd-threads.c b/gnu/usr.bin/gdb/libgdb/fbsd-threads.c index b88b73f1f248..0000cb8ff38b 100644 --- a/gnu/usr.bin/gdb/libgdb/fbsd-threads.c +++ b/gnu/usr.bin/gdb/libgdb/fbsd-threads.c @@ -961,18 +961,21 @@ fbsd_thread_store_registers (int regno) err = td_thr_getgregs_p (&th, gregset); if (err != TD_OK) error ("%s: td_thr_getgregs %s", __func__, thread_db_err_str (err)); - err = td_thr_getfpregs_p (&th, &fpregset); +#ifdef PT_GETXMMREGS + err = td_thr_getxmmregs_p (&th, xmmregs); if (err != TD_OK) - error ("%s: td_thr_getfpgregs %s", __func__, thread_db_err_str (err)); + { +#endif + err = td_thr_getfpregs_p (&th, &fpregset); + if (err != TD_OK) + error ("%s: td_thr_getfpgregs %s", __func__, thread_db_err_str (err)); +#ifdef PT_GETXMMREGS + } +#endif supply_register (regno, old_value); } fill_gregset (gregset, regno); - fill_fpregset (&fpregset, regno); -#ifdef PT_GETXMMREGS - i387_fill_fxsave (xmmregs, regno); -#endif - err = td_thr_setgregs_p (&th, gregset); if (err != TD_OK) error ("Cannot store general-purpose registers for thread %d: Thread ID=%d, %s", @@ -980,11 +983,13 @@ fbsd_thread_store_registers (int regno) thread_db_err_str (err)); #ifdef PT_GETXMMREGS + i387_fill_fxsave (xmmregs, regno); err = td_thr_setxmmregs_p (&th, xmmregs); if (err == TD_OK) return; #endif + fill_fpregset (&fpregset, regno); err = td_thr_setfpregs_p (&th, &fpregset); if (err != TD_OK) error ("Cannot store floating-point registers for thread %d: Thread ID=%d, %s", -- cgit v1.3