From 961842b289ba80b64f95f2e1a3df1f866acb229b Mon Sep 17 00:00:00 2001 From: "Jose E. Marchesi" Date: Mon, 10 Feb 2014 07:09:23 -0800 Subject: [PATCH] Add gdbarch_in_function_epilogue_p hook for sparc64. watchpoint_update and watchpoint_cond avoid checking for watchpoints when we are located at a function epilogue in the current frame. This is done in order to avoid using corrupted local registers and unwinding a corrupted/destroyed stack. The code determining whether we are in a function epilogue is provided by the backends via the gdbarch_in_function_epilogue_p hook. This commit adds such a hook for sparc64 targets. 2014-02-10 Jose E. Marchesi * sparc-tdep.c (sparc_in_function_epilogue_p): New function. (X_RETTURN): New macro. * sparc-tdep.h: sparc_in_function_epilogue_p prototype. * sparc64-tdep.c (sparc64_init_abi): Hook sparc_in_function_epilogue_p. --- gdb/ChangeLog | 9 +++++++++ gdb/sparc-tdep.c | 26 ++++++++++++++++++++++++++ gdb/sparc-tdep.h | 3 +++ gdb/sparc64-tdep.c | 1 + 4 files changed, 39 insertions(+) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 82751993cf..a53c04bd93 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,12 @@ +2014-02-10 Jose E. Marchesi + + * sparc-tdep.c (sparc_in_function_epilogue_p): New function. + (X_RETTURN): New macro. + * sparc-tdep.h: sparc_in_function_epilogue_p prototype. + + * sparc64-tdep.c (sparc64_init_abi): Hook + sparc_in_function_epilogue_p. + 2014-02-10 Gary Benson * symfile-debug.c (debug_qf_expand_symtabs_matching): diff --git a/gdb/sparc-tdep.c b/gdb/sparc-tdep.c index 38b345b888..311a156b71 100644 --- a/gdb/sparc-tdep.c +++ b/gdb/sparc-tdep.c @@ -88,6 +88,9 @@ struct regset; #define X_DISP19(i) ((((i) & 0x7ffff) ^ 0x40000) - 0x40000) #define X_DISP10(i) ((((((i) >> 11) && 0x300) | (((i) >> 5) & 0xff)) ^ 0x200) - 0x200) #define X_SIMM13(i) ((((i) & 0x1fff) ^ 0x1000) - 0x1000) +/* Macros to identify some instructions. */ +/* RETURN (RETT in V8) */ +#define X_RETTURN(i) ((X_OP (i) == 0x2) && (X_OP3 (i) == 0x39)) /* Fetch the instruction at PC. Instructions are always big-endian even if the processor operates in little-endian mode. */ @@ -452,6 +455,29 @@ sparc32_pseudo_register_write (struct gdbarch *gdbarch, regcache_raw_write (regcache, regnum + 1, buf + 4); } +/* Implement "in_function_epilogue_p". */ + +int +sparc_in_function_epilogue_p (struct gdbarch *gdbarch, CORE_ADDR pc) +{ + /* This function must return true if we are one instruction after an + instruction that destroyed the stack frame of the current + function. The SPARC instructions used to restore the callers + stack frame are RESTORE and RETURN/RETT. + + Of these RETURN/RETT is a branch instruction and thus we return + true if we are in its delay slot. + + RESTORE is almost always found in the delay slot of a branch + instruction that transfers control to the caller, such as JMPL. + Thus the next instruction is in the caller frame and we don't + need to do anything about it. */ + + unsigned int insn = sparc_fetch_instruction (pc - 4); + + return X_RETTURN (insn); +} + static CORE_ADDR sparc32_frame_align (struct gdbarch *gdbarch, CORE_ADDR address) diff --git a/gdb/sparc-tdep.h b/gdb/sparc-tdep.h index b83d7111ac..a065ebe306 100644 --- a/gdb/sparc-tdep.h +++ b/gdb/sparc-tdep.h @@ -193,6 +193,9 @@ extern struct sparc_frame_cache * extern struct sparc_frame_cache * sparc32_frame_cache (struct frame_info *this_frame, void **this_cache); +extern int + sparc_in_function_epilogue_p (struct gdbarch *gdbarch, CORE_ADDR pc); + extern int sparc_software_single_step (struct frame_info *frame); diff --git a/gdb/sparc64-tdep.c b/gdb/sparc64-tdep.c index 52958df82a..9e4db3af96 100644 --- a/gdb/sparc64-tdep.c +++ b/gdb/sparc64-tdep.c @@ -1196,6 +1196,7 @@ sparc64_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) (gdbarch, default_stabs_argument_has_addr); set_gdbarch_skip_prologue (gdbarch, sparc64_skip_prologue); + set_gdbarch_in_function_epilogue_p (gdbarch, sparc_in_function_epilogue_p); /* Hook in the DWARF CFI frame unwinder. */ dwarf2_frame_set_init_reg (gdbarch, sparc64_dwarf2_frame_init_reg); -- 2.34.1