From 5cbb98123cd3b29544e3d9d001fae62403a7e243 Mon Sep 17 00:00:00 2001 From: Thomas Schwinge Date: Mon, 5 Mar 2012 15:16:39 +0000 Subject: [PATCH] * sh-tdep.c (sh_skip_prologue): Provide an upper limit on the function prologue to sh_analyze_prologue. (sh_analyze_prologue): Make better use of such an upper limit, and generally be more cautious about accessing memory. --- gdb/ChangeLog | 7 +++++++ gdb/sh-tdep.c | 46 +++++++++++++++++++++++++++++++--------------- 2 files changed, 38 insertions(+), 15 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index ca94184e3c..47ae39f6cb 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,10 @@ +2012-03-05 Thomas Schwinge + + * sh-tdep.c (sh_skip_prologue): Provide an upper limit on the function + prologue to sh_analyze_prologue. + (sh_analyze_prologue): Make better use of such an upper limit, and + generally be more cautious about accessing memory. + 2012-03-05 Tom Tromey * ia64-vms-tdep.c (_initialize_ia64_vms_tdep): Rename from diff --git a/gdb/sh-tdep.c b/gdb/sh-tdep.c index 3983632b6b..7f1519158a 100644 --- a/gdb/sh-tdep.c +++ b/gdb/sh-tdep.c @@ -535,22 +535,18 @@ sh_breakpoint_from_pc (struct gdbarch *gdbarch, CORE_ADDR *pcptr, int *lenptr) static CORE_ADDR sh_analyze_prologue (struct gdbarch *gdbarch, - CORE_ADDR pc, CORE_ADDR current_pc, + CORE_ADDR pc, CORE_ADDR limit_pc, struct sh_frame_cache *cache, ULONGEST fpscr) { enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); ULONGEST inst; - CORE_ADDR opc; int offset; int sav_offset = 0; int r3_val = 0; int reg, sav_reg = -1; - if (pc >= current_pc) - return current_pc; - cache->uses_fp = 0; - for (opc = pc + (2 * 28); pc < opc; pc += 2) + for (; pc < limit_pc; pc += 2) { inst = read_memory_unsigned_integer (pc, 2, byte_order); /* See where the registers will be saved to. */ @@ -615,7 +611,8 @@ sh_analyze_prologue (struct gdbarch *gdbarch, } } } - else if (IS_MOVI20 (inst)) + else if (IS_MOVI20 (inst) + && (pc + 2 < limit_pc)) { if (sav_reg < 0) { @@ -657,14 +654,17 @@ sh_analyze_prologue (struct gdbarch *gdbarch, } else if (IS_MOV_SP_FP (inst)) { + pc += 2; + /* Don't go any further than six more instructions. */ + limit_pc = min (limit_pc, pc + (2 * 6)); + cache->uses_fp = 1; /* At this point, only allow argument register moves to other registers or argument register moves to @(X,fp) which are moving the register arguments onto the stack area allocated by a former add somenumber to SP call. Don't allow moving to an fp indirect address above fp + cache->sp_offset. */ - pc += 2; - for (opc = pc + 12; pc < opc; pc += 2) + for (; pc < limit_pc; pc += 2) { inst = read_memory_integer (pc, 2, byte_order); if (IS_MOV_ARG_TO_IND_R14 (inst)) @@ -696,9 +696,12 @@ sh_analyze_prologue (struct gdbarch *gdbarch, jsr, which will be very confusing. Most likely the next instruction is going to be IS_MOV_SP_FP in the delay slot. If so, note that before returning the current pc. */ - inst = read_memory_integer (pc + 2, 2, byte_order); - if (IS_MOV_SP_FP (inst)) - cache->uses_fp = 1; + if (pc + 2 < limit_pc) + { + inst = read_memory_integer (pc + 2, 2, byte_order); + if (IS_MOV_SP_FP (inst)) + cache->uses_fp = 1; + } break; } #if 0 /* This used to just stop when it found an instruction @@ -717,13 +720,13 @@ sh_analyze_prologue (struct gdbarch *gdbarch, static CORE_ADDR sh_skip_prologue (struct gdbarch *gdbarch, CORE_ADDR pc) { - CORE_ADDR post_prologue_pc, func_addr; + CORE_ADDR post_prologue_pc, func_addr, func_end_addr, limit_pc; struct sh_frame_cache cache; /* See if we can determine the end of the prologue via the symbol table. If so, then return either PC, or the PC after the prologue, whichever is greater. */ - if (find_pc_partial_function (pc, NULL, &func_addr, NULL)) + if (find_pc_partial_function (pc, NULL, &func_addr, &func_end_addr)) { post_prologue_pc = skip_prologue_using_sal (gdbarch, func_addr); if (post_prologue_pc != 0) @@ -733,8 +736,21 @@ sh_skip_prologue (struct gdbarch *gdbarch, CORE_ADDR pc) /* Can't determine prologue from the symbol table, need to examine instructions. */ + /* Find an upper limit on the function prologue using the debug + information. If the debug information could not be used to provide + that bound, then use an arbitrary large number as the upper bound. */ + limit_pc = skip_prologue_using_sal (gdbarch, pc); + if (limit_pc == 0) + /* Don't go any further than 28 instructions. */ + limit_pc = pc + (2 * 28); + + /* Do not allow limit_pc to be past the function end, if we know + where that end is... */ + if (func_end_addr != 0) + limit_pc = min (limit_pc, func_end_addr); + cache.sp_offset = -4; - post_prologue_pc = sh_analyze_prologue (gdbarch, pc, (CORE_ADDR) -1, &cache, 0); + post_prologue_pc = sh_analyze_prologue (gdbarch, pc, limit_pc, &cache, 0); if (cache.uses_fp) pc = post_prologue_pc; -- 2.34.1