From 60adf22c1440723435262b9d867ebd76300c3325 Mon Sep 17 00:00:00 2001 From: Tom de Vries Date: Thu, 4 Aug 2022 15:23:34 +0200 Subject: [PATCH] [gdb/tdep] Fix gdb.base/large-frame.exp for aarch64 On aarch64, I run into: ... FAIL: gdb.base/large-frame.exp: optimize=-O0: backtrace ... The problem is that the architecture-specific prologue analyzer fails to handle the first two insns in the prologue properly: ... 0000000000400610 : 400610: d2880210 mov x16, #0x4010 400614: cb3063ff sub sp, sp, x16 400618: a9007bfd stp x29, x30, [sp] 40061c: 910003fd mov x29, sp 400620: 910043a0 add x0, x29, #0x10 400624: 97fffff0 bl 4005e4 ... so we get: ... $ gdb -q -batch ./outputs/gdb.base/large-frame/large-frame-O0 -ex "b func" Breakpoint 1 at 0x400614 ... Fix this by: - fixing the support for the first insn to extract the immediate operand, and - adding support for the second insn, such that we have: ... Breakpoint 1 at 0x400624 ... Note that we're overshooting by one insn (0x400620 is the first insn after the prologue), but that's a pre-existing problem. Tested on aarch64-linux. Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=29408 --- gdb/aarch64-tdep.c | 22 +++++++++++++++++++++- 1 file changed, 21 insertions(+), 1 deletion(-) diff --git a/gdb/aarch64-tdep.c b/gdb/aarch64-tdep.c index 8670197a888..f747ebda1ab 100644 --- a/gdb/aarch64-tdep.c +++ b/gdb/aarch64-tdep.c @@ -340,6 +340,20 @@ aarch64_analyze_prologue (struct gdbarch *gdbarch, if (rn == AARCH64_SP_REGNUM && rd == AARCH64_FP_REGNUM) seen_stack_set = true; } + else if (inst.opcode->iclass == addsub_ext + && strcmp ("sub", inst.opcode->name) == 0) + { + unsigned rd = inst.operands[0].reg.regno; + unsigned rn = inst.operands[1].reg.regno; + unsigned rm = inst.operands[2].reg.regno; + + gdb_assert (aarch64_num_of_operands (inst.opcode) == 3); + gdb_assert (inst.operands[0].type == AARCH64_OPND_Rd_SP); + gdb_assert (inst.operands[1].type == AARCH64_OPND_Rn_SP); + gdb_assert (inst.operands[2].type == AARCH64_OPND_Rm_EXT); + + regs[rd] = pv_subtract (regs[rn], regs[rm]); + } else if (inst.opcode->iclass == pcreladdr && inst.operands[1].type == AARCH64_OPND_ADDR_ADRP) { @@ -370,14 +384,20 @@ aarch64_analyze_prologue (struct gdbarch *gdbarch, } else if (inst.opcode->op == OP_MOVZ) { + unsigned rd = inst.operands[0].reg.regno; + + gdb_assert (aarch64_num_of_operands (inst.opcode) == 2); gdb_assert (inst.operands[0].type == AARCH64_OPND_Rd); + gdb_assert (inst.operands[1].type == AARCH64_OPND_HALF); + gdb_assert (inst.operands[1].shifter.kind == AARCH64_MOD_LSL); /* If this shows up before we set the stack, keep going. Otherwise stop the analysis. */ if (seen_stack_set) break; - regs[inst.operands[0].reg.regno] = pv_unknown (); + regs[rd] = pv_constant (inst.operands[1].imm.value + << inst.operands[1].shifter.amount); } else if (inst.opcode->iclass == log_shift && strcmp (inst.opcode->name, "orr") == 0) -- 2.30.2