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| author | Yao Qi <yao@codesourcery.com> | 2011-02-15 14:26:34 +0000 |
|---|---|---|
| committer | Yao Qi <yao@codesourcery.com> | 2011-02-15 14:26:34 +0000 |
| commit | 494e194e77ee1e03d260268fc132dccf308f223e (patch) | |
| tree | 49847f1526839f4fd742587aef1a9901ed36ed93 /gdb/arm-tdep.c | |
| parent | d9492458a11ca366f79a4c8fb03e312bfe0b047e (diff) | |
| download | gdb-494e194e77ee1e03d260268fc132dccf308f223e.zip gdb-494e194e77ee1e03d260268fc132dccf308f223e.tar.gz gdb-494e194e77ee1e03d260268fc132dccf308f223e.tar.bz2 | |
2011-02-15 Yao Qi <yao@codesourcery.com>
PR tdep/12352
* arm-tdep.c (copy_ldr_str_ldrb_strb): Replace PC with SP in
order to store PC value on stack instead of text section.
2011-02-15 Yao Qi <yao@codesourcery.com>
PR tdep/12352
* gdb.arch/arm-disp-step.S : New test for str instruction.
* gdb.arch/arm-disp-step.exp : Likewise
Diffstat (limited to 'gdb/arm-tdep.c')
| -rw-r--r-- | gdb/arm-tdep.c | 29 |
1 files changed, 18 insertions, 11 deletions
diff --git a/gdb/arm-tdep.c b/gdb/arm-tdep.c index 9dfbf49..6a279d1 100644 --- a/gdb/arm-tdep.c +++ b/gdb/arm-tdep.c @@ -5930,16 +5930,24 @@ copy_ldr_str_ldrb_strb (struct gdbarch *gdbarch, uint32_t insn, /* To write PC we can do: - scratch+0: str pc, temp (*temp = scratch + 8 + offset) - scratch+4: ldr r4, temp - scratch+8: sub r4, r4, pc (r4 = scratch + 8 + offset - scratch - 8 - 8) - scratch+12: add r4, r4, #8 (r4 = offset) - scratch+16: add r0, r0, r4 - scratch+20: str r0, [r2, #imm] (or str r0, [r2, r3]) - scratch+24: <temp> + Before this sequence of instructions: + r0 is the PC value got from displaced_read_reg, so r0 = from + 8; + r2 is the Rn value got from dispalced_read_reg. + + Insn1: push {pc} Write address of STR instruction + offset on stack + Insn2: pop {r4} Read it back from stack, r4 = addr(Insn1) + offset + Insn3: sub r4, r4, pc r4 = addr(Insn1) + offset - pc + = addr(Insn1) + offset - addr(Insn3) - 8 + = offset - 16 + Insn4: add r4, r4, #8 r4 = offset - 8 + Insn5: add r0, r0, r4 r0 = from + 8 + offset - 8 + = from + offset + Insn6: str r0, [r2, #imm] (or str r0, [r2, r3]) Otherwise we don't know what value to write for PC, since the offset is - architecture-dependent (sometimes PC+8, sometimes PC+12). */ + architecture-dependent (sometimes PC+8, sometimes PC+12). More details + of this can be found in Section "Saving from r15" in + http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0204g/Cihbjifh.html */ if (load || rt != 15) { @@ -5960,9 +5968,8 @@ copy_ldr_str_ldrb_strb (struct gdbarch *gdbarch, uint32_t insn, { /* We need to use r4 as scratch. Make sure it's restored afterwards. */ dsc->u.ldst.restore_r4 = 1; - - dsc->modinsn[0] = 0xe58ff014; /* str pc, [pc, #20]. */ - dsc->modinsn[1] = 0xe59f4010; /* ldr r4, [pc, #16]. */ + dsc->modinsn[0] = 0xe92d8000; /* push {pc} */ + dsc->modinsn[1] = 0xe8bd0010; /* pop {r4} */ dsc->modinsn[2] = 0xe044400f; /* sub r4, r4, pc. */ dsc->modinsn[3] = 0xe2844008; /* add r4, r4, #8. */ dsc->modinsn[4] = 0xe0800004; /* add r0, r0, r4. */ |