diff mbox

gdb/arm-tdep: the "strd rd, [sp, #-imm]!" is the part of function prologue.

Message ID 1576927487-12185-1-git-send-email-chenzefeng2@huawei.com
State New
Headers show

Commit Message

chenzefeng Dec. 21, 2019, 11:24 a.m. UTC
The "strd rd, [sp, #-imm]!" is the part of function prologue.

Dump of assembler code for function __nanosleep:
acc68:	e16d41f8	strd	r4, [sp, #-24]!
acc6c:	ee1d5f70	mrc	15, 0, r5, cr13, cr0, {3}
acc70:	e51534c0	ldr	r3, [r5, #-1216]

Signed-off-by: chenzefeng <chenzefeng2@huawei.com>
---
 gdb/arm-tdep.c | 9 +++++++++
 1 file changed, 9 insertions(+)

Comments

Tom Tromey Jan. 3, 2020, 4:10 p.m. UTC | #1
>>>>> ">" == chenzefeng  <chenzefeng2@huawei.com> writes:

>> The "strd rd, [sp, #-imm]!" is the part of function prologue.
>> Dump of assembler code for function __nanosleep:
>> acc68:	e16d41f8	strd	r4, [sp, #-24]!
>> acc6c:	ee1d5f70	mrc	15, 0, r5, cr13, cr0, {3}
>> acc70:	e51534c0	ldr	r3, [r5, #-1216]

Thank you for the patch.

gdb patches require a ChangeLog entry.  See the GNU coding standards or
the gdb contribution checklist for details.

https://sourceware.org/gdb/wiki/ContributionChecklist

Also, do you have a copyright assignment in place?
If not, then that's something to start.

>> Signed-off-by: chenzefeng <chenzefeng2@huawei.com>
>> ---
>>  gdb/arm-tdep.c | 9 +++++++++
>>  1 file changed, 9 insertions(+)

I don't know anything about ARM, really.  I'm curious how this bug came
up.  Like, does the compiler ordinarily emit this kind of instruction in
the prologue?  Is it possible to write a test case for this, or does the
patch fix some existing test failure?

thanks,
Tom
diff mbox

Patch

diff --git a/gdb/arm-tdep.c b/gdb/arm-tdep.c
index 8a9f878..060acbf 100644
--- a/gdb/arm-tdep.c
+++ b/gdb/arm-tdep.c
@@ -1550,6 +1550,15 @@  arm_analyze_prologue (struct gdbarch *gdbarch,
 		       regs[bits (insn, 12, 15)]);
 	  continue;
 	}
+      else if ((insn & 0xffff00f0) == 0xe16d00f0) /* strd rd, [sp, #imm]! */
+	{
+          unsigned imm = ((insn & 0xf00) >> 4) + (insn & 0xf);
+          if (stack.store_would_trash (regs[ARM_SP_REGNUM]))
+            break;
+          regs[ARM_SP_REGNUM] = pv_add_constant (regs[ARM_SP_REGNUM], -imm);
+          stack.store (regs[ARM_SP_REGNUM], 4, regs[bits (insn, 12, 15)]);
+          continue;
+	}
       else if ((insn & 0xffff0000) == 0xe92d0000)
 	/* stmfd sp!, {..., fp, ip, lr, pc}
 	   or