Re: [RFC] DW_CFA_restore handling causes memory fault

Frederic RISS
2005-11-18T12:33:23Z

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On Fri, 2005-11-18 at 00:35 -0800, Jim Blandy wrote:
> Yes! But --- I apologize for not noticing this from the beginning ---
> as I see your comment, it occurs to me that probably a call to
> 'complaint' would be better than just a comment. Mark or Daniel can
> string me up if they feel this will yield another 'incomplete CFI
> data; unspecified blah blah blah' annoyance, but I think it's probably
> the right thing.

OK, third try attached. I mimiced the formatting of other complaints of
the file. I didn't put the complaint in the 'else' clause, but added a
check after the whole 'if', because an allocated register state isn't
necessarily set to a correct value.

Just a question: why are the i18n'ified strings formatted this way ?

> If you're doing this as part of your paying
> job, then the assignment from STMicroelectronics already on file

That's the case.

> For the sourceware account, see
> http://sourceware.org/cgi-bin/pdw/ps_form.cgi. List me as the person
> approving the request.

I'll do the request this evening (setting up the CVS access from work
will take some time, I'll use my home box for this patch.)

Thanks,
Fred.

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2005-11-17 FrÃ©dÃ©ric Riss <frederic.riss@st.com>

* dwarf2-frame.c: (execute_cfa_program): Don't access
past the allocated dwarf2_frame_state.initial.regs.

Index: dwarf2-frame.c
===================================================================
--- dwarf2-frame.c (revision 98)
+++ dwarf2-frame.c (working copy)
@@ -294,8 +294,16 @@
gdb_assert (fs->initial.reg);
reg = insn & 0x3f;
dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1);
- fs->regs.reg[reg] = fs->initial.reg[reg];
+ if (reg < fs->initial.num_regs)
+ fs->regs.reg[reg] = fs->initial.reg[reg];
+ else
+ fs->regs.reg[reg].how = DWARF2_FRAME_REG_UNSPECIFIED;
+
+ if (fs->regs.reg[reg].how == DWARF2_FRAME_REG_UNSPECIFIED)
+ complaint (&symfile_complaints, _("\
+incomplete CFI data; DW_CFA_restore of unspecified register state at 0x%s."),
+ paddr (fs->pc));
}
else
{