From: Matt Helsley <mhelsley@vmware.com>
To: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: <linux-kernel@vger.kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Julien Thierry <jthierry@redhat.com>,
Miroslav Benes <mbenes@suse.cz>,
Steven Rostedt <rostedt@goodmis.org>
Subject: Re: [RFC][PATCH 4/5] objtool: Enable compilation of objtool for all architectures
Date: Mon, 18 May 2020 12:50:45 -0700 [thread overview]
Message-ID: <20200518195045.GQ9040@rlwimi.vmware.com> (raw)
In-Reply-To: <20200515205610.fmdimt7wbafypuqc@treble>
On Fri, May 15, 2020 at 03:56:10PM -0500, Josh Poimboeuf wrote:
> On Mon, May 11, 2020 at 10:35:12AM -0700, Matt Helsley wrote:
> > +struct insn_state {
> > + struct cfi_reg cfa;
> > + struct cfi_reg regs[CFI_NUM_REGS];
> > + int stack_size;
> > + unsigned char type;
> > + bool bp_scratch;
> > + bool drap, end, uaccess, df;
> > + bool noinstr;
> > + s8 instr;
> > + unsigned int uaccess_stack;
> > + int drap_reg, drap_offset;
> > + struct cfi_reg vals[CFI_NUM_REGS];
> > +};
> > +
> > +struct instruction {
> > + struct list_head list;
> > + struct hlist_node hash;
> > + struct section *sec;
> > + unsigned long offset;
> > + unsigned int len;
> > + enum insn_type type;
> > + unsigned long immediate;
> > + bool alt_group, dead_end, ignore, hint, save, restore, ignore_alts;
> > + bool retpoline_safe;
> > + s8 instr;
> > + u8 visited;
> > + struct symbol *call_dest;
> > + struct instruction *jump_dest;
> > + struct instruction *first_jump_src;
> > + struct rela *jump_table;
> > + struct list_head alts;
> > + struct symbol *func;
> > + struct stack_op stack_op;
> > + struct insn_state state;
> > + struct orc_entry orc;
> > +};
>
> Why were these moved to arch.h? They're not necessarily arch-specific,
> but rather "check"-specific, so I think they still belong in check.h, if
> possible.
Ah, found it. They are arch specific due to struct orc_entry, which is
presently not defined for any archs besides x86.
Prior to the patch (-> means "includes"):
check.h -> asm/orc_types.h (defines struct orc_entry)
orc_gen.c -> check,h
After patch:
check.c -> asm/orc_types.h
orc_gen.c -> asm/orc_types.h
orc_gen.c -> check.h
orc_gen.c -> arch.h
{ now weak.c } -> check.h
So this prevents the headers, which help us keep the weak definitions
consistent with the strong definitions, from breaking compiles on archs
that lack struct orc_entry.
I'm not sure what the best way to remove this dependency is without
a nasty void * for the orc entry, or some #ifdef games related to
checking for cpp defines from asm/orc_types.h. This approach neatly
avoids conditional preprocessor games and type casting though I do
agree it's surprising.
Do you have any advice here?
Cheers,
-Matt Helsley
next prev parent reply other threads:[~2020-05-18 19:50 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-11 17:35 [RFC][PATCH 0/5] Enable objtool multiarch build Matt Helsley
2020-05-11 17:35 ` [RFC][PATCH 1/5] objtool: Exit successfully when requesting help Matt Helsley
2020-05-15 19:52 ` Josh Poimboeuf
2020-05-18 18:33 ` Matt Helsley
2020-05-11 17:35 ` [RFC][PATCH 2/5] objtool: Move struct objtool_file into arch-independent header Matt Helsley
2020-05-12 17:04 ` Julien Thierry
2020-05-12 18:07 ` Matt Helsley
2020-05-11 17:35 ` [RFC][PATCH 3/5] objtool: Add support for relocations without addends Matt Helsley
2020-05-12 17:04 ` Julien Thierry
2020-05-13 16:26 ` Matt Helsley
2020-05-13 16:55 ` Julien Thierry
2020-05-14 21:09 ` Matt Helsley
2020-05-15 20:33 ` Josh Poimboeuf
2020-05-18 19:14 ` Matt Helsley
2020-05-11 17:35 ` [RFC][PATCH 4/5] objtool: Enable compilation of objtool for all architectures Matt Helsley
2020-05-12 17:04 ` Julien Thierry
2020-05-13 15:59 ` Matt Helsley
2020-05-13 16:55 ` Julien Thierry
2020-05-15 20:51 ` Josh Poimboeuf
2020-05-18 18:26 ` Matt Helsley
2020-05-15 20:56 ` Josh Poimboeuf
2020-05-18 19:20 ` Matt Helsley
2020-05-18 19:50 ` Matt Helsley [this message]
2020-05-18 22:27 ` Josh Poimboeuf
2020-05-19 17:48 ` Matt Helsley
2020-05-11 17:35 ` [RFC][PATCH 5/5] objtool: Report missing support for subcommands Matt Helsley
2020-05-15 21:04 ` Josh Poimboeuf
2020-05-18 18:29 ` Matt Helsley
2020-05-12 17:04 ` [RFC][PATCH 0/5] Enable objtool multiarch build Julien Thierry
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