From: Peter Zijlstra <peterz@infradead.org>
To: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: tglx@linutronix.de, linux-kernel@vger.kernel.org, x86@kernel.org,
mhiramat@kernel.org, mbenes@suse.cz, brgerst@gmail.com
Subject: Re: [PATCH v2 16/19] objtool: Implement noinstr validation
Date: Wed, 18 Mar 2020 10:03:09 +0100 [thread overview]
Message-ID: <20200318090309.GC20730@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20200317210008.bda4c542b5lu7juf@treble>
On Tue, Mar 17, 2020 at 04:00:08PM -0500, Josh Poimboeuf wrote:
> On Tue, Mar 17, 2020 at 06:02:50PM +0100, Peter Zijlstra wrote:
> > Validate that any call out of .noinstr.text is in between
> > instr_begin() and instr_end() annotations.
> >
> > This annotation is useful to ensure correct behaviour wrt tracing
> > sensitive code like entry/exit and idle code. When we run code in a
> > sensitive context we want a guarantee no unknown code is ran.
> >
> > Since this validation relies on knowing the section of call
> > destination symbols, we must run it on vmlinux.o instead of on
> > individual object files.
> >
> > Add two options:
> >
> > -d/--duplicate "duplicate validation for vmlinux"
> > -l/--vmlinux "vmlinux.o validation"
>
> I'm not sure I see the point of the --vmlinux option, when it will be
> autodetected anyway?
Ah, I sometimes do stuff like:
cp vmlinux.o vmlinux.o.orig
quilt push; make -j$lots
cp vmlinux.o vmlinux.o.1
quilt push; make -j$lots
...
And then it is nice to force the mode.
> > @@ -46,5 +49,9 @@ int cmd_check(int argc, const char **arg
> >
> > objname = argv[0];
> >
> > + s = strstr(objname, "vmlinux.o");
> > + if (s && !s[9])
> > + vmlinux = true;
> > +
>
> I think this would be slightly cleaner:
>
> if (!strcmp(basename(objname), "vmlinux.o"))
> vmlinux = true;
Ah, indeed. I totally forgot userspace coding it seems..
next prev parent reply other threads:[~2020-03-18 9:03 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-17 17:02 [PATCH v2 00/19] objtool: vmlinux.o and " Peter Zijlstra
2020-03-17 17:02 ` [PATCH v2 01/19] objtool: Introduce validate_return() Peter Zijlstra
2020-03-17 17:02 ` [PATCH v2 02/19] objtool: Rename func_for_each_insn() Peter Zijlstra
2020-03-17 17:02 ` [PATCH v2 03/19] objtool: Rename func_for_each_insn_all() Peter Zijlstra
2020-03-17 17:02 ` [PATCH v2 04/19] x86/kexec: Use RIP relative addressing Peter Zijlstra
2020-03-17 17:02 ` [PATCH v2 05/19] objtool: Optimize find_symbol_by_index() Peter Zijlstra
2020-03-17 17:02 ` [PATCH v2 06/19] objtool: Add a statistics mode Peter Zijlstra
2020-03-17 17:02 ` [PATCH v2 07/19] objtool: Optimize find_section_by_index() Peter Zijlstra
2020-03-17 17:02 ` [PATCH v2 08/19] objtool: Optimize find_section_by_name() Peter Zijlstra
2020-03-17 17:02 ` [PATCH v2 09/19] objtool: Optimize find_symbol_*() and read_symbols() Peter Zijlstra
2020-03-17 17:02 ` [PATCH v2 10/19] objtool: Rename find_containing_func() Peter Zijlstra
2020-03-17 17:02 ` [PATCH v2 11/19] objtool: Resize insn_hash Peter Zijlstra
2020-03-17 17:02 ` [PATCH v2 12/19] objtool: Optimize find_symbol_by_name() Peter Zijlstra
2020-03-17 17:02 ` [PATCH v2 13/19] objtool: Optimize read_sections() Peter Zijlstra
2020-03-17 17:02 ` [PATCH v2 14/19] objtool: Delete cleanup() Peter Zijlstra
2020-03-17 17:02 ` [PATCH v2 15/19] objtool: Optimize find_rela_by_dest_range() Peter Zijlstra
2020-03-17 17:02 ` [PATCH v2 16/19] objtool: Implement noinstr validation Peter Zijlstra
2020-03-17 21:00 ` Josh Poimboeuf
2020-03-18 9:03 ` Peter Zijlstra [this message]
2020-03-18 10:06 ` Peter Zijlstra
2020-03-18 13:21 ` Peter Zijlstra
2020-03-17 17:02 ` [PATCH v2 17/19] objtool: Optimize !vmlinux.o again Peter Zijlstra
2020-03-18 13:20 ` Peter Zijlstra
2020-03-20 16:20 ` Miroslav Benes
2020-03-21 15:14 ` Peter Zijlstra
2020-03-21 16:11 ` Peter Zijlstra
2020-03-23 7:27 ` Miroslav Benes
2020-03-17 17:02 ` [PATCH v2 18/19] objtool: Use sec_offset_hash() for insn_hash Peter Zijlstra
2020-03-17 17:02 ` [PATCH v2 19/19] objtool: Detect loading function pointers across noinstr Peter Zijlstra
2020-03-17 23:39 ` kbuild test robot
2020-03-17 23:43 ` Nick Desaulniers
2020-03-18 11:02 ` Peter Zijlstra
2020-03-18 7:18 ` kbuild test robot
2020-03-17 21:05 ` [PATCH v2 00/19] objtool: vmlinux.o and noinstr validation Josh Poimboeuf
2020-03-18 13:18 ` [RFC][PATCH v2 20/19] kbuild/objtool: Add objtool-vmlinux.o pass Peter Zijlstra
2020-03-18 14:13 ` Peter Zijlstra
2020-03-18 18:34 ` Josh Poimboeuf
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