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Re: [PATCH v4 0/4] Introduce the initify gcc plugin

Message ID CAGXu5jJ_9Gbre2J1HYrY-gwnsStL8P+MKmKQwCBtY4-7m53RLA@mail.gmail.com (mailing list archive)
State New, archived
Headers show

Commit Message

Kees Cook Jan. 12, 2017, 11:40 p.m. UTC 
On Thu, Jan 12, 2017 at 3:27 PM, Kees Cook <keescook@chromium.org> wrote:
> On Thu, Jan 12, 2017 at 1:41 PM, Emese Revfy <re.emese@gmail.com> wrote:
>> On Tue, 10 Jan 2017 17:09:31 -0800
>> Kees Cook <keescook@chromium.org> wrote:
>>
>>> WARNING: vmlinux.o(.text+0x1087e7): Section mismatch in reference from
>>> the function rebind_subsystems() to the variable
>>> .init.rodata.str:__func__.4400
>>> The function rebind_subsystems() references
>>> the variable __initconst __func__.4400.
>>> This is often because rebind_subsystems lacks a __initconst
>>> annotation or the annotation of __func__.4400 is wrong.
>>
>> Thanks for the report, you can find the fix here:
>> https://github.com/ephox-gcc-plugins/initify/commit/25f34834e3373e067133bc5d39d42c50a3592d56
>
> Awesome! I can confirm, it builds without warnings now. Thanks!

Hm, actually, with an "allyesconfig" build, I'm still seeing warnings
(and possibly some nocapture verification failures).

Most look like this:

WARNING: drivers/clk/bcm/built-in.o(.text+0xec2): Section mismatch in
reference from the function clk_gate() to the variable
.init.rodata.str:__func__.29708
The function clk_gate() references
the variable __initconst __func__.29708.
This is often because clk_gate lacks a __initconst
annotation or the annotation of __func__.29708 is wrong.

And there's this (should KASAN be disabled for initify?)

mm/kasan/kasan.c: In function ‘memmove’:
mm/kasan/kasan.c:346:7: warning: ‘memmove’ captures its 2 (‘src’)
parameter, please remove it from the nocapture attribute.
 void *memmove(void *dest, const void *src, size_t len)
       ^
mm/kasan/kasan.c: In function ‘memcpy’:
mm/kasan/kasan.c:355:7: warning: ‘memcpy’ captures its 2 (‘src’)
parameter, please remove it from the nocapture attribute.
 void *memcpy(void *dest, const void *src, size_t len)
       ^

And ACPI:

drivers/acpi/acpica/utdebug.c: In function ‘acpi_debug_print’:
drivers/acpi/acpica/utdebug.c:158:1: warning: ‘acpi_debug_print’
captures its 3 (‘function_name’) parameter, please remove it from the
nocapture attribute.
 acpi_debug_print(u32 requested_debug_level,
 ^


I used my initify v5 development tree, with the following patch, with
"make allyesconfig":

http://git.kernel.org/cgit/linux/kernel/git/kees/linux.git/log/?h=for-next/gcc-plugin/initify

static analysis.
@@ -429,6 +428,7 @@ config GCC_PLUGIN_INITIFY
 config GCC_PLUGIN_INITIFY_VERBOSE
        bool "Report initification"
        depends on GCC_PLUGIN_INITIFY
+       depends on !COMPILE_TEST
        help
          Print all initified strings and all functions which should be
          __init/__exit.


I'll see if acpi needs __noverified_nocapture ...

-Kees

Comments

Emese Revfy Jan. 17, 2017, 8:31 p.m. UTC | #1 
On Thu, 12 Jan 2017 15:40:41 -0800
Kees Cook <keescook@chromium.org> wrote:

> WARNING: drivers/clk/bcm/built-in.o(.text+0xec2): Section mismatch in
> reference from the function clk_gate() to the variable
> .init.rodata.str:__func__.29708
> The function clk_gate() references
> the variable __initconst __func__.29708.
> This is often because clk_gate lacks a __initconst
> annotation or the annotation of __func__.29708 is wrong.
>
> I used my initify v5 development tree, with the following patch, with
> "make allyesconfig":
> 
> http://git.kernel.org/cgit/linux/kernel/git/kees/linux.git/log/?h=for-next/gcc-plugin/initify

Hi,

I can't reproduce this mismatch with allyesconfig. Could you please send me your .config?
Kees Cook Jan. 19, 2017, 1:22 a.m. UTC | #2 
On Tue, Jan 17, 2017 at 12:31 PM, Emese Revfy <re.emese@gmail.com> wrote:
> On Thu, 12 Jan 2017 15:40:41 -0800
> Kees Cook <keescook@chromium.org> wrote:
>
>> WARNING: drivers/clk/bcm/built-in.o(.text+0xec2): Section mismatch in
>> reference from the function clk_gate() to the variable
>> .init.rodata.str:__func__.29708
>> The function clk_gate() references
>> the variable __initconst __func__.29708.
>> This is often because clk_gate lacks a __initconst
>> annotation or the annotation of __func__.29708 is wrong.
>>
>> I used my initify v5 development tree, with the following patch, with
>> "make allyesconfig":
>>
>> http://git.kernel.org/cgit/linux/kernel/git/kees/linux.git/log/?h=for-next/gcc-plugin/initify
>
> Hi,
>
> I can't reproduce this mismatch with allyesconfig. Could you please send me your .config?

Sure, attached. (Though note this requires the patch from my earlier
email to allow allyesconfig to work with the plugins.)

-Kees
Emese Revfy Feb. 15, 2017, 12:23 a.m. UTC | #3 
On Thu, 12 Jan 2017 15:40:41 -0800
Kees Cook <keescook@chromium.org> wrote:

> WARNING: drivers/clk/bcm/built-in.o(.text+0xec2): Section mismatch in
> reference from the function clk_gate() to the variable
> .init.rodata.str:__func__.29708
> The function clk_gate() references
> the variable __initconst __func__.29708.
> This is often because clk_gate lacks a __initconst
> annotation or the annotation of __func__.29708 is wrong.

Thanks for the report, it will be fixed in the next grsec patch.
Kees Cook Feb. 15, 2017, 7:27 p.m. UTC | #4 
On Tue, Feb 14, 2017 at 4:23 PM, Emese Revfy <re.emese@gmail.com> wrote:
> On Thu, 12 Jan 2017 15:40:41 -0800
> Kees Cook <keescook@chromium.org> wrote:
>
>> WARNING: drivers/clk/bcm/built-in.o(.text+0xec2): Section mismatch in
>> reference from the function clk_gate() to the variable
>> .init.rodata.str:__func__.29708
>> The function clk_gate() references
>> the variable __initconst __func__.29708.
>> This is often because clk_gate lacks a __initconst
>> annotation or the annotation of __func__.29708 is wrong.
>
> Thanks for the report, it will be fixed in the next grsec patch.

Very cool, thanks! What did the problem turn out to be?

-Kees
Emese Revfy Feb. 20, 2017, 9:42 p.m. UTC | #5 
On Wed, 15 Feb 2017 11:27:06 -0800
Kees Cook <keescook@chromium.org> wrote:

> On Tue, Feb 14, 2017 at 4:23 PM, Emese Revfy <re.emese@gmail.com> wrote:
> > On Thu, 12 Jan 2017 15:40:41 -0800
> > Kees Cook <keescook@chromium.org> wrote:
> >
> >> WARNING: drivers/clk/bcm/built-in.o(.text+0xec2): Section mismatch in
> >> reference from the function clk_gate() to the variable
> >> .init.rodata.str:__func__.29708
> >> The function clk_gate() references
> >> the variable __initconst __func__.29708.
> >> This is often because clk_gate lacks a __initconst
> >> annotation or the annotation of __func__.29708 is wrong.
> >
> > Thanks for the report, it will be fixed in the next grsec patch.
> 
> Very cool, thanks! What did the problem turn out to be?

You can find it here:
https://github.com/ephox-gcc-plugins/initify/commit/73e857aa47bde7cc78ed865a008d1519893c0f54
diff mbox

Patch

diff --git a/arch/Kconfig b/arch/Kconfig
index b6009a21ebea..5693ef5f22c8 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -359,7 +359,6 @@  config HAVE_GCC_PLUGINS
 menuconfig GCC_PLUGINS
        bool "GCC plugins"
        depends on HAVE_GCC_PLUGINS
-       depends on !COMPILE_TEST
        help
          GCC plugins are loadable modules that provide extra features to the
          compiler. They are useful for runtime instrumentation and