# \[REGRESSION\] testing/selftests/x86/ pkeys build failures (was: Re: \[PATCH\] mm, x86: pkeys: Introduce PKEY\_ALLOC\_SIGNALINHERIT and change signal semantics)

- From: Ingo Molnar \<mingo@kernel.org\>
- Date: 2018-01-12 12:55:42 
- List: linux-api
- Page: https://ratatoskr.run/linux-api/2018/01/6486385
- Thread: https://ratatoskr.run/linux-mm/2018/01/6486321/t.md

```text

* Florian Weimer [ref] wrote:

> This patch is based on the previous discussion (pkeys: Support setting
> access rights for signal handlers):
> 
>   https://marc.info/?t=151285426000001
> 
> It aligns the signal semantics of the x86 implementation with the upcoming
> POWER implementation, and defines a new flag, so that applications can
> detect which semantics the kernel uses.
> 
> A change in this area is needed to make memory protection keys usable for
> protecting the GOT in the dynamic linker.
> 
> (Feel free to replace the trigraphs in the commit message before committing,
> or to remove the program altogether.)

Could you please send patches not as MIME attachments?

Also, the protection keys testcase first need to be fixed, before we complicate 
them - for example on a pretty regular Ubuntu x86-64 installation they fail to 
build with the build errors attached further below.

On an older Fedora 23 installation, the testcases themselves don't build at all:

 fomalhaut:~/tip2/tools/testing/selftests/x86> make protection_keys
 gcc -O2 -g -std=gnu99 -pthread -Wall -no-pie    protection_keys.c   -o protection_keys
 gcc: error: unrecognized command line option ‘-no-pie’
 <builtin>: recipe for target 'protection_keys' failed
 make: *** [protection_keys] Error 1

so it's one big mess at the moment that needs some love ...

Thanks,

	Ingo

==================>

triton:~/tip/tools/testing/selftests/x86> make
gcc -m32 -o /home/mingo/tip/tools/testing/selftests/x86/protection_keys_32 -O2 -g -std=gnu99 -pthread -Wall -no-pie  protection_keys.c -lrt -ldl -lm
In file included from /usr/include/signal.h:57:0,
                 from protection_keys.c:33:
protection_keys.c: In function ‘signal_handler’:
protection_keys.c:253:6: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘.’ token
  u64 si_pkey;
      ^
protection_keys.c:253:6: error: expected expression before ‘.’ token
protection_keys.c:295:2: error: ‘_sifields’ undeclared (first use in this function)
  si_pkey = *si_pkey_ptr;
  ^
protection_keys.c:295:2: note: each undeclared identifier is reported only once for each function it appears in
In file included from protection_keys.c:46:0:
pkey-helpers.h: In function ‘sigsafe_printf’:
pkey-helpers.h:42:3: warning: ignoring return value of ‘write’, declared with attribute warn_unused_result [-Wunused-result]
   write(1, dprint_in_signal_buffer, len);
   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
protection_keys.c: In function ‘dumpit’:
protection_keys.c:419:3: warning: ignoring return value of ‘write’, declared with attribute warn_unused_result [-Wunused-result]
   write(1, buf, nr_read);
   ^~~~~~~~~~~~~~~~~~~~~~
Makefile:47: recipe for target '/home/mingo/tip/tools/testing/selftests/x86/protection_keys_32' failed

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