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.)
Thanks,
Florian
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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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?
My mail infrastructure corrupts patches not sent as attachments, sorry.
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.
I can fix things up so that they build on Fedora 26, Debian stretch, and
Red Hat Enterprise Linux 7. Would that be sufficient?
Fedora 23 is out of support and I'd prefer not invest any work into it.
Note that I find it strange to make this a precondition for even looking
at the patch.
Thanks,
Florian
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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:
The Ubuntu build failure seems to have gone away after a 'make clean', what
remains is an ugly build warning:
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
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);
^~~~~~~~~~~~~~~~~~~~~~
gcc -m64 -o /home/mingo/tip/tools/testing/selftests/x86/protection_keys_64 -O2 -g -std=gnu99 -pthread -Wall -no-pie protection_keys.c -lrt -ldl
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);
^~~~~~~~~~~~~~~~~~~~~~
If this build warning and the Fedora build failure is fixed we can apply your
patch too I think.
Thanks,
Ingo
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To unsubscribe, send a message with 'unsubscribe linux-mm' in
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Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
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?
My mail infrastructure corrupts patches not sent as attachments, sorry.
Your headers suggest the following mail client:
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101
Thunderbird/52.5.0
Have you seen the suggestions in Documentation/process/email-clients.rst, which
lists a handful of Thunderbird tips:
Thunderbird (GUI)
*****************
Thunderbird is an Outlook clone that likes to mangle text, but there are ways
to coerce it into behaving.
?
quoted
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.
I can fix things up so that they build on Fedora 26, Debian stretch, and Red
Hat Enterprise Linux 7. Would that be sufficient?
Yeah, I think so.
Fedora 23 is out of support and I'd prefer not invest any work into it.
Note that I find it strange to make this a precondition for even looking at
the patch.
I wanted to try the patch to give review feedback, but found these annoyances.
It's customary to make new features dependent on the cleanliness of the underlying
code.
Thanks,
Ingo