<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/arch/powerpc/kernel/Makefile, branch linux-5.11.y</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>powerpc/syscall: Rename syscall_64.c into interrupt.c</title>
<updated>2021-05-14T08:50:11+00:00</updated>
<author>
<name>Christophe Leroy</name>
<email>christophe.leroy@csgroup.eu</email>
</author>
<published>2021-02-08T15:10:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=672bd0b0631c7b3737504299e5015e4d7483b60f'/>
<id>672bd0b0631c7b3737504299e5015e4d7483b60f</id>
<content type='text'>
[ Upstream commit ab1a517d55b01b54ba70f5d54f926f5ab4b18339 ]

syscall_64.c will be reused almost as is for PPC32.

As this file also contains functions to handle other types
of interrupts rename it interrupt.c

Signed-off-by: Christophe Leroy &lt;christophe.leroy@csgroup.eu&gt;
Reviewed-by: Nicholas Piggin &lt;npiggin@gmail.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/cddc2deaa8f049d3ec419738e69804934919b935.1612796617.git.christophe.leroy@csgroup.eu
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit ab1a517d55b01b54ba70f5d54f926f5ab4b18339 ]

syscall_64.c will be reused almost as is for PPC32.

As this file also contains functions to handle other types
of interrupts rename it interrupt.c

Signed-off-by: Christophe Leroy &lt;christophe.leroy@csgroup.eu&gt;
Reviewed-by: Nicholas Piggin &lt;npiggin@gmail.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/cddc2deaa8f049d3ec419738e69804934919b935.1612796617.git.christophe.leroy@csgroup.eu
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/vdso: Make sure vdso_wrapper.o is rebuilt everytime vdso.so is rebuilt</title>
<updated>2021-04-14T06:47:14+00:00</updated>
<author>
<name>Christophe Leroy</name>
<email>christophe.leroy@csgroup.eu</email>
</author>
<published>2021-03-31T09:12:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=8f7d66db9bb157058ca688b08c37fcda7dffef3e'/>
<id>8f7d66db9bb157058ca688b08c37fcda7dffef3e</id>
<content type='text'>
commit 791f9e36599d94af5a76d3f74d04e16326761aae upstream.

Commit bce74491c300 ("powerpc/vdso: fix unnecessary rebuilds of
vgettimeofday.o") moved vdso32_wrapper.o and vdso64_wrapper.o out
of arch/powerpc/kernel/vdso[32/64]/ and removed the dependencies in
the Makefile. This leads to the wrappers not being re-build hence the
kernel embedding the old vdso library.

Add back missing dependencies to ensure vdso32_wrapper.o and vdso64_wrapper.o
are rebuilt when vdso32.so.dbg and vdso64.so.dbg are changed.

Fixes: bce74491c300 ("powerpc/vdso: fix unnecessary rebuilds of vgettimeofday.o")
Cc: stable@vger.kernel.org
Signed-off-by: Christophe Leroy &lt;christophe.leroy@csgroup.eu&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/8bb015bc98c51d8ced581415b7e3d157e18da7c9.1617181918.git.christophe.leroy@csgroup.eu
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 791f9e36599d94af5a76d3f74d04e16326761aae upstream.

Commit bce74491c300 ("powerpc/vdso: fix unnecessary rebuilds of
vgettimeofday.o") moved vdso32_wrapper.o and vdso64_wrapper.o out
of arch/powerpc/kernel/vdso[32/64]/ and removed the dependencies in
the Makefile. This leads to the wrappers not being re-build hence the
kernel embedding the old vdso library.

Add back missing dependencies to ensure vdso32_wrapper.o and vdso64_wrapper.o
are rebuilt when vdso32.so.dbg and vdso64.so.dbg are changed.

Fixes: bce74491c300 ("powerpc/vdso: fix unnecessary rebuilds of vgettimeofday.o")
Cc: stable@vger.kernel.org
Signed-off-by: Christophe Leroy &lt;christophe.leroy@csgroup.eu&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/8bb015bc98c51d8ced581415b7e3d157e18da7c9.1617181918.git.christophe.leroy@csgroup.eu
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/vdso: fix unnecessary rebuilds of vgettimeofday.o</title>
<updated>2021-01-30T11:23:42+00:00</updated>
<author>
<name>Masahiro Yamada</name>
<email>masahiroy@kernel.org</email>
</author>
<published>2020-12-23T17:11:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=bce74491c3008e27dd6e8f79a83b4faa77a08f7e'/>
<id>bce74491c3008e27dd6e8f79a83b4faa77a08f7e</id>
<content type='text'>
vgettimeofday.o is unnecessarily rebuilt. Adding it to 'targets' is not
enough to fix the issue. Kbuild is correctly rebuilding it because the
command line is changed.

PowerPC builds each vdso directory twice; first in vdso_prepare to
generate vdso{32,64}-offsets.h, second as part of the ordinary build
process to embed vdso{32,64}.so.dbg into the kernel.

The problem shows up when CONFIG_PPC_WERROR=y due to the following line
in arch/powerpc/Kbuild:

  subdir-ccflags-$(CONFIG_PPC_WERROR) := -Werror

In the preparation stage, Kbuild directly visits the vdso directories,
hence it does not inherit subdir-ccflags-y. In the second descend,
Kbuild adds -Werror, which results in the command line flipping
with/without -Werror.

It implies a potential danger; if a more critical flag that would impact
the resulted vdso, the offsets recorded in the headers might be different
from real offsets in the embedded vdso images.

Removing the unneeded second descend solves the problem.

Reported-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Signed-off-by: Masahiro Yamada &lt;masahiroy@kernel.org&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/linuxppc-dev/87tuslxhry.fsf@mpe.ellerman.id.au/
Link: https://lore.kernel.org/r/20201223171142.707053-1-masahiroy@kernel.org
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
vgettimeofday.o is unnecessarily rebuilt. Adding it to 'targets' is not
enough to fix the issue. Kbuild is correctly rebuilding it because the
command line is changed.

PowerPC builds each vdso directory twice; first in vdso_prepare to
generate vdso{32,64}-offsets.h, second as part of the ordinary build
process to embed vdso{32,64}.so.dbg into the kernel.

The problem shows up when CONFIG_PPC_WERROR=y due to the following line
in arch/powerpc/Kbuild:

  subdir-ccflags-$(CONFIG_PPC_WERROR) := -Werror

In the preparation stage, Kbuild directly visits the vdso directories,
hence it does not inherit subdir-ccflags-y. In the second descend,
Kbuild adds -Werror, which results in the command line flipping
with/without -Werror.

It implies a potential danger; if a more critical flag that would impact
the resulted vdso, the offsets recorded in the headers might be different
from real offsets in the embedded vdso images.

Removing the unneeded second descend solves the problem.

Reported-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Signed-off-by: Masahiro Yamada &lt;masahiroy@kernel.org&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/linuxppc-dev/87tuslxhry.fsf@mpe.ellerman.id.au/
Link: https://lore.kernel.org/r/20201223171142.707053-1-masahiroy@kernel.org
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc: Avoid broken GCC __attribute__((optimize))</title>
<updated>2020-11-19T03:50:14+00:00</updated>
<author>
<name>Ard Biesheuvel</name>
<email>ardb@kernel.org</email>
</author>
<published>2020-10-28T08:04:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=a7223f5bfcaeade4a86d35263493bcda6c940891'/>
<id>a7223f5bfcaeade4a86d35263493bcda6c940891</id>
<content type='text'>
Commit 7053f80d9696 ("powerpc/64: Prevent stack protection in early
boot") introduced a couple of uses of __attribute__((optimize)) with
function scope, to disable the stack protector in some early boot
code.

Unfortunately, and this is documented in the GCC man pages [0],
overriding function attributes for optimization is broken, and is only
supported for debug scenarios, not for production: the problem appears
to be that setting GCC -f flags using this method will cause it to
forget about some or all other optimization settings that have been
applied.

So the only safe way to disable the stack protector is to disable it
for the entire source file.

[0] https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html

Fixes: 7053f80d9696 ("powerpc/64: Prevent stack protection in early boot")
Signed-off-by: Ard Biesheuvel &lt;ardb@kernel.org&gt;
[mpe: Drop one remaining use of __nostackprotector, reported by snowpatch]
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20201028080433.26799-1-ardb@kernel.org
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Commit 7053f80d9696 ("powerpc/64: Prevent stack protection in early
boot") introduced a couple of uses of __attribute__((optimize)) with
function scope, to disable the stack protector in some early boot
code.

Unfortunately, and this is documented in the GCC man pages [0],
overriding function attributes for optimization is broken, and is only
supported for debug scenarios, not for production: the problem appears
to be that setting GCC -f flags using this method will cause it to
forget about some or all other optimization settings that have been
applied.

So the only safe way to disable the stack protector is to disable it
for the entire source file.

[0] https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html

Fixes: 7053f80d9696 ("powerpc/64: Prevent stack protection in early boot")
Signed-off-by: Ard Biesheuvel &lt;ardb@kernel.org&gt;
[mpe: Drop one remaining use of __nostackprotector, reported by snowpatch]
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20201028080433.26799-1-ardb@kernel.org
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/32s: Rename head_32.S to head_book3s_32.S</title>
<updated>2020-10-08T10:17:14+00:00</updated>
<author>
<name>Christophe Leroy</name>
<email>christophe.leroy@csgroup.eu</email>
</author>
<published>2020-10-06T09:05:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=533090e5a980ad80bbe0961b4ed45a9bcf55cc0c'/>
<id>533090e5a980ad80bbe0961b4ed45a9bcf55cc0c</id>
<content type='text'>
Unlike PPC64 which had a single head_64.S, PPC32 are multiple ones.
There is the head_32.S, selected by default based on the value of BITS
and overridden based on some CONFIG_ values. This leads to thinking
that it may be selected by different types of PPC32 platform but
indeed it ends up being selected by book3s/32 only.

Make that explicit by:
- Not doing any default selection based on BITS.
- Renaming head_32.S to head_book3s_32.S.
- Get head_book3s_32.S selected only by CONFIG_PPC_BOOK3S_32.

Signed-off-by: Christophe Leroy &lt;christophe.leroy@csgroup.eu&gt;
[mpe: Fix head_$(BITS).o reference in arch/powerpc/Makefile]
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/319d379f696412681c66a987cc75e6abf8f958d2.1601975100.git.christophe.leroy@csgroup.eu
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Unlike PPC64 which had a single head_64.S, PPC32 are multiple ones.
There is the head_32.S, selected by default based on the value of BITS
and overridden based on some CONFIG_ values. This leads to thinking
that it may be selected by different types of PPC32 platform but
indeed it ends up being selected by book3s/32 only.

Make that explicit by:
- Not doing any default selection based on BITS.
- Renaming head_32.S to head_book3s_32.S.
- Get head_book3s_32.S selected only by CONFIG_PPC_BOOK3S_32.

Signed-off-by: Christophe Leroy &lt;christophe.leroy@csgroup.eu&gt;
[mpe: Fix head_$(BITS).o reference in arch/powerpc/Makefile]
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/319d379f696412681c66a987cc75e6abf8f958d2.1601975100.git.christophe.leroy@csgroup.eu
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/watchpoint: Move DAWR detection logic outside of hw_breakpoint.c</title>
<updated>2020-09-15T12:13:19+00:00</updated>
<author>
<name>Ravi Bangoria</name>
<email>ravi.bangoria@linux.ibm.com</email>
</author>
<published>2020-09-02T04:29:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=edc8dd99b29e4d705c45e2a3a6c01b096ee056db'/>
<id>edc8dd99b29e4d705c45e2a3a6c01b096ee056db</id>
<content type='text'>
Power10 hw has multiple DAWRs but hw doesn't tell which DAWR caused
the exception. So we have a sw logic to detect that in hw_breakpoint.c.
But hw_breakpoint.c gets compiled only with CONFIG_HAVE_HW_BREAKPOINT=Y.
Move DAWR detection logic outside of hw_breakpoint.c so that it can be
reused when CONFIG_HAVE_HW_BREAKPOINT is not set.

Signed-off-by: Ravi Bangoria &lt;ravi.bangoria@linux.ibm.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20200902042945.129369-5-ravi.bangoria@linux.ibm.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Power10 hw has multiple DAWRs but hw doesn't tell which DAWR caused
the exception. So we have a sw logic to detect that in hw_breakpoint.c.
But hw_breakpoint.c gets compiled only with CONFIG_HAVE_HW_BREAKPOINT=Y.
Move DAWR detection logic outside of hw_breakpoint.c so that it can be
reused when CONFIG_HAVE_HW_BREAKPOINT is not set.

Signed-off-by: Ravi Bangoria &lt;ravi.bangoria@linux.ibm.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20200902042945.129369-5-ravi.bangoria@linux.ibm.com
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'kbuild-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild</title>
<updated>2020-08-09T21:10:26+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2020-08-09T21:10:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=fc80c51fd4b23ec007e88d4c688f2cac1b8648e7'/>
<id>fc80c51fd4b23ec007e88d4c688f2cac1b8648e7</id>
<content type='text'>
Pull Kbuild updates from Masahiro Yamada:

 - run the checker (e.g. sparse) after the compiler

 - remove unneeded cc-option tests for old compiler flags

 - fix tar-pkg to install dtbs

 - introduce ccflags-remove-y and asflags-remove-y syntax

 - allow to trace functions in sub-directories of lib/

 - introduce hostprogs-always-y and userprogs-always-y syntax

 - various Makefile cleanups

* tag 'kbuild-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kbuild: stop filtering out $(GCC_PLUGINS_CFLAGS) from cc-option base
  kbuild: include scripts/Makefile.* only when relevant CONFIG is enabled
  kbuild: introduce hostprogs-always-y and userprogs-always-y
  kbuild: sort hostprogs before passing it to ifneq
  kbuild: move host .so build rules to scripts/gcc-plugins/Makefile
  kbuild: Replace HTTP links with HTTPS ones
  kbuild: trace functions in subdirectories of lib/
  kbuild: introduce ccflags-remove-y and asflags-remove-y
  kbuild: do not export LDFLAGS_vmlinux
  kbuild: always create directories of targets
  powerpc/boot: add DTB to 'targets'
  kbuild: buildtar: add dtbs support
  kbuild: remove cc-option test of -ffreestanding
  kbuild: remove cc-option test of -fno-stack-protector
  Revert "kbuild: Create directory for target DTB"
  kbuild: run the checker after the compiler
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull Kbuild updates from Masahiro Yamada:

 - run the checker (e.g. sparse) after the compiler

 - remove unneeded cc-option tests for old compiler flags

 - fix tar-pkg to install dtbs

 - introduce ccflags-remove-y and asflags-remove-y syntax

 - allow to trace functions in sub-directories of lib/

 - introduce hostprogs-always-y and userprogs-always-y syntax

 - various Makefile cleanups

* tag 'kbuild-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kbuild: stop filtering out $(GCC_PLUGINS_CFLAGS) from cc-option base
  kbuild: include scripts/Makefile.* only when relevant CONFIG is enabled
  kbuild: introduce hostprogs-always-y and userprogs-always-y
  kbuild: sort hostprogs before passing it to ifneq
  kbuild: move host .so build rules to scripts/gcc-plugins/Makefile
  kbuild: Replace HTTP links with HTTPS ones
  kbuild: trace functions in subdirectories of lib/
  kbuild: introduce ccflags-remove-y and asflags-remove-y
  kbuild: do not export LDFLAGS_vmlinux
  kbuild: always create directories of targets
  powerpc/boot: add DTB to 'targets'
  kbuild: buildtar: add dtbs support
  kbuild: remove cc-option test of -ffreestanding
  kbuild: remove cc-option test of -fno-stack-protector
  Revert "kbuild: Create directory for target DTB"
  kbuild: run the checker after the compiler
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/pseries: Add KVM guest doorbell restrictions</title>
<updated>2020-07-29T11:02:10+00:00</updated>
<author>
<name>Nicholas Piggin</name>
<email>npiggin@gmail.com</email>
</author>
<published>2020-07-26T03:51:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=107c55005fbd5243ee31fb13b6f166cde9e3ade1'/>
<id>107c55005fbd5243ee31fb13b6f166cde9e3ade1</id>
<content type='text'>
KVM guests have certain restrictions and performance quirks when using
doorbells. This patch moves the EPAPR KVM guest test so it can be shared
with PSERIES, and uses that in doorbell setup code to apply the KVM
guest quirks and  improves IPI performance for two cases:

 - PowerVM guests may now use doorbells even if they are secure.

 - KVM guests no longer use doorbells if XIVE is available.

There is a valid complaint that "KVM guest" is not a very reasonable
thing to test for, it's preferable for the hypervisor to advertise
particular behaviours to the guest so they could change if the
hypervisor implementation or configuration changes. However in this case
we were already assuming a KVM guest worst case, so this patch is about
containing those quirks. If KVM later advertises fast doorbells, we
should test for that and override the quirks.

Signed-off-by: Nicholas Piggin &lt;npiggin@gmail.com&gt;
Tested-by: Cédric Le Goater &lt;clg@kaod.org&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20200726035155.1424103-4-npiggin@gmail.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
KVM guests have certain restrictions and performance quirks when using
doorbells. This patch moves the EPAPR KVM guest test so it can be shared
with PSERIES, and uses that in doorbell setup code to apply the KVM
guest quirks and  improves IPI performance for two cases:

 - PowerVM guests may now use doorbells even if they are secure.

 - KVM guests no longer use doorbells if XIVE is available.

There is a valid complaint that "KVM guest" is not a very reasonable
thing to test for, it's preferable for the hypervisor to advertise
particular behaviours to the guest so they could change if the
hypervisor implementation or configuration changes. However in this case
we were already assuming a KVM guest worst case, so this patch is about
containing those quirks. If KVM later advertises fast doorbells, we
should test for that and override the quirks.

Signed-off-by: Nicholas Piggin &lt;npiggin@gmail.com&gt;
Tested-by: Cédric Le Goater &lt;clg@kaod.org&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20200726035155.1424103-4-npiggin@gmail.com
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/eeh: Remove eeh_dev.c</title>
<updated>2020-07-26T13:34:20+00:00</updated>
<author>
<name>Oliver O'Halloran</name>
<email>oohall@gmail.com</email>
</author>
<published>2020-07-25T08:12:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d74ee8e9d12e2071014ecec96a1ce2744f77639d'/>
<id>d74ee8e9d12e2071014ecec96a1ce2744f77639d</id>
<content type='text'>
The only thing in this file is eeh_dev_init() which is allocates and
initialises an eeh_dev based on a pci_dn. This is only ever called from
pci_dn.c so move it into there and remove the file.

Signed-off-by: Oliver O'Halloran &lt;oohall@gmail.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20200725081231.39076-2-oohall@gmail.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The only thing in this file is eeh_dev_init() which is allocates and
initialises an eeh_dev based on a pci_dn. This is only ever called from
pci_dn.c so move it into there and remove the file.

Signed-off-by: Oliver O'Halloran &lt;oohall@gmail.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20200725081231.39076-2-oohall@gmail.com
</pre>
</div>
</content>
</entry>
<entry>
<title>kbuild: remove cc-option test of -fno-stack-protector</title>
<updated>2020-07-07T02:13:10+00:00</updated>
<author>
<name>Masahiro Yamada</name>
<email>masahiroy@kernel.org</email>
</author>
<published>2020-06-26T18:59:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=893ab00439a45513cae55781fc8e3b7108ee1cda'/>
<id>893ab00439a45513cae55781fc8e3b7108ee1cda</id>
<content type='text'>
Some Makefiles already pass -fno-stack-protector unconditionally.
For example, arch/arm64/kernel/vdso/Makefile, arch/x86/xen/Makefile.

No problem report so far about hard-coding this option. So, we can
assume all supported compilers know -fno-stack-protector.

GCC 4.8 and Clang support this option (https://godbolt.org/z/_HDGzN)

Get rid of cc-option from -fno-stack-protector.

Remove CONFIG_CC_HAS_STACKPROTECTOR_NONE, which is always 'y'.

Note:
arch/mips/vdso/Makefile adds -fno-stack-protector twice, first
unconditionally, and second conditionally. I removed the second one.

Signed-off-by: Masahiro Yamada &lt;masahiroy@kernel.org&gt;
Reviewed-by: Kees Cook &lt;keescook@chromium.org&gt;
Acked-by: Ard Biesheuvel &lt;ardb@kernel.org&gt;
Reviewed-by: Nick Desaulniers &lt;ndesaulniers@google.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Some Makefiles already pass -fno-stack-protector unconditionally.
For example, arch/arm64/kernel/vdso/Makefile, arch/x86/xen/Makefile.

No problem report so far about hard-coding this option. So, we can
assume all supported compilers know -fno-stack-protector.

GCC 4.8 and Clang support this option (https://godbolt.org/z/_HDGzN)

Get rid of cc-option from -fno-stack-protector.

Remove CONFIG_CC_HAS_STACKPROTECTOR_NONE, which is always 'y'.

Note:
arch/mips/vdso/Makefile adds -fno-stack-protector twice, first
unconditionally, and second conditionally. I removed the second one.

Signed-off-by: Masahiro Yamada &lt;masahiroy@kernel.org&gt;
Reviewed-by: Kees Cook &lt;keescook@chromium.org&gt;
Acked-by: Ard Biesheuvel &lt;ardb@kernel.org&gt;
Reviewed-by: Nick Desaulniers &lt;ndesaulniers@google.com&gt;
</pre>
</div>
</content>
</entry>
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