<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/arch/powerpc, branch v6.2.8</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>powerpc/64: Replace -mcpu=e500mc64 by -mcpu=e5500</title>
<updated>2023-03-22T12:38:10+00:00</updated>
<author>
<name>Christophe Leroy</name>
<email>christophe.leroy@csgroup.eu</email>
</author>
<published>2022-12-19T18:45:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=2e85937c84af2009f90fe65146c28f18e8a5d97d'/>
<id>2e85937c84af2009f90fe65146c28f18e8a5d97d</id>
<content type='text'>
commit 77e82fa1f9781a958a6ea4aed7aec41239a5a22f upstream.

E500MC64 is a processor pre-dating E5500 that has never been
commercialised. Use -mcpu=e5500 for E5500 core.

More details at https://gcc.gnu.org/PR108149

Signed-off-by: Christophe Leroy &lt;christophe.leroy@csgroup.eu&gt;
Acked-by: Pali Rohár &lt;pali@kernel.org&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/fa71ed20d22c156225436374f0ab847daac893bc.1671475543.git.christophe.leroy@csgroup.eu
Cc: Naresh Kamboju &lt;naresh.kamboju@linaro.org&gt;
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 77e82fa1f9781a958a6ea4aed7aec41239a5a22f upstream.

E500MC64 is a processor pre-dating E5500 that has never been
commercialised. Use -mcpu=e5500 for E5500 core.

More details at https://gcc.gnu.org/PR108149

Signed-off-by: Christophe Leroy &lt;christophe.leroy@csgroup.eu&gt;
Acked-by: Pali Rohár &lt;pali@kernel.org&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/fa71ed20d22c156225436374f0ab847daac893bc.1671475543.git.christophe.leroy@csgroup.eu
Cc: Naresh Kamboju &lt;naresh.kamboju@linaro.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc: Disable CPU unknown by CLANG when CC_IS_CLANG</title>
<updated>2023-03-22T12:38:10+00:00</updated>
<author>
<name>Christophe Leroy</name>
<email>christophe.leroy@csgroup.eu</email>
</author>
<published>2023-02-02T11:01:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=375e00eab2dba35ab697be05607b53bf884a1e36'/>
<id>375e00eab2dba35ab697be05607b53bf884a1e36</id>
<content type='text'>
commit 4b10306e98456aed03cad75ce467e8b1efdccca0 upstream.

CLANG only knows the following CPUs:

generic, 440, 450, 601, 602, 603, 603e, 603ev, 604, 604e, 620, 630,
g3, 7400, g4, 7450, g4+, 750, 8548, 970, g5, a2, e500, e500mc, e5500,
power3, pwr3, power4, pwr4, power5, pwr5, power5x, pwr5x, power6,
pwr6, power6x, pwr6x, power7, pwr7, power8, pwr8, power9, pwr9,
power10, pwr10, powerpc, ppc, ppc32, powerpc64, ppc64, powerpc64le,
ppc64le, futur

Disable other ones when CC_IS_CLANG.

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/e62892e32c14a7a5738c597e39e0082cb0abf21c.1675335659.git.christophe.leroy@csgroup.eu
Cc: Nick Desaulniers &lt;ndesaulniers@google.com&gt;
Cc: Naresh Kamboju &lt;naresh.kamboju@linaro.org&gt;
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 4b10306e98456aed03cad75ce467e8b1efdccca0 upstream.

CLANG only knows the following CPUs:

generic, 440, 450, 601, 602, 603, 603e, 603ev, 604, 604e, 620, 630,
g3, 7400, g4, 7450, g4+, 750, 8548, 970, g5, a2, e500, e500mc, e5500,
power3, pwr3, power4, pwr4, power5, pwr5, power5x, pwr5x, power6,
pwr6, power6x, pwr6x, power7, pwr7, power8, pwr8, power9, pwr9,
power10, pwr10, powerpc, ppc, ppc32, powerpc64, ppc64, powerpc64le,
ppc64le, futur

Disable other ones when CC_IS_CLANG.

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/e62892e32c14a7a5738c597e39e0082cb0abf21c.1675335659.git.christophe.leroy@csgroup.eu
Cc: Nick Desaulniers &lt;ndesaulniers@google.com&gt;
Cc: Naresh Kamboju &lt;naresh.kamboju@linaro.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc: Pass correct CPU reference to assembler</title>
<updated>2023-03-22T12:38:09+00:00</updated>
<author>
<name>Christophe Leroy</name>
<email>christophe.leroy@csgroup.eu</email>
</author>
<published>2022-12-19T18:45:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=8804d8e330e1ea2a783e28a9aacdfd1576eacd25'/>
<id>8804d8e330e1ea2a783e28a9aacdfd1576eacd25</id>
<content type='text'>
commit bfb03af71a3798b5a88a945a9c19ad67e1c4986d upstream.

Jan-Benedict reported issue with building ppc64e_defconfig
with mainline GCC work:

  powerpc64-linux-gcc -Wp,-MMD,arch/powerpc/kernel/vdso/.gettimeofday-64.o.d -nostdinc -I./arch/powerpc/include -I./arch/powerpc/include/generated  -I./include -I./arch/powerpc/include/uapi -I./arch/powerpc/include/generated/uapi -I./include/uapi -I./include/generated/uapi -include ./include/linux/compiler-version.h -include ./include/linux/kconfig.h -D__KERNEL__ -I ./arch/powerpc -DHAVE_AS_ATHIGH=1 -fmacro-prefix-map=./= -D__ASSEMBLY__ -fno-PIE -m64 -Wl,-a64 -mabi=elfv1 -Wa,-me500 -Wa,-me500mc -mabi=elfv1 -mbig-endian    -Wl,-soname=linux-vdso64.so.1 -D__VDSO64__ -s -c -o arch/powerpc/kernel/vdso/gettimeofday-64.o arch/powerpc/kernel/vdso/gettimeofday.S
	arch/powerpc/kernel/vdso/gettimeofday.S: Assembler messages:
	arch/powerpc/kernel/vdso/gettimeofday.S:72: Error: unrecognized opcode: `stdu'
	arch/powerpc/kernel/vdso/gettimeofday.S:72: Error: unrecognized opcode: `stdu'
	arch/powerpc/kernel/vdso/gettimeofday.S:72: Error: unrecognized opcode: `std'
	arch/powerpc/kernel/vdso/gettimeofday.S:72: Error: unrecognized opcode: `std'
	arch/powerpc/kernel/vdso/gettimeofday.S:72: Error: unrecognized opcode: `ld'
	arch/powerpc/kernel/vdso/gettimeofday.S:72: Error: unrecognized opcode: `ld'
	...
	make[1]: *** [arch/powerpc/kernel/vdso/Makefile:76: arch/powerpc/kernel/vdso/gettimeofday-64.o] Error 1
	make: *** [arch/powerpc/Makefile:387: vdso_prepare] Error 2

This is due to assembler being called with -me500mc which is
a 32 bits target.

The problem comes from the fact that CONFIG_PPC_E500MC is selected for
both the e500mc (32 bits) and the e5500 (64 bits), and therefore the
following makefile rule is wrong:

  cpu-as-$(CONFIG_PPC_E500MC)    += $(call as-option,-Wa$(comma)-me500mc)

Today we have CONFIG_TARGET_CPU which provides the identification of the
expected CPU, it is used for GCC. Once GCC knows the target CPU, it adds
the correct CPU option to assembler, no need to add it explicitly.

With that change (And also commit 45f7091aac35 ("powerpc/64: Set default
CPU in Kconfig")), it now is:

  powerpc64-linux-gcc -Wp,-MMD,arch/powerpc/kernel/vdso/.gettimeofday-64.o.d -nostdinc -I./arch/powerpc/include -I./arch/powerpc/include/generated  -I./include -I./arch/powerpc/include/uapi -I./arch/powerpc/include/generated/uapi -I./include/uapi -I./include/generated/uapi -include ./include/linux/compiler-version.h -include ./include/linux/kconfig.h -D__KERNEL__ -I ./arch/powerpc -DHAVE_AS_ATHIGH=1 -fmacro-prefix-map=./= -D__ASSEMBLY__ -fno-PIE -m64 -Wl,-a64 -mabi=elfv1 -mcpu=e500mc64 -mabi=elfv1 -mbig-endian    -Wl,-soname=linux-vdso64.so.1 -D__VDSO64__ -s -c -o arch/powerpc/kernel/vdso/gettimeofday-64.o arch/powerpc/kernel/vdso/gettimeofday.S

Reported-by: Jan-Benedict Glaw &lt;jbglaw@lug-owl.de&gt;
Signed-off-by: Christophe Leroy &lt;christophe.leroy@csgroup.eu&gt;
Acked-by: Pali Rohár &lt;pali@kernel.org&gt;
[mpe: Retain -Wa,-mpower4 -Wa,-many for Book3S 64 builds for now]
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/758ad54128fa9dd2fdedc4c511592111cbded900.1671475543.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 bfb03af71a3798b5a88a945a9c19ad67e1c4986d upstream.

Jan-Benedict reported issue with building ppc64e_defconfig
with mainline GCC work:

  powerpc64-linux-gcc -Wp,-MMD,arch/powerpc/kernel/vdso/.gettimeofday-64.o.d -nostdinc -I./arch/powerpc/include -I./arch/powerpc/include/generated  -I./include -I./arch/powerpc/include/uapi -I./arch/powerpc/include/generated/uapi -I./include/uapi -I./include/generated/uapi -include ./include/linux/compiler-version.h -include ./include/linux/kconfig.h -D__KERNEL__ -I ./arch/powerpc -DHAVE_AS_ATHIGH=1 -fmacro-prefix-map=./= -D__ASSEMBLY__ -fno-PIE -m64 -Wl,-a64 -mabi=elfv1 -Wa,-me500 -Wa,-me500mc -mabi=elfv1 -mbig-endian    -Wl,-soname=linux-vdso64.so.1 -D__VDSO64__ -s -c -o arch/powerpc/kernel/vdso/gettimeofday-64.o arch/powerpc/kernel/vdso/gettimeofday.S
	arch/powerpc/kernel/vdso/gettimeofday.S: Assembler messages:
	arch/powerpc/kernel/vdso/gettimeofday.S:72: Error: unrecognized opcode: `stdu'
	arch/powerpc/kernel/vdso/gettimeofday.S:72: Error: unrecognized opcode: `stdu'
	arch/powerpc/kernel/vdso/gettimeofday.S:72: Error: unrecognized opcode: `std'
	arch/powerpc/kernel/vdso/gettimeofday.S:72: Error: unrecognized opcode: `std'
	arch/powerpc/kernel/vdso/gettimeofday.S:72: Error: unrecognized opcode: `ld'
	arch/powerpc/kernel/vdso/gettimeofday.S:72: Error: unrecognized opcode: `ld'
	...
	make[1]: *** [arch/powerpc/kernel/vdso/Makefile:76: arch/powerpc/kernel/vdso/gettimeofday-64.o] Error 1
	make: *** [arch/powerpc/Makefile:387: vdso_prepare] Error 2

This is due to assembler being called with -me500mc which is
a 32 bits target.

The problem comes from the fact that CONFIG_PPC_E500MC is selected for
both the e500mc (32 bits) and the e5500 (64 bits), and therefore the
following makefile rule is wrong:

  cpu-as-$(CONFIG_PPC_E500MC)    += $(call as-option,-Wa$(comma)-me500mc)

Today we have CONFIG_TARGET_CPU which provides the identification of the
expected CPU, it is used for GCC. Once GCC knows the target CPU, it adds
the correct CPU option to assembler, no need to add it explicitly.

With that change (And also commit 45f7091aac35 ("powerpc/64: Set default
CPU in Kconfig")), it now is:

  powerpc64-linux-gcc -Wp,-MMD,arch/powerpc/kernel/vdso/.gettimeofday-64.o.d -nostdinc -I./arch/powerpc/include -I./arch/powerpc/include/generated  -I./include -I./arch/powerpc/include/uapi -I./arch/powerpc/include/generated/uapi -I./include/uapi -I./include/generated/uapi -include ./include/linux/compiler-version.h -include ./include/linux/kconfig.h -D__KERNEL__ -I ./arch/powerpc -DHAVE_AS_ATHIGH=1 -fmacro-prefix-map=./= -D__ASSEMBLY__ -fno-PIE -m64 -Wl,-a64 -mabi=elfv1 -mcpu=e500mc64 -mabi=elfv1 -mbig-endian    -Wl,-soname=linux-vdso64.so.1 -D__VDSO64__ -s -c -o arch/powerpc/kernel/vdso/gettimeofday-64.o arch/powerpc/kernel/vdso/gettimeofday.S

Reported-by: Jan-Benedict Glaw &lt;jbglaw@lug-owl.de&gt;
Signed-off-by: Christophe Leroy &lt;christophe.leroy@csgroup.eu&gt;
Acked-by: Pali Rohár &lt;pali@kernel.org&gt;
[mpe: Retain -Wa,-mpower4 -Wa,-many for Book3S 64 builds for now]
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/758ad54128fa9dd2fdedc4c511592111cbded900.1671475543.git.christophe.leroy@csgroup.eu
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/boot: Don't always pass -mcpu=powerpc when building 32-bit uImage</title>
<updated>2023-03-22T12:38:07+00:00</updated>
<author>
<name>Pali Rohár</name>
<email>pali@kernel.org</email>
</author>
<published>2023-01-25T07:39:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=8f77a5ebb836e4cae9df69572e4ba080c024713d'/>
<id>8f77a5ebb836e4cae9df69572e4ba080c024713d</id>
<content type='text'>
commit ff7c76f66d8bad4e694c264c789249e1d3a8205d upstream.

When CONFIG_TARGET_CPU is specified then pass its value to the compiler
-mcpu option. This fixes following build error when building kernel with
powerpc e500 SPE capable cross compilers:

    BOOTAS  arch/powerpc/boot/crt0.o
  powerpc-linux-gnuspe-gcc: error: unrecognized argument in option ‘-mcpu=powerpc’
  powerpc-linux-gnuspe-gcc: note: valid arguments to ‘-mcpu=’ are: 8540 8548 native
  make[1]: *** [arch/powerpc/boot/Makefile:231: arch/powerpc/boot/crt0.o] Error 1

Similar change was already introduced for the main powerpc Makefile in
commit 446cda1b21d9 ("powerpc/32: Don't always pass -mcpu=powerpc to the
compiler").

Fixes: 40a75584e526 ("powerpc/boot: Build wrapper for an appropriate CPU")
Cc: stable@vger.kernel.org # v5.19+
Signed-off-by: Pali Rohár &lt;pali@kernel.org&gt;
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/2ae3ae5887babfdacc34435bff0944b3f336100a.1674632329.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 ff7c76f66d8bad4e694c264c789249e1d3a8205d upstream.

When CONFIG_TARGET_CPU is specified then pass its value to the compiler
-mcpu option. This fixes following build error when building kernel with
powerpc e500 SPE capable cross compilers:

    BOOTAS  arch/powerpc/boot/crt0.o
  powerpc-linux-gnuspe-gcc: error: unrecognized argument in option ‘-mcpu=powerpc’
  powerpc-linux-gnuspe-gcc: note: valid arguments to ‘-mcpu=’ are: 8540 8548 native
  make[1]: *** [arch/powerpc/boot/Makefile:231: arch/powerpc/boot/crt0.o] Error 1

Similar change was already introduced for the main powerpc Makefile in
commit 446cda1b21d9 ("powerpc/32: Don't always pass -mcpu=powerpc to the
compiler").

Fixes: 40a75584e526 ("powerpc/boot: Build wrapper for an appropriate CPU")
Cc: stable@vger.kernel.org # v5.19+
Signed-off-by: Pali Rohár &lt;pali@kernel.org&gt;
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/2ae3ae5887babfdacc34435bff0944b3f336100a.1674632329.git.christophe.leroy@csgroup.eu
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/64: Set default CPU in Kconfig</title>
<updated>2023-03-22T12:38:07+00:00</updated>
<author>
<name>Christophe Leroy</name>
<email>christophe.leroy@csgroup.eu</email>
</author>
<published>2023-01-25T07:38:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d5ccac793b9078bfeff57a7b59e7be4dc606dd7b'/>
<id>d5ccac793b9078bfeff57a7b59e7be4dc606dd7b</id>
<content type='text'>
commit 45f7091aac3546ef8112bf62836650ca0bbf0b79 upstream.

Since commit 0069f3d14e7a ("powerpc/64e: Tie PPC_BOOK3E_64 to
PPC_E500MC"), the only possible BOOK3E/64 are E500, so no need of a
default CPU over the E5500.

When the user selects book3e, they must have an e500 compatible
compiler, and it won't work anymore with the default -mcpu=power64, see
commit d6b551b8f90c ("powerpc/64e: Fix build failure with GCC
12 (unrecognized opcode: `wrteei')").

For book3s/64, replace GENERIC_CPU by POWERPC64_CPU to match the PPC32
POWERPC_CPU, and set a default mpcu value in Kconfig directly.

When a user selects a particular CPU, they must ensure the compiler has
the requested capability. Therefore, remove hidden fallback, instead
offer user the possibility to say they want to use the toolchain
default.

Fixes: d6b551b8f90c ("powerpc/64e: Fix build failure with GCC 12 (unrecognized opcode: `wrteei')")
Reported-by: Pali Rohár &lt;pali@kernel.org&gt;
Tested-by: Pali Rohár &lt;pali@kernel.org&gt;
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/76c11197b058193dcb8e8b26adffba09cfbdab11.1674632329.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 45f7091aac3546ef8112bf62836650ca0bbf0b79 upstream.

Since commit 0069f3d14e7a ("powerpc/64e: Tie PPC_BOOK3E_64 to
PPC_E500MC"), the only possible BOOK3E/64 are E500, so no need of a
default CPU over the E5500.

When the user selects book3e, they must have an e500 compatible
compiler, and it won't work anymore with the default -mcpu=power64, see
commit d6b551b8f90c ("powerpc/64e: Fix build failure with GCC
12 (unrecognized opcode: `wrteei')").

For book3s/64, replace GENERIC_CPU by POWERPC64_CPU to match the PPC32
POWERPC_CPU, and set a default mpcu value in Kconfig directly.

When a user selects a particular CPU, they must ensure the compiler has
the requested capability. Therefore, remove hidden fallback, instead
offer user the possibility to say they want to use the toolchain
default.

Fixes: d6b551b8f90c ("powerpc/64e: Fix build failure with GCC 12 (unrecognized opcode: `wrteei')")
Reported-by: Pali Rohár &lt;pali@kernel.org&gt;
Tested-by: Pali Rohár &lt;pali@kernel.org&gt;
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/76c11197b058193dcb8e8b26adffba09cfbdab11.1674632329.git.christophe.leroy@csgroup.eu
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/mm: Fix false detection of read faults</title>
<updated>2023-03-22T12:37:50+00:00</updated>
<author>
<name>Russell Currey</name>
<email>ruscur@russell.cc</email>
</author>
<published>2023-03-10T05:08:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=2e5b756b6af96748592898515f1e09849cf9640e'/>
<id>2e5b756b6af96748592898515f1e09849cf9640e</id>
<content type='text'>
[ Upstream commit f2c7e3562b4c4f1699acc1538ebf3e75f5cced35 ]

To support detection of read faults with Radix execute-only memory, the
vma_is_accessible() check in access_error() (which checks for PROT_NONE)
was replaced with a check to see if VM_READ was missing, and if so,
returns true to assert the fault was caused by a bad read.

This is incorrect, as it ignores that both VM_WRITE and VM_EXEC imply
read on powerpc, as defined in protection_map[].  This causes mappings
containing VM_WRITE or VM_EXEC without VM_READ to misreport the cause of
page faults, since the MMU is still allowing reads.

Correct this by restoring the original vma_is_accessible() check for
PROT_NONE mappings, and adding a separate check for Radix PROT_EXEC-only
mappings.

Fixes: 395cac7752b9 ("powerpc/mm: Support execute-only memory on the Radix MMU")
Reported-by: Michal Suchánek &lt;msuchanek@suse.de&gt;
Link: https://lore.kernel.org/r/20230308152702.GR19419@kitsune.suse.cz
Tested-by: Benjamin Gray &lt;bgray@linux.ibm.com&gt;
Signed-off-by: Russell Currey &lt;ruscur@russell.cc&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://msgid.link/20230310050834.63105-1-ruscur@russell.cc
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 f2c7e3562b4c4f1699acc1538ebf3e75f5cced35 ]

To support detection of read faults with Radix execute-only memory, the
vma_is_accessible() check in access_error() (which checks for PROT_NONE)
was replaced with a check to see if VM_READ was missing, and if so,
returns true to assert the fault was caused by a bad read.

This is incorrect, as it ignores that both VM_WRITE and VM_EXEC imply
read on powerpc, as defined in protection_map[].  This causes mappings
containing VM_WRITE or VM_EXEC without VM_READ to misreport the cause of
page faults, since the MMU is still allowing reads.

Correct this by restoring the original vma_is_accessible() check for
PROT_NONE mappings, and adding a separate check for Radix PROT_EXEC-only
mappings.

Fixes: 395cac7752b9 ("powerpc/mm: Support execute-only memory on the Radix MMU")
Reported-by: Michal Suchánek &lt;msuchanek@suse.de&gt;
Link: https://lore.kernel.org/r/20230308152702.GR19419@kitsune.suse.cz
Tested-by: Benjamin Gray &lt;bgray@linux.ibm.com&gt;
Signed-off-by: Russell Currey &lt;ruscur@russell.cc&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://msgid.link/20230310050834.63105-1-ruscur@russell.cc
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/kcsan: Exclude udelay to prevent recursive instrumentation</title>
<updated>2023-03-17T07:58:02+00:00</updated>
<author>
<name>Rohan McLure</name>
<email>rmclure@linux.ibm.com</email>
</author>
<published>2023-02-06T02:17:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=ce3c0a592031b4c289fdd641073b90fc551c3b6e'/>
<id>ce3c0a592031b4c289fdd641073b90fc551c3b6e</id>
<content type='text'>
[ Upstream commit 2a7ce82dc46c591c9244057d89a6591c9639b9b9 ]

In order for KCSAN to increase its likelihood of observing a data race,
it sets a watchpoint on memory accesses and stalls, allowing for
detection of conflicting accesses by other kernel threads or interrupts.

Stalls are implemented by injecting a call to udelay in instrumented code.
To prevent recursive instrumentation, exclude udelay from being instrumented.

Signed-off-by: Rohan McLure &lt;rmclure@linux.ibm.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20230206021801.105268-3-rmclure@linux.ibm.com
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 2a7ce82dc46c591c9244057d89a6591c9639b9b9 ]

In order for KCSAN to increase its likelihood of observing a data race,
it sets a watchpoint on memory accesses and stalls, allowing for
detection of conflicting accesses by other kernel threads or interrupts.

Stalls are implemented by injecting a call to udelay in instrumented code.
To prevent recursive instrumentation, exclude udelay from being instrumented.

Signed-off-by: Rohan McLure &lt;rmclure@linux.ibm.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20230206021801.105268-3-rmclure@linux.ibm.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/64: Move paca allocation to early_setup()</title>
<updated>2023-03-17T07:58:02+00:00</updated>
<author>
<name>Nicholas Piggin</name>
<email>npiggin@gmail.com</email>
</author>
<published>2022-12-16T11:59:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=46ac7f7187f0080bc39531983be95157f61f9c5d'/>
<id>46ac7f7187f0080bc39531983be95157f61f9c5d</id>
<content type='text'>
[ Upstream commit dc222fa7737212fe0da513e5b8937c156d02225d ]

The early paca and boot cpuid dance is complicated and currently does
not quite work as expected for boot cpuid != 0 cases.

early_init_devtree() currently allocates the paca_ptrs and boot cpuid
paca, but until that returns and early_setup() calls setup_paca(), this
thread is currently still executing with smp_processor_id() == 0.

One problem this causes is the paca_ptrs[smp_processor_id()] pointer is
poisoned, so valid_emergency_stack() (any backtrace) and any similar
users will crash.

Another is that the hardware id which is set here will not be returned
by get_hard_smp_processor_id(smp_processor_id()), but it would work
correctly for boot_cpuid == 0, which could lead to difficult to
reproduce or find bugs. The hard id does not seem to be used by the rest
of early_init_devtree(), it just looks like all this code might have
been put here to allocate somewhere to store boot CPU hardware id while
scanning the devtree.

Rearrange things so the hwid is put in a global variable like
boot_cpuid, and do all the paca allocation and boot paca setup in the
64-bit early_setup() after we have everything ready to go.

The paca_ptrs[0] re-poisoning code in early_setup does not seem to have
ever worked, because paca_ptrs[0] was never not-poisoned when boot_cpuid
is not 0.

Signed-off-by: Nicholas Piggin &lt;npiggin@gmail.com&gt;
[mpe: Fix build error on 32-bit]
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20221216115930.2667772-4-npiggin@gmail.com
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 dc222fa7737212fe0da513e5b8937c156d02225d ]

The early paca and boot cpuid dance is complicated and currently does
not quite work as expected for boot cpuid != 0 cases.

early_init_devtree() currently allocates the paca_ptrs and boot cpuid
paca, but until that returns and early_setup() calls setup_paca(), this
thread is currently still executing with smp_processor_id() == 0.

One problem this causes is the paca_ptrs[smp_processor_id()] pointer is
poisoned, so valid_emergency_stack() (any backtrace) and any similar
users will crash.

Another is that the hardware id which is set here will not be returned
by get_hard_smp_processor_id(smp_processor_id()), but it would work
correctly for boot_cpuid == 0, which could lead to difficult to
reproduce or find bugs. The hard id does not seem to be used by the rest
of early_init_devtree(), it just looks like all this code might have
been put here to allocate somewhere to store boot CPU hardware id while
scanning the devtree.

Rearrange things so the hwid is put in a global variable like
boot_cpuid, and do all the paca allocation and boot paca setup in the
64-bit early_setup() after we have everything ready to go.

The paca_ptrs[0] re-poisoning code in early_setup does not seem to have
ever worked, because paca_ptrs[0] was never not-poisoned when boot_cpuid
is not 0.

Signed-off-by: Nicholas Piggin &lt;npiggin@gmail.com&gt;
[mpe: Fix build error on 32-bit]
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20221216115930.2667772-4-npiggin@gmail.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/64: Fix task_cpu in early boot when booting non-zero cpuid</title>
<updated>2023-03-17T07:58:01+00:00</updated>
<author>
<name>Nicholas Piggin</name>
<email>npiggin@gmail.com</email>
</author>
<published>2022-12-16T11:59:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=655b4da61d260a97fbcae41a9eb2b989f4d50812'/>
<id>655b4da61d260a97fbcae41a9eb2b989f4d50812</id>
<content type='text'>
[ Upstream commit 9fa24404f5044967753a6cd3e5e36f57686bec6e ]

powerpc/64 can boot on a non-zero SMP processor id. Initially, the boot
CPU is said to be "assumed to be 0" until early_init_devtree() discovers
the id from the device tree. That is not a good description because the
assumption can be wrong and that has to be handled, the better
description is that 0 is used as a placeholder, and things are fixed
after the real id is discovered.

smp_processor_id() is set to the boot cpuid, but task_cpu(current) is
not, which causes the smp_processor_id() == task_cpu(current) invariant
to be broken until init_idle() in sched_init().

This is quite fragile and could lead to subtle bugs in future. One bug
is that validate_sp_size uses task_cpu() to get the process stack, so
any stack trace from the booting CPU between early_init_devtree()
and sched_init() will have problems. Early on paca_ptrs[0] will be
poisoned, so that can cause machine checks dereferencing that memory
in real mode. Later, validating the current stack pointer against the
idle task of a different secondary will probably cause no stack trace
to be printed.

Fix this by setting thread_info-&gt;cpu right after smp_processor_id() is
set to the boot cpuid.

Signed-off-by: Nicholas Piggin &lt;npiggin@gmail.com&gt;
[mpe: Fix SMP=n build as reported by sfr]
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20221216115930.2667772-3-npiggin@gmail.com
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 9fa24404f5044967753a6cd3e5e36f57686bec6e ]

powerpc/64 can boot on a non-zero SMP processor id. Initially, the boot
CPU is said to be "assumed to be 0" until early_init_devtree() discovers
the id from the device tree. That is not a good description because the
assumption can be wrong and that has to be handled, the better
description is that 0 is used as a placeholder, and things are fixed
after the real id is discovered.

smp_processor_id() is set to the boot cpuid, but task_cpu(current) is
not, which causes the smp_processor_id() == task_cpu(current) invariant
to be broken until init_idle() in sched_init().

This is quite fragile and could lead to subtle bugs in future. One bug
is that validate_sp_size uses task_cpu() to get the process stack, so
any stack trace from the booting CPU between early_init_devtree()
and sched_init() will have problems. Early on paca_ptrs[0] will be
poisoned, so that can cause machine checks dereferencing that memory
in real mode. Later, validating the current stack pointer against the
idle task of a different secondary will probably cause no stack trace
to be printed.

Fix this by setting thread_info-&gt;cpu right after smp_processor_id() is
set to the boot cpuid.

Signed-off-by: Nicholas Piggin &lt;npiggin@gmail.com&gt;
[mpe: Fix SMP=n build as reported by sfr]
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20221216115930.2667772-3-npiggin@gmail.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/bpf/32: Only set a stack frame when necessary</title>
<updated>2023-03-17T07:58:01+00:00</updated>
<author>
<name>Christophe Leroy</name>
<email>christophe.leroy@csgroup.eu</email>
</author>
<published>2023-02-01T10:04:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=24ba28c4c941236641aa97d68ab24253e1ca8207'/>
<id>24ba28c4c941236641aa97d68ab24253e1ca8207</id>
<content type='text'>
[ Upstream commit d084dcf256bc4565b4b1af9b00297ac7b51c7049 ]

Until now a stack frame was set at all time due to the need
to keep tail call counter in the stack.

But since commit 89d21e259a94 ("powerpc/bpf/32: Fix Oops on tail call
tests") the tail call counter is passed via register r4. It is therefore
not necessary anymore to have a stack frame for that.

Just like PPC64, implement bpf_has_stack_frame() and only sets the frame
when needed.

The difference with PPC64 is that PPC32 doesn't have a redzone, so
the stack is required as soon as non volatile registers are used or
when tail call count is set up.

Signed-off-by: Christophe Leroy &lt;christophe.leroy@csgroup.eu&gt;
[mpe: Fix commit reference in change log]
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/62d7b654a3cfe73d998697cb29bbc5ffd89bfdb1.1675245773.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 d084dcf256bc4565b4b1af9b00297ac7b51c7049 ]

Until now a stack frame was set at all time due to the need
to keep tail call counter in the stack.

But since commit 89d21e259a94 ("powerpc/bpf/32: Fix Oops on tail call
tests") the tail call counter is passed via register r4. It is therefore
not necessary anymore to have a stack frame for that.

Just like PPC64, implement bpf_has_stack_frame() and only sets the frame
when needed.

The difference with PPC64 is that PPC32 doesn't have a redzone, so
the stack is required as soon as non volatile registers are used or
when tail call count is set up.

Signed-off-by: Christophe Leroy &lt;christophe.leroy@csgroup.eu&gt;
[mpe: Fix commit reference in change log]
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/62d7b654a3cfe73d998697cb29bbc5ffd89bfdb1.1675245773.git.christophe.leroy@csgroup.eu
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
