linux-stable.git/arch, branch v6.2.13 Linux kernel stable tree purgatory: fix disabling debug info 2023-04-26T12:30:07+00:00 Alyssa Ross hi@alyssa.is 2023-03-26T18:21:21+00:00 6402e1238e725139b17c3689c8a8566be9080ac5 commit d83806c4c0cccc0d6d3c3581a11983a9c186a138 upstream. Since 32ef9e5054ec, -Wa,-gdwarf-2 is no longer used in KBUILD_AFLAGS. Instead, it includes -g, the appropriate -gdwarf-* flag, and also the -Wa versions of both of those if building with Clang and GNU as. As a result, debug info was being generated for the purgatory objects, even though the intention was that it not be. Fixes: 32ef9e5054ec ("Makefile.debug: re-enable debug info for .S files") Signed-off-by: Alyssa Ross <hi@alyssa.is> Cc: stable@vger.kernel.org Acked-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit d83806c4c0cccc0d6d3c3581a11983a9c186a138 upstream.

Since 32ef9e5054ec, -Wa,-gdwarf-2 is no longer used in KBUILD_AFLAGS.
Instead, it includes -g, the appropriate -gdwarf-* flag, and also the
-Wa versions of both of those if building with Clang and GNU as.  As a
result, debug info was being generated for the purgatory objects, even
though the intention was that it not be.

Fixes: 32ef9e5054ec ("Makefile.debug: re-enable debug info for .S files")
Signed-off-by: Alyssa Ross <hi@alyssa.is>
Cc: stable@vger.kernel.org
Acked-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
LoongArch: Make WriteCombine configurable for ioremap() 2023-04-26T12:30:07+00:00 Huacai Chen chenhuacai@loongson.cn 2023-04-18T11:38:58+00:00 9d9f5b437684d2e0d613332df711a4fdd1188885 commit 16c52e503043aed1e2a2ce38d9249de5936c1f6b upstream. LoongArch maintains cache coherency in hardware, but when paired with LS7A chipsets the WUC attribute (Weak-ordered UnCached, which is similar to WriteCombine) is out of the scope of cache coherency machanism for PCIe devices (this is a PCIe protocol violation, which may be fixed in newer chipsets). This means WUC can only used for write-only memory regions now, so this option is disabled by default, making WUC silently fallback to SUC for ioremap(). You can enable this option if the kernel is ensured to run on hardware without this bug. Kernel parameter writecombine=on/off can be used to override the Kconfig option. Cc: stable@vger.kernel.org Suggested-by: WANG Xuerui <kernel@xen0n.name> Reviewed-by: WANG Xuerui <kernel@xen0n.name> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 16c52e503043aed1e2a2ce38d9249de5936c1f6b upstream.

LoongArch maintains cache coherency in hardware, but when paired with
LS7A chipsets the WUC attribute (Weak-ordered UnCached, which is similar
to WriteCombine) is out of the scope of cache coherency machanism for
PCIe devices (this is a PCIe protocol violation, which may be fixed in
newer chipsets).

This means WUC can only used for write-only memory regions now, so this
option is disabled by default, making WUC silently fallback to SUC for
ioremap(). You can enable this option if the kernel is ensured to run on
hardware without this bug.

Kernel parameter writecombine=on/off can be used to override the Kconfig
option.

Cc: stable@vger.kernel.org
Suggested-by: WANG Xuerui <kernel@xen0n.name>
Reviewed-by: WANG Xuerui <kernel@xen0n.name>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
LoongArch: Make -mstrict-align configurable 2023-04-26T12:30:07+00:00 Huacai Chen chenhuacai@loongson.cn 2023-02-25T07:52:56+00:00 13e28ed3bfbb474a511e9cfdb92180ec53568247 commit 41596803302d83a67a80dc1efef4e51ac46acabb upstream. Introduce Kconfig option ARCH_STRICT_ALIGN to make -mstrict-align be configurable. Not all LoongArch cores support h/w unaligned access, we can use the -mstrict-align build parameter to prevent unaligned accesses. CPUs with h/w unaligned access support: Loongson-2K2000/2K3000/3A5000/3C5000/3D5000. CPUs without h/w unaligned access support: Loongson-2K500/2K1000. This option is enabled by default to make the kernel be able to run on all LoongArch systems. But you can disable it manually if you want to run kernel only on systems with h/w unaligned access support in order to optimise for performance. Reviewed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 41596803302d83a67a80dc1efef4e51ac46acabb upstream.

Introduce Kconfig option ARCH_STRICT_ALIGN to make -mstrict-align be
configurable.

Not all LoongArch cores support h/w unaligned access, we can use the
-mstrict-align build parameter to prevent unaligned accesses.

CPUs with h/w unaligned access support:
Loongson-2K2000/2K3000/3A5000/3C5000/3D5000.

CPUs without h/w unaligned access support:
Loongson-2K500/2K1000.

This option is enabled by default to make the kernel be able to run on
all LoongArch systems. But you can disable it manually if you want to
run kernel only on systems with h/w unaligned access support in order to
optimise for performance.

Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
MIPS: Define RUNTIME_DISCARD_EXIT in LD script 2023-04-26T12:30:07+00:00 Jiaxun Yang jiaxun.yang@flygoat.com 2023-04-08T20:33:48+00:00 587bc862f72f400653230f2074faf28de27c18d2 commit 6dcbd0a69c84a8ae7a442840a8cf6b1379dc8f16 upstream. MIPS's exit sections are discarded at runtime as well. Fixes link error: `.exit.text' referenced in section `__jump_table' of fs/fuse/inode.o: defined in discarded section `.exit.text' of fs/fuse/inode.o Fixes: 99cb0d917ffa ("arch: fix broken BuildID for arm64 and riscv") Reported-by: "kernelci.org bot" <bot@kernelci.org> Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 6dcbd0a69c84a8ae7a442840a8cf6b1379dc8f16 upstream.

MIPS's exit sections are discarded at runtime as well.

Fixes link error:
`.exit.text' referenced in section `__jump_table' of fs/fuse/inode.o:
defined in discarded section `.exit.text' of fs/fuse/inode.o

Fixes: 99cb0d917ffa ("arch: fix broken BuildID for arm64 and riscv")
Reported-by: "kernelci.org bot" <bot@kernelci.org>
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
KVM: arm64: Fix buffer overflow in kvm_arm_set_fw_reg() 2023-04-26T12:30:07+00:00 Dan Carpenter dan.carpenter@linaro.org 2023-04-19T10:16:13+00:00 9762e58cbda22d1ca360ecca5715a3424c1e3bd3 commit a25bc8486f9c01c1af6b6c5657234b2eee2c39d6 upstream. The KVM_REG_SIZE() comes from the ioctl and it can be a power of two between 0-32768 but if it is more than sizeof(long) this will corrupt memory. Fixes: 99adb567632b ("KVM: arm/arm64: Add save/restore support for firmware workaround state") Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org> Reviewed-by: Steven Price <steven.price@arm.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Reviewed-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/4efbab8c-640f-43b2-8ac6-6d68e08280fe@kili.mountain Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit a25bc8486f9c01c1af6b6c5657234b2eee2c39d6 upstream.

The KVM_REG_SIZE() comes from the ioctl and it can be a power of two
between 0-32768 but if it is more than sizeof(long) this will corrupt
memory.

Fixes: 99adb567632b ("KVM: arm/arm64: Add save/restore support for firmware workaround state")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Steven Price <steven.price@arm.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/4efbab8c-640f-43b2-8ac6-6d68e08280fe@kili.mountain
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
KVM: arm64: Make vcpu flag updates non-preemptible 2023-04-26T12:30:07+00:00 Marc Zyngier maz@kernel.org 2023-04-18T12:57:37+00:00 7a7d89a089fce5607a9bcc0d9ebf581de017fda8 commit 35dcb3ac663a16510afc27ba2725d70c15e012a5 upstream. Per-vcpu flags are updated using a non-atomic RMW operation. Which means it is possible to get preempted between the read and write operations. Another interesting thing to note is that preemption also updates flags, as we have some flag manipulation in both the load and put operations. It is thus possible to lose information communicated by either load or put, as the preempted flag update will overwrite the flags when the thread is resumed. This is specially critical if either load or put has stored information which depends on the physical CPU the vcpu runs on. This results in really elusive bugs, and kudos must be given to Mostafa for the long hours of debugging, and finally spotting the problem. Fix it by disabling preemption during the RMW operation, which ensures that the state stays consistent. Also upgrade vcpu_get_flag path to use READ_ONCE() to make sure the field is always atomically accessed. Fixes: e87abb73e594 ("KVM: arm64: Add helpers to manipulate vcpu flags among a set") Reported-by: Mostafa Saleh <smostafa@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20230418125737.2327972-1-maz@kernel.org Signed-off-by: Oliver Upton <oliver.upton@linux.dev> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 35dcb3ac663a16510afc27ba2725d70c15e012a5 upstream.

Per-vcpu flags are updated using a non-atomic RMW operation.
Which means it is possible to get preempted between the read and
write operations.

Another interesting thing to note is that preemption also updates
flags, as we have some flag manipulation in both the load and put
operations.

It is thus possible to lose information communicated by either
load or put, as the preempted flag update will overwrite the flags
when the thread is resumed. This is specially critical if either
load or put has stored information which depends on the physical
CPU the vcpu runs on.

This results in really elusive bugs, and kudos must be given to
Mostafa for the long hours of debugging, and finally spotting
the problem.

Fix it by disabling preemption during the RMW operation, which
ensures that the state stays consistent. Also upgrade vcpu_get_flag
path to use READ_ONCE() to make sure the field is always atomically
accessed.

Fixes: e87abb73e594 ("KVM: arm64: Add helpers to manipulate vcpu flags among a set")
Reported-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230418125737.2327972-1-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
LoongArch: Mark 3 symbol exports as non-GPL 2023-04-26T12:30:03+00:00 Huacai Chen chenhuacai@loongson.cn 2023-04-18T11:38:58+00:00 60864decd6a55733f2cb7b951ffb481e4e90d51c commit dce5ea1d0f45fa612f5760b88614a3f32bc75e3f upstream. vm_map_base, empty_zero_page and invalid_pmd_table could be accessed widely by some out-of-tree non-GPL but important file systems or drivers (e.g. OpenZFS). Let's use EXPORT_SYMBOL() instead of EXPORT_SYMBOL_GPL() to export them, so as to avoid build errors. 1, Details about vm_map_base: This is a LoongArch-specific symbol and may be referenced through macros PCI_IOBASE, VMALLOC_START and VMALLOC_END. 2, Details about empty_zero_page: As it stands today, only 3 architectures export empty_zero_page as a GPL symbol: IA64, LoongArch and MIPS. LoongArch gets the GPL export by inheriting from MIPS, and the MIPS export was first introduced in commit 497d2adcbf50b ("[MIPS] Export empty_zero_page for sake of the ext4 module."). The IA64 export was similar: commit a7d57ecf4216e ("[IA64] Export three symbols for module use") did so for kvm. In both IA64 and MIPS, the export of empty_zero_page was done for satisfying some in-kernel component built as module (kvm and ext4 respectively), and given its reasonably low-level nature, GPL is a reasonable choice. But looking at the bigger picture it is evident most other architectures do not regard it as GPL, so in effect the symbol probably should not be treated as such, in favor of consistency. 3, Details about invalid_pmd_table: Keep consistency with invalid_pte_table and make it be possible by some modules. Cc: stable@vger.kernel.org Reviewed-by: WANG Xuerui <git@xen0n.name> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit dce5ea1d0f45fa612f5760b88614a3f32bc75e3f upstream.

vm_map_base, empty_zero_page and invalid_pmd_table could be accessed
widely by some out-of-tree non-GPL but important file systems or drivers
(e.g. OpenZFS). Let's use EXPORT_SYMBOL() instead of EXPORT_SYMBOL_GPL()
to export them, so as to avoid build errors.

1, Details about vm_map_base:

This is a LoongArch-specific symbol and may be referenced through macros
PCI_IOBASE, VMALLOC_START and VMALLOC_END.

2, Details about empty_zero_page:

As it stands today, only 3 architectures export empty_zero_page as a GPL
symbol: IA64, LoongArch and MIPS. LoongArch gets the GPL export by
inheriting from MIPS, and the MIPS export was first introduced in commit
497d2adcbf50b ("[MIPS] Export empty_zero_page for sake of the ext4
module."). The IA64 export was similar: commit a7d57ecf4216e ("[IA64]
Export three symbols for module use") did so for kvm.

In both IA64 and MIPS, the export of empty_zero_page was done for
satisfying some in-kernel component built as module (kvm and ext4
respectively), and given its reasonably low-level nature, GPL is a
reasonable choice. But looking at the bigger picture it is evident most
other architectures do not regard it as GPL, so in effect the symbol
probably should not be treated as such, in favor of consistency.

3, Details about invalid_pmd_table:

Keep consistency with invalid_pte_table and make it be possible by some
modules.

Cc: stable@vger.kernel.org
Reviewed-by: WANG Xuerui <git@xen0n.name>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
LoongArch: Fix probing of the CRC32 feature 2023-04-26T12:30:03+00:00 Huacai Chen chenhuacai@loongson.cn 2023-04-18T11:38:58+00:00 737001c15c888925fc6ba784a5ed9ac04bf92514 commit df830336045db1246d3245d3737fee9939c5f731 upstream. Not all LoongArch processors support CRC32 instructions. This feature is indicated by CPUCFG1.CRC32 (Bit25) but it is wrongly defined in the previous versions of the ISA manual (and so does in loongarch.h). The CRC32 feature is set unconditionally now, so fix it. BTW, expose the CRC32 feature in /proc/cpuinfo. Cc: stable@vger.kernel.org Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit df830336045db1246d3245d3737fee9939c5f731 upstream.

Not all LoongArch processors support CRC32 instructions. This feature
is indicated by CPUCFG1.CRC32 (Bit25) but it is wrongly defined in the
previous versions of the ISA manual (and so does in loongarch.h). The
CRC32 feature is set unconditionally now, so fix it.

BTW, expose the CRC32 feature in /proc/cpuinfo.

Cc: stable@vger.kernel.org
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
LoongArch: Check unwind_error() in arch_stack_walk() 2023-04-26T12:30:03+00:00 Tiezhu Yang yangtiezhu@loongson.cn 2023-04-19T04:07:27+00:00 f6711d9a35e77754ce80e6095c4055c00443b7e2 commit 370a3b8f58743eceb97c5256538d6048c26d2d03 upstream. We can see the following messages with CONFIG_PROVE_LOCKING=y on LoongArch: BUG: MAX_STACK_TRACE_ENTRIES too low! turning off the locking correctness validator. This is because stack_trace_save() returns a big value after call arch_stack_walk(), here is the call trace: save_trace() stack_trace_save() arch_stack_walk() stack_trace_consume_entry() arch_stack_walk() should return immediately if unwind_next_frame() failed, no need to do the useless loops to increase the value of c->len in stack_trace_consume_entry(), then we can fix the above problem. Cc: stable@vger.kernel.org Reported-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/all/8a44ad71-68d2-4926-892f-72bfc7a67e2a@roeck-us.net/ Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 370a3b8f58743eceb97c5256538d6048c26d2d03 upstream.

We can see the following messages with CONFIG_PROVE_LOCKING=y on
LoongArch:

  BUG: MAX_STACK_TRACE_ENTRIES too low!
  turning off the locking correctness validator.

This is because stack_trace_save() returns a big value after call
arch_stack_walk(), here is the call trace:

  save_trace()
    stack_trace_save()
      arch_stack_walk()
        stack_trace_consume_entry()

arch_stack_walk() should return immediately if unwind_next_frame()
failed, no need to do the useless loops to increase the value of c->len
in stack_trace_consume_entry(), then we can fix the above problem.

Cc: stable@vger.kernel.org
Reported-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/all/8a44ad71-68d2-4926-892f-72bfc7a67e2a@roeck-us.net/
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
LoongArch: module: set section addresses to 0x0 2023-04-26T12:30:02+00:00 Huacai Chen chenhuacai@loongson.cn 2023-04-18T11:38:58+00:00 1ec1e1dcb2d84e2497c1800765809ce2223edb80 commit 93eb1215ed794a18ba8753e0654f069d58838966 upstream. These got*, plt* and .text.ftrace_trampoline sections specified for LoongArch have non-zero addressses. Non-zero section addresses in a relocatable ELF would confuse GDB when it tries to compute the section offsets and it ends up printing wrong symbol addresses. Therefore, set them to zero, which mirrors the change in commit 5d8591bc0fbaeb6ded ("arm64 module: set plt* section addresses to 0x0"). Cc: stable@vger.kernel.org Reviewed-by: Guo Ren <guoren@kernel.org> Signed-off-by: Chong Qiao <qiaochong@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 93eb1215ed794a18ba8753e0654f069d58838966 upstream.

These got*, plt* and .text.ftrace_trampoline sections specified for
LoongArch have non-zero addressses. Non-zero section addresses in a
relocatable ELF would confuse GDB when it tries to compute the section
offsets and it ends up printing wrong symbol addresses. Therefore, set
them to zero, which mirrors the change in commit 5d8591bc0fbaeb6ded
("arm64 module: set plt* section addresses to 0x0").

Cc: stable@vger.kernel.org
Reviewed-by: Guo Ren <guoren@kernel.org>
Signed-off-by: Chong Qiao <qiaochong@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>