linux-stable.git/arch/powerpc/kernel/Makefile, branch v5.10.78 Linux kernel stable tree powerpc: Avoid broken GCC __attribute__((optimize)) 2020-12-30T10:53:15+00:00 Ard Biesheuvel ardb@kernel.org 2020-10-28T08:04:33+00:00 b1a0097b8298f03e5885fa580053520435fd3209 [ Upstream commit a7223f5bfcaeade4a86d35263493bcda6c940891 ] 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 <ardb@kernel.org> [mpe: Drop one remaining use of __nostackprotector, reported by snowpatch] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201028080433.26799-1-ardb@kernel.org Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit a7223f5bfcaeade4a86d35263493bcda6c940891 ]

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 <ardb@kernel.org>
[mpe: Drop one remaining use of __nostackprotector, reported by snowpatch]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201028080433.26799-1-ardb@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
powerpc/32s: Rename head_32.S to head_book3s_32.S 2020-10-08T10:17:14+00:00 Christophe Leroy christophe.leroy@csgroup.eu 2020-10-06T09:05:26+00:00 533090e5a980ad80bbe0961b4ed45a9bcf55cc0c 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 <christophe.leroy@csgroup.eu> [mpe: Fix head_$(BITS).o reference in arch/powerpc/Makefile] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/319d379f696412681c66a987cc75e6abf8f958d2.1601975100.git.christophe.leroy@csgroup.eu 
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 <christophe.leroy@csgroup.eu>
[mpe: Fix head_$(BITS).o reference in arch/powerpc/Makefile]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/319d379f696412681c66a987cc75e6abf8f958d2.1601975100.git.christophe.leroy@csgroup.eu
powerpc/watchpoint: Move DAWR detection logic outside of hw_breakpoint.c 2020-09-15T12:13:19+00:00 Ravi Bangoria ravi.bangoria@linux.ibm.com 2020-09-02T04:29:41+00:00 edc8dd99b29e4d705c45e2a3a6c01b096ee056db 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 <ravi.bangoria@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200902042945.129369-5-ravi.bangoria@linux.ibm.com 
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 <ravi.bangoria@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200902042945.129369-5-ravi.bangoria@linux.ibm.com
Merge tag 'kbuild-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild 2020-08-09T21:10:26+00:00 Linus Torvalds torvalds@linux-foundation.org 2020-08-09T21:10:26+00:00 fc80c51fd4b23ec007e88d4c688f2cac1b8648e7 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 
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
powerpc/pseries: Add KVM guest doorbell restrictions 2020-07-29T11:02:10+00:00 Nicholas Piggin npiggin@gmail.com 2020-07-26T03:51:55+00:00 107c55005fbd5243ee31fb13b6f166cde9e3ade1 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 <npiggin@gmail.com> Tested-by: Cédric Le Goater <clg@kaod.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200726035155.1424103-4-npiggin@gmail.com 
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 <npiggin@gmail.com>
Tested-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200726035155.1424103-4-npiggin@gmail.com
powerpc/eeh: Remove eeh_dev.c 2020-07-26T13:34:20+00:00 Oliver O'Halloran oohall@gmail.com 2020-07-25T08:12:19+00:00 d74ee8e9d12e2071014ecec96a1ce2744f77639d 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 <oohall@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200725081231.39076-2-oohall@gmail.com 
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 <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200725081231.39076-2-oohall@gmail.com
kbuild: remove cc-option test of -fno-stack-protector 2020-07-07T02:13:10+00:00 Masahiro Yamada masahiroy@kernel.org 2020-06-26T18:59:12+00:00 893ab00439a45513cae55781fc8e3b7108ee1cda 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 <masahiroy@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> 
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 <masahiroy@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
powerpc/64s: Disable sanitisers for C syscall/interrupt entry/exit code 2020-05-29T11:12:09+00:00 Daniel Axtens dja@axtens.net 2020-05-29T06:14:46+00:00 2f26ed1764b42a8c40d9c48441c73a70d805decf syzkaller is picking up a bunch of crashes that look like this: Unrecoverable exception 380 at c00000000037ed60 (msr=8000000000001031) Oops: Unrecoverable exception, sig: 6 [#1] LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries Modules linked in: CPU: 0 PID: 874 Comm: syz-executor.0 Not tainted 5.7.0-rc7-syzkaller-00016-gb0c3ba31be3e #0 NIP: c00000000037ed60 LR: c00000000004bac8 CTR: c000000000030990 REGS: c0000000555a7230 TRAP: 0380 Not tainted (5.7.0-rc7-syzkaller-00016-gb0c3ba31be3e) MSR: 8000000000001031 <SF,ME,IR,DR,LE> CR: 48222882 XER: 20000000 CFAR: c00000000004bac4 IRQMASK: 0 GPR00: c00000000004bb68 c0000000555a74c0 c0000000024b3500 0000000000000005 GPR04: 0000000000000000 0000000000000000 c00000000004bb88 c008000000910000 GPR08: 00000000000b0000 c00000000004bac8 0000000000016000 c000000002503500 GPR12: c000000000030990 c000000003190000 00000000106a5898 00000000106a0000 GPR16: 00000000106a5890 c000000007a92000 c000000008180e00 c000000007a8f700 GPR20: c000000007a904b0 0000000010110000 c00000000259d318 5deadbeef0000100 GPR24: 5deadbeef0000122 c000000078422700 c000000009ee88b8 c000000078422778 GPR28: 0000000000000001 800000000280b033 0000000000000000 c0000000555a75a0 NIP [c00000000037ed60] __sanitizer_cov_trace_pc+0x40/0x50 LR [c00000000004bac8] interrupt_exit_kernel_prepare+0x118/0x310 Call Trace: [c0000000555a74c0] [c00000000004bb68] interrupt_exit_kernel_prepare+0x1b8/0x310 (unreliable) [c0000000555a7530] [c00000000000f9a8] interrupt_return+0x118/0x1c0 --- interrupt: 900 at __sanitizer_cov_trace_pc+0x0/0x50 ...<random previous call chain>... This is caused by __sanitizer_cov_trace_pc() causing an SLB fault after MSR[RI] has been cleared by __hard_EE_RI_disable(), which we can not recover from. Do not instrument the new syscall/interrupt entry/exit code with KCOV, GCOV or UBSAN. Reported-by: syzbot-ppc64 <ozlabsyz@au1.ibm.com> Fixes: 68b34588e202 ("powerpc/64/sycall: Implement syscall entry/exit logic in C") Signed-off-by: Daniel Axtens <dja@axtens.net> Acked-by: Andrew Donnellan <ajd@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> 
syzkaller is picking up a bunch of crashes that look like this:

  Unrecoverable exception 380 at c00000000037ed60 (msr=8000000000001031)
  Oops: Unrecoverable exception, sig: 6 [#1]
  LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries
  Modules linked in:
  CPU: 0 PID: 874 Comm: syz-executor.0 Not tainted 5.7.0-rc7-syzkaller-00016-gb0c3ba31be3e #0
  NIP:  c00000000037ed60 LR: c00000000004bac8 CTR: c000000000030990
  REGS: c0000000555a7230 TRAP: 0380   Not tainted  (5.7.0-rc7-syzkaller-00016-gb0c3ba31be3e)
  MSR:  8000000000001031 <SF,ME,IR,DR,LE>  CR: 48222882  XER: 20000000
  CFAR: c00000000004bac4 IRQMASK: 0
  GPR00: c00000000004bb68 c0000000555a74c0 c0000000024b3500 0000000000000005
  GPR04: 0000000000000000 0000000000000000 c00000000004bb88 c008000000910000
  GPR08: 00000000000b0000 c00000000004bac8 0000000000016000 c000000002503500
  GPR12: c000000000030990 c000000003190000 00000000106a5898 00000000106a0000
  GPR16: 00000000106a5890 c000000007a92000 c000000008180e00 c000000007a8f700
  GPR20: c000000007a904b0 0000000010110000 c00000000259d318 5deadbeef0000100
  GPR24: 5deadbeef0000122 c000000078422700 c000000009ee88b8 c000000078422778
  GPR28: 0000000000000001 800000000280b033 0000000000000000 c0000000555a75a0
  NIP [c00000000037ed60] __sanitizer_cov_trace_pc+0x40/0x50
  LR [c00000000004bac8] interrupt_exit_kernel_prepare+0x118/0x310
  Call Trace:
  [c0000000555a74c0] [c00000000004bb68] interrupt_exit_kernel_prepare+0x1b8/0x310 (unreliable)
  [c0000000555a7530] [c00000000000f9a8] interrupt_return+0x118/0x1c0
  --- interrupt: 900 at __sanitizer_cov_trace_pc+0x0/0x50
  ...<random previous call chain>...

This is caused by __sanitizer_cov_trace_pc() causing an SLB fault
after MSR[RI] has been cleared by __hard_EE_RI_disable(), which we
can not recover from.

Do not instrument the new syscall/interrupt entry/exit code with KCOV,
GCOV or UBSAN.

Reported-by: syzbot-ppc64 <ozlabsyz@au1.ibm.com>
Fixes: 68b34588e202 ("powerpc/64/sycall: Implement syscall entry/exit logic in C")
Signed-off-by: Daniel Axtens <dja@axtens.net>
Acked-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
powerpc/64: make buildable without CONFIG_COMPAT 2020-04-02T13:10:00+00:00 Michal Suchanek msuchanek@suse.de 2020-03-20T10:20:16+00:00 0a7601b6ffddec11d7cc0bc3264daf0159f5e1a6 There are numerous references to 32bit functions in generic and 64bit code so ifdef them out. Signed-off-by: Michal Suchanek <msuchanek@suse.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/e5619617020ef3a1f54f0c076e7d74cb9ec9f3bf.1584699455.git.msuchanek@suse.de 
There are numerous references to 32bit functions in generic and 64bit
code so ifdef them out.

Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/e5619617020ef3a1f54f0c076e7d74cb9ec9f3bf.1584699455.git.msuchanek@suse.de
powerpc: Move ptrace into a subdirectory. 2020-04-01T03:30:41+00:00 Christophe Leroy christophe.leroy@c-s.fr 2020-02-28T00:14:37+00:00 da9a1c10e2c7311e923210b6ccd9fbd1ac9132df In order to allow splitting of ptrace depending on the different CONFIG_ options, create a subdirectory dedicated to ptrace and move ptrace.c and ptrace32.c into it. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/9ebcbe37834e9d447dd97f4381084795a673260c.1582848567.git.christophe.leroy@c-s.fr 
In order to allow splitting of ptrace depending on the different
CONFIG_ options, create a subdirectory dedicated to ptrace and move
ptrace.c and ptrace32.c into it.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/9ebcbe37834e9d447dd97f4381084795a673260c.1582848567.git.christophe.leroy@c-s.fr