[ Upstream commit 33bc69cf66 ]
VFIO EEH recovery for PCI passthrough devices fails on PowerNV and pseries
platforms due to missing host-side PE bridge reconfiguration. In the
current implementation, eeh_pe_configure() only performs RTAS or OPAL-based
bridge reconfiguration for native host devices, but skips it entirely for
PEs managed through VFIO in guest passthrough scenarios.
This leads to incomplete EEH recovery when a PCI error affects a
passthrough device assigned to a QEMU/KVM guest. Although VFIO triggers the
EEH recovery flow through VFIO_EEH_PE_ENABLE ioctl, the platform-specific
bridge reconfiguration step is silently bypassed. As a result, the PE's
config space is not fully restored, causing subsequent config space access
failures or EEH freeze-on-access errors inside the guest.
This patch fixes the issue by ensuring that eeh_pe_configure() always
invokes the platform's configure_bridge() callback (e.g.,
pseries_eeh_phb_configure_bridge) even for VFIO-managed PEs. This ensures
that RTAS or OPAL calls to reconfigure the PE bridge are correctly issued
on the host side, restoring the PE's configuration space after an EEH
event.
This fix is essential for reliable EEH recovery in QEMU/KVM guests using
VFIO PCI passthrough on PowerNV and pseries systems.
Tested with:
- QEMU/KVM guest using VFIO passthrough (IBM Power9,(lpar)Power11 host)
- Injected EEH errors with pseries EEH errinjct tool on host, recovery
verified on qemu guest.
- Verified successful config space access and CAP_EXP DevCtl restoration
after recovery
Fixes: 212d16cdca ("powerpc/eeh: EEH support for VFIO PCI device")
Signed-off-by: Narayana Murty N <nnmlinux@linux.ibm.com>
Reviewed-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Reviewed-by: Ganesh Goudar <ganeshgr@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20250508062928.146043-1-nnmlinux@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit cf89c9434a ]
On some powermacs `escc` nodes are missing `#size-cells` properties,
which is deprecated and now triggers a warning at boot since commit
045b14ca5c ("of: WARN on deprecated #address-cells/#size-cells
handling").
For example:
Missing '#size-cells' in /pci@f2000000/mac-io@c/escc@13000
WARNING: CPU: 0 PID: 0 at drivers/of/base.c:133 of_bus_n_size_cells+0x98/0x108
Hardware name: PowerMac3,1 7400 0xc0209 PowerMac
...
Call Trace:
of_bus_n_size_cells+0x98/0x108 (unreliable)
of_bus_default_count_cells+0x40/0x60
__of_get_address+0xc8/0x21c
__of_address_to_resource+0x5c/0x228
pmz_init_port+0x5c/0x2ec
pmz_probe.isra.0+0x144/0x1e4
pmz_console_init+0x10/0x48
console_init+0xcc/0x138
start_kernel+0x5c4/0x694
As powermacs boot via prom_init it's possible to add the missing
properties to the device tree during boot, avoiding the warning. Note
that `escc-legacy` nodes are also missing `#size-cells` properties, but
they are skipped by the macio driver, so leave them alone.
Depends-on: 045b14ca5c ("of: WARN on deprecated #address-cells/#size-cells handling")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20241126025710.591683-1-mpe@ellerman.id.au
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit d677ce5213 ]
Under certain conditions, the 64-bit '-mstack-protector-guard' flags may
end up in the 32-bit vDSO flags, resulting in build failures due to the
structure of clang's argument parsing of the stack protector options,
which validates the arguments of the stack protector guard flags
unconditionally in the frontend, choking on the 64-bit values when
targeting 32-bit:
clang: error: invalid value 'r13' in 'mstack-protector-guard-reg=', expected one of: r2
clang: error: invalid value 'r13' in 'mstack-protector-guard-reg=', expected one of: r2
make[3]: *** [arch/powerpc/kernel/vdso/Makefile:85: arch/powerpc/kernel/vdso/vgettimeofday-32.o] Error 1
make[3]: *** [arch/powerpc/kernel/vdso/Makefile:87: arch/powerpc/kernel/vdso/vgetrandom-32.o] Error 1
Remove these flags by adding them to the CC32FLAGSREMOVE variable, which
already handles situations similar to this. Additionally, reformat and
align a comment better for the expanding CONFIG_CC_IS_CLANG block.
Cc: stable@vger.kernel.org # v6.1+
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://patch.msgid.link/20241030-powerpc-vdso-drop-stackp-flags-clang-v1-1-d95e7376d29c@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit a6b67eb099 ]
In order to avoid two much duplication when we add new VDSO
functionnalities in C like getrandom, refactor common CFLAGS.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Stable-dep-of: d677ce5213 ("powerpc/vdso: Drop -mstack-protector-guard flags in 32-bit files with clang")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit a7e5eb53bf ]
A future change will move CLANG_FLAGS from KBUILD_{A,C}FLAGS to
KBUILD_CPPFLAGS so that '--target' is available while preprocessing.
When that occurs, the following error appears when building the compat
PowerPC vDSO:
clang: error: unsupported option '-mbig-endian' for target 'x86_64-pc-linux-gnu'
make[3]: *** [.../arch/powerpc/kernel/vdso/Makefile:76: arch/powerpc/kernel/vdso/vdso32.so.dbg] Error 1
Explicitly add CLANG_FLAGS to ldflags-y, so that '--target' will always
be present.
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Stable-dep-of: d677ce5213 ("powerpc/vdso: Drop -mstack-protector-guard flags in 32-bit files with clang")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 05e05bfc92 ]
When clang's -Qunused-arguments is dropped from KBUILD_CPPFLAGS, it
warns:
clang-16: error: argument unused during compilation: '-fno-stack-clash-protection' [-Werror,-Wunused-command-line-argument]
This warning happens because vgettimeofday-32.c gets its base CFLAGS
from the main kernel, which may contain flags that are only supported on
a 64-bit target but not a 32-bit one, which is the case here.
-fstack-clash-protection and its negation are only suppported by the
64-bit powerpc target but that flag is included in an invocation for a
32-bit powerpc target, so clang points out that while the flag is one
that it recognizes, it is not actually used by this compiler job.
To eliminate the warning, remove -fno-stack-clash-protection from
vgettimeofday-32.c's CFLAGS when using clang, as has been done for other
flags previously.
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
Tested-by: Anders Roxell <anders.roxell@linaro.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Stable-dep-of: d677ce5213 ("powerpc/vdso: Drop -mstack-protector-guard flags in 32-bit files with clang")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit f0a42fbab4 ]
When clang's -Qunused-arguments is dropped from KBUILD_CPPFLAGS, there
are several warnings in the PowerPC vDSO:
clang-16: error: -Wl,-soname=linux-vdso32.so.1: 'linker' input unused [-Werror,-Wunused-command-line-argument]
clang-16: error: -Wl,--hash-style=both: 'linker' input unused [-Werror,-Wunused-command-line-argument]
clang-16: error: argument unused during compilation: '-shared' [-Werror,-Wunused-command-line-argument]
clang-16: error: argument unused during compilation: '-nostdinc' [-Werror,-Wunused-command-line-argument]
clang-16: error: argument unused during compilation: '-Wa,-maltivec' [-Werror,-Wunused-command-line-argument]
The first group of warnings point out that linker flags were being added
to all invocations of $(CC), even though they will only be used during
the final vDSO link. Move those flags to ldflags-y.
The second group of warnings are compiler or assembler flags that will
be unused during linking. Filter them out from KBUILD_CFLAGS so that
they are not used during linking.
Additionally, '-z noexecstack' was added directly to the ld_and_check
rule in commit 1d53c0192b ("powerpc/vdso: link with -z noexecstack")
but now that there is a common ldflags variable, it can be moved there.
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
Tested-by: Anders Roxell <anders.roxell@linaro.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Stable-dep-of: d677ce5213 ("powerpc/vdso: Drop -mstack-protector-guard flags in 32-bit files with clang")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 024734d132 ]
When clang's -Qunused-arguments is dropped from KBUILD_CPPFLAGS, it
warns:
clang-16: error: argument unused during compilation: '-s' [-Werror,-Wunused-command-line-argument]
The compiler's '-s' flag is a linking option (it is passed along to the
linker directly), which means it does nothing when the linker is not
invoked by the compiler. The kernel builds all .o files with '-c', which
stops the compilation pipeline before linking, so '-s' can be safely
dropped from ASFLAGS.
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Segher Boessenkool <segher@kernel.crashing.org>
Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
Tested-by: Anders Roxell <anders.roxell@linaro.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Stable-dep-of: d677ce5213 ("powerpc/vdso: Drop -mstack-protector-guard flags in 32-bit files with clang")
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 44e5d21e6d upstream.
As per the kernel documentation[1], hardlockup detector should
be disabled in KVM guests as it may give false positives. On
PPC, hardlockup detector is enabled inside KVM guests because
disable_hardlockup_detector() is marked as early_initcall and it
relies on kvm_guest static key (is_kvm_guest()) which is initialized
later during boot by check_kvm_guest(), which is a core_initcall.
check_kvm_guest() is also called in pSeries_smp_probe(), which is called
before initcalls, but it is skipped if KVM guest does not have doorbell
support or if the guest is launched with SMT=1.
Call check_kvm_guest() in disable_hardlockup_detector() so that
is_kvm_guest() check goes through fine and hardlockup detector can be
disabled inside the KVM guest.
[1]: Documentation/admin-guide/sysctl/kernel.rst
Fixes: 633c8e9800 ("powerpc/pseries: Enable hardlockup watchdog for PowerVM partitions")
Cc: stable@vger.kernel.org # v5.14+
Signed-off-by: Gautam Menghani <gautam@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://patch.msgid.link/20241108094839.33084-1-gautam@linux.ibm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 05b94cae1c ]
During early init CMA_MIN_ALIGNMENT_BYTES can be PAGE_SIZE,
since pageblock_order is still zero and it gets initialized
later during initmem_init() e.g.
setup_arch() -> initmem_init() -> sparse_init() -> set_pageblock_order()
One such use case where this causes issue is -
early_setup() -> early_init_devtree() -> fadump_reserve_mem() -> fadump_cma_init()
This causes CMA memory alignment check to be bypassed in
cma_init_reserved_mem(). Then later cma_activate_area() can hit
a VM_BUG_ON_PAGE(pfn & ((1 << order) - 1)) if the reserved memory
area was not pageblock_order aligned.
Fix it by moving the fadump_cma_init() after initmem_init(),
where other such cma reservations also gets called.
<stack trace>
==============
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10010
flags: 0x13ffff800000000(node=1|zone=0|lastcpupid=0x7ffff) CMA
raw: 013ffff800000000 5deadbeef0000100 5deadbeef0000122 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: VM_BUG_ON_PAGE(pfn & ((1 << order) - 1))
------------[ cut here ]------------
kernel BUG at mm/page_alloc.c:778!
Call Trace:
__free_one_page+0x57c/0x7b0 (unreliable)
free_pcppages_bulk+0x1a8/0x2c8
free_unref_page_commit+0x3d4/0x4e4
free_unref_page+0x458/0x6d0
init_cma_reserved_pageblock+0x114/0x198
cma_init_reserved_areas+0x270/0x3e0
do_one_initcall+0x80/0x2f8
kernel_init_freeable+0x33c/0x530
kernel_init+0x34/0x26c
ret_from_kernel_user_thread+0x14/0x1c
Fixes: 11ac3e87ce ("mm: cma: use pageblock_order as the single alignment")
Suggested-by: David Hildenbrand <david@redhat.com>
Reported-by: Sachin P Bappalige <sachinpb@linux.ibm.com>
Acked-by: Hari Bathini <hbathini@linux.ibm.com>
Reviewed-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://patch.msgid.link/3ae208e48c0d9cefe53d2dc4f593388067405b7d.1729146153.git.ritesh.list@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit adfaec30ff ]
We anyway don't use any return values from fadump_cma_init(). Since
fadump_reserve_mem() from where fadump_cma_init() gets called today,
already has the required checks.
This patch makes this function return type as void. Let's also handle
extra cases like return if fadump_supported is false or dump_active, so
that in later patches we can call fadump_cma_init() separately from
setup_arch().
Acked-by: Hari Bathini <hbathini@linux.ibm.com>
Reviewed-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://patch.msgid.link/a2afc3d6481a87a305e89cfc4a3f3d2a0b8ceab3.1729146153.git.ritesh.list@gmail.com
Stable-dep-of: 05b94cae1c ("powerpc/fadump: Move fadump_cma_init to setup_arch() after initmem_init()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit c73049389e ]
When running in a non-root time namespace, the global VDSO data page
is replaced by a dedicated namespace data page and the global data
page is mapped next to it. Detailed explanations can be found at
commit 660fd04f93 ("lib/vdso: Prepare for time namespace support").
When it happens, __kernel_get_syscall_map and __kernel_get_tbfreq
and __kernel_sync_dicache don't work anymore because they read 0
instead of the data they need.
To address that, clock_mode has to be read. When it is set to
VDSO_CLOCKMODE_TIMENS, it means it is a dedicated namespace data page
and the global data is located on the following page.
Add a macro called get_realdatapage which reads clock_mode and add
PAGE_SIZE to the pointer provided by get_datapage macro when
clock_mode is equal to VDSO_CLOCKMODE_TIMENS. Use this new macro
instead of get_datapage macro except for time functions as they handle
it internally.
Fixes: 74205b3fc2 ("powerpc/vdso: Add support for time namespaces")
Reported-by: Jason A. Donenfeld <Jason@zx2c4.com>
Closes: https://lore.kernel.org/all/ZtnYqZI-nrsNslwy@zx2c4.com/
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit dc5dac748a ]
Add an option to build kernel and module with prefixed instructions if
the CPU and toolchain support it.
This is not related to kernel support for userspace execution of
prefixed instructions.
Building with prefixed instructions breaks some extended inline asm
memory addressing, for example it will provide immediates that exceed
the range of simple load/store displacement. Whether this is a
toolchain or a kernel asm problem remains to be seen. For now, these
are replaced with simpler and less efficient direct register addressing
when compiling with prefixed.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230408021752.862660-4-npiggin@gmail.com
Stable-dep-of: 39190ac7cf ("powerpc/atomic: Use YZ constraints for DS-form instructions")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 65a82e117f ]
Since commit 9132a2e82a ("powerpc/8xx: Define a MODULE area below
kernel text"), module exec space is below PAGE_OFFSET so not only
space above PAGE_OFFSET, but space above TASK_SIZE need to be seen
as kernel space.
Until now the problem went undetected because by default TASK_SIZE
is 0x8000000 which means address space is determined by just
checking upper address bit. But when TASK_SIZE is over 0x80000000,
PAGE_OFFSET is used for comparison, leading to thinking module
addresses are part of user space.
Fix it by using TASK_SIZE instead of PAGE_OFFSET for address
comparison.
Fixes: 9132a2e82a ("powerpc/8xx: Define a MODULE area below kernel text")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/3f574c9845ff0a023b46cb4f38d2c45aecd769bd.1724173828.git.christophe.leroy@csgroup.eu
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 7bdd1c6c87 ]
cur_cpu_spec->cpu_name is appended to ppc_hw_desc before cur_cpu_spec
has taken on its final value. This is illustrated on pseries by
comparing the CPU name as reported at boot ("POWER8E (raw)") to the
contents of /proc/cpuinfo ("POWER8 (architected)"):
$ dmesg | grep Hardware
Hardware name: IBM,8408-E8E POWER8E (raw) 0x4b0201 0xf000004 \
of:IBM,FW860.50 (SV860_146) hv:phyp pSeries
$ grep -m 1 ^cpu /proc/cpuinfo
cpu : POWER8 (architected), altivec supported
Some 44x models would appear to be affected as well; see
identical_pvr_fixup().
This results in incorrect CPU information in stack dumps --
ppc_hw_desc is an input to dump_stack_set_arch_desc().
Delay gathering the CPU name until after all potential calls to
identify_cpu().
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Fixes: bd649d40e0 ("powerpc: Add PVR & CPU name to hardware description")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240603-fix-cpu-hwdesc-v1-1-945f2850fcaa@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 0db880fc86 ]
nmi_enter()/nmi_exit() touches per cpu variables which can lead to kernel
crash when invoked during real mode interrupt handling (e.g. early HMI/MCE
interrupt handler) if percpu allocation comes from vmalloc area.
Early HMI/MCE handlers are called through DEFINE_INTERRUPT_HANDLER_NMI()
wrapper which invokes nmi_enter/nmi_exit calls. We don't see any issue when
percpu allocation is from the embedded first chunk. However with
CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK enabled there are chances where percpu
allocation can come from the vmalloc area.
With kernel command line "percpu_alloc=page" we can force percpu allocation
to come from vmalloc area and can see kernel crash in machine_check_early:
[ 1.215714] NIP [c000000000e49eb4] rcu_nmi_enter+0x24/0x110
[ 1.215717] LR [c0000000000461a0] machine_check_early+0xf0/0x2c0
[ 1.215719] --- interrupt: 200
[ 1.215720] [c000000fffd73180] [0000000000000000] 0x0 (unreliable)
[ 1.215722] [c000000fffd731b0] [0000000000000000] 0x0
[ 1.215724] [c000000fffd73210] [c000000000008364] machine_check_early_common+0x134/0x1f8
Fix this by avoiding use of nmi_enter()/nmi_exit() in real mode if percpu
first chunk is not embedded.
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Tested-by: Shirisha Ganta <shirisha@linux.ibm.com>
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240410043006.81577-1-mahesh@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit d3882564a7 upstream.
Using sys_io_pgetevents() as the entry point for compat mode tasks
works almost correctly, but misses the sign extension for the min_nr
and nr arguments.
This was addressed on parisc by switching to
compat_sys_io_pgetevents_time64() in commit 6431e92fc8 ("parisc:
io_pgetevents_time64() needs compat syscall in 32-bit compat mode"),
as well as by using more sophisticated system call wrappers on x86 and
s390. However, arm64, mips, powerpc, sparc and riscv still have the
same bug.
Change all of them over to use compat_sys_io_pgetevents_time64()
like parisc already does. This was clearly the intention when the
function was originally added, but it got hooked up incorrectly in
the tables.
Cc: stable@vger.kernel.org
Fixes: 48166e6ea4 ("y2038: add 64-bit time_t syscalls to all 32-bit architectures")
Acked-by: Heiko Carstens <hca@linux.ibm.com> # s390
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit b1e31c134a ]
A couple of system calls were inadventently removed from the table during
a bugfix for 32-bit powerpc entry. Restore the original behavior.
Fixes: e237506238 ("powerpc/32: fix syscall wrappers with 64-bit arguments of unaligned register-pairs")
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit eb6d871f4b upstream.
Commit e320a76db4 ("powerpc/cputable: Split cpu_specs[] out of
cputable.h") moved the cpu_specs to separate header files. Previously
PPC_FEATURE_BOOKE was enabled by CONFIG_PPC_BOOK3E_64. The definition in
cpu_specs_e500mc.h for PPC64 no longer enables PPC_FEATURE_BOOKE.
This breaks user space reading the ELF hwcaps and expect
PPC_FEATURE_BOOKE. Debugging an application with gdb is no longer
working on e5500/e6500 because the 64-bit detection relies on
PPC_FEATURE_BOOKE for Book-E.
Fixes: e320a76db4 ("powerpc/cputable: Split cpu_specs[] out of cputable.h")
Cc: stable@vger.kernel.org # v6.1+
Signed-off-by: David Engraf <david.engraf@sysgo.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240207092758.1058893-1-david.engraf@sysgo.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit aad98efd0b upstream.
Nysal reported that userspace backtraces are missing in offcputime bcc
tool. As an example:
$ sudo ./bcc/tools/offcputime.py -uU
Tracing off-CPU time (us) of user threads by user stack... Hit Ctrl-C to end.
^C
write
- python (9107)
8
write
- sudo (9105)
9
mmap
- python (9107)
16
clock_nanosleep
- multipathd (697)
3001604
The offcputime bcc tool attaches a bpf program to a kprobe on
finish_task_switch(), which is usually hit on a syscall from userspace.
With the switch to system call vectored, we started setting
pt_regs->link to zero. This is because system call vectored behaves like
a function call with LR pointing to the system call return address, and
with no modification to SRR0/SRR1. The LR value does indicate our next
instruction, so it is being saved as pt_regs->nip, and pt_regs->link is
being set to zero. This is not a problem by itself, but BPF uses perf
callchain infrastructure for capturing stack traces, and that stores LR
as the second entry in the stack trace. perf has code to cope with the
second entry being zero, and skips over it. However, generic userspace
unwinders assume that a zero entry indicates end of the stack trace,
resulting in a truncated userspace stack trace.
Rather than fixing all userspace unwinders to ignore/skip past the
second entry, store the real LR value in pt_regs->link so that there
continues to be a valid, though duplicate entry in the stack trace.
With this change:
$ sudo ./bcc/tools/offcputime.py -uU
Tracing off-CPU time (us) of user threads by user stack... Hit Ctrl-C to end.
^C
write
write
[unknown]
[unknown]
[unknown]
[unknown]
[unknown]
PyObject_VectorcallMethod
[unknown]
[unknown]
PyObject_CallOneArg
PyFile_WriteObject
PyFile_WriteString
[unknown]
[unknown]
PyObject_Vectorcall
_PyEval_EvalFrameDefault
PyEval_EvalCode
[unknown]
[unknown]
[unknown]
_PyRun_SimpleFileObject
_PyRun_AnyFileObject
Py_RunMain
[unknown]
Py_BytesMain
[unknown]
__libc_start_main
- python (1293)
7
write
write
[unknown]
sudo_ev_loop_v1
sudo_ev_dispatch_v1
[unknown]
[unknown]
[unknown]
[unknown]
__libc_start_main
- sudo (1291)
7
syscall
syscall
bpf_open_perf_buffer_opts
[unknown]
[unknown]
[unknown]
[unknown]
_PyObject_MakeTpCall
PyObject_Vectorcall
_PyEval_EvalFrameDefault
PyEval_EvalCode
[unknown]
[unknown]
[unknown]
_PyRun_SimpleFileObject
_PyRun_AnyFileObject
Py_RunMain
[unknown]
Py_BytesMain
[unknown]
__libc_start_main
- python (1293)
11
clock_nanosleep
clock_nanosleep
nanosleep
sleep
[unknown]
[unknown]
__clone
- multipathd (698)
3001661
Fixes: 7fa95f9ada ("powerpc/64s: system call support for scv/rfscv instructions")
Cc: stable@vger.kernel.org
Reported-by: "Nysal Jan K.A" <nysal@linux.ibm.com>
Signed-off-by: Naveen N Rao <naveen@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240202154316.395276-1-naveen@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 68fb3ca0e4 upstream.
We've had issues with gcc and 'asm goto' before, and we created a
'asm_volatile_goto()' macro for that in the past: see commits
3f0116c323 ("compiler/gcc4: Add quirk for 'asm goto' miscompilation
bug") and a9f180345f ("compiler/gcc4: Make quirk for
asm_volatile_goto() unconditional").
Then, much later, we ended up removing the workaround in commit
43c249ea0b ("compiler-gcc.h: remove ancient workaround for gcc PR
58670") because we no longer supported building the kernel with the
affected gcc versions, but we left the macro uses around.
Now, Sean Christopherson reports a new version of a very similar
problem, which is fixed by re-applying that ancient workaround. But the
problem in question is limited to only the 'asm goto with outputs'
cases, so instead of re-introducing the old workaround as-is, let's
rename and limit the workaround to just that much less common case.
It looks like there are at least two separate issues that all hit in
this area:
(a) some versions of gcc don't mark the asm goto as 'volatile' when it
has outputs:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98619https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110420
which is easy to work around by just adding the 'volatile' by hand.
(b) Internal compiler errors:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110422
which are worked around by adding the extra empty 'asm' as a
barrier, as in the original workaround.
but the problem Sean sees may be a third thing since it involves bad
code generation (not an ICE) even with the manually added 'volatile'.
The same old workaround works for this case, even if this feels a
bit like voodoo programming and may only be hiding the issue.
Reported-and-tested-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/all/20240208220604.140859-1-seanjc@google.com/
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Uros Bizjak <ubizjak@gmail.com>
Cc: Jakub Jelinek <jakub@redhat.com>
Cc: Andrew Pinski <quic_apinski@quicinc.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit f8d3555355 ]
With CONFIG_GENERIC_BUG=n the build fails with:
arch/powerpc/kernel/traps.c:1442:5: error: no previous prototype for ‘is_valid_bugaddr’ [-Werror=missing-prototypes]
1442 | int is_valid_bugaddr(unsigned long addr)
| ^~~~~~~~~~~~~~~~
The prototype is only defined, and the function is only needed, when
CONFIG_GENERIC_BUG=y, so move the implementation under that.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231130114433.3053544-2-mpe@ellerman.id.au
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 4b3338aaa7 ]
Commit 41a506ef71 ("powerpc/ftrace: Create a dummy stackframe to fix
stack unwind") added use of a new stack frame on ftrace entry to fix
stack unwind. However, the commit missed updating the offset used while
tearing down the ftrace stack when ftrace is disabled. Fix the same.
In addition, the commit missed saving the correct stack pointer in
pt_regs. Update the same.
Fixes: 41a506ef71 ("powerpc/ftrace: Create a dummy stackframe to fix stack unwind")
Cc: stable@vger.kernel.org # v6.5+
Signed-off-by: Naveen N Rao <naveen@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231130065947.2188860-1-naveen@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 5e1d824f9a upstream.
During floating point and vector save to thread data f0/vs0 are
clobbered by the FPSCR/VSCR store routine. This has been obvserved to
lead to userspace register corruption and application data corruption
with io-uring.
Fix it by restoring f0/vs0 after FPSCR/VSCR store has completed for
all the FP, altivec, VMX register save paths.
Tested under QEMU in kvm mode, running on a Talos II workstation with
dual POWER9 DD2.2 CPUs.
Additional detail (mpe):
Typically save_fpu() is called from __giveup_fpu() which saves the FP
regs and also *turns off FP* in the tasks MSR, meaning the kernel will
reload the FP regs from the thread struct before letting the task use FP
again. So in that case save_fpu() is free to clobber f0 because the FP
regs no longer hold live values for the task.
There is another case though, which is the path via:
sys_clone()
...
copy_process()
dup_task_struct()
arch_dup_task_struct()
flush_all_to_thread()
save_all()
That path saves the FP regs but leaves them live. That's meant as an
optimisation for a process that's using FP/VSX and then calls fork(),
leaving the regs live means the parent process doesn't have to take a
fault after the fork to get its FP regs back. The optimisation was added
in commit 8792468da5 ("powerpc: Add the ability to save FPU without
giving it up").
That path does clobber f0, but f0 is volatile across function calls,
and typically programs reach copy_process() from userspace via a syscall
wrapper function. So in normal usage f0 being clobbered across a
syscall doesn't cause visible data corruption.
But there is now a new path, because io-uring can call copy_process()
via create_io_thread() from the signal handling path. That's OK if the
signal is handled as part of syscall return, but it's not OK if the
signal is handled due to some other interrupt.
That path is:
interrupt_return_srr_user()
interrupt_exit_user_prepare()
interrupt_exit_user_prepare_main()
do_notify_resume()
get_signal()
task_work_run()
create_worker_cb()
create_io_worker()
copy_process()
dup_task_struct()
arch_dup_task_struct()
flush_all_to_thread()
save_all()
if (tsk->thread.regs->msr & MSR_FP)
save_fpu()
# f0 is clobbered and potentially live in userspace
Note the above discussion applies equally to save_altivec().
Fixes: 8792468da5 ("powerpc: Add the ability to save FPU without giving it up")
Cc: stable@vger.kernel.org # v4.6+
Closes: https://lore.kernel.org/all/480932026.45576726.1699374859845.JavaMail.zimbra@raptorengineeringinc.com/
Closes: https://lore.kernel.org/linuxppc-dev/480221078.47953493.1700206777956.JavaMail.zimbra@raptorengineeringinc.com/
Tested-by: Timothy Pearson <tpearson@raptorengineering.com>
Tested-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Timothy Pearson <tpearson@raptorengineering.com>
[mpe: Reword change log to describe exact path of corruption & other minor tweaks]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/1921539696.48534988.1700407082933.JavaMail.zimbra@raptorengineeringinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit dc158d23b3 upstream.
Before running a guest, the host process (e.g., QEMU) FP/VEC registers
are saved if they were being used, similarly to when the kernel uses FP
registers. The guest values are then loaded into regs, and the host
process registers will be restored lazily when it uses FP/VEC.
KVM HV has a bug here: the host process registers do get saved, but the
user MSR bits remain enabled, which indicates the registers are valid
for the process. After they are clobbered by running the guest, this
valid indication causes the host process to take on the FP/VEC register
values of the guest.
Fixes: 34e119c96b ("KVM: PPC: Book3S HV P9: Reduce mtmsrd instructions required to save host SPRs")
Cc: stable@vger.kernel.org # v5.17+
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231122025811.2973-1-npiggin@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit daa9ada209 ]
Erhard reported that his G5 was crashing with v6.6-rc kernels:
mpic: Setting up HT PICs workarounds for U3/U4
BUG: Unable to handle kernel data access at 0xfeffbb62ffec65fe
Faulting instruction address: 0xc00000000005dc40
Oops: Kernel access of bad area, sig: 11 [#1]
BE PAGE_SIZE=4K MMU=Hash SMP NR_CPUS=2 PowerMac
Modules linked in:
CPU: 0 PID: 0 Comm: swapper/0 Tainted: G T 6.6.0-rc3-PMacGS #1
Hardware name: PowerMac11,2 PPC970MP 0x440101 PowerMac
NIP: c00000000005dc40 LR: c000000000066660 CTR: c000000000007730
REGS: c0000000022bf510 TRAP: 0380 Tainted: G T (6.6.0-rc3-PMacGS)
MSR: 9000000000001032 <SF,HV,ME,IR,DR,RI> CR: 44004242 XER: 00000000
IRQMASK: 3
GPR00: 0000000000000000 c0000000022bf7b0 c0000000010c0b00 00000000000001ac
GPR04: 0000000003c80000 0000000000000300 c0000000f20001ae 0000000000000300
GPR08: 0000000000000006 feffbb62ffec65ff 0000000000000001 0000000000000000
GPR12: 9000000000001032 c000000002362000 c000000000f76b80 000000000349ecd8
GPR16: 0000000002367ba8 0000000002367f08 0000000000000006 0000000000000000
GPR20: 00000000000001ac c000000000f6f920 c0000000022cd985 000000000000000c
GPR24: 0000000000000300 00000003b0a3691d c0003e008030000e 0000000000000000
GPR28: c00000000000000c c0000000f20001ee feffbb62ffec65fe 00000000000001ac
NIP hash_page_do_lazy_icache+0x50/0x100
LR __hash_page_4K+0x420/0x590
Call Trace:
hash_page_mm+0x364/0x6f0
do_hash_fault+0x114/0x2b0
data_access_common_virt+0x198/0x1f0
--- interrupt: 300 at mpic_init+0x4bc/0x10c4
NIP: c000000002020a5c LR: c000000002020a04 CTR: 0000000000000000
REGS: c0000000022bf9f0 TRAP: 0300 Tainted: G T (6.6.0-rc3-PMacGS)
MSR: 9000000000001032 <SF,HV,ME,IR,DR,RI> CR: 24004248 XER: 00000000
DAR: c0003e008030000e DSISR: 40000000 IRQMASK: 1
...
NIP mpic_init+0x4bc/0x10c4
LR mpic_init+0x464/0x10c4
--- interrupt: 300
pmac_setup_one_mpic+0x258/0x2dc
pmac_pic_init+0x28c/0x3d8
init_IRQ+0x90/0x140
start_kernel+0x57c/0x78c
start_here_common+0x1c/0x20
A bisect pointed to the breakage beginning with commit 9fee28baa6 ("powerpc:
implement the new page table range API").
Analysis of the oops pointed to a struct page with a corrupted
compound_head being loaded via page_folio() -> _compound_head() in
hash_page_do_lazy_icache().
The access by the mpic code is to an MMIO address, so the expectation
is that the struct page for that address would be initialised by
init_unavailable_range(), as pointed out by Aneesh.
Instrumentation showed that was not the case, which eventually lead to
the realisation that pfn_valid() was returning false for that address,
causing the struct page to not be initialised.
Because the system is using FLATMEM, the version of pfn_valid() in
memory_model.h is used:
static inline int pfn_valid(unsigned long pfn)
{
...
return pfn >= pfn_offset && (pfn - pfn_offset) < max_mapnr;
}
Which relies on max_mapnr being initialised. Early in boot max_mapnr is
zero meaning no PFNs are valid.
max_mapnr is initialised in mem_init() called via:
start_kernel()
mm_core_init() # init/main.c:928
mem_init()
But that is too late for the usage in init_unavailable_range() called via:
start_kernel()
setup_arch() # init/main.c:893
paging_init()
free_area_init()
init_unavailable_range()
Although max_mapnr is currently set in mem_init(), the value is actually
already available much earlier, as soon as mem_topology_setup() has
completed, which is also before paging_init() is called. So move the
initialisation there, which causes paging_init() to correctly initialise
the struct page and fixes the bug.
This bug seems to have been lurking for years, but went unnoticed
because the pre-folio code was inspecting the uninitialised page->flags
but not dereferencing it.
Thanks to Erhard and Aneesh for help debugging.
Reported-by: Erhard Furtner <erhard_f@mailbox.org>
Closes: https://lore.kernel.org/all/20230929132750.3cd98452@yea/
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231023112500.1550208-1-mpe@ellerman.id.au
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit f0eee815ba upstream.
Eddie reported that newer kernels were crashing during boot on his 476
FSP2 system:
kernel tried to execute user page (b7ee2000) - exploit attempt? (uid: 0)
BUG: Unable to handle kernel instruction fetch
Faulting instruction address: 0xb7ee2000
Oops: Kernel access of bad area, sig: 11 [#1]
BE PAGE_SIZE=4K FSP-2
Modules linked in:
CPU: 0 PID: 61 Comm: mount Not tainted 6.1.55-d23900f.ppcnf-fsp2 #1
Hardware name: ibm,fsp2 476fpe 0x7ff520c0 FSP-2
NIP: b7ee2000 LR: 8c008000 CTR: 00000000
REGS: bffebd83 TRAP: 0400 Not tainted (6.1.55-d23900f.ppcnf-fs p2)
MSR: 00000030 <IR,DR> CR: 00001000 XER: 20000000
GPR00: c00110ac bffebe63 bffebe7e bffebe88 8c008000 00001000 00000d12 b7ee2000
GPR08: 00000033 00000000 00000000 c139df10 48224824 1016c314 10160000 00000000
GPR16: 10160000 10160000 00000008 00000000 10160000 00000000 10160000 1017f5b0
GPR24: 1017fa50 1017f4f0 1017fa50 1017f740 1017f630 00000000 00000000 1017f4f0
NIP [b7ee2000] 0xb7ee2000
LR [8c008000] 0x8c008000
Call Trace:
Instruction dump:
XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX
XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX
---[ end trace 0000000000000000 ]---
The problem is in ret_from_syscall where the check for
icache_44x_need_flush is done. When the flush is needed the code jumps
out-of-line to do the flush, and then intends to jump back to continue
the syscall return.
However the branch back to label 1b doesn't return to the correct
location, instead branching back just prior to the return to userspace,
causing bogus register values to be used by the rfi.
The breakage was introduced by commit 6f76a01173
("powerpc/syscall: implement system call entry/exit logic in C for PPC32") which
inadvertently removed the "1" label and reused it elsewhere.
Fix it by adding named local labels in the correct locations. Note that
the return label needs to be outside the ifdef so that CONFIG_PPC_47x=n
compiles.
Fixes: 6f76a01173 ("powerpc/syscall: implement system call entry/exit logic in C for PPC32")
Cc: stable@vger.kernel.org # v5.12+
Reported-by: Eddie James <eajames@linux.ibm.com>
Tested-by: Eddie James <eajames@linux.ibm.com>
Link: https://lore.kernel.org/linuxppc-dev/fdaadc46-7476-9237-e104-1d2168526e72@linux.ibm.com/
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Link: https://msgid.link/20231010114750.847794-1-mpe@ellerman.id.au
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 3241f260eb ]
This is called in an atomic context, so is not allowed to sleep if a
user page needs to be faulted in and has nowhere it can be deferred to.
The pagefault_disabled() function is documented as preventing user
access methods from sleeping.
In practice the page will be mapped in nearly always because we are
reading the instruction that just triggered the watchpoint trap.
Signed-off-by: Benjamin Gray <bgray@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230829063457.54157-3-bgray@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit cc879ab3ce ]
thread_change_pc() uses CPU local data, so must be protected from
swapping CPUs while it is reading the breakpoint struct.
The error is more noticeable after 1e60f3564b ("powerpc/watchpoints:
Track perf single step directly on the breakpoint"), which added an
unconditional __this_cpu_read() call in thread_change_pc(). However the
existing __this_cpu_read() that runs if a breakpoint does need to be
re-inserted has the same issue.
Signed-off-by: Benjamin Gray <bgray@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230829063457.54157-2-bgray@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit c37b6908f7 ]
fail_iommu_setup() registers the fail_iommu_bus_notifier struct to both
PCI and VIO buses. struct notifier_block is a linked list node, so this
causes any notifiers later registered to either bus type to also be
registered to the other since they share the same node.
This causes issues in (at least) the vgaarb code, which registers a
notifier for PCI buses. pci_notify() ends up being called on a vio
device, converted with to_pci_dev() even though it's not a PCI device,
and finally makes a bad access in vga_arbiter_add_pci_device() as
discovered with KASAN:
BUG: KASAN: slab-out-of-bounds in vga_arbiter_add_pci_device+0x60/0xe00
Read of size 4 at addr c000000264c26fdc by task swapper/0/1
Call Trace:
dump_stack_lvl+0x1bc/0x2b8 (unreliable)
print_report+0x3f4/0xc60
kasan_report+0x244/0x698
__asan_load4+0xe8/0x250
vga_arbiter_add_pci_device+0x60/0xe00
pci_notify+0x88/0x444
notifier_call_chain+0x104/0x320
blocking_notifier_call_chain+0xa0/0x140
device_add+0xac8/0x1d30
device_register+0x58/0x80
vio_register_device_node+0x9ac/0xce0
vio_bus_scan_register_devices+0xc4/0x13c
__machine_initcall_pseries_vio_device_init+0x94/0xf0
do_one_initcall+0x12c/0xaa8
kernel_init_freeable+0xa48/0xba8
kernel_init+0x64/0x400
ret_from_kernel_thread+0x5c/0x64
Fix this by creating separate notifier_block structs for each bus type.
Fixes: d6b9a81b2a ("powerpc: IOMMU fault injection")
Reported-by: Nageswara R Sastry <rnsastry@linux.ibm.com>
Signed-off-by: Russell Currey <ruscur@russell.cc>
Tested-by: Nageswara R Sastry <rnsastry@linux.ibm.com>
Reviewed-by: Andrew Donnellan <ajd@linux.ibm.com>
[mpe: Add #ifdef to fix CONFIG_IBMVIO=n build]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230322035322.328709-1-ruscur@russell.cc
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit d1eb75e0df ]
In case fadump_reserve_mem() fails to reserve memory, the
reserve_dump_area_size variable will retain the reserve area size. This
will lead to /sys/kernel/fadump/mem_reserved node displaying an incorrect
memory reserved by fadump.
To fix this problem, reserve dump area size variable is set to 0 if fadump
failed to reserve memory.
Fixes: 8255da95e5 ("powerpc/fadump: release all the memory above boot memory size")
Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Acked-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230704050715.203581-1-sourabhjain@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 4f3175979e upstream.
With hardened usercopy enabled (CONFIG_HARDENED_USERCOPY=y), using the
/proc/powerpc/rtas/firmware_update interface to prepare a system
firmware update yields a BUG():
kernel BUG at mm/usercopy.c:102!
Oops: Exception in kernel mode, sig: 5 [#1]
LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries
Modules linked in:
CPU: 0 PID: 2232 Comm: dd Not tainted 6.5.0-rc3+ #2
Hardware name: IBM,8408-E8E POWER8E (raw) 0x4b0201 0xf000004 of:IBM,FW860.50 (SV860_146) hv:phyp pSeries
NIP: c0000000005991d0 LR: c0000000005991cc CTR: 0000000000000000
REGS: c0000000148c76a0 TRAP: 0700 Not tainted (6.5.0-rc3+)
MSR: 8000000000029033 <SF,EE,ME,IR,DR,RI,LE> CR: 24002242 XER: 0000000c
CFAR: c0000000001fbd34 IRQMASK: 0
[ ... GPRs omitted ... ]
NIP usercopy_abort+0xa0/0xb0
LR usercopy_abort+0x9c/0xb0
Call Trace:
usercopy_abort+0x9c/0xb0 (unreliable)
__check_heap_object+0x1b4/0x1d0
__check_object_size+0x2d0/0x380
rtas_flash_write+0xe4/0x250
proc_reg_write+0xfc/0x160
vfs_write+0xfc/0x4e0
ksys_write+0x90/0x160
system_call_exception+0x178/0x320
system_call_common+0x160/0x2c4
The blocks of the firmware image are copied directly from user memory
to objects allocated from flash_block_cache, so flash_block_cache must
be created using kmem_cache_create_usercopy() to mark it safe for user
access.
Fixes: 6d07d1cd30 ("usercopy: Restrict non-usercopy caches to size 0")
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
[mpe: Trim and indent oops]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230810-rtas-flash-vs-hardened-usercopy-v2-1-dcf63793a938@linux.ibm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 5bcedc5931 upstream.
Nageswara reported that /proc/self/status was showing "vulnerable" for
the Speculation_Store_Bypass feature on Power10, eg:
$ grep Speculation_Store_Bypass: /proc/self/status
Speculation_Store_Bypass: vulnerable
But at the same time the sysfs files, and lscpu, were showing "Not
affected".
This turns out to simply be a bug in the reporting of the
Speculation_Store_Bypass, aka. PR_SPEC_STORE_BYPASS, case.
When SEC_FTR_STF_BARRIER was added, so that firmware could communicate
the vulnerability was not present, the code in ssb_prctl_get() was not
updated to check the new flag.
So add the check for SEC_FTR_STF_BARRIER being disabled. Rather than
adding the new check to the existing if block and expanding the comment
to cover both cases, rewrite the three cases to be separate so they can
be commented separately for clarity.
Fixes: 84ed26fd00 ("powerpc/security: Add a security feature for STF barrier")
Cc: stable@vger.kernel.org # v5.14+
Reported-by: Nageswara R Sastry <rnsastry@linux.ibm.com>
Tested-by: Nageswara R Sastry <rnsastry@linux.ibm.com>
Reviewed-by: Russell Currey <ruscur@russell.cc>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230517074945.53188-1-mpe@ellerman.id.au
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit b684c09f09 ]
ppc_save_regs() skips one stack frame while saving the CPU register states.
Instead of saving current R1, it pulls the previous stack frame pointer.
When vmcores caused by direct panic call (such as `echo c >
/proc/sysrq-trigger`), are debugged with gdb, gdb fails to show the
backtrace correctly. On further analysis, it was found that it was because
of mismatch between r1 and NIP.
GDB uses NIP to get current function symbol and uses corresponding debug
info of that function to unwind previous frames, but due to the
mismatching r1 and NIP, the unwinding does not work, and it fails to
unwind to the 2nd frame and hence does not show the backtrace.
GDB backtrace with vmcore of kernel without this patch:
---------
(gdb) bt
#0 0xc0000000002a53e8 in crash_setup_regs (oldregs=<optimized out>,
newregs=0xc000000004f8f8d8) at ./arch/powerpc/include/asm/kexec.h:69
#1 __crash_kexec (regs=<optimized out>) at kernel/kexec_core.c:974
#2 0x0000000000000063 in ?? ()
#3 0xc000000003579320 in ?? ()
---------
Further analysis revealed that the mismatch occurred because
"ppc_save_regs" was saving the previous stack's SP instead of the current
r1. This patch fixes this by storing current r1 in the saved pt_regs.
GDB backtrace with vmcore of patched kernel:
--------
(gdb) bt
#0 0xc0000000002a53e8 in crash_setup_regs (oldregs=0x0, newregs=0xc00000000670b8d8)
at ./arch/powerpc/include/asm/kexec.h:69
#1 __crash_kexec (regs=regs@entry=0x0) at kernel/kexec_core.c:974
#2 0xc000000000168918 in panic (fmt=fmt@entry=0xc000000001654a60 "sysrq triggered crash\n")
at kernel/panic.c:358
#3 0xc000000000b735f8 in sysrq_handle_crash (key=<optimized out>) at drivers/tty/sysrq.c:155
#4 0xc000000000b742cc in __handle_sysrq (key=key@entry=99, check_mask=check_mask@entry=false)
at drivers/tty/sysrq.c:602
#5 0xc000000000b7506c in write_sysrq_trigger (file=<optimized out>, buf=<optimized out>,
count=2, ppos=<optimized out>) at drivers/tty/sysrq.c:1163
#6 0xc00000000069a7bc in pde_write (ppos=<optimized out>, count=<optimized out>,
buf=<optimized out>, file=<optimized out>, pde=0xc00000000362cb40) at fs/proc/inode.c:340
#7 proc_reg_write (file=<optimized out>, buf=<optimized out>, count=<optimized out>,
ppos=<optimized out>) at fs/proc/inode.c:352
#8 0xc0000000005b3bbc in vfs_write (file=file@entry=0xc000000006aa6b00,
buf=buf@entry=0x61f498b4f60 <error: Cannot access memory at address 0x61f498b4f60>,
count=count@entry=2, pos=pos@entry=0xc00000000670bda0) at fs/read_write.c:582
#9 0xc0000000005b4264 in ksys_write (fd=<optimized out>,
buf=0x61f498b4f60 <error: Cannot access memory at address 0x61f498b4f60>, count=2)
at fs/read_write.c:637
#10 0xc00000000002ea2c in system_call_exception (regs=0xc00000000670be80, r0=<optimized out>)
at arch/powerpc/kernel/syscall.c:171
#11 0xc00000000000c270 in system_call_vectored_common ()
at arch/powerpc/kernel/interrupt_64.S:192
--------
Nick adds:
So this now saves regs as though it was an interrupt taken in the
caller, at the instruction after the call to ppc_save_regs, whereas
previously the NIP was there, but R1 came from the caller's caller and
that mismatch is what causes gdb's dwarf unwinder to go haywire.
Signed-off-by: Aditya Gupta <adityag@linux.ibm.com>
Fixes: d16a58f885 ("powerpc: Improve ppc_save_regs()")
Reivewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230615091047.90433-1-adityag@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit a03b1a0b19 ]
Looking at generated code for handle_signal32() shows calls to a
function called __unsafe_save_user_regs.constprop.0 while user access
is open.
And that __unsafe_save_user_regs.constprop.0 function has two nops at
the begining, allowing it to be traced, which is unexpected during
user access open window.
The solution could be to mark __unsafe_save_user_regs() no trace, but
to be on the safe side the most efficient is to flag it __always_inline
as already done for function __unsafe_restore_general_regs(). The
function is relatively small and only called twice, so the size
increase will remain in the noise.
Do the same with save_tm_user_regs_unsafe() as it may suffer the
same issue.
Fixes: ef75e73182 ("powerpc/signal32: Transform save_user_regs() and save_tm_user_regs() in 'unsafe' version")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/7e469c8f01860a69c1ada3ca6a5e2aa65f0f74b2.1685955220.git.christophe.leroy@csgroup.eu
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 0eb089a72f ]
A disassembly of interrupt_exit_kernel_prepare() shows a useless read
of MSR register. This is shown by r9 being re-used immediately without
doing anything with the value read.
c000e0e0: 60 00 00 00 nop
c000e0e4: 7d 3a c2 a6 mfmd_ap r9
c000e0e8: 7d 20 00 a6 mfmsr r9
c000e0ec: 7c 51 13 a6 mtspr 81,r2
c000e0f0: 81 3f 00 84 lwz r9,132(r31)
c000e0f4: 71 29 80 00 andi. r9,r9,32768
This is due to the use of local_irq_save(). The flags read by
local_irq_save() are never used, use local_irq_disable() instead.
Fixes: 13799748b9 ("powerpc/64: use interrupt restart table to speed up return from interrupt")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/df36c6205ab64326fb1b991993c82057e92ace2f.1685955214.git.christophe.leroy@csgroup.eu
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 1f7aacc5eb upstream.
For an SR-IOV device, while enabling DDW, a new table is created and
added at index 1 in the group. In the below 2 scenarios, the table is
incorrectly referenced at index 0 (which is where the table is for
default DMA window).
1. When adding DDW
This issue is exposed with "slub_debug". Error thrown out from
dma_iommu_dma_supported()
Warning: IOMMU offset too big for device mask
mask: 0xffffffff, table offset: 0x800000000000000
2. During Dynamic removal of the PCI device.
Error is from iommu_tce_table_put() since a NULL table pointer is
passed in.
Fixes: 381ceda88c ("powerpc/pseries/iommu: Make use of DDW for indirect mapping")
Cc: stable@vger.kernel.org # v5.15+
Signed-off-by: Gaurav Batra <gbatra@linux.vnet.ibm.com>
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230505184701.91613-1-gbatra@linux.vnet.ibm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
