commit 0db880fc865ffb522141ced4bfa66c12ab1fbb70 upstream.
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
[ Conflicts in arch/powerpc/include/asm/interrupt.h
because machine_check_early() and machine_check_exception()
has been refactored. ]
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit a1216e62d039bf63a539bbe718536ec789a853dd ]
If a PCI device is removed during eeh_pe_report_edev(), edev->pdev
will change and can cause a crash, hold the PCI rescan/remove lock
while taking a copy of edev->pdev->bus.
Signed-off-by: Ganesh Goudar <ganeshgr@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240617140240.580453-1-ganeshgr@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit d3882564a77c21eb746ba5364f3fa89b88de3d61 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 6431e92fc827 ("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 27646b2e02b096a6936b3e3b6ba334ae20763eab ]
It can be easy to miss that the notifier mechanism invokes the callbacks
in an atomic context, so add some comments to that effect on the two
handlers we register here.
Signed-off-by: Benjamin Gray <bgray@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230829063457.54157-4-bgray@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 3d2ffcdd2a982e8bbe65fa0f94fb21bf304c281e ]
POWER10 DD1 has an issue where it generates watchpoint exceptions when
it shouldn't. The conditions where this occur are:
- octword op
- ending address of DAWR range is less than starting address of op
- those addresses need to be in the same or in two consecutive 512B
blocks
- 'op address + 64B' generates an address that has a carry into bit
52 (crosses 2K boundary)
Handle such spurious exception by considering them as extraneous and
emulating/single-steeping instruction without generating an event.
[ravi: Fixed build warning reported by lkp@intel.com]
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/20201106045650.278987-1-ravi.bangoria@linux.ibm.com
Stable-dep-of: 27646b2e02b0 ("powerpc/watchpoints: Annotate atomic context in more places")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit f8d3555355653848082c351fa90775214fb8a4fa ]
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>
commit b684c09f09e7a6af3794d4233ef785819e72db79 upstream.
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
Cc: stable@vger.kernel.org
Signed-off-by: Aditya Gupta <adityag@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 4b3338aaa74d7d4ec5b6734dc298f0db94ec83d2 upstream.
Commit 41a506ef71eb ("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: 41a506ef71eb ("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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 5e1d824f9a283cbf90f25241b66d1f69adb3835b 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>
[ Upstream commit daa9ada2093ed23d52b4c1fe6e13cf78f55cc85f ]
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 9fee28baa601 ("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>
[ Upstream commit cc879ab3ce39bc39f9b1d238b283f43a5f6f957d ]
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 1e60f3564bad ("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 c37b6908f7b2bd24dcaaf14a180e28c9132b9c58 ]
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 d1eb75e0dfed80d2d85b664e28a39f65b290ab55 ]
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 4f3175979e62de3b929bfa54a0db4b87d36257a7 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>
[ Upstream commit 271208ee5e335cb1ad280d22784940daf7ddf820 ]
Using memcpy() isn't safe when buf is identical to rtas_err_buf, which
can happen during boot before slab is up. Full context which may not
be obvious from the diff:
if (altbuf) {
buf = altbuf;
} else {
buf = rtas_err_buf;
if (slab_is_available())
buf = kmalloc(RTAS_ERROR_LOG_MAX, GFP_ATOMIC);
}
if (buf)
memcpy(buf, rtas_err_buf, RTAS_ERROR_LOG_MAX);
This was found by inspection and I'm not aware of it causing problems
in practice. It appears to have been introduced by commit
033ef338b6 ("powerpc: Merge rtas.c into arch/powerpc/kernel"); the
old ppc64 version of this code did not have this problem.
Use memmove() instead.
Fixes: 033ef338b6 ("powerpc: Merge rtas.c into arch/powerpc/kernel")
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Reviewed-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230220-rtas-queue-for-6-4-v1-2-010e4416f13f@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 1c6b5a7e74052768977855f95d6b8812f6e7772c ]
PAPR interface currently supports two different ways of communicating resource
grouping details to the OS. These are referred to as Form 0 and Form 1
associativity grouping. Form 0 is the older format and is now considered
deprecated. This patch adds another resource grouping named FORM2.
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210812132223.225214-6-aneesh.kumar@linux.ibm.com
Stable-dep-of: b277fc793daf ("powerpc/papr_scm: Update the NUMA distance table for the target node")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 0eacd06bb8adea8dd9edb0a30144166d9f227e64 ]
Also make related code cleanup that will allow adding FORM2_AFFINITY in
later patches. No functional change in this patch.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210812132223.225214-3-aneesh.kumar@linux.ibm.com
Stable-dep-of: b277fc793daf ("powerpc/papr_scm: Update the NUMA distance table for the target node")
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit fd7276189450110ed835eb0a334e62d2f1c4e3be upstream.
powerpc sets up PF_KTHREAD and PF_IO_WORKER with a NULL pt_regs, which
from my (arguably very short) checking is not commonly done for other
archs. This is fine, except when PF_IO_WORKER's have been created and
the task does something that causes a coredump to be generated. Then we
get this crash:
Kernel attempted to read user page (160) - exploit attempt? (uid: 1000)
BUG: Kernel NULL pointer dereference on read at 0x00000160
Faulting instruction address: 0xc0000000000c3a60
Oops: Kernel access of bad area, sig: 11 [#1]
LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=32 NUMA pSeries
Modules linked in: bochs drm_vram_helper drm_kms_helper xts binfmt_misc ecb ctr syscopyarea sysfillrect cbc sysimgblt drm_ttm_helper aes_generic ttm sg libaes evdev joydev virtio_balloon vmx_crypto gf128mul drm dm_mod fuse loop configfs drm_panel_orientation_quirks ip_tables x_tables autofs4 hid_generic usbhid hid xhci_pci xhci_hcd usbcore usb_common sd_mod
CPU: 1 PID: 1982 Comm: ppc-crash Not tainted 6.3.0-rc2+ #88
Hardware name: IBM pSeries (emulated by qemu) POWER9 (raw) 0x4e1202 0xf000005 of:SLOF,HEAD hv:linux,kvm pSeries
NIP: c0000000000c3a60 LR: c000000000039944 CTR: c0000000000398e0
REGS: c0000000041833b0 TRAP: 0300 Not tainted (6.3.0-rc2+)
MSR: 800000000280b033 <SF,VEC,VSX,EE,FP,ME,IR,DR,RI,LE> CR: 88082828 XER: 200400f8
...
NIP memcpy_power7+0x200/0x7d0
LR ppr_get+0x64/0xb0
Call Trace:
ppr_get+0x40/0xb0 (unreliable)
__regset_get+0x180/0x1f0
regset_get_alloc+0x64/0x90
elf_core_dump+0xb98/0x1b60
do_coredump+0x1c34/0x24a0
get_signal+0x71c/0x1410
do_notify_resume+0x140/0x6f0
interrupt_exit_user_prepare_main+0x29c/0x320
interrupt_exit_user_prepare+0x6c/0xa0
interrupt_return_srr_user+0x8/0x138
Because ppr_get() is trying to copy from a PF_IO_WORKER with a NULL
pt_regs.
Check for a valid pt_regs in both ppc_get/ppr_set, and return an error
if not set. The actual error value doesn't seem to be important here, so
just pick -EINVAL.
Fixes: fa439810cc ("powerpc/ptrace: Enable support for NT_PPPC_TAR, NT_PPC_PPR, NT_PPC_DSCR")
Cc: stable@vger.kernel.org # v4.8+
Signed-off-by: Jens Axboe <axboe@kernel.dk>
[mpe: Trim oops in change log, add Fixes & Cc stable]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/d9f63344-fe7c-56ae-b420-4a1a04a2ae4c@kernel.dk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 07b050f9290ee012a407a0f64151db902a1520f5 upstream.
Relocatable kernels must not discard relocations, they need to be
processed at runtime. As such they are included for CONFIG_RELOCATABLE
builds in the powerpc linker script (line 340).
However they are also unconditionally discarded later in the
script (line 414). Previously that worked because the earlier inclusion
superseded the discard.
However commit 99cb0d917ffa ("arch: fix broken BuildID for arm64 and
riscv") introduced an earlier use of DISCARD as part of the RO_DATA
macro (line 137). With binutils < 2.36 that causes the DISCARD
directives later in the script to be applied earlier, causing .rela* to
actually be discarded at link time, leading to build warnings and a
kernel that doesn't boot:
ld: warning: discarding dynamic section .rela.init.rodata
Fix it by conditionally discarding .rela* only when CONFIG_RELOCATABLE
is disabled.
Fixes: 99cb0d917ffa ("arch: fix broken BuildID for arm64 and riscv")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20230105132349.384666-2-mpe@ellerman.id.au
Signed-off-by: Tom Saeger <tom.saeger@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 4b9880dbf3bdba3a7c56445137c3d0e30aaa0a40 upstream.
The powerpc linker script explicitly includes .exit.text, because
otherwise the link fails due to references from __bug_table and
__ex_table. The code is freed (discarded) at runtime along with
.init.text and data.
That has worked in the past despite powerpc not defining
RUNTIME_DISCARD_EXIT because DISCARDS appears late in the powerpc linker
script (line 410), and the explicit inclusion of .exit.text
earlier (line 280) supersedes the discard.
However commit 99cb0d917ffa ("arch: fix broken BuildID for arm64 and
riscv") introduced an earlier use of DISCARD as part of the RO_DATA
macro (line 136). With binutils < 2.36 that causes the DISCARD
directives later in the script to be applied earlier [1], causing
.exit.text to actually be discarded at link time, leading to build
errors:
'.exit.text' referenced in section '__bug_table' of crypto/algboss.o: defined in
discarded section '.exit.text' of crypto/algboss.o
'.exit.text' referenced in section '__ex_table' of drivers/nvdimm/core.o: defined in
discarded section '.exit.text' of drivers/nvdimm/core.o
Fix it by defining RUNTIME_DISCARD_EXIT, which causes the generic
DISCARDS macro to not include .exit.text at all.
1: https://lore.kernel.org/lkml/87fscp2v7k.fsf@igel.home/
Fixes: 99cb0d917ffa ("arch: fix broken BuildID for arm64 and riscv")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20230105132349.384666-1-mpe@ellerman.id.au
Signed-off-by: Tom Saeger <tom.saeger@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ 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 <rmclure@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20230206021801.105268-3-rmclure@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 9efcdaac36e1643a1b7f5337e6143ce142d381b1 ]
When a PCI error is encountered 6th time in an hour we
set the channel state to perm_failure and notify the
driver about the permanent failure.
However, after upstream commit 38ddc01147 ("powerpc/eeh:
Make permanently failed devices non-actionable"), EEH handler
stops calling any routine once the device is marked as
permanent failure. This issue can lead to fatal consequences
like kernel hang with certain PCI devices.
Following log is observed with lpfc driver, with and without
this change, Without this change kernel hangs, If PCI error
is encountered 6 times for a device in an hour.
Without the change
EEH: Beginning: 'error_detected(permanent failure)'
PCI 0132:60:00.0#600000: EEH: not actionable (1,1,1)
PCI 0132:60:00.1#600000: EEH: not actionable (1,1,1)
EEH: Finished:'error_detected(permanent failure)'
With the change
EEH: Beginning: 'error_detected(permanent failure)'
EEH: Invoking lpfc->error_detected(permanent failure)
EEH: lpfc driver reports: 'disconnect'
EEH: Invoking lpfc->error_detected(permanent failure)
EEH: lpfc driver reports: 'disconnect'
EEH: Finished:'error_detected(permanent failure)'
To fix the issue, set channel state to permanent failure after
notifying the drivers.
Fixes: 38ddc01147 ("powerpc/eeh: Make permanently failed devices non-actionable")
Suggested-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Signed-off-by: Ganesh Goudar <ganeshgr@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20230209105649.127707-1-ganeshgr@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 10b34ece132ee46dc4e6459c765d180c422a09fa ]
The control flow of eeh_handle_normal_event() is a bit tricky.
Break out one of the error handling paths - rather than be in an else
block, we'll make it part of the regular body of the function and put a
'goto out;' in the true limb of the if.
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211015070628.1331635-1-dja@axtens.net
Stable-dep-of: 9efcdaac36e1 ("powerpc/eeh: Set channel state after notifying the drivers")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 836b5b9fcc8e09cea7e8a59a070349a00e818308 ]
Some RTAS functions that have work area parameters impose alignment
requirements on the work area passed to them by the OS. Examples
include:
- ibm,configure-connector
- ibm,update-nodes
- ibm,update-properties
4KB is the greatest alignment required by PAPR for such
buffers. rtas_data_buf used to have a __page_aligned attribute in the
arch/ppc64 days, but that was changed to __cacheline_aligned for
unknown reasons by commit 033ef338b6 ("powerpc: Merge rtas.c into
arch/powerpc/kernel"). That works out to 128-byte alignment
on ppc64, which isn't right.
This was found by inspection and I'm not aware of any real problems
caused by this. Either current RTAS implementations don't enforce the
alignment constraints, or rtas_data_buf is always being placed at a
4KB boundary by accident (or both, perhaps).
Use __aligned(SZ_4K) to ensure the rtas_data_buf has alignment
appropriate for all users.
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Fixes: 033ef338b6 ("powerpc: Merge rtas.c into arch/powerpc/kernel")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20230125-b4-powerpc-rtas-queue-v3-6-26929c8cce78@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 9bce6243848dfd0ff7c2be6e8d82ab9b1e6c7858 ]
The first symbol exports of RTAS functions and data came with the (now
removed) scanlog driver in 2003:
https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git/commit/?id=f92e361842d5251e50562b09664082dcbd0548bb
At the time this was applied, EXPORT_SYMBOL_GPL() was very new, and
the exports of rtas_call() etc have remained non-GPL. As new APIs have
been added to the RTAS subsystem, their symbol exports have followed
the convention set by existing code.
However, the historical evidence is that RTAS function exports have been
added over time only to satisfy the needs of in-kernel users, and these
clients must have fairly intimate knowledge of how the APIs work to use
them safely. No out of tree users are known, and future ones seem
unlikely.
Arguably the default for RTAS symbols should have become
EXPORT_SYMBOL_GPL once it was available. Let's make it so now, and
exceptions can be evaluated as needed.
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Reviewed-by: Laurent Dufour <laurent.dufour@fr.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20230124140448.45938-3-nathanl@linux.ibm.com
Stable-dep-of: 836b5b9fcc8e ("powerpc/rtas: ensure 4KB alignment for rtas_data_buf")
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 0e25498f8cd43c1b5aa327f373dd094e9a006da7 upstream.
There are two big uses of do_exit. The first is it's design use to be
the guts of the exit(2) system call. The second use is to terminate
a task after something catastrophic has happened like a NULL pointer
in kernel code.
Add a function make_task_dead that is initialy exactly the same as
do_exit to cover the cases where do_exit is called to handle
catastrophic failure. In time this can probably be reduced to just a
light wrapper around do_task_dead. For now keep it exactly the same so
that there will be no behavioral differences introducing this new
concept.
Replace all of the uses of do_exit that use it for catastraphic
task cleanup with make_task_dead to make it clear what the code
is doing.
As part of this rename rewind_stack_do_exit
rewind_stack_and_make_dead.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit ed2213bfb192ab51f09f12e9b49b5d482c6493f3 ]
rtas_os_term() is called during panic. Its behavior depends on a couple
of conditions in the /rtas node of the device tree, the traversal of
which entails locking and local IRQ state changes. If the kernel panics
while devtree_lock is held, rtas_os_term() as currently written could
hang.
Instead of discovering the relevant characteristics at panic time,
cache them in file-static variables at boot. Note the lookup for
"ibm,extended-os-term" is converted to of_property_read_bool() since it
is a boolean property, not an RTAS function token.
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Andrew Donnellan <ajd@linux.ibm.com>
[mpe: Incorporate suggested change from Nick]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221118150751.469393-4-nathanl@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 0100e6bbdbb79404e56939313662b42737026574 ]
In the arch addition of PF_IO_WORKER, I missed parisc and powerpc for
some reason. Fix that up, ensuring they handle PF_IO_WORKER like they do
PF_KTHREAD in copy_thread().
Reported-by: Bruno Goncalves <bgoncalv@redhat.com>
Fixes: 4727dc20e042 ("arch: setup PF_IO_WORKER threads like PF_KTHREAD")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 110a1fcb6c4d55144d8179983a475f17a1d6f832 ]
In pci_add_device_node_info(), use of_node_put() to drop the reference
to 'parent' returned by of_get_parent() to keep refcount balance.
Fixes: cca87d303c ("powerpc/pci: Refactor pci_dn")
Co-authored-by: Miaoqian Lin <linmq006@gmail.com>
Signed-off-by: Liang He <windhl@126.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Link: https://lore.kernel.org/r/20220701131750.240170-1-windhl@126.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit c7acee3d2f128a38b68fb7af85dbbd91bfd0b4ad upstream.
Christophe Leroy reported that commit 7b4537199a4a ("kbuild: link
symbol CRCs at final link, removing CONFIG_MODULE_REL_CRCS") broke
mpc85xx_defconfig + CONFIG_RELOCATABLE=y.
LD vmlinux
SYSMAP System.map
SORTTAB vmlinux
CHKREL vmlinux
WARNING: 451 bad relocations
c0b312a9 R_PPC_UADDR32 .head.text-0x3ff9ed54
c0b312ad R_PPC_UADDR32 .head.text-0x3ffac224
c0b312b1 R_PPC_UADDR32 .head.text-0x3ffb09f4
c0b312b5 R_PPC_UADDR32 .head.text-0x3fe184dc
c0b312b9 R_PPC_UADDR32 .head.text-0x3fe183a8
...
The compiler emits a bunch of R_PPC_UADDR32, which is not supported by
arch/powerpc/kernel/reloc_32.S.
The reason is there exists an unaligned symbol.
$ powerpc-linux-gnu-nm -n vmlinux
...
c0b31258 d spe_aligninfo
c0b31298 d __func__.0
c0b312a9 D sys_call_table
c0b319b8 d __func__.0
Commit 7b4537199a4a is not the root cause. Even before that, I can
reproduce the same issue for mpc85xx_defconfig + CONFIG_RELOCATABLE=y
+ CONFIG_MODVERSIONS=n.
It is just that nobody noticed because when CONFIG_MODVERSIONS is
enabled, a __crc_* symbol inserted before sys_call_table was hiding the
unalignment issue.
Adding alignment to the syscall table for ppc32 fixes the issue.
Cc: stable@vger.kernel.org
Reported-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Christophe Leroy <christophe.leroy@csgroup.eu>
[mpe: Trim change log discussion, add Cc stable]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/lkml/38605f6a-a568-f884-f06f-ea4da5b214f0@csgroup.eu/
Link: https://lore.kernel.org/r/20220820165129.1147589-1-masahiroy@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit ca829e05d3d4f728810cc5e4b468d9ebc7745eb3 ]
On 64-bit, calling jump_label_init() in setup_feature_keys() is too
late because static keys may be used in subroutines of
parse_early_param() which is again subroutine of early_init_devtree().
For example booting with "threadirqs":
static_key_enable_cpuslocked(): static key '0xc000000002953260' used before call to jump_label_init()
WARNING: CPU: 0 PID: 0 at kernel/jump_label.c:166 static_key_enable_cpuslocked+0xfc/0x120
...
NIP static_key_enable_cpuslocked+0xfc/0x120
LR static_key_enable_cpuslocked+0xf8/0x120
Call Trace:
static_key_enable_cpuslocked+0xf8/0x120 (unreliable)
static_key_enable+0x30/0x50
setup_forced_irqthreads+0x28/0x40
do_early_param+0xa0/0x108
parse_args+0x290/0x4e0
parse_early_options+0x48/0x5c
parse_early_param+0x58/0x84
early_init_devtree+0xd4/0x518
early_setup+0xb4/0x214
So call jump_label_init() just before parse_early_param() in
early_init_devtree().
Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Zhouyi Zhou <zhouzhouyi@gmail.com>
[mpe: Add call trace to change log and minor wording edits.]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220726015747.11754-1-zhouzhouyi@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 8d48562a2729742f767b0fdd994d6b2a56a49c63 upstream.
The recent change to get_phb_number() causes a DEBUG_ATOMIC_SLEEP
warning on some systems:
BUG: sleeping function called from invalid context at kernel/locking/mutex.c:580
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 1, name: swapper
preempt_count: 1, expected: 0
RCU nest depth: 0, expected: 0
1 lock held by swapper/1:
#0: c157efb0 (hose_spinlock){+.+.}-{2:2}, at: pcibios_alloc_controller+0x64/0x220
Preemption disabled at:
[<00000000>] 0x0
CPU: 0 PID: 1 Comm: swapper Not tainted 5.19.0-yocto-standard+ #1
Call Trace:
[d101dc90] [c073b264] dump_stack_lvl+0x50/0x8c (unreliable)
[d101dcb0] [c0093b70] __might_resched+0x258/0x2a8
[d101dcd0] [c0d3e634] __mutex_lock+0x6c/0x6ec
[d101dd50] [c0a84174] of_alias_get_id+0x50/0xf4
[d101dd80] [c002ec78] pcibios_alloc_controller+0x1b8/0x220
[d101ddd0] [c140c9dc] pmac_pci_init+0x198/0x784
[d101de50] [c140852c] discover_phbs+0x30/0x4c
[d101de60] [c0007fd4] do_one_initcall+0x94/0x344
[d101ded0] [c1403b40] kernel_init_freeable+0x1a8/0x22c
[d101df10] [c00086e0] kernel_init+0x34/0x160
[d101df30] [c001b334] ret_from_kernel_thread+0x5c/0x64
This is because pcibios_alloc_controller() holds hose_spinlock but
of_alias_get_id() takes of_mutex which can sleep.
The hose_spinlock protects the phb_bitmap, and also the hose_list, but
it doesn't need to be held while get_phb_number() calls the OF routines,
because those are only looking up information in the device tree.
So fix it by having get_phb_number() take the hose_spinlock itself, only
where required, and then dropping the lock before returning.
pcibios_alloc_controller() then needs to take the lock again before the
list_add() but that's safe, the order of the list is not important.
Fixes: 0fe1e96fef0a ("powerpc/pci: Prefer PCI domain assignment via DT 'linux,pci-domain' and alias")
Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220815065550.1303620-1-mpe@ellerman.id.au
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit f4b39e88b42d13366b831270306326b5c20971ca ]
The recent change to the PHB numbering logic has a logic error in the
handling of "ibm,opal-phbid".
When an "ibm,opal-phbid" property is present, &prop is written to and
ret is set to zero.
The following call to of_alias_get_id() is skipped because ret == 0.
But then the if (ret >= 0) is true, and the body of that if statement
sets prop = ret which throws away the value that was just read from
"ibm,opal-phbid".
Fix the logic by only doing the ret >= 0 check in the of_alias_get_id()
case.
Fixes: 0fe1e96fef0a ("powerpc/pci: Prefer PCI domain assignment via DT 'linux,pci-domain' and alias")
Reviewed-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220802105723.1055178-1-mpe@ellerman.id.au
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 0fe1e96fef0a5c53b4c0d1500d356f3906000f81 ]
Other Linux architectures use DT property 'linux,pci-domain' for
specifying fixed PCI domain of PCI controller specified in Device-Tree.
And lot of Freescale powerpc boards have defined numbered pci alias in
Device-Tree for every PCIe controller which number specify preferred PCI
domain.
So prefer usage of DT property 'linux,pci-domain' (via function
of_get_pci_domain_nr()) and DT pci alias (via function
of_alias_get_id()) on powerpc architecture for assigning PCI domain to
PCI controller.
Fixes: 63a72284b1 ("powerpc/pci: Assign fixed PHB number based on device-tree properties")
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220706102148.5060-2-pali@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit be640317a1d0b9cf42fedb2debc2887a7cfa38de ]
With GCC 12 allmodconfig prom_init fails to build:
Error: External symbol 'memset' referenced from prom_init.c
make[2]: *** [arch/powerpc/kernel/Makefile:204: arch/powerpc/kernel/prom_init_check] Error 1
The allmodconfig build enables KASAN, so all calls to memset in
prom_init should be converted to __memset by the #ifdefs in
asm/string.h, because prom_init must use the non-KASAN instrumented
versions.
The build failure happens because there's a call to memset that hasn't
been caught by the pre-processor and converted to __memset. Typically
that's because it's a memset generated by the compiler itself, and that
is the case here.
With GCC 12, allmodconfig enables CONFIG_INIT_STACK_ALL_PATTERN, which
causes the compiler to emit memset calls to initialise on-stack
variables with a pattern.
Because prom_init is non-user-facing boot-time only code, as a
workaround just disable stack variable initialisation to unbreak the
build.
Reported-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220718134418.354114-1-mpe@ellerman.id.au
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 6886da5f49e6d86aad76807a93f3eef5e4f01b10 upstream.
When searching for config options, use the KCONFIG_CONFIG shell variable
so that builds using non-standard config locations work.
Fixes: 26deb04342 ("powerpc: prepare string/mem functions for KASAN")
Cc: stable@vger.kernel.org # v5.2+
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220624011745.4060795-1-Liam.Howlett@oracle.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7bc08056a6dabc3a1442216daf527edf61ac24b6 upstream.
Add a special case to block_rtas_call() to allow the ibm,platform-dump RTAS
call through the RTAS filter if the buffer address is 0.
According to PAPR, ibm,platform-dump is called with a null buffer address
to notify the platform firmware that processing of a particular dump is
finished.
Without this, on a pseries machine with CONFIG_PPC_RTAS_FILTER enabled, an
application such as rtas_errd that is attempting to retrieve a dump will
encounter an error at the end of the retrieval process.
Fixes: bd59380c5b ("powerpc/rtas: Restrict RTAS requests from userspace")
Cc: stable@vger.kernel.org
Reported-by: Sathvika Vasireddy <sathvika@linux.ibm.com>
Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>
Reviewed-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Reviewed-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220614134952.156010-1-ajd@linux.ibm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit a1b29ba2f2c171b9bea73be993bfdf0a62d37d15 ]
The following KASAN warning was reported in our kernel.
BUG: KASAN: stack-out-of-bounds in get_wchan+0x188/0x250
Read of size 4 at addr d216f958 by task ps/14437
CPU: 3 PID: 14437 Comm: ps Tainted: G O 5.10.0 #1
Call Trace:
[daa63858] [c0654348] dump_stack+0x9c/0xe4 (unreliable)
[daa63888] [c035cf0c] print_address_description.constprop.3+0x8c/0x570
[daa63908] [c035d6bc] kasan_report+0x1ac/0x218
[daa63948] [c00496e8] get_wchan+0x188/0x250
[daa63978] [c0461ec8] do_task_stat+0xce8/0xe60
[daa63b98] [c0455ac8] proc_single_show+0x98/0x170
[daa63bc8] [c03cab8c] seq_read_iter+0x1ec/0x900
[daa63c38] [c03cb47c] seq_read+0x1dc/0x290
[daa63d68] [c037fc94] vfs_read+0x164/0x510
[daa63ea8] [c03808e4] ksys_read+0x144/0x1d0
[daa63f38] [c005b1dc] ret_from_syscall+0x0/0x38
--- interrupt: c00 at 0x8fa8f4
LR = 0x8fa8cc
The buggy address belongs to the page:
page:98ebcdd2 refcount:0 mapcount:0 mapping:00000000 index:0x2 pfn:0x1216f
flags: 0x0()
raw: 00000000 00000000 01010122 00000000 00000002 00000000 ffffffff 00000000
raw: 00000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
d216f800: 00 00 00 00 00 f1 f1 f1 f1 00 00 00 00 00 00 00
d216f880: f2 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>d216f900: 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00
^
d216f980: f2 f2 f2 f2 f2 f2 f2 00 00 00 00 00 00 00 00 00
d216fa00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
After looking into this issue, I find the buggy address belongs
to the task stack region. It seems KASAN has something wrong.
I look into the code of __get_wchan in x86 architecture and
find the same issue has been resolved by the commit
f7d27c35dd ("x86/mm, kasan: Silence KASAN warnings in get_wchan()").
The solution could be applied to powerpc architecture too.
As Andrey Ryabinin said, get_wchan() is racy by design, it may
access volatile stack of running task, thus it may access
redzone in a stack frame and cause KASAN to warn about this.
Use READ_ONCE_NOCHECK() to silence these warnings.
Reported-by: Wanming Hu <huwanming@huaweil.com>
Signed-off-by: He Ying <heying24@huawei.com>
Signed-off-by: Chen Jingwen <chenjingwen6@huawei.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220121014418.155675-1-heying24@huawei.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit d51f86cfd8e378d4907958db77da3074f6dce3ba upstream.
The dssall ("Data Stream Stop All") instruction is obsolete altogether
with other Data Cache Instructions since ISA 2.03 (year 2006).
LLVM IAS does not support it but PPC970 seems to be using it.
This switches dssall to .long as there is no much point in fixing LLVM.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211221055904.555763-6-aik@ozlabs.ru
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 8e1278444446fc97778a5e5c99bca1ce0bbc5ec9 upstream.
The ptrace PEEKUSR/POKEUSR (aka PEEKUSER/POKEUSER) API allows a process
to read/write registers of another process.
To get/set a register, the API takes an index into an imaginary address
space called the "USER area", where the registers of the process are
laid out in some fashion.
The kernel then maps that index to a particular register in its own data
structures and gets/sets the value.
The API only allows a single machine-word to be read/written at a time.
So 4 bytes on 32-bit kernels and 8 bytes on 64-bit kernels.
The way floating point registers (FPRs) are addressed is somewhat
complicated, because double precision float values are 64-bit even on
32-bit CPUs. That means on 32-bit kernels each FPR occupies two
word-sized locations in the USER area. On 64-bit kernels each FPR
occupies one word-sized location in the USER area.
Internally the kernel stores the FPRs in an array of u64s, or if VSX is
enabled, an array of pairs of u64s where one half of each pair stores
the FPR. Which half of the pair stores the FPR depends on the kernel's
endianness.
To handle the different layouts of the FPRs depending on VSX/no-VSX and
big/little endian, the TS_FPR() macro was introduced.
Unfortunately the TS_FPR() macro does not take into account the fact
that the addressing of each FPR differs between 32-bit and 64-bit
kernels. It just takes the index into the "USER area" passed from
userspace and indexes into the fp_state.fpr array.
On 32-bit there are 64 indexes that address FPRs, but only 32 entries in
the fp_state.fpr array, meaning the user can read/write 256 bytes past
the end of the array. Because the fp_state sits in the middle of the
thread_struct there are various fields than can be overwritten,
including some pointers. As such it may be exploitable.
It has also been observed to cause systems to hang or otherwise
misbehave when using gdbserver, and is probably the root cause of this
report which could not be easily reproduced:
https://lore.kernel.org/linuxppc-dev/dc38afe9-6b78-f3f5-666b-986939e40fc6@keymile.com/
Rather than trying to make the TS_FPR() macro even more complicated to
fix the bug, or add more macros, instead add a special-case for 32-bit
kernels. This is more obvious and hopefully avoids a similar bug
happening again in future.
Note that because 32-bit kernels never have VSX enabled the code doesn't
need to consider TS_FPRWIDTH/OFFSET at all. Add a BUILD_BUG_ON() to
ensure that 32-bit && VSX is never enabled.
Fixes: 87fec0514f ("powerpc: PTRACE_PEEKUSR/PTRACE_POKEUSER of FPR registers in little endian builds")
Cc: stable@vger.kernel.org # v3.13+
Reported-by: Ariel Miculas <ariel.miculas@belden.com>
Tested-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220609133245.573565-1-mpe@ellerman.id.au
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit b793a01000122d2bd133ba451a76cc135b5e162c ]
__setup() handlers should return 1 to obsolete_checksetup() in
init/main.c to indicate that the boot option has been handled.
A return of 0 causes the boot option/value to be listed as an Unknown
kernel parameter and added to init's (limited) argument or environment
strings.
Also, error return codes don't mean anything to obsolete_checksetup() --
only non-zero (usually 1) or zero. So return 1 from powersave_off().
Fixes: 302eca184f ("[POWERPC] cell: use ppc_md->power_save instead of cbe_idle_loop")
Reported-by: Igor Zhbanov <izh1979@gmail.com>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220502192925.19954-1-rdunlap@infradead.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 15eb77f873255cf9f4d703b63cfbd23c46579654 ]
Boot memory area is setup as separate PT_LOAD segment in the vmcore
as it is moved by f/w, on crash, to a destination address provided by
the kernel. Having separate PT_LOAD segment helps in handling the
different physical address and offset for boot memory area in the
vmcore.
Commit ced1bf52f4 ("powerpc/fadump: merge adjacent memory ranges to
reduce PT_LOAD segements") inadvertly broke this pre-condition for
cases where some of the first kernel memory is available adjacent to
boot memory area. This scenario is rare but possible when memory for
fadump could not be reserved adjacent to boot memory area owing to
memory hole or such. Reading memory from a vmcore exported in such
scenario provides incorrect data. Fix it by ensuring no other region
is folded into boot memory area.
Fixes: ced1bf52f4 ("powerpc/fadump: merge adjacent memory ranges to reduce PT_LOAD segements")
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220406093839.206608-2-hbathini@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 7c5ed82b800d8615cdda00729e7b62e5899f0b13 ]
On large config LPARs (having 192 and more cores), Linux fails to boot
due to insufficient memory in the first memblock. It is due to the
memory reservation for the crash kernel which starts at 128MB offset of
the first memblock. This memory reservation for the crash kernel doesn't
leave enough space in the first memblock to accommodate other essential
system resources.
The crash kernel start address was set to 128MB offset by default to
ensure that the crash kernel get some memory below the RMA region which
is used to be of size 256MB. But given that the RMA region size can be
512MB or more, setting the crash kernel offset to mid of RMA size will
leave enough space for the kernel to allocate memory for other system
resources.
Since the above crash kernel offset change is only applicable to the LPAR
platform, the LPAR feature detection is pushed before the crash kernel
reservation. The rest of LPAR specific initialization will still
be done during pseries_probe_fw_features as usual.
This patch is dependent on changes to paca allocation for boot CPU. It
expect boot CPU to discover 1T segment support which is introduced by
the patch posted here:
https://lists.ozlabs.org/pipermail/linuxppc-dev/2022-January/239175.html
Reported-by: Abdul haleem <abdhalee@linux.vnet.ibm.com>
Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220204085601.107257-1-sourabhjain@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
