In restore_tm_sigcontexts() we take the trap value directly from the
user sigcontext with no checking:
err |= __get_user(regs->trap, &sc->gp_regs[PT_TRAP]);
This means we can be in the kernel with an arbitrary regs->trap value.
Although that's not immediately problematic, there is a risk we could
trigger one of the uses of CHECK_FULL_REGS():
#define CHECK_FULL_REGS(regs) BUG_ON(regs->trap & 1)
It can also cause us to unnecessarily save non-volatile GPRs again in
save_nvgprs(), which shouldn't be problematic but is still wrong.
It's also possible it could trick the syscall restart machinery, which
relies on regs->trap not being == 0xc00 (see 9a81c16b52 ("powerpc:
fix double syscall restarts")), though I haven't been able to make
that happen.
Finally it doesn't match the behaviour of the non-TM case, in
restore_sigcontext() which zeroes regs->trap.
So change restore_tm_sigcontexts() to zero regs->trap.
This was discovered while testing Nick's upcoming rewrite of the
syscall entry path. In that series the call to save_nvgprs() prior to
signal handling (do_notify_resume()) is removed, which leaves the
low-bit of regs->trap uncleared which can then trigger the FULL_REGS()
WARNs in setup_tm_sigcontexts().
Fixes: 2b0a576d15 ("powerpc: Add new transactional memory state to the signal context")
Cc: stable@vger.kernel.org # v3.9+
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200401023836.3286664-1-mpe@ellerman.id.au
memcpy_mcsafe has been implemented for power machines which is used
by pmem infrastructure, so that an UE encountered during memcpy from
pmem devices would not result in panic instead a right error code
is returned. The implementation expects machine check handler to ignore
the event and set nip to continue the execution from fixup code.
Appropriate changes are already made to powernv machine check handler,
make similar changes to pseries machine check handler to ignore the
the event and set nip to continue execution at the fixup entry if we
hit UE at an instruction with a fixup entry.
while we are at it, have a common function which searches the exception
table entry and updates nip with fixup address, and any future common
changes can be made in this function that are valid for both architectures.
powernv changes are made by
commit 895e3dceeb ("powerpc/mce: Handle UE event for memcpy_mcsafe")
Reviewed-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Reviewed-by: Santosh S <santosh@fossix.org>
Signed-off-by: Ganesh Goudar <ganeshgr@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200326184916.31172-1-ganeshgr@linux.ibm.com
We can avoid the #ifdef by using IS_ENABLED() in the existing
condition check.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200313112020.28235-2-mpe@ellerman.id.au
We don't need the NULL check of np, the result is the same because the
OF helpers cope with NULL, of_node_to_nid(NULL) == NUMA_NO_NODE (-1).
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200313112020.28235-1-mpe@ellerman.id.au
Reported-by: Sedat Dilek <sedat.dilek@gmail.com>
Suggested-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
[mpe: Drop changes to a/p/boot which doesn't use linux headers]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190812215052.71840-10-ndesaulniers@google.com
When a program check exception happens while MMU translation is
disabled, following Oops happens in kprobe_handler() in the following
code:
} else if (*addr != BREAKPOINT_INSTRUCTION) {
BUG: Unable to handle kernel data access on read at 0x0000e268
Faulting instruction address: 0xc000ec34
Oops: Kernel access of bad area, sig: 11 [#1]
BE PAGE_SIZE=16K PREEMPT CMPC885
Modules linked in:
CPU: 0 PID: 429 Comm: cat Not tainted 5.6.0-rc1-s3k-dev-00824-g84195dc6c58a #3267
NIP: c000ec34 LR: c000ecd8 CTR: c019cab8
REGS: ca4d3b58 TRAP: 0300 Not tainted (5.6.0-rc1-s3k-dev-00824-g84195dc6c58a)
MSR: 00001032 <ME,IR,DR,RI> CR: 2a4d3c52 XER: 00000000
DAR: 0000e268 DSISR: c0000000
GPR00: c000b09c ca4d3c10 c66d0620 00000000 ca4d3c60 00000000 00009032 00000000
GPR08: 00020000 00000000 c087de44 c000afe0 c66d0ad0 100d3dd6 fffffff3 00000000
GPR16: 00000000 00000041 00000000 ca4d3d70 00000000 00000000 0000416d 00000000
GPR24: 00000004 c53b6128 00000000 0000e268 00000000 c07c0000 c07bb6fc ca4d3c60
NIP [c000ec34] kprobe_handler+0x128/0x290
LR [c000ecd8] kprobe_handler+0x1cc/0x290
Call Trace:
[ca4d3c30] [c000b09c] program_check_exception+0xbc/0x6fc
[ca4d3c50] [c000e43c] ret_from_except_full+0x0/0x4
--- interrupt: 700 at 0xe268
Instruction dump:
913e0008 81220000 38600001 3929ffff 91220000 80010024 bb410008 7c0803a6
38210020 4e800020 38600000 4e800020 <813b0000> 6d2a7fe0 2f8a0008 419e0154
---[ end trace 5b9152d4cdadd06d ]---
kprobe is not prepared to handle events in real mode and functions
running in real mode should have been blacklisted, so kprobe_handler()
can safely bail out telling 'this trap is not mine' for any trap that
happened while in real-mode.
If the trap happened with MSR_IR or MSR_DR cleared, return 0
immediately.
Reported-by: Larry Finger <Larry.Finger@lwfinger.net>
Fixes: 6cc89bad60 ("powerpc/kprobes: Invoke handlers directly")
Cc: stable@vger.kernel.org # v4.10+
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/424331e2006e7291a1bfe40e7f3fa58825f565e1.1582054578.git.christophe.leroy@c-s.fr
With the EEH early probe now being pseries specific there's no need for
eeh_ops->probe() to take a pci_dn. Instead, we can make it take a pci_dev
and use the probe function to map a pci_dev to an eeh_dev. This allows
the platform to implement it's own method for finding (or creating) an
eeh_dev for a given pci_dev which also removes a use of pci_dn in
generic EEH code.
This patch also renames eeh_device_add_late() to eeh_device_probe(). This
better reflects what it does does and removes the last vestiges of the
early/late EEH probe split.
Reviewed-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200306073904.4737-6-oohall@gmail.com
The eeh_ops->probe() function is called from two different contexts:
1. On pseries, where we set EEH_PROBE_MODE_DEVTREE, it's called in
eeh_add_device_early() which is supposed to run before we create
a pci_dev.
2. On PowerNV, where we set EEH_PROBE_MODE_DEV, it's called in
eeh_device_add_late() which is supposed to run *after* the
pci_dev is created.
The "early" probe is required because PAPR requires that we perform an RTAS
call to enable EEH support on a device before we start interacting with it
via config space or MMIO. This requirement doesn't exist on PowerNV and
shoehorning two completely separate initialisation paths into a common
interface just results in a convoluted code everywhere.
Additionally the early probe requires the probe function to take an pci_dn
rather than a pci_dev argument. We'd like to make pci_dn a pseries specific
data structure since there's no real requirement for them on PowerNV. To
help both goals move the early probe into the pseries containment zone
so the platform depedence is more explicit.
Reviewed-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200306073904.4737-5-oohall@gmail.com
This check for a missing PHB has existing in various forms since the
initial PPC64 port was upstreamed in 2002. The idea seems to be that we
need to guard against creating pci-specific data structures for the non-pci
children of a PCI device tree node (e.g. USB devices). However, we only
create pci_dn structures for DT nodes that correspond to PCI devices so
there's not much point in doing this check in the eeh_probe path.
Reviewed-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200306073904.4737-4-oohall@gmail.com
The pci hotplug helper (pci_hp_add_devices()) calls
eeh_add_device_tree_early() to scan the device-tree for new PCI devices and
do the early EEH probe before the device is scanned. This early probe is a
no-op in a lot of cases because:
a) The early init is only required to satisfy a PAPR requirement that EEH
be configured before we start doing config accesses. On PowerNV it is
a no-op.
b) It's a no-op for devices that have already had their eeh_dev
initialised.
There are four callers of pci_hp_add_devices():
1. arch/powerpc/kernel/eeh_driver.c
Here the hotplug helper is called when re-scanning pci_devs that
were removed during an EEH recovery pass. The EEH stat for each
removed device (the eeh_dev) is retained across a recovery pass
so the early init is a no-op in this case.
2. drivers/pci/hotplug/pnv_php.c
This is also a no-op since the PowerNV hotplug driver is, suprisingly,
PowerNV specific.
3. drivers/pci/hotplug/rpaphp_core.c
4. drivers/pci/hotplug/rpaphp_pci.c
In these two cases new devices have been hotplugged and FW has
provided new DT nodes for each. These are the only two cases where
the EEH we might have new PCI device nodes in the DT so these are
the only two cases where the early EEH probe needs to be done.
We can move the calls to eeh_add_device_tree_early() to the locations where
it's needed and remove it from the generic path. This is preparation for
making the early EEH probe pseries specific.
Reviewed-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200306073904.4737-3-oohall@gmail.com
On pseries and PowerNV pcibios_bus_add_device() calls eeh_add_device_late()
so there's no need to do a separate tree traversal to bind the eeh_dev and
pci_dev together setting up the PHB at boot. As a result we can remove
eeh_add_device_tree_late().
Reviewed-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200306073904.4737-2-oohall@gmail.com
Move creating the EEH specific sysfs files into eeh_add_device_late()
rather than being open-coded all over the place. Calling the function is
generally done immediately after calling eeh_add_device_late() anyway. This
is also a correctness fix since currently the sysfs files will be added
even if the EEH probe happens to fail.
Similarly, on pseries we currently add the sysfs files before calling
eeh_add_device_late(). This is flat-out broken since the sysfs files
require the pci_dev->dev.archdata.edev pointer to be set, and that is done
in eeh_add_device_late().
Reviewed-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200306073904.4737-1-oohall@gmail.com
The previous commit reduced the amount of code that is run before we
setup a paca. However there are still a few remaining functions that
run with no paca, or worse, with an arbitrary value in r13 that will
be used as a paca pointer.
In particular the stack protector canary is stored in the paca, so if
stack protector is activated for any of these functions we will read
the stack canary from wherever r13 points. If r13 happens to point
outside of memory we will get a machine check / checkstop.
For example if we modify initialise_paca() to trigger stack
protection, and then boot in the mambo simulator with r13 poisoned in
skiboot before calling the kernel:
DEBUG: 19952232: (19952232): INSTRUCTION: PC=0xC0000000191FC1E8: [0x3C4C006D]: addis r2,r12,0x6D [fetch]
DEBUG: 19952236: (19952236): INSTRUCTION: PC=0xC00000001807EAD8: [0x7D8802A6]: mflr r12 [fetch]
FATAL ERROR: 19952276: (19952276): Check Stop for 0:0: Machine Check with ME bit of MSR off
DEBUG: 19952276: (19952276): INSTRUCTION: PC=0xC0000000191FCA7C: [0xE90D0CF8]: ld r8,0xCF8(r13) [Instruction Failed]
INFO: 19952276: (19952277): ** Execution stopped: Mambo Error, Machine Check Stop, **
systemsim % bt
pc: 0xC0000000191FCA7C initialise_paca+0x54
lr: 0xC0000000191FC22C early_setup+0x44
stack:0x00000000198CBED0 0x0 +0x0
stack:0x00000000198CBF00 0xC0000000191FC22C early_setup+0x44
stack:0x00000000198CBF90 0x1801C968 +0x1801C968
So annotate the relevant functions to ensure stack protection is never
enabled for them.
Fixes: 06ec27aea9 ("powerpc/64: add stack protector support")
Cc: stable@vger.kernel.org # v4.20+
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200320032116.1024773-2-mpe@ellerman.id.au
Currently we set up the paca after parsing the device tree for CPU
features. Prior to that, r13 contains random data, which means there
is random data in r13 while we're running the generic dt parsing code.
This random data varies depending on whether we boot through a vmlinux
or a zImage: for the vmlinux case it's usually around zero, but for
zImages we see random values like 912a72603d420015.
This is poor practice, and can also lead to difficult-to-debug
crashes. For example, when kcov is enabled, the kcov instrumentation
attempts to read preempt_count out of the current task, which goes via
the paca. This then crashes in the zImage case.
Similarly stack protector can cause crashes if r13 is bogus, by
reading from the stack canary in the paca.
To resolve this:
- move the paca setup to before the CPU feature parsing.
- because we no longer have access to CPU feature flags in paca
setup, change the HV feature test in the paca setup path to consider
the actual value of the MSR rather than the CPU feature.
Translations get switched on once we leave early_setup, so I think
we'd already catch any other cases where the paca or task aren't set
up.
Boot tested on a P9 guest and host.
Fixes: fb0b0a73b2 ("powerpc: Enable kcov")
Fixes: 06ec27aea9 ("powerpc/64: add stack protector support")
Cc: stable@vger.kernel.org # v4.20+
Reviewed-by: Andrew Donnellan <ajd@linux.ibm.com>
Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Daniel Axtens <dja@axtens.net>
[mpe: Reword comments & change log a bit to mention stack protector]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200320032116.1024773-1-mpe@ellerman.id.au
Reorder Linux PTE bits to (almost) match Hash PTE bits.
RW Kernel : PP = 00
RO Kernel : PP = 00
RW User : PP = 01
RO User : PP = 11
So naturally, we should have
_PAGE_USER = 0x001
_PAGE_RW = 0x002
Today 0x001 and 0x002 and _PAGE_PRESENT and _PAGE_HASHPTE which
both are software only bits.
Switch _PAGE_USER and _PAGE_PRESET
Switch _PAGE_RW and _PAGE_HASHPTE
This allows to remove a few insns.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/c4d6c18a7f8d9d3b899bc492f55fbc40ef38896a.1583861325.git.christophe.leroy@c-s.fr
At the time being we have something like
if (something) {
p = get();
if (p) {
if (something_wrong)
goto out;
...
return;
} else if (a != b) {
if (some_error)
goto out;
...
}
goto out;
}
p = get();
if (!p) {
if (a != b) {
if (some_error)
goto out;
...
}
goto out;
}
This is similar to
p = get();
if (!p) {
if (a != b) {
if (some_error)
goto out;
...
}
goto out;
}
if (something) {
if (something_wrong)
goto out;
...
return;
}
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
[mpe: Reflow the comment that was moved]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/07a17425743600460ce35fa9432d42487a825583.1582099499.git.christophe.leroy@c-s.fr
We currently have two section mismatch warnings:
The function __boot_from_prom() references
the function __init prom_init().
The function start_here_common() references
the function __init start_kernel().
The warnings are correct, we do have branches from non-init code into
init code, which is freed after boot. But we don't expect to ever
execute any of that early boot code after boot, if we did that would
be a bug. In particular calling into OF after boot would be fatal
because OF is no longer resident.
So for now fix the warnings by marking the relevant functions as
__REF, which puts them in the ".ref.text" section.
This causes some reordering of the functions in the final link:
@@ -217,10 +217,9 @@
c00000000000b088 t generic_secondary_common_init
c00000000000b124 t __mmu_off
c00000000000b14c t __start_initialization_multiplatform
-c00000000000b1ac t __boot_from_prom
-c00000000000b1ec t __after_prom_start
-c00000000000b260 t p_end
-c00000000000b27c T copy_and_flush
+c00000000000b1ac t __after_prom_start
+c00000000000b220 t p_end
+c00000000000b23c T copy_and_flush
c00000000000b300 T __secondary_start
c00000000000b300 t copy_to_here
c00000000000b344 t start_secondary_prolog
@@ -228,8 +227,9 @@
c00000000000b36c t enable_64b_mode
c00000000000b388 T relative_toc
c00000000000b3a8 t p_toc
-c00000000000b3b0 t start_here_common
-c00000000000b3d0 t start_here_multiplatform
+c00000000000b3b0 t __boot_from_prom
+c00000000000b3f0 t start_here_multiplatform
+c00000000000b480 t start_here_common
c00000000000b880 T system_call_common
c00000000000b974 t system_call
c00000000000b9dc t system_call_exit
In particular __boot_from_prom moves after copy_to_here, which means
it's not copied to zero in the first stage of copy of the kernel to
zero.
But that's OK, because we only call __boot_from_prom before we do the
copy, so it makes no difference when it's copied. The call sequence
is:
__start
-> __start_initialization_multiplatform
-> __boot_from_prom
-> __start
-> __start_initialization_multiplatform
-> __after_prom_start
-> copy_and_flush
-> copy_and_flush (relocated to 0)
-> start_here_multiplatform
-> early_setup
Reported-by: Mauricio Faria de Oliveira <mauricfo@linux.ibm.com>
Reported-by: Roman Bolshakov <r.bolshakov@yadro.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225031328.14676-1-mpe@ellerman.id.au
The "os-term" RTAS calls has one argument with a message address of OS
termination cause. rtas_os_term() already passes it but the recently
added prom_init's version of that missed it; it also does not fill
args correctly.
This passes the message address and initializes the number of arguments.
Fixes: 6a9c930bd7 ("powerpc/prom_init: Add the ESM call to prom_init")
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200312074404.87293-1-aik@ozlabs.ru
Simplify gen_btf logic to make it work with llvm-objcopy. The existing
'file format' and 'architecture' parsing logic is brittle and does not
work with llvm-objcopy/llvm-objdump.
'file format' output of llvm-objdump>=11 will match GNU objdump, but
'architecture' (bfdarch) may not.
.BTF in .tmp_vmlinux.btf is non-SHF_ALLOC. Add the SHF_ALLOC flag
because it is part of vmlinux image used for introspection. C code
can reference the section via linker script defined __start_BTF and
__stop_BTF. This fixes a small problem that previous .BTF had the
SHF_WRITE flag (objcopy -I binary -O elf* synthesized .data).
Additionally, `objcopy -I binary` synthesized symbols
_binary__btf_vmlinux_bin_start and _binary__btf_vmlinux_bin_stop (not
used elsewhere) are replaced with more commonplace __start_BTF and
__stop_BTF.
Add 2>/dev/null because GNU objcopy (but not llvm-objcopy) warns
"empty loadable segment detected at vaddr=0xffffffff81000000, is this intentional?"
We use a dd command to change the e_type field in the ELF header from
ET_EXEC to ET_REL so that lld will accept .btf.vmlinux.bin.o. Accepting
ET_EXEC as an input file is an extremely rare GNU ld feature that lld
does not intend to support, because this is error-prone.
The output section description .BTF in include/asm-generic/vmlinux.lds.h
avoids potential subtle orphan section placement issues and suppresses
--orphan-handling=warn warnings.
Fixes: df786c9b94 ("bpf: Force .BTF section start to zero when dumping from vmlinux")
Fixes: cb0cc635c7 ("powerpc: Include .BTF section")
Reported-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Fangrui Song <maskray@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Stanislav Fomichev <sdf@google.com>
Tested-by: Andrii Nakryiko <andriin@fb.com>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Link: https://github.com/ClangBuiltLinux/linux/issues/871
Link: https://lore.kernel.org/bpf/20200318222746.173648-1-maskray@google.com
The original 2005 patch that introduced the powerpc vdso, pre-git
("ppc64: Implement a vDSO and use it for signal trampoline") notes that:
... symbols exposed by the vDSO aren't "normal" function symbols, apps
can't be expected to link against them directly, the vDSO's are both
seen as if they were linked at 0 and the symbols just contain offsets
to the various functions. This is done on purpose to avoid a
relocation step (ppc64 functions normally have descriptors with abs
addresses in them). When glibc uses those functions, it's expected to
use it's own trampolines that know how to reach them.
Despite that explanation, there remains dead #ifdef
VDS64_HAS_DESCRIPTORS code-blocks that provide alternate function
definitions that setup function descriptors.
Since VDS64_HAS_DESCRIPTORS has been unused for all these years, we
might as well finally remove it from the codebase.
Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200224211848.26087-1-joe.lawrence@redhat.com
With commit ("powerpc/numa: Early request for home node associativity"),
commit 2ea6263068 ("powerpc/topology: Get topology for shared
processors at boot") which was requesting home node associativity
becomes redundant.
Hence remove the late request for home node associativity.
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Reported-by: Abdul Haleem <abdhalee@linux.vnet.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/20200129135301.24739-6-srikar@linux.vnet.ibm.com
package_id is to match cores that are part of the same chip. On
PowerNV machines, package_id defaults to chip_id. However ibm,chip_id
property is not present in device-tree of PowerVM LPARs. Hence lscpu
output shows one core per socket and multiple cores.
To overcome this, use nid as the package_id on PowerVM LPARs.
Before the patch:
Architecture: ppc64le
Byte Order: Little Endian
CPU(s): 128
On-line CPU(s) list: 0-127
Thread(s) per core: 8
Core(s) per socket: 1 <----------------------
Socket(s): 16 <----------------------
NUMA node(s): 2
Model: 2.2 (pvr 004e 0202)
Model name: POWER9 (architected), altivec supported
Hypervisor vendor: pHyp
Virtualization type: para
L1d cache: 32K
L1i cache: 32K
L2 cache: 512K
L3 cache: 10240K
NUMA node0 CPU(s): 0-63
NUMA node1 CPU(s): 64-127
#
# cat /sys/devices/system/cpu/cpu0/topology/physical_package_id
-1
After the patch:
Architecture: ppc64le
Byte Order: Little Endian
CPU(s): 128
On-line CPU(s) list: 0-127
Thread(s) per core: 8 <---------------------
Core(s) per socket: 8 <---------------------
Socket(s): 2
NUMA node(s): 2
Model: 2.2 (pvr 004e 0202)
Model name: POWER9 (architected), altivec supported
Hypervisor vendor: pHyp
Virtualization type: para
L1d cache: 32K
L1i cache: 32K
L2 cache: 512K
L3 cache: 10240K
NUMA node0 CPU(s): 0-63
NUMA node1 CPU(s): 64-127
#
# cat /sys/devices/system/cpu/cpu0/topology/physical_package_id
0
Now lscpu output is more in line with the system configuration.
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
[mpe: Use pkg_id instead of ppid, tweak change log and comment]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200129135121.24617-1-srikar@linux.vnet.ibm.com
Until commit 7306e83ccf ("powerpc: Don't use CURRENT_THREAD_INFO to
find the stack"), the current stack base address was obtained by
calling current_thread_info(). That inline function was simply masking
out the value of r1.
In that commit, it was changed to using current_stack_pointer() (since
renamed current_stack_frame()), which is a heavier function as it is
an outline assembly function which cannot be inlined and which reads
the content of the stack at 0(r1).
Convert to using current_stack_pointer for geting r1 and masking out
its value to obtain the base address of the stack pointer as before.
Fixes: 7306e83ccf ("powerpc: Don't use CURRENT_THREAD_INFO to find the stack")
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200220115141.2707-5-mpe@ellerman.id.au
Instead of #ifdef, use IS_ENABLED(CONFIG_DEBUG_STACKOVERFLOW).
This enable GCC to check for code validity even when the option
is not selected.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200220115141.2707-4-mpe@ellerman.id.au
The purpose of check_stack_overflow() is to verify that the stack has
not overflowed.
To really know whether the stack pointer is still within boundaries,
the check must be done directly on the value of r1.
So use current_stack_pointer, which returns the current value of r1,
rather than current_stack_frame() which causes a frame to be created
and then returns that value.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200220115141.2707-3-mpe@ellerman.id.au
current_stack_pointer(), which was called __get_SP(), used to just
return the value in r1.
But that caused problems in some cases, so it was turned into a
function in commit bfe9a2cfe9 ("powerpc: Reimplement __get_SP() as a
function not a define").
Because it's a function in a separate compilation unit to all its
callers, it has the effect of causing a stack frame to be created, and
then returns the address of that frame. This is good in some cases
like those described in the above commit, but in other cases it's
overkill, we just need to know what stack page we're on.
On some other arches current_stack_pointer is just a register global
giving the stack pointer, and we'd like to do that too. So rename our
current_stack_pointer() to current_stack_frame() to make that
possible.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Link: https://lore.kernel.org/r/20200220115141.2707-1-mpe@ellerman.id.au
Many of the performance monitoring unit (PMU) SPRs are
exposed in the sysfs. This may not be a desirable since
"perf" API is the primary interface to program PMU and
collect counter data in the system. But that said, we
cant remove these sysfs files since we dont whether
anyone/anything is using them.
So the patch adds a new CONFIG option 'CONFIG_PMU_SYSFS'
(user selectable) to be used in sysfs file creation for
PMU SPRs. New option by default is disabled, but can be
enabled if user needs it.
Tested this patch behaviour in powernv and pseries machines.
Patch is also tested for pmac32_defconfig.
Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
Tested-by: Nageswara R Sastry <nasastry@in.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200214080606.26872-2-kjain@linux.ibm.com
An attempt to refactor the current sysfs.c file.
To start with a big chuck of macro #defines and dscr
functions are moved to start of the file. Secondly,
HAS_ #define macros are cleanup based on CONFIG_ options
Finally new HAS_ macro added:
1. HAS_PPC_PA6T (for PA6T) to separate out non-PMU SPRs.
2. HAS_PPC_PMC56 to separate out PMC SPR's from HAS_PPC_PMC_CLASSIC
which come under CONFIG_PPC64.
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200214080606.26872-1-kjain@linux.ibm.com
When calling debugfs functions, there is no need to ever check the
return value. The function can work or not, but the code logic should
never do something different based on this.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200209105901.1620958-1-gregkh@linuxfoundation.org
PowerVM systems running compatibility mode on a few Power8 revisions are
still vulnerable to the hardware defect that loses PMU exceptions arriving
prior to a context switch.
The software fix for this issue is enabled through the CPU_FTR_PMAO_BUG
cpu_feature bit, nevertheless this bit also needs to be set for PowerVM
compatibility mode systems.
Fixes: 68f2f0d431 ("powerpc: Add a cpu feature CPU_FTR_PMAO_BUG")
Signed-off-by: Desnes A. Nunes do Rosario <desnesn@linux.ibm.com>
Reviewed-by: Leonardo Bras <leonardo@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200227134715.9715-1-desnesn@linux.ibm.com
Since commit b86fb88855 ("powerpc/32: implement fast entry for
syscalls on non BOOKE") and commit 1a4b739bbb ("powerpc/32:
implement fast entry for syscalls on BOOKE"), syscalls don't
use the exception entry path anymore. It is therefore pointless
to restore r0 and r6-r8 after calling trace_hardirqs_off().
In the meantime, drop the '2:' label which is unused and misleading.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/d2c6dc65d27e83964eb05f16a126161ab6455eea.1578388585.git.christophe.leroy@c-s.fr
Selecting CONFIG_DEBUG_INFO_BTF results in the below warning from ld:
ld: warning: orphan section `.BTF' from `.btf.vmlinux.bin.o' being placed in section `.BTF'
Include .BTF section in vmlinux explicitly to fix the same.
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200220113132.857132-1-naveen.n.rao@linux.vnet.ibm.com
DAR is set to the first byte of overlap between actual access and
watched range at DSI on Book3S processor. But actual access range
might or might not be within user asked range. So for Book3S, it
must not call dar_within_range().
This revert portion of commit 39413ae009 ("powerpc/hw_breakpoints:
Rewrite 8xx breakpoints to allow any address range size.").
Before patch:
# ./tools/testing/selftests/powerpc/ptrace/perf-hwbreak
...
TESTED: No overlap
FAILED: Partial overlap: 0 != 2
TESTED: Partial overlap
TESTED: No overlap
FAILED: Full overlap: 0 != 2
failure: perf_hwbreak
After patch:
TESTED: No overlap
TESTED: Partial overlap
TESTED: Partial overlap
TESTED: No overlap
TESTED: Full overlap
success: perf_hwbreak
Fixes: 39413ae009 ("powerpc/hw_breakpoints: Rewrite 8xx breakpoints to allow any address range size.")
Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200222082049.330435-1-ravi.bangoria@linux.ibm.com
CR0 can be saved later, and CTR can also be used for saving.
Keep SRR1 in r9 and stash SRR0 in CTR, this avoids using thread_struct
in memory for that.
Saves 3 cycles (ie 1%) in null_syscall selftest on 8xx.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/b94c3bc03bac9431fec2dadb686384c481889422.1580470483.git.christophe.leroy@c-s.fr
Since commit b86fb88855 ("powerpc/32: implement fast entry for
syscalls on non BOOKE") and commit 1a4b739bbb ("powerpc/32:
implement fast entry for syscalls on BOOKE"), syscalls from
kernel are unexpected and can have catastrophic consequences
as it will destroy the kernel stack.
Test MSR_PR on syscall entry. In case syscall is from kernel,
emit a warning and return ENOSYS error.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/8ee3bdbbdfdfc64ca7001e90c43b2aee6f333578.1580470482.git.christophe.leroy@c-s.fr
Add a sys interface to allow querying the memory reserved by FADump for
saving the crash dump.
Also added Documentation/ABI for the new sysfs file.
Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191211160910.21656-7-sourabhjain@linux.ibm.com
As the number of FADump sysfs files increases it is hard to manage all
of them inside /sys/kernel directory. It's better to have all the
FADump related sysfs files in a dedicated directory
/sys/kernel/fadump. But in order to maintain backward compatibility a
symlink has been added for every sysfs that has moved to new location.
As the FADump sysfs files are now part of a dedicated directory there
is no need to prefix their name with fadump_, hence sysfs file names
are also updated. For example fadump_enabled sysfs file is now
referred as enabled.
Also consolidate ABI documentation for all the FADump sysfs files in a
single file Documentation/ABI/testing/sysfs-kernel-fadump.
Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Tested-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191211160910.21656-4-sourabhjain@linux.ibm.com
power_save_ppc32_restore() is called during exception entry, before
re-enabling the MMU. It substracts KERNELBASE from the address
of nap_save_msscr0 to access it.
With CONFIG_VMAP_STACK enabled, data MMU translation has already been
re-enabled, so power_save_ppc32_restore() has to access
nap_save_msscr0 by its virtual address.
Reported-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Fixes: cd08f109e2 ("powerpc/32s: Enable CONFIG_VMAP_STACK")
Tested-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/7bce32ccbab3ba3e3e0f27da6961bf6313df97ed.1581663140.git.christophe.leroy@c-s.fr
hash_page() needs to read page tables from kernel memory. When entire
kernel memory is mapped by BATs, which is normally the case when
CONFIG_STRICT_KERNEL_RWX is not set, it works even if the page hosting
the page table is not referenced in the MMU hash table.
However, if the page where the page table resides is not covered by
a BAT, a DSI fault can be encountered from hash_page(), and it loops
forever. This can happen when CONFIG_STRICT_KERNEL_RWX is selected
and the alignment of the different regions is too small to allow
covering the entire memory with BATs. This also happens when
CONFIG_DEBUG_PAGEALLOC is selected or when booting with 'nobats'
flag.
Also, if the page containing the kernel stack is not present in the
MMU hash table, registers cannot be saved and a recursive DSI fault
is encountered.
To allow hash_page() to properly do its job at all time and load the
MMU hash table whenever needed, it must run with data MMU disabled.
This means it must be called before re-enabling data MMU. To allow
this, registers clobbered by hash_page() and create_hpte() have to
be saved in the thread struct together with SRR0, SSR1, DAR and DSISR.
It is also necessary to ensure that DSI prolog doesn't overwrite
regs saved by prolog of the current running exception. That means:
- DSI can only use SPRN_SPRG_SCRATCH0
- Exceptions must free SPRN_SPRG_SCRATCH0 before writing to the stack.
This also fixes the Oops reported by Erhard when create_hpte() is
called by add_hash_page().
Due to prolog size increase, a few more exceptions had to get split
in two parts.
Fixes: cd08f109e2 ("powerpc/32s: Enable CONFIG_VMAP_STACK")
Reported-by: Erhard F. <erhard_f@mailbox.org>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Tested-by: Erhard F. <erhard_f@mailbox.org>
Tested-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=206501
Link: https://lore.kernel.org/r/64a4aa44686e9fd4b01333401367029771d9b231.1581761633.git.christophe.leroy@c-s.fr
After a treclaim, we expect to be in non-transactional state. If we
don't clear the current thread's MSR[TS] before we get preempted, then
tm_recheckpoint_new_task() will recheckpoint and we get rescheduled in
suspended transaction state.
When handling a signal caught in transactional state,
handle_rt_signal64() calls get_tm_stackpointer() that treclaims the
transaction using tm_reclaim_current() but without clearing the
thread's MSR[TS]. This can cause the TM Bad Thing exception below if
later we pagefault and get preempted trying to access the user's
sigframe, using __put_user(). Afterwards, when we are rescheduled back
into do_page_fault() (but now in suspended state since the thread's
MSR[TS] was not cleared), upon executing 'rfid' after completion of
the page fault handling, the exception is raised because a transition
from suspended to non-transactional state is invalid.
Unexpected TM Bad Thing exception at c00000000000de44 (msr 0x8000000302a03031) tm_scratch=800000010280b033
Oops: Unrecoverable exception, sig: 6 [#1]
LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries
CPU: 25 PID: 15547 Comm: a.out Not tainted 5.4.0-rc2 #32
NIP: c00000000000de44 LR: c000000000034728 CTR: 0000000000000000
REGS: c00000003fe7bd70 TRAP: 0700 Not tainted (5.4.0-rc2)
MSR: 8000000302a03031 <SF,VEC,VSX,FP,ME,IR,DR,LE,TM[SE]> CR: 44000884 XER: 00000000
CFAR: c00000000000dda4 IRQMASK: 0
PACATMSCRATCH: 800000010280b033
GPR00: c000000000034728 c000000f65a17c80 c000000001662800 00007fffacf3fd78
GPR04: 0000000000001000 0000000000001000 0000000000000000 c000000f611f8af0
GPR08: 0000000000000000 0000000078006001 0000000000000000 000c000000000000
GPR12: c000000f611f84b0 c00000003ffcb200 0000000000000000 0000000000000000
GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
GPR20: 0000000000000000 0000000000000000 0000000000000000 c000000f611f8140
GPR24: 0000000000000000 00007fffacf3fd68 c000000f65a17d90 c000000f611f7800
GPR28: c000000f65a17e90 c000000f65a17e90 c000000001685e18 00007fffacf3f000
NIP [c00000000000de44] fast_exception_return+0xf4/0x1b0
LR [c000000000034728] handle_rt_signal64+0x78/0xc50
Call Trace:
[c000000f65a17c80] [c000000000034710] handle_rt_signal64+0x60/0xc50 (unreliable)
[c000000f65a17d30] [c000000000023640] do_notify_resume+0x330/0x460
[c000000f65a17e20] [c00000000000dcc4] ret_from_except_lite+0x70/0x74
Instruction dump:
7c4ff120 e8410170 7c5a03a6 38400000 f8410060 e8010070 e8410080 e8610088
60000000 60000000 e8810090 e8210078 <4c000024> 48000000 e8610178 88ed0989
---[ end trace 93094aa44b442f87 ]---
The simplified sequence of events that triggers the above exception is:
... # userspace in NON-TRANSACTIONAL state
tbegin # userspace in TRANSACTIONAL state
signal delivery # kernelspace in SUSPENDED state
handle_rt_signal64()
get_tm_stackpointer()
treclaim # kernelspace in NON-TRANSACTIONAL state
__put_user()
page fault happens. We will never get back here because of the TM Bad Thing exception.
page fault handling kicks in and we voluntarily preempt ourselves
do_page_fault()
__schedule()
__switch_to(other_task)
our task is rescheduled and we recheckpoint because the thread's MSR[TS] was not cleared
__switch_to(our_task)
switch_to_tm()
tm_recheckpoint_new_task()
trechkpt # kernelspace in SUSPENDED state
The page fault handling resumes, but now we are in suspended transaction state
do_page_fault() completes
rfid <----- trying to get back where the page fault happened (we were non-transactional back then)
TM Bad Thing # illegal transition from suspended to non-transactional
This patch fixes that issue by clearing the current thread's MSR[TS]
just after treclaim in get_tm_stackpointer() so that we stay in
non-transactional state in case we are preempted. In order to make
treclaim and clearing the thread's MSR[TS] atomic from a preemption
perspective when CONFIG_PREEMPT is set, preempt_disable/enable() is
used. It's also necessary to save the previous value of the thread's
MSR before get_tm_stackpointer() is called so that it can be exposed
to the signal handler later in setup_tm_sigcontexts() to inform the
userspace MSR at the moment of the signal delivery.
Found with tm-signal-context-force-tm kernel selftest.
Fixes: 2b0a576d15 ("powerpc: Add new transactional memory state to the signal context")
Cc: stable@vger.kernel.org # v3.9
Signed-off-by: Gustavo Luiz Duarte <gustavold@linux.ibm.com>
Acked-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200211033831.11165-1-gustavold@linux.ibm.com
In ITLB miss handled the line supposed to clear bits 20-23 on the L2
ITLB entry is buggy and does indeed nothing, leading to undefined
value which could allow execution when it shouldn't.
Properly do the clearing with the relevant instruction.
Fixes: 74fabcadfd ("powerpc/8xx: don't use r12/SPRN_SPRG_SCRATCH2 in TLB Miss handlers")
Cc: stable@vger.kernel.org # v5.0+
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Leonardo Bras <leonardo@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/4f70c2778163affce8508a210f65d140e84524b4.1581272050.git.christophe.leroy@c-s.fr
Recovering a dead PHB can currently cause a deadlock as the PCI
rescan/remove lock is taken twice.
This is caused as part of an existing bug in
eeh_handle_special_event(). The pe is processed while traversing the
PHBs even though the pe is unrelated to the loop. This causes the pe
to be, incorrectly, processed more than once.
Untangling this section can move the pe processing out of the loop and
also outside the locked section, correcting both problems.
Fixes: 2e25505147 ("powerpc/eeh: Fix crash when edev->pdev changes")
Cc: stable@vger.kernel.org # 5.4+
Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Reviewed-by: Frederic Barrat <fbarrat@linux.ibm.com>
Tested-by: Frederic Barrat <fbarrat@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/0547e82dbf90ee0729a2979a8cac5c91665c621f.1581051445.git.sbobroff@linux.ibm.com
Let's use the struct of_pci_range.flags field instead so we can remove
the pci_space field.
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Rob Herring <robh@kernel.org>
