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
Add a way to manually invoke a fast-reboot rather than setting the NVRAM
flag. The idea is to allow userspace to invoke a fast-reboot using the
optional string argument to the reboot() system call, or using the xmon
zr command so we don't need to leave around a persistent changes on
a system to use the feature.
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200217024833.30580-2-oohall@gmail.com
Treat an empty reboot cmd string the same as a NULL string. This squashes a
spurious unsupported reboot message that sometimes gets out when using
xmon.
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200217024833.30580-1-oohall@gmail.com
Some of our phony targets are not marked as such. This can lead to
confusing errors, eg:
$ make clean
$ touch install
$ make install
make: 'install' is up to date.
$
Fix it by adding them to the PHONY variable which is marked phony in
the top-level Makefile, or in scripts/Makefile.build for the boot
Makefile.
Suggested-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200219000434.15872-1-mpe@ellerman.id.au
On PPC32, pte_offset_map() does a kmap_atomic() in order to support
page tables allocated in high memory, just like ARM and x86/32.
But since at least 2008 and commit 8054a3428f ("powerpc: Remove dead
CONFIG_HIGHPTE"), page tables are never allocated in high memory.
When the page is in low mem, kmap_atomic() just returns the page
address but still disable preemption and pagefault. And it is
not an inlined function, so we suffer function call for no reason.
Make pte_offset_map() the same as pte_offset_kernel() and make
pte_unmap() void, in the same way as PPC64 which doesn't have HIGHMEM.
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/03c97f0f6b3790d164822563be80f2fd4713a955.1581932480.git.christophe.leroy@c-s.fr
The last jump to free_exit in mm_iommu_do_alloc() happens after page
pointers in struct mm_iommu_table_group_mem_t were already converted to
physical addresses. Thus calling put_page() on these physical addresses
will likely crash.
This moves the loop which calculates the pageshift and converts page
struct pointers to physical addresses later after the point when
we cannot fail; thus eliminating the need to convert pointers back.
Fixes: eb9d7a62c3 ("powerpc/mm_iommu: Fix potential deadlock")
Reported-by: Jan Kara <jack@suse.cz>
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191223060351.26359-1-aik@ozlabs.ru
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>
Reviewed-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200209105901.1620958-6-gregkh@linuxfoundation.org
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/20200209105901.1620958-5-gregkh@linuxfoundation.org
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/20200209105901.1620958-4-gregkh@linuxfoundation.org
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/20200209105901.1620958-3-gregkh@linuxfoundation.org
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.
Because of this cleanup, we get to remove a few fields in struct
kvm_arch that are now unused.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[mpe: Fix build error in kvm/timing.c, adapt kvmppc_remove_cpu_debugfs()]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200209105901.1620958-2-gregkh@linuxfoundation.org
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
In some error handling path, we should call "of_node_put(np_par)" or
some resource may be leaking in case of error.
Fixes: 8159df72d4 ("83xx: add support for the kmeter1 board.")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Acked-by: Scott Wood <oss@buserror.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200208140920.7652-1-christophe.jaillet@wanadoo.fr
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
Commit 8d30c14cab ("powerpc/mm: Rework I$/D$ coherency (v3)") and
commit 90ac19a8b2 ("[POWERPC] Abolish iopa(), mm_ptov(),
io_block_mapping() from arch/powerpc") removed the use of get_pteptr()
outside of mm/pgtable_32.c
In mm/pgtable_32.c, the only user of get_pteptr() is change_page_attr()
which operates on kernel context and on lowmem pages only.
Make virt_to_kpte() available outside of mm/mem.c and use it instead
of get_pteptr(), and drop get_pteptr()
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/788378c6c3ba5c5298caab7c7f95e6c3c88244b8.1578558199.git.christophe.leroy@c-s.fr
At several places pmd pointer is retrieved through the same action:
pmd = pmd_offset(pud_offset(pgd_offset(mm, addr), addr), addr);
or
pmd = pmd_offset(pud_offset(pgd_offset_k(addr), addr), addr);
Refactor this by implementing two helpers pmd_ptr() and pmd_ptr_k()
This will help when adding the p4d level.
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/7b065c5be35726af4066cab238ee35cabceda1fa.1578558199.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 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
_tlbia() is a function used only on 603/603e core, ie on CPUs which
don't have a hash table.
_tlbia() uses the tlbia macro which implements a loop of 1024 tlbie.
On the 603/603e core, flushing the entire TLB requires no more than
32 tlbie.
Replace tlbia by a loop of 32 tlbie.
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/12f4f4f0ff89aeab3b937fc96c84fb35e1b2517e.1580748445.git.christophe.leroy@c-s.fr
In guests without hotplugagble memory drmem structure is only zero
initialized. Trying to manipulate DLPAR parameters results in a crash.
$ echo "memory add count 1" > /sys/kernel/dlpar
Oops: Kernel access of bad area, sig: 11 [#1]
LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries
...
NIP: c0000000000ff294 LR: c0000000000ff248 CTR: 0000000000000000
REGS: c0000000fb9d3880 TRAP: 0300 Tainted: G E (5.5.0-rc6-2-default)
MSR: 8000000000009033 <SF,EE,ME,IR,DR,RI,LE> CR: 28242428 XER: 20000000
CFAR: c0000000009a6c10 DAR: 0000000000000010 DSISR: 40000000 IRQMASK: 0
...
NIP dlpar_memory+0x6e4/0xd00
LR dlpar_memory+0x698/0xd00
Call Trace:
dlpar_memory+0x698/0xd00 (unreliable)
handle_dlpar_errorlog+0xc0/0x190
dlpar_store+0x198/0x4a0
kobj_attr_store+0x30/0x50
sysfs_kf_write+0x64/0x90
kernfs_fop_write+0x1b0/0x290
__vfs_write+0x3c/0x70
vfs_write+0xd0/0x260
ksys_write+0xdc/0x130
system_call+0x5c/0x68
Taking closer look at the code, I can see that for_each_drmem_lmb is a
macro expanding into `for (lmb = &drmem_info->lmbs[0]; lmb <=
&drmem_info->lmbs[drmem_info->n_lmbs - 1]; lmb++)`. When drmem_info->lmbs
is NULL, the loop would iterate through the whole address range if it
weren't stopped by the NULL pointer dereference on the next line.
This patch aligns for_each_drmem_lmb and for_each_drmem_lmb_in_range
macro behavior with the common C semantics, where the end marker does
not belong to the scanned range, and alters get_lmb_range() semantics.
As a side effect, the wraparound observed in the crash is prevented.
Fixes: 6c6ea53725 ("powerpc/mm: Separate ibm, dynamic-memory data from DT format")
Cc: stable@vger.kernel.org # v4.16+
Signed-off-by: Libor Pechacek <lpechacek@suse.cz>
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200131132829.10281-1-msuchanek@suse.de
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
When flushing any memory range, the flushing function
flushes all TLBs.
When (start) and (end - 1) are in the same memory page,
flush that page instead.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Segher Boessenkool <segher@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/b30b2eae6960502eaf0d9e36c60820b839693c33.1580542939.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
Add a deprecation note in FADump sysfs ABI documentation files and
move them from ABI/testing to ABI/obsolete directory.
Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com>
[mpe: Use a proper table to fix errors from the documentation build]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191211160910.21656-6-sourabhjain@linux.ibm.com
The /sys/firmware/opal/core and /sys/kernel/fadump_release_opalcore
sysfs files are used to export and release the OPAL memory on PowerNV
platform. let's organize them into a new kobject under
/sys/firmware/opal/mpipl/ directory.
A symlink is added to maintain the backward compatibility for
/sys/firmware/opal/core 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/20191211160910.21656-5-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
The __compat_only_sysfs_link_entry_to_kobj function creates a symlink
to a kobject but doesn't provide an option to change the symlink file
name.
This patch adds a wrapper function compat_only_sysfs_link_entry_to_kobj
that extends the __compat_only_sysfs_link_entry_to_kobj functionality
which allows function caller to customize the symlink name.
Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com>
[mpe: Fix compile error when CONFIG_SYSFS=n]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191211160910.21656-3-sourabhjain@linux.ibm.com
Function papr_scm_ndctl() is neither exported from the module nor
called directly from outside 'papr.c' hence should be marked 'static'.
Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200130040206.79998-1-vaibhav@linux.ibm.com
The pseries Makefile (arch/powerpc/platforms/pseries/Makefile) is only
included by the platform Makefile (arch/powerpc/platform/Makefile)
when CONFIG_PPC_PSERIES is selected, so checking for
CONFIG_PPC_PSERIES in the pseries Makefile is pointless.
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Reviewed-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200130063153.19915-2-oohall@gmail.com
vio.c is in platforms/pseries, which is only built if PPC_PSERIES=y.
In other words, this ifdef is pointless.
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Reviewed-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200130063153.19915-1-oohall@gmail.com
The ls (lookup symbol) and zr (reboot) commands use xmon's getstring()
helper to read a string argument from the xmon prompt. This function
skips over leading whitespace, but doesn't check if the first
"non-whitespace" character is a newline which causes some odd
behaviour (<enter> indicates a the enter key was pressed):
0:mon> ls printk<enter>
printk: c0000000001680c4
0:mon> ls<enter>
printk<enter>
Symbol '
printk' not found.
0:mon>
With commit 2d9b332d99 ("powerpc/xmon: Allow passing an argument to
ppc_md.restart()") we have a similar problem with the zr command.
Previously zr took no arguments so "zr<enter> would trigger a reboot.
With that patch applied a second newline needs to be sent in order for
the reboot to occur. Fix this by checking if the leading whitespace
ended on a newline:
0:mon> ls<enter>
Symbol '' not found.
Fixes: 2d9b332d99 ("powerpc/xmon: Allow passing an argument to ppc_md.restart()")
Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200217041343.2454-1-oohall@gmail.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
With HW assistance all page tables must be 4k aligned, the 8xx drops
the last 12 bits during the walk.
Redefine HUGEPD_SHIFT_MASK to mask last 12 bits out. HUGEPD_SHIFT_MASK
is used to for alignment of page table cache.
Fixes: 22569b881d ("powerpc/8xx: Enable 8M hugepage support with HW assistance")
Cc: stable@vger.kernel.org # v5.0+
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/778b1a248c4c7ca79640eeff7740044da6a220a0.1581264115.git.christophe.leroy@c-s.fr
Commit 55c8fc3f49 ("powerpc/8xx: reintroduce 16K pages with HW
assistance") redefined pte_t as a struct of 4 pte_basic_t, because
in 16K pages mode there are four identical entries in the
page table. But the size of hugepage tables is calculated based
of the size of (void *). Therefore, we end up with page tables
of size 1k instead of 4k for 512k pages.
As 512k hugepage tables are the same size as standard page tables,
ie 4k, use the standard page tables instead of PGT_CACHE tables.
Fixes: 3fb69c6a1a ("powerpc/8xx: Enable 512k hugepage support with HW assistance")
Cc: stable@vger.kernel.org # v5.0+
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/90ec56a2315be602494619ed0223bba3b0b8d619.1580997007.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
I know this is late; I've been travelling and, well, I've been
distracted.
This is just a few bug fixes and adding i2c support to the IPMB driver,
which is something I wanted from the beginning for it. It would be
nice for the people doing IPMB to get this in.
-corey
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Merge tag 'for-linus-5.6-1' of https://github.com/cminyard/linux-ipmi
Pull IPMI update from Corey Minyard:
"Minor bug fixes for IPMI
I know this is late; I've been travelling and, well, I've been
distracted.
This is just a few bug fixes and adding i2c support to the IPMB
driver, which is something I wanted from the beginning for it"
* tag 'for-linus-5.6-1' of https://github.com/cminyard/linux-ipmi:
drivers: ipmi: fix off-by-one bounds check that leads to a out-of-bounds write
ipmi:ssif: Handle a possible NULL pointer reference
drivers: ipmi: Modify max length of IPMB packet
drivers: ipmi: Support raw i2c packet in IPMB
KVM documentation to rst format, which was very welcome.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM fixes from Paolo Bonzini:
"Bugfixes and improvements to selftests.
On top of this, Mauro converted the KVM documentation to rst format,
which was very welcome"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (44 commits)
docs: virt: guest-halt-polling.txt convert to ReST
docs: kvm: review-checklist.txt: rename to ReST
docs: kvm: Convert timekeeping.txt to ReST format
docs: kvm: Convert s390-diag.txt to ReST format
docs: kvm: Convert ppc-pv.txt to ReST format
docs: kvm: Convert nested-vmx.txt to ReST format
docs: kvm: Convert mmu.txt to ReST format
docs: kvm: Convert locking.txt to ReST format
docs: kvm: Convert hypercalls.txt to ReST format
docs: kvm: arm/psci.txt: convert to ReST
docs: kvm: convert arm/hyp-abi.txt to ReST
docs: kvm: Convert api.txt to ReST format
docs: kvm: convert devices/xive.txt to ReST
docs: kvm: convert devices/xics.txt to ReST
docs: kvm: convert devices/vm.txt to ReST
docs: kvm: convert devices/vfio.txt to ReST
docs: kvm: convert devices/vcpu.txt to ReST
docs: kvm: convert devices/s390_flic.txt to ReST
docs: kvm: convert devices/mpic.txt to ReST
docs: kvm: convert devices/arm-vgit.txt to ReST
...
Robert Richter.
Debug options like DEBUG_TEST_DRIVER_REMOVE, KASAN and DEBUG_KMEMLEAK
unearthed issues with the lifespan of memory allocated by the EDAC
memory controller descriptor due to misdesigned memory freeing, done
partially by the EDAC core *and* the driver core, which is problematic
to say the least.
These two are minimal fixes to take care of stable - a proper rework is
following which cleans up that mess properly.
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Merge tag 'edac_urgent_for_5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras
Pull EDAC fixes from Borislav Petkov:
"Two fixes for use-after-free and memory leaking in the EDAC core, by
Robert Richter.
Debug options like DEBUG_TEST_DRIVER_REMOVE, KASAN and DEBUG_KMEMLEAK
unearthed issues with the lifespan of memory allocated by the EDAC
memory controller descriptor due to misdesigned memory freeing, done
partially by the EDAC core *and* the driver core, which is problematic
to say the least.
These two are minimal fixes to take care of stable - a proper rework
is following which cleans up that mess properly"
* tag 'edac_urgent_for_5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras:
EDAC/sysfs: Remove csrow objects on errors
EDAC/mc: Fix use-after-free and memleaks during device removal
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Merge tag 'block-5.6-2020-02-16' of git://git.kernel.dk/linux-block
Pull block fixes from Jens Axboe:
"Not a lot here, which is great, basically just three small bcache
fixes from Coly, and four NVMe fixes via Keith"
* tag 'block-5.6-2020-02-16' of git://git.kernel.dk/linux-block:
nvme: fix the parameter order for nvme_get_log in nvme_get_fw_slot_info
nvme/pci: move cqe check after device shutdown
nvme: prevent warning triggered by nvme_stop_keep_alive
nvme/tcp: fix bug on double requeue when send fails
bcache: remove macro nr_to_fifo_front()
bcache: Revert "bcache: shrink btree node cache after bch_btree_check()"
bcache: ignore pending signals when creating gc and allocator thread
Madhavan Srinivasan