8304 Commits

Author SHA1 Message Date
Christophe Leroy
afd3287c88 powerpc/optprobes: Minimise casts
nip is already an unsigned long, no cast needed.

op_callback_addr and emulate_step_addr are kprobe_opcode_t *.
There value is obtained with ppc_kallsyms_lookup_name() which
returns 'unsigned long', and there values are used create_branch()
which expects 'unsigned long'. So change them to 'unsigned long'
to avoid casting them back and forth.

can_optimize() used p->addr several times as 'unsigned long'.
Use a local 'unsigned long' variable and avoid casting multiple times.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/e03192a6d4123242a275e71ce2ba0bb4d90700c1.1621516826.git.christophe.leroy@csgroup.eu
2021-06-17 00:09:06 +10:00
Christophe Leroy
69d4d6e5fd powerpc: Don't use 'struct ppc_inst' to reference instruction location
'struct ppc_inst' is an internal representation of an instruction, but
in-memory instructions are and will remain a table of 'u32' forever.

Replace all 'struct ppc_inst *' used for locating an instruction in
memory by 'u32 *'. This removes a lot of undue casts to 'struct
ppc_inst *'.

It also helps locating ab-use of 'struct ppc_inst' dereference.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
[mpe: Fix ppc_inst_next(), use u32 instead of unsigned int]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/7062722b087228e42cbd896e39bfdf526d6a340a.1621516826.git.christophe.leroy@csgroup.eu
2021-06-17 00:09:00 +10:00
Christophe Leroy
18c85964b1 powerpc: Do not dereference code as 'struct ppc_inst' (uprobe, code-patching, feature-fixups)
'struct ppc_inst' is an internal structure to represent an instruction,
it is not directly the representation of that instruction in text code.
It is not meant to map and dereference code.

Dereferencing code directly through 'struct ppc_inst' has two main issues:
- On powerpc, structs are expected to be 8 bytes aligned while code is
spread every 4 byte.
- Should a non prefixed instruction lie at the end of the page and the
following page not be mapped, it would generate a page fault.

In-memory code must be accessed with ppc_inst_read().

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/c9a1201dd0a66b4a0f91f0fb46d9385cbf030feb.1621516826.git.christophe.leroy@csgroup.eu
2021-06-16 23:35:57 +10:00
Christophe Leroy
f30becb5e9 powerpc: Replace PPC_INST_NOP by PPC_RAW_NOP()
On the road to removing all PPC_INST_xx defines in
asm/ppc-opcodes.h, change PPC_INST_NOP to PPC_RAW_NOP().

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/ad46c195ca1b8572629ef07ba6bfe247585239a6.1621506159.git.christophe.leroy@csgroup.eu
2021-06-16 00:16:49 +10:00
Christophe Leroy
deefd0ae99 powerpc/traps: Start using PPC_RAW_xx() macros
Start using PPC_RAW_xx() macros where relevant.

PPC_INST_SYNC is used to both represent the 'sync' instruction and
the family of synchronisation instructions. Keep it for the later,
maybe we'll change the name in the future to avoid confusion.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/0945c155d6cb113431185fc1296ac127359fe29b.1621506159.git.christophe.leroy@csgroup.eu
2021-06-16 00:16:48 +10:00
Christophe Leroy
5a03e1e972 powerpc/ftrace: Use PPC_RAW_MFLR() and PPC_RAW_NOP()
Use PPC_RAW_MFLR() instead of open coding with PPC_INST_MFLR.

Same for PPC_INST_NOP.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/98fd4d717810b7c4032a1edf62dd6fe638e64329.1621506159.git.christophe.leroy@csgroup.eu
2021-06-16 00:16:48 +10:00
Christophe Leroy
e730459756 powerpc/security: Use PPC_RAW_BLR() and PPC_RAW_NOP()
On the road to remove all use of PPC_INST_xxx, replace
PPC_INST_BLR by PPC_RAW_BLR(). Same for PPC_INST_NOP.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/c04f88d0e53d2122fbbe92226892a01ebc668b6a.1621506159.git.christophe.leroy@csgroup.eu
2021-06-16 00:16:48 +10:00
Christophe Leroy
47b04699d0 powerpc/modules: Use PPC_RAW_xx() macros
To improve readability, use PPC_RAW_xx() macros instead of
open coding. Those macros are self-explanatory so the comments
can go as well.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/99d9ee8849d3992beeadb310a665aae01c3abfb1.1621506159.git.christophe.leroy@csgroup.eu
2021-06-16 00:16:48 +10:00
Christophe Leroy
1c9debbc2e powerpc/signal: Use PPC_RAW_xx() macros
To improve readability, use PPC_RAW_xx() macros instead of
open coding. Those macros are self-explanatory so the comments
can go as well.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/4ca2bfdca2f47a293d05f61eb3c4e487ee170f1f.1621506159.git.christophe.leroy@csgroup.eu
2021-06-16 00:16:47 +10:00
Christophe Leroy
8804d5beef powerpc/lib/code-patching: Use PPC_RAW_() macros
Instead of open coding with PPC_INST_ defines, use
PPC_RAW_() macros. It improves readability.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/8c92f1d9e825ee47c6f88fe43ad42d2a8cc2ab4a.1621506159.git.christophe.leroy@csgroup.eu
2021-06-16 00:16:47 +10:00
Christophe Leroy
359c2ca74d powerpc: Don't handle ALTIVEC/SPE in ASM in _switch(). Do it in C.
_switch() saves and restores ALTIVEC and SPE status.
For altivec this is redundant with what __switch_to() does with
save_sprs() and restore_sprs() and giveup_all() before
calling _switch().

Add support for SPI in save_sprs() and restore_sprs() and
remove things from _switch().

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/8ab21fd93d6e0047aa71e6509e5e312f14b2991b.1620998075.git.christophe.leroy@csgroup.eu
2021-06-16 00:16:47 +10:00
Michael Ellerman
a4785e93aa Merge branch 'fixes' into next
Merge our fixes branch which has a number of important fixes, notably
the fix for initrd corruption, as well as the fixes for scv vs ptrace.
2021-06-16 00:14:55 +10:00
Finn Thain
ddf4a7bcd0 powerpc/tau: Remove superfluous parameter in alloc_workqueue() call
This avoids an (optional) compiler warning:

arch/powerpc/kernel/tau_6xx.c: In function 'TAU_init':
arch/powerpc/kernel/tau_6xx.c:204:30: error: too many arguments for format [-Werror=format-extra-args]
  tau_workq = alloc_workqueue("tau", WQ_UNBOUND, 1, 0);

Fixes: b1c6a0a10bfa ("powerpc/tau: Convert from timer to workqueue")
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Finn Thain <fthain@linux-m68k.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/a1456e8bbd33ef702e3ff6f14b1bf3919241c62b.1623398307.git.fthain@linux-m68k.org
2021-06-15 23:47:10 +10:00
Andy Shevchenko
4cfdd9201c powerpc/prom_init: Move custom isspace() to its own namespace
If by some reason any of the headers will include ctype.h
we will have a name collision. Avoid this by moving isspace()
to the dedicate namespace.

First appearance of the code is in the commit cf68787b68a2
("powerpc/prom_init: Evaluate mem kernel parameter for early allocation").

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
[mpe: Reformat prom_isxdigit() now that we allow longer lines]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210510144925.58195-1-andriy.shevchenko@linux.intel.com
2021-06-15 17:12:27 +10:00
Michael Ellerman
e41d6c3f4f powerpc/signal64: Copy siginfo before changing regs->nip
In commit 96d7a4e06fab ("powerpc/signal64: Rewrite handle_rt_signal64()
to minimise uaccess switches") the 64-bit signal code was rearranged to
use user_write_access_begin/end().

As part of that change the call to copy_siginfo_to_user() was moved
later in the function, so that it could be done after the
user_write_access_end().

In particular it was moved after we modify regs->nip to point to the
signal trampoline. That means if copy_siginfo_to_user() fails we exit
handle_rt_signal64() with an error but with regs->nip modified, whereas
previously we would not modify regs->nip until the copy succeeded.

Returning an error from signal delivery but with regs->nip updated
leaves the process in a sort of half-delivered state. We do immediately
force a SEGV in signal_setup_done(), called from do_signal(), so the
process should never run in the half-delivered state.

However that SEGV is not delivered until we've gone around to
do_notify_resume() again, so it's possible some tracing could observe
the half-delivered state.

There are other cases where we fail signal delivery with regs partly
updated, eg. the write to newsp and SA_SIGINFO, but the latter at least
is very unlikely to fail as it reads back from the frame we just wrote
to.

Looking at other arches they seem to be more careful about leaving regs
unchanged until the copy operations have succeeded, and in general that
seems like good hygenie.

So although the current behaviour is not cleary buggy, it's also not
clearly correct. So move the call to copy_siginfo_to_user() up prior to
the modification of regs->nip, which is closer to the old behaviour, and
easier to reason about.

Fixes: 96d7a4e06fab ("powerpc/signal64: Rewrite handle_rt_signal64() to minimise uaccess switches")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210608134605.2783677-1-mpe@ellerman.id.au
2021-06-14 22:14:54 +10:00
Nicholas Piggin
9769a7fd79 KVM: PPC: Book3S HV: Remove radix guest support from P7/8 path
The P9 path now runs all supported radix guest combinations, so
remove radix guest support from the P7/8 path.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210528090752.3542186-24-npiggin@gmail.com
2021-06-10 22:12:14 +10:00
Nicholas Piggin
89d35b2391 KVM: PPC: Book3S HV P9: Implement the rest of the P9 path in C
Almost all logic is moved to C, by introducing a new in_guest mode for
the P9 path that branches very early in the KVM interrupt handler to P9
exit code.

The main P9 entry and exit assembly is now only about 160 lines of low
level stack setup and register save/restore, plus a bad-interrupt
handler.

There are two motivations for this, the first is just make the code more
maintainable being in C. The second is to reduce the amount of code
running in a special KVM mode, "realmode". In quotes because with radix
it is no longer necessarily real-mode in the MMU, but it still has to be
treated specially because it may be in real-mode, and has various
important registers like PID, DEC, TB, etc set to guest. This is hostile
to the rest of Linux and can't use arbitrary kernel functionality or be
instrumented well.

This initial patch is a reasonably faithful conversion of the asm code,
but it does lack any loop to return quickly back into the guest without
switching out of realmode in the case of unimportant or easily handled
interrupts. As explained in previous changes, handling HV interrupts
very quickly in this low level realmode is not so important for P9
performance, and are important to avoid for security, observability,
debugability reasons.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210528090752.3542186-15-npiggin@gmail.com
2021-06-10 22:12:13 +10:00
Nicholas Piggin
6ffe2c6e6d KVM: PPC: Book3S HV P9: Reduce irq_work vs guest decrementer races
irq_work's use of the DEC SPR is racy with guest<->host switch and guest
entry which flips the DEC interrupt to guest, which could lose a host
work interrupt.

This patch closes one race, and attempts to comment another class of
races.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210528090752.3542186-11-npiggin@gmail.com
2021-06-10 22:12:13 +10:00
Nicholas Piggin
e2762743c6 KVM: PPC: Book3S 64: Minimise hcall handler calling convention differences
This sets up the same calling convention from interrupt entry to
KVM interrupt handler for system calls as exists for other interrupt
types.

This is a better API, it uses a save area rather than SPR, and it has
more registers free to use. Using a single common API helps maintain
it, and it becomes easier to use in C in a later patch.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210528090752.3542186-8-npiggin@gmail.com
2021-06-10 22:12:12 +10:00
Nicholas Piggin
69fdd67499 KVM: PPC: Book3S 64: Move interrupt early register setup to KVM
Like the earlier patch for hcalls, KVM interrupt entry requires a
different calling convention than the Linux interrupt handlers
set up. Move the code that converts from one to the other into KVM.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210528090752.3542186-6-npiggin@gmail.com
2021-06-10 22:12:12 +10:00
Nicholas Piggin
04ece7b60b KVM: PPC: Book3S 64: Move hcall early register setup to KVM
System calls / hcalls have a different calling convention than
other interrupts, so there is code in the KVMTEST to massage these
into the same form as other interrupt handlers.

Move this work into the KVM hcall handler. This means teaching KVM
a little more about the low level interrupt handler setup, PACA save
areas, etc., although that's not obviously worse than the current
approach of coming up with an entirely different interrupt register
/ save convention.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210528090752.3542186-5-npiggin@gmail.com
2021-06-10 22:12:12 +10:00
Nicholas Piggin
31c67cfe2a KVM: PPC: Book3S 64: add hcall interrupt handler
Add a separate hcall entry point. This can be used to deal with the
different calling convention.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210528090752.3542186-4-npiggin@gmail.com
2021-06-10 22:12:12 +10:00
Nicholas Piggin
f33e0702d9 KVM: PPC: Book3S 64: Move GUEST_MODE_SKIP test into KVM
Move the GUEST_MODE_SKIP logic into KVM code. This is quite a KVM
internal detail that has no real need to be in common handlers.

Add a comment explaining the what and why of KVM "skip" interrupts.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210528090752.3542186-3-npiggin@gmail.com
2021-06-10 22:12:11 +10:00
Nicholas Piggin
f36011569b KVM: PPC: Book3S 64: move KVM interrupt entry to a common entry point
Rather than bifurcate the call depending on whether or not HV is
possible, and have the HV entry test for PR, just make a single
common point which does the demultiplexing. This makes it simpler
to add another type of exit handler.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Acked-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210528090752.3542186-2-npiggin@gmail.com
2021-06-10 22:12:01 +10:00
Marc Zyngier
13a9a5d17d powerpc: Add missing linux/{of.h,irqdomain.h} include directives
A bunch of PPC files are missing the inclusion of linux/of.h and
linux/irqdomain.h, relying on transitive inclusion from another
file.

As we are about to break this dependency, make sure these dependencies
are explicit.

Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-06-10 13:09:16 +01:00
Jan Kara
65ffb3d69e quota: Wire up quotactl_fd syscall
Wire up the quotactl_fd syscall.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
2021-06-07 12:11:24 +02:00
Linus Torvalds
bd7b12aa60 powerpc fixes for 5.13 #5
Fix our KVM reverse map real-mode handling since we enabled huge vmalloc (in some
 configurations).
 
 Revert a recent change to our IOMMU code which broke some devices.
 
 Fix KVM handling of FSCR on P7/P8, which could have possibly let a guest crash it's Qemu.
 
 Fix kprobes validation of prefixed instructions across page boundary.
 
 Thanks to: Alexey Kardashevskiy, Christophe Leroy, Fabiano Rosas, Frederic Barrat, Naveen
 N. Rao, Nicholas Piggin.
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Merge tag 'powerpc-5.13-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc fixes from Michael Ellerman:
 "Fix our KVM reverse map real-mode handling since we enabled huge
  vmalloc (in some configurations).

  Revert a recent change to our IOMMU code which broke some devices.

  Fix KVM handling of FSCR on P7/P8, which could have possibly let a
  guest crash it's Qemu.

  Fix kprobes validation of prefixed instructions across page boundary.

  Thanks to Alexey Kardashevskiy, Christophe Leroy, Fabiano Rosas,
  Frederic Barrat, Naveen N. Rao, and Nicholas Piggin"

* tag 'powerpc-5.13-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  Revert "powerpc/kernel/iommu: Align size for IOMMU_PAGE_SIZE() to save TCEs"
  KVM: PPC: Book3S HV: Save host FSCR in the P7/8 path
  powerpc: Fix reverse map real-mode address lookup with huge vmalloc
  powerpc/kprobes: Fix validation of prefixed instructions across page boundary
2021-06-06 12:39:36 -07:00
Ingo Molnar
a9e906b71f Merge branch 'sched/urgent' into sched/core, to pick up fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2021-06-03 19:00:49 +02:00
Naveen N. Rao
2e38eb04c9 kprobes: Do not increment probe miss count in the fault handler
Kprobes has a counter 'nmissed', that is used to count the number of
times a probe handler was not called. This generally happens when we hit
a kprobe while handling another kprobe.

However, if one of the probe handlers causes a fault, we are currently
incrementing 'nmissed'. The comment in fault handler indicates that this
can be used to account faults taken by the probe handlers. But, this has
never been the intention as is evident from the comment above 'nmissed'
in 'struct kprobe':

	/*count the number of times this probe was temporarily disarmed */
	unsigned long nmissed;

Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Link: https://lkml.kernel.org/r/20210601120150.672652-1-naveen.n.rao@linux.vnet.ibm.com
2021-06-03 15:47:26 +02:00
Peter Zijlstra
ec6aba3d2b kprobes: Remove kprobe::fault_handler
The reason for kprobe::fault_handler(), as given by their comment:

 * We come here because instructions in the pre/post
 * handler caused the page_fault, this could happen
 * if handler tries to access user space by
 * copy_from_user(), get_user() etc. Let the
 * user-specified handler try to fix it first.

Is just plain bad. Those other handlers are ran from non-preemptible
context and had better use _nofault() functions. Also, there is no
upstream usage of this.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Link: https://lore.kernel.org/r/20210525073213.561116662@infradead.org
2021-06-01 16:00:08 +02:00
Frederic Barrat
59cc84c802 Revert "powerpc/kernel/iommu: Align size for IOMMU_PAGE_SIZE() to save TCEs"
This reverts commit 3c0468d4451eb6b4f6604370639f163f9637a479.

That commit was breaking alignment guarantees for the DMA address when
allocating coherent mappings, as described in
Documentation/core-api/dma-api-howto.rst

It was also noticed by Mellanox' driver:
[ 1515.763621] mlx5_core c002:01:00.0: mlx5_frag_buf_alloc_node:146:(pid 13402): unexpected map alignment: 0x0800000000c61000, page_shift=16
[ 1515.763635] mlx5_core c002:01:00.0: mlx5_cqwq_create:181:(pid
13402): mlx5_frag_buf_alloc_node() failed, -12

Fixes: 3c0468d4451e ("powerpc/kernel/iommu: Align size for  IOMMU_PAGE_SIZE() to save TCEs")
Signed-off-by: Frederic Barrat <fbarrat@linux.ibm.com>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210526144540.117795-1-fbarrat@linux.ibm.com
2021-06-01 11:17:08 +10:00
Nicholas Piggin
5362a4b6ee powerpc: Fix reverse map real-mode address lookup with huge vmalloc
real_vmalloc_addr() does not currently work for huge vmalloc, which is
what the reverse map can be allocated with for radix host, hash guest.

Extract the hugepage aware equivalent from eeh code into a helper, and
convert existing sites including this one to use it.

Fixes: 8abddd968a30 ("powerpc/64s/radix: Enable huge vmalloc mappings")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210526120005.3432222-1-npiggin@gmail.com
2021-05-28 22:54:27 +10:00
Naveen N. Rao
82123a3d1d powerpc/kprobes: Fix validation of prefixed instructions across page boundary
When checking if the probed instruction is the suffix of a prefixed
instruction, we access the instruction at the previous word. If the
probed instruction is the very first word of a module, we can end up
trying to access an invalid page.

Fix this by skipping the check for all instructions at the beginning of
a page. Prefixed instructions cannot cross a 64-byte boundary and as
such, we don't expect to encounter a suffix as the very first word in a
page for kernel text. Even if there are prefixed instructions crossing
a page boundary (from a module, for instance), the instruction will be
illegal, so preventing probing on the suffix of such prefix instructions
isn't worthwhile.

Fixes: b4657f7650ba ("powerpc/kprobes: Don't allow breakpoints on suffixes")
Cc: stable@vger.kernel.org # v5.8+
Reported-by: Christophe Leroy <christophe.leroy@csgroup.eu>
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/0df9a032a05576a2fa8e97d1b769af2ff0eafbd6.1621416666.git.naveen.n.rao@linux.vnet.ibm.com
2021-05-28 21:52:42 +10:00
Linus Torvalds
28ceac6959 powerpc fixes for 5.13 #4
Fix breakage of strace (and other ptracers etc.) when using the new scv ABI (Power9 or
 later with glibc >= 2.33).
 
 Fix early_ioremap() on 64-bit, which broke booting on some machines.
 
 Thanks to: Dmitry V. Levin, Nicholas Piggin, Alexey Kardashevskiy, Christophe Leroy.
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Merge tag 'powerpc-5.13-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc fixes from Michael Ellerman:

 - Fix breakage of strace (and other ptracers etc.) when using the new
   scv ABI (Power9 or later with glibc >= 2.33).

 - Fix early_ioremap() on 64-bit, which broke booting on some machines.

Thanks to Dmitry V. Levin, Nicholas Piggin, Alexey Kardashevskiy, and
Christophe Leroy.

* tag 'powerpc-5.13-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/64s/syscall: Fix ptrace syscall info with scv syscalls
  powerpc/64s/syscall: Use pt_regs.trap to distinguish syscall ABI difference between sc and scv syscalls
  powerpc: Fix early setup to make early_ioremap() work
2021-05-23 06:07:33 -10:00
Christophe Leroy
b73c8cccd7 powerpc/kprobes: Replace ppc_optinsn by common optinsn
Commit 51c9c0843993 ("powerpc/kprobes: Implement Optprobes")
implemented a powerpc specific version of optinsn in order
to workaround the 32Mb limitation for direct branches.

Instead of implementing a dedicated powerpc version, use the
common optinsn and override the allocation and freeing functions.

This also indirectly remove the CLANG warning about
is_kprobe_ppc_optinsn_slot() not being use, and the powerpc will
now benefit from commit 5b485629ba0d ("kprobes, extable: Identify
kprobes trampolines as kernel text area")

Suggested-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/ec5e85f9f9abcfecc959a03495f4a7858eb4d203.1620896780.git.christophe.leroy@csgroup.eu
2021-05-23 20:51:35 +10:00
Linus Torvalds
7ac177143c \n
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Merge tag 'quota_for_v5.13-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs

Pull quota fixes from Jan Kara:
 "The most important part in the pull is disablement of the new syscall
  quotactl_path() which was added in rc1.

  The reason is some people at LWN discussion pointed out dirfd would be
  useful for this path based syscall and Christian Brauner agreed.

  Without dirfd it may be indeed problematic for containers. So let's
  just disable the syscall for now when it doesn't have users yet so
  that we have more time to mull over how to best specify the filesystem
  we want to work on"

* tag 'quota_for_v5.13-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
  quota: Disable quotactl_path syscall
  quota: Use 'hlist_for_each_entry' to simplify code
2021-05-20 06:20:15 -10:00
Alexey Kardashevskiy
e2f5efd0f0 powerpc: Fix early setup to make early_ioremap() work
The immediate problem is that after commit
0bd3f9e953bd ("powerpc/legacy_serial: Use early_ioremap()") the kernel
silently reboots on some systems.

The reason is that early_ioremap() returns broken addresses as it uses
slot_virt[] array which initialized with offsets from FIXADDR_TOP ==
IOREMAP_END+FIXADDR_SIZE == KERN_IO_END - FIXADDR_SIZ + FIXADDR_SIZE ==
__kernel_io_end which is 0 when early_ioremap_setup() is called.
__kernel_io_end is initialized little bit later in early_init_mmu().

This fixes the initialization by swapping early_ioremap_setup() and
early_init_mmu().

Fixes: 265c3491c4bc ("powerpc: Add support for GENERIC_EARLY_IOREMAP")
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
[mpe: Drop unrelated cleanup & cleanup change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210520032919.358935-1-aik@ozlabs.ru
2021-05-20 16:43:26 +10:00
Jan Kara
5b9fedb31e quota: Disable quotactl_path syscall
In commit fa8b90070a80 ("quota: wire up quotactl_path") we have wired up
new quotactl_path syscall. However some people in LWN discussion have
objected that the path based syscall is missing dirfd and flags argument
which is mostly standard for contemporary path based syscalls. Indeed
they have a point and after a discussion with Christian Brauner and
Sascha Hauer I've decided to disable the syscall for now and update its
API. Since there is no userspace currently using that syscall and it
hasn't been released in any major release, we should be fine.

CC: Christian Brauner <christian.brauner@ubuntu.com>
CC: Sascha Hauer <s.hauer@pengutronix.de>
Link: https://lore.kernel.org/lkml/20210512153621.n5u43jsytbik4yze@wittgenstein
Signed-off-by: Jan Kara <jack@suse.cz>
2021-05-17 14:39:56 +02:00
Christophe Leroy
70d6ebf82b powerpc/603: Avoid a pile of NOPs when not using SW LRU in TLB exceptions
The SW LRU is in an MMU feature section. When not used, that's a
dozen of NOPs to fetch for nothing.

Define an ALT section that does the few remaining operations.

That also avoids a double read on SRR1 in the SW LRU case.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/603725297466959419628ef7964aaf3417fb647d.1620363691.git.christophe.leroy@csgroup.eu
2021-05-17 15:27:16 +10:00
Christophe Leroy
13c7dad951 powerpc/paca: Remove mm_ctx_id and mm_ctx_slb_addr_limit
mm_ctx_id and mm_ctx_slb_addr_limit are not used anymore.

Remove them.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/6e1813953da38c452c131fe3e2a2761a0fddb975.1620223303.git.christophe.leroy@csgroup.eu
2021-05-17 15:27:15 +10:00
Christophe Leroy
1a3c6ceed2 powerpc/asm-offset: Remove unused items
Following PACA related items are not used anymore by ASM code:
PACA_SIZE, PACACONTEXTID, PACALOWSLICESPSIZE, PACAHIGHSLICEPSIZE,
PACA_SLB_ADDR_LIMIT, MMUPSIZEDEFSIZE, PACASLBCACHE, PACASLBCACHEPTR,
PACASTABRR, PACAVMALLOCSLLP, MMUPSIZESLLP, PACACONTEXTSLLP,
PACALPPACAPTR, LPPACA_DTLIDX and PACA_DTL_RIDX.

Following items are also not used anymore:
SIGSEGV, NMI_MASK, THREAD_DBCR0, KUAP, TI_FLAGS, TI_PREEMPT,
DCACHEL1BLOCKSPERPAGE, ICACHEL1BLOCKSIZE, ICACHEL1LOGBLOCKSIZE,
ICACHEL1BLOCKSPERPAGE, STACK_REGS_KUAP, KVM_NEED_FLUSH, KVM_FWNMI,
VCPU_DEC, VCPU_SPMC, HSTATE_XICS_PHYS, HSTATE_SAVED_XIRR and
PPC_DBELL_MSGTYPE.

Remove all of them.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1c80981548dc0c4f145109cdd473022c1aad8d2b.1620223302.git.christophe.leroy@csgroup.eu
2021-05-17 15:27:15 +10:00
Christophe Leroy
3a5988b884 powerpc/32s: Remove m8260_gorom()
Last user of m8260_gorom() was removed by
Commit 917f0af9e5a9 ("powerpc: Remove arch/ppc and include/asm-ppc")
removed last user of m8260_gorom().

In fact m8260_gorom() was ported to arch/powerpc/ but the
platform using it died with arch/ppc/

Remove it.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/13f7532f21df3196e8c78b4f82a9c8d5487aca35.1620292185.git.christophe.leroy@csgroup.eu
2021-05-17 15:27:15 +10:00
Nicholas Piggin
c6ac667b07 powerpc/64e/interrupt: Fix nvgprs being clobbered
Some interrupt handlers have an "extra" that saves 1 or 2
registers (r14, r15) in the paca save area and makes them available to
use by the handler.

The change to always save nvgprs in exception handlers lead to some
interrupt handlers saving those scratch r14 / r15 registers into the
interrupt frame's GPR saves, which get restored on interrupt exit.

Fix this by always reloading those scratch registers from paca before
the EXCEPTION_COMMON that saves nvgprs.

Fixes: 4228b2c3d20e ("powerpc/64e/interrupt: always save nvgprs on interrupt")
Reported-by: Christian Zigotzky <chzigotzky@xenosoft.de>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Tested-by: Christian Zigotzky <chzigotzky@xenosoft.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210514044008.1955783-1-npiggin@gmail.com
2021-05-14 17:28:54 +10:00
Valentin Schneider
f1a0a376ca sched/core: Initialize the idle task with preemption disabled
As pointed out by commit

  de9b8f5dcbd9 ("sched: Fix crash trying to dequeue/enqueue the idle thread")

init_idle() can and will be invoked more than once on the same idle
task. At boot time, it is invoked for the boot CPU thread by
sched_init(). Then smp_init() creates the threads for all the secondary
CPUs and invokes init_idle() on them.

As the hotplug machinery brings the secondaries to life, it will issue
calls to idle_thread_get(), which itself invokes init_idle() yet again.
In this case it's invoked twice more per secondary: at _cpu_up(), and at
bringup_cpu().

Given smp_init() already initializes the idle tasks for all *possible*
CPUs, no further initialization should be required. Now, removing
init_idle() from idle_thread_get() exposes some interesting expectations
with regards to the idle task's preempt_count: the secondary startup always
issues a preempt_disable(), requiring some reset of the preempt count to 0
between hot-unplug and hotplug, which is currently served by
idle_thread_get() -> idle_init().

Given the idle task is supposed to have preemption disabled once and never
see it re-enabled, it seems that what we actually want is to initialize its
preempt_count to PREEMPT_DISABLED and leave it there. Do that, and remove
init_idle() from idle_thread_get().

Secondary startups were patched via coccinelle:

  @begone@
  @@

  -preempt_disable();
  ...
  cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);

Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210512094636.2958515-1-valentin.schneider@arm.com
2021-05-12 13:01:45 +02:00
Christophe Leroy
63970f3c37 powerpc/legacy_serial: Fix UBSAN: array-index-out-of-bounds
UBSAN complains when a pointer is calculated with invalid
'legacy_serial_console' index, allthough the index is verified
before dereferencing the pointer.

Fix it by checking 'legacy_serial_console' validity before
calculating pointers.

Fixes: 0bd3f9e953bd ("powerpc/legacy_serial: Use early_ioremap()")
Reported-by: Paul Menzel <pmenzel@molgen.mpg.de>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210511010712.750096-1-mpe@ellerman.id.au
2021-05-12 11:07:39 +10:00
Christophe Leroy
bc581dbab2 powerpc/signal: Fix possible build failure with unsafe_copy_fpr_{to/from}_user
When neither CONFIG_VSX nor CONFIG_PPC_FPU_REGS are selected,
unsafe_copy_fpr_to_user() and unsafe_copy_fpr_from_user() are
doing nothing.

Then, unless the 'label' operand is used elsewhere, GCC complains
about it being defined but not used.

To fix that, add an impossible 'goto label'.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/cadc0a328bc8e6c5bf133193e7547d5c10ae7895.1620465920.git.christophe.leroy@csgroup.eu
2021-05-12 11:07:39 +10:00
Christophe Leroy
5d510ed78b powerpc/syscall: Calling kuap_save_and_lock() is wrong
kuap_save_and_lock() is only for interrupts inside kernel.

system call are only from user, calling kuap_save_and_lock()
is wrong.

Fixes: c16728835eec ("powerpc/32: Manage KUAP in C")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/332773775cf24a422105dee2d383fb8f04589045.1620302182.git.christophe.leroy@csgroup.eu
2021-05-12 11:07:38 +10:00
Christophe Leroy
a78339698a powerpc/interrupts: Fix kuep_unlock() call
Same as kuap_user_restore(), kuep_unlock() has to be called when
really returning to user, that is in interrupt_exit_user_prepare(),
not in interrupt_exit_prepare().

Fixes: b5efec00b671 ("powerpc/32s: Move KUEP locking/unlocking in C")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/b831e54a2579db24fbef836ed415588ce2b3e825.1620312573.git.christophe.leroy@csgroup.eu
2021-05-12 11:07:37 +10:00
Nicholas Piggin
8abddd968a powerpc/64s/radix: Enable huge vmalloc mappings
This reduces TLB misses by nearly 30x on a `git diff` workload on a
2-node POWER9 (59,800 -> 2,100) and reduces CPU cycles by 0.54%, due
to vfs hashes being allocated with 2MB pages.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210503091755.613393-1-npiggin@gmail.com
2021-05-04 11:06:45 +10:00
Linus Torvalds
17ae69aba8 Add Landlock, a new LSM from Mickaël Salaün <mic@linux.microsoft.com>
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Merge tag 'landlock_v34' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security

Pull Landlock LSM from James Morris:
 "Add Landlock, a new LSM from Mickaël Salaün.

  Briefly, Landlock provides for unprivileged application sandboxing.

  From Mickaël's cover letter:
    "The goal of Landlock is to enable to restrict ambient rights (e.g.
     global filesystem access) for a set of processes. Because Landlock
     is a stackable LSM [1], it makes possible to create safe security
     sandboxes as new security layers in addition to the existing
     system-wide access-controls. This kind of sandbox is expected to
     help mitigate the security impact of bugs or unexpected/malicious
     behaviors in user-space applications. Landlock empowers any
     process, including unprivileged ones, to securely restrict
     themselves.

     Landlock is inspired by seccomp-bpf but instead of filtering
     syscalls and their raw arguments, a Landlock rule can restrict the
     use of kernel objects like file hierarchies, according to the
     kernel semantic. Landlock also takes inspiration from other OS
     sandbox mechanisms: XNU Sandbox, FreeBSD Capsicum or OpenBSD
     Pledge/Unveil.

     In this current form, Landlock misses some access-control features.
     This enables to minimize this patch series and ease review. This
     series still addresses multiple use cases, especially with the
     combined use of seccomp-bpf: applications with built-in sandboxing,
     init systems, security sandbox tools and security-oriented APIs [2]"

  The cover letter and v34 posting is here:

      https://lore.kernel.org/linux-security-module/20210422154123.13086-1-mic@digikod.net/

  See also:

      https://landlock.io/

  This code has had extensive design discussion and review over several
  years"

Link: https://lore.kernel.org/lkml/50db058a-7dde-441b-a7f9-f6837fe8b69f@schaufler-ca.com/ [1]
Link: https://lore.kernel.org/lkml/f646e1c7-33cf-333f-070c-0a40ad0468cd@digikod.net/ [2]

* tag 'landlock_v34' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  landlock: Enable user space to infer supported features
  landlock: Add user and kernel documentation
  samples/landlock: Add a sandbox manager example
  selftests/landlock: Add user space tests
  landlock: Add syscall implementations
  arch: Wire up Landlock syscalls
  fs,security: Add sb_delete hook
  landlock: Support filesystem access-control
  LSM: Infrastructure management of the superblock
  landlock: Add ptrace restrictions
  landlock: Set up the security framework and manage credentials
  landlock: Add ruleset and domain management
  landlock: Add object management
2021-05-01 18:50:44 -07:00