20829 Commits

Author SHA1 Message Date
Michael Ellerman
4c732e81bd powerpc/64s: Disable STRICT_KERNEL_RWX
[ Upstream commit 8659a0e0efdd975c73355dbc033f79ba3b31e82c ]

Several strange crashes have been eventually traced back to
STRICT_KERNEL_RWX and its interaction with code patching.

Various paths in our ftrace, kprobes and other patching code need to
be hardened against patching failures, otherwise we can end up running
with partially/incorrectly patched ftrace paths, kprobes or jump
labels, which can then cause strange crashes.

Although fixes for those are in development, they're not -rc material.

There also seem to be problems with the underlying strict RWX logic,
which needs further debugging.

So for now disable STRICT_KERNEL_RWX on 64-bit to prevent people from
enabling the option and tripping over the bugs.

Fixes: 1e0fc9d1eb2b ("powerpc/Kconfig: Enable STRICT_KERNEL_RWX for some configs")
Cc: stable@vger.kernel.org # v4.13+
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200520133605.972649-1-mpe@ellerman.id.au
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-05-27 17:46:44 +02:00
Russell Currey
b67da9dbdb powerpc: Remove STRICT_KERNEL_RWX incompatibility with RELOCATABLE
[ Upstream commit c55d7b5e64265fdca45c85b639013e770bde2d0e ]

I have tested this with the Radix MMU and everything seems to work, and
the previous patch for Hash seems to fix everything too.
STRICT_KERNEL_RWX should still be disabled by default for now.

Please test STRICT_KERNEL_RWX + RELOCATABLE!

Signed-off-by: Russell Currey <ruscur@russell.cc>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191224064126.183670-2-ruscur@russell.cc
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-05-27 17:46:44 +02:00
Christophe Leroy
4e06196336 powerpc/32s: Fix build failure with CONFIG_PPC_KUAP_DEBUG
commit 4833ce06e6855d526234618b746ffb71d6612c9a upstream.

gpr2 is not a parametre of kuap_check(), it doesn't exist.

Use gpr instead.

Fixes: a68c31fc01ef ("powerpc/32s: Implement Kernel Userspace Access Protection")
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/ea599546f2a7771bde551393889e44e6b2632332.1587368807.git.christophe.leroy@c-s.fr
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-20 08:20:33 +02:00
Christophe Leroy
3160e84aba powerpc/mm: Fix CONFIG_PPC_KUAP_DEBUG on PPC32
commit feb8e960d780e170e992a70491eec9dd68f4dbf2 upstream.

CONFIG_PPC_KUAP_DEBUG is not selectable because it depends on PPC_32
which doesn't exists.

Fixing it leads to a deadlock due to a vital register getting
clobbered in _switch().

Change dependency to PPC32 and use r0 instead of r4 in _switch()

Fixes: e2fb9f544431 ("powerpc/32: Prepare for Kernel Userspace Access Protection")
Cc: stable@vger.kernel.org # v5.2+
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/540242f7d4573f7cdf1b3bf46bb35f743b2cd68f.1587124651.git.christophe.leroy@c-s.fr
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-29 16:33:25 +02:00
Michael Ellerman
b48331b52a powerpc/kuap: PPC_KUAP_DEBUG should depend on PPC_KUAP
commit 61da50b76b62fd815aa82d853bf82bf4f69568f5 upstream.

Currently you can enable PPC_KUAP_DEBUG when PPC_KUAP is disabled,
even though the former has not effect without the latter.

Fix it so that PPC_KUAP_DEBUG can only be enabled when PPC_KUAP is
enabled, not when the platform could support KUAP (PPC_HAVE_KUAP).

Fixes: 890274c2dc4c ("powerpc/64s: Implement KUAP for Radix MMU")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200301111738.22497-1-mpe@ellerman.id.au
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-29 16:33:25 +02:00
Chris Packham
dba6465408 powerpc/setup_64: Set cache-line-size based on cache-block-size
commit 94c0b013c98583614e1ad911e8795ca36da34a85 upstream.

If {i,d}-cache-block-size is set and {i,d}-cache-line-size is not, use
the block-size value for both. Per the devicetree spec cache-line-size
is only needed if it differs from the block size.

Originally the code would fallback from block size to line size. An
error message was printed if both properties were missing.

Later the code was refactored to use clearer names and logic but it
inadvertently made line size a required property, meaning on systems
without a line size property we fall back to the default from the
cputable.

On powernv (OPAL) platforms, since the introduction of device tree CPU
features (5a61ef74f269 ("powerpc/64s: Support new device tree binding
for discovering CPU features")), that has led to the wrong value being
used, as the fallback value is incorrect for Power8/Power9 CPUs.

The incorrect values flow through to the VDSO and also to the sysconf
values, SC_LEVEL1_ICACHE_LINESIZE etc.

Fixes: bd067f83b084 ("powerpc/64: Fix naming of cache block vs. cache line")
Cc: stable@vger.kernel.org # v4.11+
Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Reported-by: Qian Cai <cai@lca.pw>
[mpe: Add even more detail to change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200416221908.7886-1-chris.packham@alliedtelesis.co.nz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-29 16:33:20 +02:00
Ganesh Goudar
de1263d430 powerpc/pseries: Fix MCE handling on pseries
[ Upstream commit a95a0a1654f16366360399574e10efd87e867b39 ]

MCE handling on pSeries platform fails as recent rework to use common
code for pSeries and PowerNV in machine check error handling tries to
access per-cpu variables in realmode. The per-cpu variables may be
outside the RMO region on pSeries platform and needs translation to be
enabled for access. Just moving these per-cpu variable into RMO region
did'nt help because we queue some work to workqueues in real mode, which
again tries to touch per-cpu variables. Also fwnmi_release_errinfo()
cannot be called when translation is not enabled.

This patch fixes this by enabling translation in the exception handler
when all required real mode handling is done. This change only affects
the pSeries platform.

Without this fix below kernel crash is seen on injecting
SLB multihit:

BUG: Unable to handle kernel data access on read at 0xc00000027b205950
Faulting instruction address: 0xc00000000003b7e0
Oops: Kernel access of bad area, sig: 11 [#1]
LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries
Modules linked in: mcetest_slb(OE+) af_packet(E) xt_tcpudp(E) ip6t_rpfilter(E) ip6t_REJECT(E) ipt_REJECT(E) xt_conntrack(E) ip_set(E) nfnetlink(E) ebtable_nat(E) ebtable_broute(E) ip6table_nat(E) ip6table_mangle(E) ip6table_raw(E) ip6table_security(E) iptable_nat(E) nf_nat(E) nf_conntrack(E) nf_defrag_ipv6(E) nf_defrag_ipv4(E) iptable_mangle(E) iptable_raw(E) iptable_security(E) ebtable_filter(E) ebtables(E) ip6table_filter(E) ip6_tables(E) iptable_filter(E) ip_tables(E) x_tables(E) xfs(E) ibmveth(E) vmx_crypto(E) gf128mul(E) uio_pdrv_genirq(E) uio(E) crct10dif_vpmsum(E) rtc_generic(E) btrfs(E) libcrc32c(E) xor(E) zstd_decompress(E) zstd_compress(E) raid6_pq(E) sr_mod(E) sd_mod(E) cdrom(E) ibmvscsi(E) scsi_transport_srp(E) crc32c_vpmsum(E) dm_mod(E) sg(E) scsi_mod(E)
CPU: 34 PID: 8154 Comm: insmod Kdump: loaded Tainted: G OE 5.5.0-mahesh #1
NIP: c00000000003b7e0 LR: c0000000000f2218 CTR: 0000000000000000
REGS: c000000007dcb960 TRAP: 0300 Tainted: G OE (5.5.0-mahesh)
MSR: 8000000000001003 <SF,ME,RI,LE> CR: 28002428 XER: 20040000
CFAR: c0000000000f2214 DAR: c00000027b205950 DSISR: 40000000 IRQMASK: 0
GPR00: c0000000000f2218 c000000007dcbbf0 c000000001544800 c000000007dcbd70
GPR04: 0000000000000001 c000000007dcbc98 c008000000d00258 c0080000011c0000
GPR08: 0000000000000000 0000000300000003 c000000001035950 0000000003000048
GPR12: 000000027a1d0000 c000000007f9c000 0000000000000558 0000000000000000
GPR16: 0000000000000540 c008000001110000 c008000001110540 0000000000000000
GPR20: c00000000022af10 c00000025480fd70 c008000001280000 c00000004bfbb300
GPR24: c000000001442330 c00800000800000d c008000008000000 4009287a77000510
GPR28: 0000000000000000 0000000000000002 c000000001033d30 0000000000000001
NIP [c00000000003b7e0] save_mce_event+0x30/0x240
LR [c0000000000f2218] pseries_machine_check_realmode+0x2c8/0x4f0
Call Trace:
Instruction dump:
3c4c0151 38429050 7c0802a6 60000000 fbc1fff0 fbe1fff8 f821ffd1 3d42ffaf
3fc2ffaf e98d0030 394a1150 3bdef530 <7d6a62aa> 1d2b0048 2f8b0063 380b0001
---[ end trace 46fd63f36bbdd940 ]---

Fixes: 9ca766f9891d ("powerpc/64s/pseries: machine check convert to use common event code")
Reviewed-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Ganesh Goudar <ganeshgr@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200320110119.10207-1-ganeshgr@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-04-29 16:33:01 +02:00
Nicholas Piggin
107290a8f0 Revert "powerpc/64: irq_work avoid interrupt when called with hardware irqs enabled"
[ Upstream commit abc3fce76adbdfa8f87272c784b388cd20b46049 ]

This reverts commit ebb37cf3ffd39fdb6ec5b07111f8bb2f11d92c5f.

That commit does not play well with soft-masked irq state
manipulations in idle, interrupt replay, and possibly others due to
tracing code sometimes using irq_work_queue (e.g., in
trace_hardirqs_on()). That can cause PACA_IRQ_DEC to become set when
it is not expected, and be ignored or cleared or cause warnings.

The net result seems to be missing an irq_work until the next timer
interrupt in the worst case which is usually not going to be noticed,
however it could be a long time if the tick is disabled, which is
against the spirit of irq_work and might cause real problems.

The idea is still solid, but it would need more work. It's not really
clear if it would be worth added complexity, so revert this for
now (not a straight revert, but replace with a comment explaining why
we might see interrupts happening, and gives git blame something to
find).

Fixes: ebb37cf3ffd3 ("powerpc/64: irq_work avoid interrupt when called with hardware irqs enabled")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200402120401.1115883-1-npiggin@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-04-29 16:33:01 +02:00
Nathan Chancellor
fd80f4a680 powerpc/maple: Fix declaration made after definition
[ Upstream commit af6cf95c4d003fccd6c2ecc99a598fb854b537e7 ]

When building ppc64 defconfig, Clang errors (trimmed for brevity):

  arch/powerpc/platforms/maple/setup.c:365:1: error: attribute declaration
  must precede definition [-Werror,-Wignored-attributes]
  machine_device_initcall(maple, maple_cpc925_edac_setup);
  ^

machine_device_initcall expands to __define_machine_initcall, which in
turn has the macro machine_is used in it, which declares mach_##name
with an __attribute__((weak)). define_machine actually defines
mach_##name, which in this file happens before the declaration, hence
the warning.

To fix this, move define_machine after machine_device_initcall so that
the declaration occurs before the definition, which matches how
machine_device_initcall and define_machine work throughout
arch/powerpc.

While we're here, remove some spaces before tabs.

Fixes: 8f101a051ef0 ("edac: cpc925 MC platform device setup")
Reported-by: Nick Desaulniers <ndesaulniers@google.com>
Suggested-by: Ilie Halip <ilie.halip@gmail.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200323222729.15365-1-natechancellor@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-04-23 10:36:35 +02:00
Alexey Kardashevskiy
bee9bc3e02 powerpc/prom_init: Pass the "os-term" message to hypervisor
[ Upstream commit 74bb84e5117146fa73eb9d01305975c53022b3c3 ]

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: 6a9c930bd775 ("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
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-04-23 10:36:34 +02:00
Michael Roth
ffbad91b66 KVM: PPC: Book3S HV: Fix H_CEDE return code for nested guests
[ Upstream commit 1f50cc1705350a4697923203fedd7d8fb1087fe2 ]

The h_cede_tm kvm-unit-test currently fails when run inside an L1 guest
via the guest/nested hypervisor.

  ./run-tests.sh -v
  ...
  TESTNAME=h_cede_tm TIMEOUT=90s ACCEL= ./powerpc/run powerpc/tm.elf -smp 2,threads=2 -machine cap-htm=on -append "h_cede_tm"
  FAIL h_cede_tm (2 tests, 1 unexpected failures)

While the test relates to transactional memory instructions, the actual
failure is due to the return code of the H_CEDE hypercall, which is
reported as 224 instead of 0. This happens even when no TM instructions
are issued.

224 is the value placed in r3 to execute a hypercall for H_CEDE, and r3
is where the caller expects the return code to be placed upon return.

In the case of guest running under a nested hypervisor, issuing H_CEDE
causes a return from H_ENTER_NESTED. In this case H_CEDE is
specially-handled immediately rather than later in
kvmppc_pseries_do_hcall() as with most other hcalls, but we forget to
set the return code for the caller, hence why kvm-unit-test sees the
224 return code and reports an error.

Guest kernels generally don't check the return value of H_CEDE, so
that likely explains why this hasn't caused issues outside of
kvm-unit-tests so far.

Fix this by setting r3 to 0 after we finish processing the H_CEDE.

RHBZ: 1778556

Fixes: 4bad77799fed ("KVM: PPC: Book3S HV: Handle hypercalls correctly when nested")
Cc: linuxppc-dev@ozlabs.org
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-04-23 10:36:32 +02:00
Christophe Leroy
c1f3e1d8d7 powerpc/kasan: Fix kasan_remap_early_shadow_ro()
[ Upstream commit af92bad615be75c6c0d1b1c5b48178360250a187 ]

At the moment kasan_remap_early_shadow_ro() does nothing, because
k_end is 0 and k_cur < 0 is always true.

Change the test to k_cur != k_end, as done in
kasan_init_shadow_page_tables()

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Fixes: cbd18991e24f ("powerpc/mm: Fix an Oops in kasan_mmu_init()")
Cc: stable@vger.kernel.org
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/4e7b56865e01569058914c991143f5961b5d4719.1583507333.git.christophe.leroy@c-s.fr
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-04-17 10:50:25 +02:00
Clement Courbet
ba7581be85 powerpc: Make setjmp/longjmp signature standard
commit c17eb4dca5a353a9dbbb8ad6934fe57af7165e91 upstream.

Declaring setjmp()/longjmp() as taking longs makes the signature
non-standard, and makes clang complain. In the past, this has been
worked around by adding -ffreestanding to the compile flags.

The implementation looks like it only ever propagates the value
(in longjmp) or sets it to 1 (in setjmp), and we only call longjmp
with integer parameters.

This allows removing -ffreestanding from the compilation flags.

Fixes: c9029ef9c957 ("powerpc: Avoid clang warnings around setjmp and longjmp")
Cc: stable@vger.kernel.org # v4.14+
Signed-off-by: Clement Courbet <courbet@google.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Tested-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200330080400.124803-1-courbet@google.com
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-17 10:50:23 +02:00
Michael Ellerman
e294f8a5ad powerpc/64: Prevent stack protection in early boot
commit 7053f80d96967d8e72e9f2a724bbfc3906ce2b07 upstream.

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: 06ec27aea9fc ("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
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-17 10:50:23 +02:00
Christophe Leroy
fc8755dc01 powerpc/kprobes: Ignore traps that happened in real mode
commit 21f8b2fa3ca5b01f7a2b51b89ce97a3705a15aa0 upstream.

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: 6cc89bad60a6 ("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
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-17 10:50:23 +02:00
Cédric Le Goater
ed6f6b2b39 powerpc/xive: Fix xmon support on the PowerNV platform
commit 97ef275077932c65b1b8ec5022abd737a9fbf3e0 upstream.

The PowerNV platform has multiple IRQ chips and the xmon command
dumping the state of the XIVE interrupt should only operate on the
XIVE IRQ chip.

Fixes: 5896163f7f91 ("powerpc/xmon: Improve output of XIVE interrupts")
Cc: stable@vger.kernel.org # v5.4+
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200306150143.5551-3-clg@kaod.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-17 10:50:23 +02:00
Daniel Axtens
1ab730b659 powerpc/64: Setup a paca before parsing device tree etc.
commit d4a8e98621543d5798421eed177978bf2b3cdd11 upstream.

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: fb0b0a73b223 ("powerpc: Enable kcov")
Fixes: 06ec27aea9fc ("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
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-17 10:50:23 +02:00
Cédric Le Goater
9240f83aa9 powerpc/xive: Use XIVE_BAD_IRQ instead of zero to catch non configured IPIs
commit b1a504a6500df50e83b701b7946b34fce27ad8a3 upstream.

When a CPU is brought up, an IPI number is allocated and recorded
under the XIVE CPU structure. Invalid IPI numbers are tracked with
interrupt number 0x0.

On the PowerNV platform, the interrupt number space starts at 0x10 and
this works fine. However, on the sPAPR platform, it is possible to
allocate the interrupt number 0x0 and this raises an issue when CPU 0
is unplugged. The XIVE spapr driver tracks allocated interrupt numbers
in a bitmask and it is not correctly updated when interrupt number 0x0
is freed. It stays allocated and it is then impossible to reallocate.

Fix by using the XIVE_BAD_IRQ value instead of zero on both platforms.

Reported-by: David Gibson <david@gibson.dropbear.id.au>
Fixes: eac1e731b59e ("powerpc/xive: guest exploitation of the XIVE interrupt controller")
Cc: stable@vger.kernel.org # v4.14+
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Tested-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200306150143.5551-2-clg@kaod.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-17 10:50:22 +02:00
Aneesh Kumar K.V
bd0fa14473 powerpc/hash64/devmap: Use H_PAGE_THP_HUGE when setting up huge devmap PTE entries
commit 36b78402d97a3b9aeab136feb9b00d8647ec2c20 upstream.

H_PAGE_THP_HUGE is used to differentiate between a THP hugepage and
hugetlb hugepage entries. The difference is WRT how we handle hash
fault on these address. THP address enables MPSS in segments. We want
to manage devmap hugepage entries similar to THP pt entries. Hence use
H_PAGE_THP_HUGE for devmap huge PTE entries.

With current code while handling hash PTE fault, we do set is_thp =
true when finding devmap PTE huge PTE entries.

Current code also does the below sequence we setting up huge devmap
entries.

	entry = pmd_mkhuge(pfn_t_pmd(pfn, prot));
	if (pfn_t_devmap(pfn))
		entry = pmd_mkdevmap(entry);

In that case we would find both H_PAGE_THP_HUGE and PAGE_DEVMAP set
for huge devmap PTE entries. This results in false positive error like
below.

  kernel BUG at /home/kvaneesh/src/linux/mm/memory.c:4321!
  Oops: Exception in kernel mode, sig: 5 [#1]
  LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries
  Modules linked in:
  CPU: 56 PID: 67996 Comm: t_mmap_dio Not tainted 5.6.0-rc4-59640-g371c804dedbc #128
  ....
  NIP [c00000000044c9e4] __follow_pte_pmd+0x264/0x900
  LR [c0000000005d45f8] dax_writeback_one+0x1a8/0x740
  Call Trace:
    str_spec.74809+0x22ffb4/0x2d116c (unreliable)
    dax_writeback_one+0x1a8/0x740
    dax_writeback_mapping_range+0x26c/0x700
    ext4_dax_writepages+0x150/0x5a0
    do_writepages+0x68/0x180
    __filemap_fdatawrite_range+0x138/0x180
    file_write_and_wait_range+0xa4/0x110
    ext4_sync_file+0x370/0x6e0
    vfs_fsync_range+0x70/0xf0
    sys_msync+0x220/0x2e0
    system_call+0x5c/0x68

This is because our pmd_trans_huge check doesn't exclude _PAGE_DEVMAP.

To make this all consistent, update pmd_mkdevmap to set
H_PAGE_THP_HUGE and pmd_trans_huge check now excludes _PAGE_DEVMAP
correctly.

Fixes: ebd31197931d ("powerpc/mm: Add devmap support for ppc64")
Cc: stable@vger.kernel.org # v4.13+
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200313094842.351830-1-aneesh.kumar@linux.ibm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-17 10:50:22 +02:00
Laurentiu Tudor
81b9336ab2 powerpc/fsl_booke: Avoid creating duplicate tlb1 entry
commit aa4113340ae6c2811e046f08c2bc21011d20a072 upstream.

In the current implementation, the call to loadcam_multi() is wrapped
between switch_to_as1() and restore_to_as0() calls so, when it tries
to create its own temporary AS=1 TLB1 entry, it ends up duplicating
the existing one created by switch_to_as1(). Add a check to skip
creating the temporary entry if already running in AS=1.

Fixes: d9e1831a4202 ("powerpc/85xx: Load all early TLB entries at once")
Cc: stable@vger.kernel.org # v4.4+
Signed-off-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Acked-by: Scott Wood <oss@buserror.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200123111914.2565-1-laurentiu.tudor@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-17 10:50:22 +02:00
Michael Ellerman
38aa7f32df powerpc/64/tm: Don't let userspace set regs->trap via sigreturn
commit c7def7fbdeaa25feaa19caf4a27c5d10bd8789e4 upstream.

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 9a81c16b5275 ("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: 2b0a576d15e0 ("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
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-17 10:50:22 +02:00
Libor Pechacek
27993365c0 powerpc/pseries: Avoid NULL pointer dereference when drmem is unavailable
commit a83836dbc53e96f13fec248ecc201d18e1e3111d upstream.

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: 6c6ea53725b3 ("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
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-17 10:50:20 +02:00
YueHaibing
a0f079ac13 powerpc/pseries: Drop pointless static qualifier in vpa_debugfs_init()
commit 11dd34f3eae5a468013bb161a1dcf1fecd2ca321 upstream.

There is no need to have the 'struct dentry *vpa_dir' variable static
since new value always be assigned before use it.

Fixes: c6c26fb55e8e ("powerpc/pseries: Export raw per-CPU VPA data via debugfs")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Reviewed-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190218125644.87448-1-yuehaibing@huawei.com
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-17 10:50:16 +02:00
Naveen N. Rao
a7393e6f2e powerpc: Include .BTF section
[ Upstream commit cb0cc635c7a9fa8a3a0f75d4d896721819c63add ]

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
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-03-25 08:25:42 +01:00
Desnes A. Nunes do Rosario
da44902fcf powerpc: fix hardware PMU exception bug on PowerVM compatibility mode systems
commit fc37a1632d40c80c067eb1bc235139f5867a2667 upstream.

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: 68f2f0d431d9ea4 ("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
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-12 13:00:31 +01:00
Michael Ellerman
b408bfa79b powerpc/mm: Fix missing KUAP disable in flush_coherent_icache()
[ Upstream commit 59bee45b9712c759ea4d3dcc4eff1752f3a66558 ]

Stefan reported a strange kernel fault which turned out to be due to a
missing KUAP disable in flush_coherent_icache() called from
flush_icache_range().

The fault looks like:

  Kernel attempted to access user page (7fffc30d9c00) - exploit attempt? (uid: 1009)
  BUG: Unable to handle kernel data access on read at 0x7fffc30d9c00
  Faulting instruction address: 0xc00000000007232c
  Oops: Kernel access of bad area, sig: 11 [#1]
  LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA PowerNV
  CPU: 35 PID: 5886 Comm: sigtramp Not tainted 5.6.0-rc2-gcc-8.2.0-00003-gfc37a1632d40 #79
  NIP:  c00000000007232c LR: c00000000003b7fc CTR: 0000000000000000
  REGS: c000001e11093940 TRAP: 0300   Not tainted  (5.6.0-rc2-gcc-8.2.0-00003-gfc37a1632d40)
  MSR:  900000000280b033 <SF,HV,VEC,VSX,EE,FP,ME,IR,DR,RI,LE>  CR: 28000884  XER: 00000000
  CFAR: c0000000000722fc DAR: 00007fffc30d9c00 DSISR: 08000000 IRQMASK: 0
  GPR00: c00000000003b7fc c000001e11093bd0 c0000000023ac200 00007fffc30d9c00
  GPR04: 00007fffc30d9c18 0000000000000000 c000001e11093bd4 0000000000000000
  GPR08: 0000000000000000 0000000000000001 0000000000000000 c000001e1104ed80
  GPR12: 0000000000000000 c000001fff6ab380 c0000000016be2d0 4000000000000000
  GPR16: c000000000000000 bfffffffffffffff 0000000000000000 0000000000000000
  GPR20: 00007fffc30d9c00 00007fffc30d8f58 00007fffc30d9c18 00007fffc30d9c20
  GPR24: 00007fffc30d9c18 0000000000000000 c000001e11093d90 c000001e1104ed80
  GPR28: c000001e11093e90 0000000000000000 c0000000023d9d18 00007fffc30d9c00
  NIP flush_icache_range+0x5c/0x80
  LR  handle_rt_signal64+0x95c/0xc2c
  Call Trace:
    0xc000001e11093d90 (unreliable)
    handle_rt_signal64+0x93c/0xc2c
    do_notify_resume+0x310/0x430
    ret_from_except_lite+0x70/0x74
  Instruction dump:
  409e002c 7c0802a6 3c62ff31 3863f6a0 f8010080 48195fed 60000000 48fe4c8d
  60000000 e8010080 7c0803a6 7c0004ac <7c00ffac> 7c0004ac 4c00012c 38210070

This path through handle_rt_signal64() to setup_trampoline() and
flush_icache_range() is only triggered by 64-bit processes that have
unmapped their VDSO, which is rare.

flush_icache_range() takes a range of addresses to flush. In
flush_coherent_icache() we implement an optimisation for CPUs where we
know we don't actually have to flush the whole range, we just need to
do a single icbi.

However we still execute the icbi on the user address of the start of
the range we're flushing. On CPUs that also implement KUAP (Power9)
that leads to the spurious fault above.

We should be able to pass any address, including a kernel address, to
the icbi on these CPUs, which would avoid any interaction with KUAP.
But I don't want to make that change in a bug fix, just in case it
surfaces some strange behaviour on some CPU.

So for now just disable KUAP around the icbi. Note the icbi is treated
as a load, so we allow read access, not write as you'd expect.

Fixes: 890274c2dc4c ("powerpc/64s: Implement KUAP for Radix MMU")
Cc: stable@vger.kernel.org # v5.2+
Reported-by: Stefan Berger <stefanb@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200303235708.26004-1-mpe@ellerman.id.au
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-03-12 13:00:25 +01:00
Alastair D'Silva
42dac16dc4 powerpc: Convert flush_icache_range & friends to C
[ Upstream commit 23eb7f560a2a6a1b0dbaaaae8685da75314347e4 ]

Similar to commit 22e9c88d486a
("powerpc/64: reuse PPC32 static inline flush_dcache_range()")
this patch converts the following ASM symbols to C:
    flush_icache_range()
    __flush_dcache_icache()
    __flush_dcache_icache_phys()

This was done as we discovered a long-standing bug where the length of the
range was truncated due to using a 32 bit shift instead of a 64 bit one.

By converting these functions to C, it becomes easier to maintain.

flush_dcache_icache_phys() retains a critical assembler section as we must
ensure there are no memory accesses while the data MMU is disabled
(authored by Christophe Leroy). Since this has no external callers, it has
also been made static, allowing the compiler to inline it within
flush_dcache_icache_page().

Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
[mpe: Minor fixups, don't export __flush_dcache_icache()]
Link: https://lore.kernel.org/r/20191104023305.9581-5-alastair@au1.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-03-12 13:00:25 +01:00
Alastair D'Silva
ec21f6d52b powerpc: define helpers to get L1 icache sizes
[ Upstream commit 7a0745c5e03ff1129864bc6d80f5c4417e8d7893 ]

This patch adds helpers to retrieve icache sizes, and renames the existing
helpers to make it clear that they are for dcache.

Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191104023305.9581-4-alastair@au1.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-03-12 13:00:25 +01:00
Christophe Leroy
9b9374cf1e powerpc/hugetlb: Fix 8M hugepages on 8xx
commit 50a175dd18de7a647e72aca7daf4744e3a5a81e3 upstream.

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: 22569b881d37 ("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
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-28 17:22:18 +01:00
Christophe Leroy
723a44f228 powerpc/hugetlb: Fix 512k hugepages on 8xx with 16k page size
commit f2b67ef90b0d5eca0f2255e02cf2f620bc0ddcdb upstream.

Commit 55c8fc3f4930 ("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: 3fb69c6a1a13 ("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
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-28 17:22:18 +01:00
Christophe Leroy
2ffeef3db3 powerpc/entry: Fix an #if which should be an #ifdef in entry_32.S
commit 9eb425b2e04e0e3006adffea5bf5f227a896f128 upstream.

Fixes: 12c3f1fd87bf ("powerpc/32s: get rid of CPU_FTR_601 feature")
Cc: stable@vger.kernel.org # v5.4+
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/a99fc0ad65b87a1ba51cfa3e0e9034ee294c3e07.1582034961.git.christophe.leroy@c-s.fr
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-28 17:22:18 +01:00
Gustavo Luiz Duarte
04e3f1d1e1 powerpc/tm: Fix clearing MSR[TS] in current when reclaiming on signal delivery
commit 2464cc4c345699adea52c7aef75707207cb8a2f6 upstream.

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: 2b0a576d15e0 ("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
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-28 17:22:17 +01:00
Sam Bobroff
a03b3cea86 powerpc/eeh: Fix deadlock handling dead PHB
commit d4f194ed9eb9841a8f978710e4d24296f791a85b upstream.

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: 2e25505147b8 ("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
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-28 17:22:17 +01:00
Christophe Leroy
9e1fab4450 powerpc/8xx: Fix clearing of bits 20-23 in ITLB miss
commit a4031afb9d10d97f4d0285844abbc0ab04245304 upstream.

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: 74fabcadfd43 ("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
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-28 17:22:17 +01:00
Alexandre Ghiti
a531e6ba85 powerpc: Do not consider weak unresolved symbol relocations as bad
[ Upstream commit 43e76cd368fbb67e767da5363ffeaa3989993c8c ]

Commit 8580ac9404f6 ("bpf: Process in-kernel BTF") introduced two weak
symbols that may be unresolved at link time which result in an absolute
relocation to 0. relocs_check.sh emits the following warning:

"WARNING: 2 bad relocations
c000000001a41478 R_PPC64_ADDR64    _binary__btf_vmlinux_bin_start
c000000001a41480 R_PPC64_ADDR64    _binary__btf_vmlinux_bin_end"

whereas those relocations are legitimate even for a relocatable kernel
compiled with -pie option.

relocs_check.sh already excluded some weak unresolved symbols explicitly:
remove those hardcoded symbols and add some logic that parses the symbols
using nm, retrieves all the weak unresolved symbols and excludes those from
the list of the potential bad relocations.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200118170335.21440-1-alex@ghiti.fr
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-02-24 08:37:00 +01:00
Christophe Leroy
7288d5338c powerpc/mm: Don't log user reads to 0xffffffff
[ Upstream commit 0f9aee0cb9da7db7d96f63cfa2dc5e4f1bffeb87 ]

Running vdsotest leaves many times the following log:

  [   79.629901] vdsotest[396]: User access of kernel address (ffffffff) - exploit attempt? (uid: 0)

A pointer set to (-1) is likely a programming error similar to
a NULL pointer and is not worth logging as an exploit attempt.

Don't log user accesses to 0xffffffff.

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/0728849e826ba16f1fbd6fa7f5c6cc87bd64e097.1577087627.git.christophe.leroy@c-s.fr
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-02-24 08:36:58 +01:00
Michael Bringmann
93df1b23b1 powerpc/pseries/lparcfg: Fix display of Maximum Memory
[ Upstream commit f1dbc1c5c70d0d4c60b5d467ba941fba167c12f6 ]

Correct overflow problem in calculation and display of Maximum Memory
value to syscfg.

Signed-off-by: Michael Bringmann <mwb@linux.ibm.com>
[mpe: Only n_lmbs needs casting to unsigned long]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/5577aef8-1d5a-ca95-ff0a-9c7b5977e5bf@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-02-24 08:36:57 +01:00
Oliver O'Halloran
3f6c8de753 powerpc/sriov: Remove VF eeh_dev state when disabling SR-IOV
[ Upstream commit 1fb4124ca9d456656a324f1ee29b7bf942f59ac8 ]

When disabling virtual functions on an SR-IOV adapter we currently do not
correctly remove the EEH state for the now-dead virtual functions. When
removing the pci_dn that was created for the VF when SR-IOV was enabled
we free the corresponding eeh_dev without removing it from the child device
list of the eeh_pe that contained it. This can result in crashes due to the
use-after-free.

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Reviewed-by: Sam Bobroff <sbobroff@linux.ibm.com>
Tested-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190821062655.19735-1-oohall@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-02-24 08:36:56 +01:00
zhengbin
88cf251d3c KVM: PPC: Remove set but not used variable 'ra', 'rs', 'rt'
[ Upstream commit 4de0a8355463e068e443b48eb5ae32370155368b ]

Fixes gcc '-Wunused-but-set-variable' warning:

arch/powerpc/kvm/emulate_loadstore.c: In function kvmppc_emulate_loadstore:
arch/powerpc/kvm/emulate_loadstore.c:87:6: warning: variable ra set but not used [-Wunused-but-set-variable]
arch/powerpc/kvm/emulate_loadstore.c: In function kvmppc_emulate_loadstore:
arch/powerpc/kvm/emulate_loadstore.c:87:10: warning: variable rs set but not used [-Wunused-but-set-variable]
arch/powerpc/kvm/emulate_loadstore.c: In function kvmppc_emulate_loadstore:
arch/powerpc/kvm/emulate_loadstore.c:87:14: warning: variable rt set but not used [-Wunused-but-set-variable]

They are not used since commit 2b33cb585f94 ("KVM: PPC: Reimplement
LOAD_FP/STORE_FP instruction mmio emulation with analyse_instr() input")

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: zhengbin <zhengbin13@huawei.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-02-24 08:36:51 +01:00
Oliver O'Halloran
8be3ac46ef powerpc/iov: Move VF pdev fixup into pcibios_fixup_iov()
[ Upstream commit 965c94f309be58fbcc6c8d3e4f123376c5970d79 ]

An ioda_pe for each VF is allocated in pnv_pci_sriov_enable() before
the pci_dev for the VF is created. We need to set the pe->pdev pointer
at some point after the pci_dev is created. Currently we do that in:

pcibios_bus_add_device()
	pnv_pci_dma_dev_setup() (via phb->ops.dma_dev_setup)
		/* fixup is done here */
		pnv_pci_ioda_dma_dev_setup() (via pnv_phb->dma_dev_setup)

The fixup needs to be done before setting up DMA for for the VF's PE,
but there's no real reason to delay it until this point. Move the
fixup into pnv_pci_ioda_fixup_iov() so the ordering is:

	pcibios_add_device()
		pnv_pci_ioda_fixup_iov() (via ppc_md.pcibios_fixup_sriov)

	pcibios_bus_add_device()
		...

This isn't strictly required, but it's a slightly more logical place
to do the fixup and it simplifies pnv_pci_dma_dev_setup().

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200110070207.439-4-oohall@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-02-24 08:36:30 +01:00
Oliver O'Halloran
271b18405e powerpc/powernv/iov: Ensure the pdn for VFs always contains a valid PE number
[ Upstream commit 3b5b9997b331e77ce967eba2c4bc80dc3134a7fe ]

On pseries there is a bug with adding hotplugged devices to an IOMMU
group. For a number of dumb reasons fixing that bug first requires
re-working how VFs are configured on PowerNV. For background, on
PowerNV we use the pcibios_sriov_enable() hook to do two things:

  1. Create a pci_dn structure for each of the VFs, and
  2. Configure the PHB's internal BARs so the MMIO range for each VF
     maps to a unique PE.

Roughly speaking a PE is the hardware counterpart to a Linux IOMMU
group since all the devices in a PE share the same IOMMU table. A PE
also defines the set of devices that should be isolated in response to
a PCI error (i.e. bad DMA, UR/CA, AER events, etc). When isolated all
MMIO and DMA traffic to and from devicein the PE is blocked by the
root complex until the PE is recovered by the OS.

The requirement to block MMIO causes a giant headache because the P8
PHB generally uses a fixed mapping between MMIO addresses and PEs. As
a result we need to delay configuring the IOMMU groups for device
until after MMIO resources are assigned. For physical devices (i.e.
non-VFs) the PE assignment is done in pcibios_setup_bridge() which is
called immediately after the MMIO resources for downstream
devices (and the bridge's windows) are assigned. For VFs the setup is
more complicated because:

  a) pcibios_setup_bridge() is not called again when VFs are activated, and
  b) The pci_dev for VFs are created by generic code which runs after
     pcibios_sriov_enable() is called.

The work around for this is a two step process:

  1. A fixup in pcibios_add_device() is used to initialised the cached
     pe_number in pci_dn, then
  2. A bus notifier then adds the device to the IOMMU group for the PE
     specified in pci_dn->pe_number.

A side effect fixing the pseries bug mentioned in the first paragraph
is moving the fixup out of pcibios_add_device() and into
pcibios_bus_add_device(), which is called much later. This results in
step 2. failing because pci_dn->pe_number won't be initialised when
the bus notifier is run.

We can fix this by removing the need for the fixup. The PE for a VF is
known before the VF is even scanned so we can initialise
pci_dn->pe_number pcibios_sriov_enable() instead. Unfortunately,
moving the initialisation causes two problems:

  1. We trip the WARN_ON() in the current fixup code, and
  2. The EEH core clears pdn->pe_number when recovering a VF and
     relies on the fixup to correctly re-set it.

The only justification for either of these is a comment in
eeh_rmv_device() suggesting that pdn->pe_number *must* be set to
IODA_INVALID_PE in order for the VF to be scanned. However, this
comment appears to have no basis in reality. Both bugs can be fixed by
just deleting the code.

Tested-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191028085424.12006-1-oohall@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-02-24 08:36:26 +01:00
Alexey Kardashevskiy
c4faf627c7 powerpc/pseries: Allow not having ibm, hypertas-functions::hcall-multi-tce for DDW
commit 7559d3d295f3365ea7ac0c0274c05e633fe4f594 upstream.

By default a pseries guest supports a H_PUT_TCE hypercall which maps
a single IOMMU page in a DMA window. Additionally the hypervisor may
support H_PUT_TCE_INDIRECT/H_STUFF_TCE which update multiple TCEs at once;
this is advertised via the device tree /rtas/ibm,hypertas-functions
property which Linux converts to FW_FEATURE_MULTITCE.

FW_FEATURE_MULTITCE is checked when dma_iommu_ops is used; however
the code managing the huge DMA window (DDW) ignores it and calls
H_PUT_TCE_INDIRECT even if it is explicitly disabled via
the "multitce=off" kernel command line parameter.

This adds FW_FEATURE_MULTITCE checking to the DDW code path.

This changes tce_build_pSeriesLP to take liobn and page size as
the huge window does not have iommu_table descriptor which usually
the place to store these numbers.

Fixes: 4e8b0cf46b25 ("powerpc/pseries: Add support for dynamic dma windows")
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Tested-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191216041924.42318-3-aik@ozlabs.ru
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-14 16:34:16 -05:00
Tyrel Datwyler
cff30edec9 powerpc/pseries/vio: Fix iommu_table use-after-free refcount warning
commit aff8c8242bc638ba57247ae1ec5f272ac3ed3b92 upstream.

Commit e5afdf9dd515 ("powerpc/vfio_spapr_tce: Add reference counting to
iommu_table") missed an iommu_table allocation in the pseries vio code.
The iommu_table is allocated with kzalloc and as a result the associated
kref gets a value of zero. This has the side effect that during a DLPAR
remove of the associated virtual IOA the iommu_tce_table_put() triggers
a use-after-free underflow warning.

Call Trace:
[c0000002879e39f0] [c00000000071ecb4] refcount_warn_saturate+0x184/0x190
(unreliable)
[c0000002879e3a50] [c0000000000500ac] iommu_tce_table_put+0x9c/0xb0
[c0000002879e3a70] [c0000000000f54e4] vio_dev_release+0x34/0x70
[c0000002879e3aa0] [c00000000087cfa4] device_release+0x54/0xf0
[c0000002879e3b10] [c000000000d64c84] kobject_cleanup+0xa4/0x240
[c0000002879e3b90] [c00000000087d358] put_device+0x28/0x40
[c0000002879e3bb0] [c0000000007a328c] dlpar_remove_slot+0x15c/0x250
[c0000002879e3c50] [c0000000007a348c] remove_slot_store+0xac/0xf0
[c0000002879e3cd0] [c000000000d64220] kobj_attr_store+0x30/0x60
[c0000002879e3cf0] [c0000000004ff13c] sysfs_kf_write+0x6c/0xa0
[c0000002879e3d10] [c0000000004fde4c] kernfs_fop_write+0x18c/0x260
[c0000002879e3d60] [c000000000410f3c] __vfs_write+0x3c/0x70
[c0000002879e3d80] [c000000000415408] vfs_write+0xc8/0x250
[c0000002879e3dd0] [c0000000004157dc] ksys_write+0x7c/0x120
[c0000002879e3e20] [c00000000000b278] system_call+0x5c/0x68

Further, since the refcount was always zero the iommu_tce_table_put()
fails to call the iommu_table release function resulting in a leak.

Fix this issue be initilizing the iommu_table kref immediately after
allocation.

Fixes: e5afdf9dd515 ("powerpc/vfio_spapr_tce: Add reference counting to iommu_table")
Signed-off-by: Tyrel Datwyler <tyreld@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/1579558202-26052-1-git-send-email-tyreld@linux.ibm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-14 16:34:16 -05:00
Vaibhav Jain
5ca556d5ed powerpc/papr_scm: Fix leaking 'bus_desc.provider_name' in some paths
commit 5649607a8d0b0e019a4db14aab3de1e16c3a2b4f upstream.

String 'bus_desc.provider_name' allocated inside
papr_scm_nvdimm_init() will leaks in case call to
nvdimm_bus_register() fails or when papr_scm_remove() is called.

This minor patch ensures that 'bus_desc.provider_name' is freed in
error path for nvdimm_bus_register() as well as in papr_scm_remove().

Fixes: b5beae5e224f ("powerpc/pseries: Add driver for PAPR SCM regions")
Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200122155140.120429-1-vaibhav@linux.ibm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-14 16:34:16 -05:00
Christophe Leroy
05a23f4364 powerpc/ptdump: Only enable PPC_CHECK_WX with STRICT_KERNEL_RWX
commit f509247b08f2dcf7754d9ed85ad69a7972aa132b upstream.

ptdump_check_wx() is called from mark_rodata_ro() which only exists
when CONFIG_STRICT_KERNEL_RWX is selected.

Fixes: 453d87f6a8ae ("powerpc/mm: Warn if W+X pages found on boot")
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/922d4939c735c6b52b4137838bcc066fffd4fc33.1578989545.git.christophe.leroy@c-s.fr
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-14 16:34:16 -05:00
Christophe Leroy
17f37249d7 powerpc/ptdump: Fix W+X verification call in mark_rodata_ro()
commit e26ad936dd89d79f66c2b567f700e0c2a7103070 upstream.

ptdump_check_wx() also have to be called when pages are mapped
by blocks.

Fixes: 453d87f6a8ae ("powerpc/mm: Warn if W+X pages found on boot")
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/37517da8310f4457f28921a4edb88fb21d27b62a.1578989531.git.christophe.leroy@c-s.fr
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-14 16:34:16 -05:00
Ram Pai
6d7edac146 Revert "powerpc/pseries/iommu: Don't use dma_iommu_ops on secure guests"
commit d862b44133b7a1d7de25288e09eabf4df415e971 upstream.

This reverts commit edea902c1c1efb855f77e041f9daf1abe7a9768a.

At the time the change allowed direct DMA ops for secure VMs; however
since then we switched on using SWIOTLB backed with IOMMU (direct mapping)
and to make this work, we need dma_iommu_ops which handles all cases
including TCE mapping I/O pages in the presence of an IOMMU.

Fixes: edea902c1c1e ("powerpc/pseries/iommu: Don't use dma_iommu_ops on secure guests")
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
[aik: added "revert" and "fixes:"]
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Tested-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191216041924.42318-2-aik@ozlabs.ru
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-14 16:34:16 -05:00
Christophe Leroy
866323ccc1 powerpc/kuap: Fix set direction in allow/prevent_user_access()
[ Upstream commit 1d8f739b07bd538f272f60bf53f10e7e6248d295 ]

__builtin_constant_p() always return 0 for pointers, so on RADIX
we always end up opening both direction (by writing 0 in SPR29):

  0000000000000170 <._copy_to_user>:
  ...
   1b0:	4c 00 01 2c 	isync
   1b4:	39 20 00 00 	li      r9,0
   1b8:	7d 3d 03 a6 	mtspr   29,r9
   1bc:	4c 00 01 2c 	isync
   1c0:	48 00 00 01 	bl      1c0 <._copy_to_user+0x50>
  			1c0: R_PPC64_REL24	.__copy_tofrom_user
  ...
  0000000000000220 <._copy_from_user>:
  ...
   2ac:	4c 00 01 2c 	isync
   2b0:	39 20 00 00 	li      r9,0
   2b4:	7d 3d 03 a6 	mtspr   29,r9
   2b8:	4c 00 01 2c 	isync
   2bc:	7f c5 f3 78 	mr      r5,r30
   2c0:	7f 83 e3 78 	mr      r3,r28
   2c4:	48 00 00 01 	bl      2c4 <._copy_from_user+0xa4>
  			2c4: R_PPC64_REL24	.__copy_tofrom_user
  ...

Use an explicit parameter for direction selection, so that GCC
is able to see it is a constant:

  00000000000001b0 <._copy_to_user>:
  ...
   1f0:	4c 00 01 2c 	isync
   1f4:	3d 20 40 00 	lis     r9,16384
   1f8:	79 29 07 c6 	rldicr  r9,r9,32,31
   1fc:	7d 3d 03 a6 	mtspr   29,r9
   200:	4c 00 01 2c 	isync
   204:	48 00 00 01 	bl      204 <._copy_to_user+0x54>
  			204: R_PPC64_REL24	.__copy_tofrom_user
  ...
  0000000000000260 <._copy_from_user>:
  ...
   2ec:	4c 00 01 2c 	isync
   2f0:	39 20 ff ff 	li      r9,-1
   2f4:	79 29 00 04 	rldicr  r9,r9,0,0
   2f8:	7d 3d 03 a6 	mtspr   29,r9
   2fc:	4c 00 01 2c 	isync
   300:	7f c5 f3 78 	mr      r5,r30
   304:	7f 83 e3 78 	mr      r3,r28
   308:	48 00 00 01 	bl      308 <._copy_from_user+0xa8>
  			308: R_PPC64_REL24	.__copy_tofrom_user
  ...

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
[mpe: Spell out the directions, s/KUAP_R/KUAP_READ/ etc.]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/f4e88ec4941d5facb35ce75026b0112f980086c3.1579866752.git.christophe.leroy@c-s.fr
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-02-11 04:35:55 -08:00
Sean Christopherson
7426ddf01f KVM: Use vcpu-specific gva->hva translation when querying host page size
[ Upstream commit f9b84e19221efc5f493156ee0329df3142085f28 ]

Use kvm_vcpu_gfn_to_hva() when retrieving the host page size so that the
correct set of memslots is used when handling x86 page faults in SMM.

Fixes: 54bf36aac520 ("KVM: x86: use vcpu-specific functions to read/write/translate GFNs")
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-02-11 04:35:54 -08:00
Nathan Chancellor
bf45386cef powerpc/44x: Adjust indentation in ibm4xx_denali_fixup_memsize
commit c3aae14e5d468d18dbb5d7c0c8c7e2968cc14aad upstream.

Clang warns:

../arch/powerpc/boot/4xx.c:231:3: warning: misleading indentation;
statement is not part of the previous 'else' [-Wmisleading-indentation]
        val = SDRAM0_READ(DDR0_42);
        ^
../arch/powerpc/boot/4xx.c:227:2: note: previous statement is here
        else
        ^

This is because there is a space at the beginning of this line; remove
it so that the indentation is consistent according to the Linux kernel
coding style and clang no longer warns.

Fixes: d23f5099297c ("[POWERPC] 4xx: Adds decoding of 440SPE memory size to boot wrapper library")
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://github.com/ClangBuiltLinux/linux/issues/780
Link: https://lore.kernel.org/r/20191209200338.12546-1-natechancellor@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-11 04:35:45 -08:00