linux-stable.git/include, branch v5.4.80 Linux kernel stable tree spi: Introduce device-managed SPI controller allocation 2020-11-24T12:29:22+00:00 Lukas Wunner lukas@wunner.de 2020-11-11T19:07:10+00:00 3e04a4976addbedcad326f47b0dd4efc570a1fac commit 5e844cc37a5cbaa460e68f9a989d321d63088a89 upstream. SPI driver probing currently comprises two steps, whereas removal comprises only one step: spi_alloc_master() spi_register_controller() spi_unregister_controller() That's because spi_unregister_controller() calls device_unregister() instead of device_del(), thereby releasing the reference on the spi_controller which was obtained by spi_alloc_master(). An SPI driver's private data is contained in the same memory allocation as the spi_controller struct. Thus, once spi_unregister_controller() has been called, the private data is inaccessible. But some drivers need to access it after spi_unregister_controller() to perform further teardown steps. Introduce devm_spi_alloc_master() and devm_spi_alloc_slave(), which release a reference on the spi_controller struct only after the driver has unbound, thereby keeping the memory allocation accessible. Change spi_unregister_controller() to not release a reference if the spi_controller was allocated by one of these new devm functions. The present commit is small enough to be backportable to stable. It allows fixing drivers which use the private data in their ->remove() hook after it's been freed. It also allows fixing drivers which neglect to release a reference on the spi_controller in the probe error path. Long-term, most SPI drivers shall be moved over to the devm functions introduced herein. The few that can't shall be changed in a treewide commit to explicitly release the last reference on the controller. That commit shall amend spi_unregister_controller() to no longer release a reference, thereby completing the migration. As a result, the behaviour will be less surprising and more consistent with subsystems such as IIO, which also includes the private data in the allocation of the generic iio_dev struct, but calls device_del() in iio_device_unregister(). Signed-off-by: Lukas Wunner <lukas@wunner.de> Link: https://lore.kernel.org/r/272bae2ef08abd21388c98e23729886663d19192.1605121038.git.lukas@wunner.de Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 5e844cc37a5cbaa460e68f9a989d321d63088a89 upstream.

SPI driver probing currently comprises two steps, whereas removal
comprises only one step:

    spi_alloc_master()
    spi_register_controller()

    spi_unregister_controller()

That's because spi_unregister_controller() calls device_unregister()
instead of device_del(), thereby releasing the reference on the
spi_controller which was obtained by spi_alloc_master().

An SPI driver's private data is contained in the same memory allocation
as the spi_controller struct.  Thus, once spi_unregister_controller()
has been called, the private data is inaccessible.  But some drivers
need to access it after spi_unregister_controller() to perform further
teardown steps.

Introduce devm_spi_alloc_master() and devm_spi_alloc_slave(), which
release a reference on the spi_controller struct only after the driver
has unbound, thereby keeping the memory allocation accessible.  Change
spi_unregister_controller() to not release a reference if the
spi_controller was allocated by one of these new devm functions.

The present commit is small enough to be backportable to stable.
It allows fixing drivers which use the private data in their ->remove()
hook after it's been freed.  It also allows fixing drivers which neglect
to release a reference on the spi_controller in the probe error path.

Long-term, most SPI drivers shall be moved over to the devm functions
introduced herein.  The few that can't shall be changed in a treewide
commit to explicitly release the last reference on the controller.
That commit shall amend spi_unregister_controller() to no longer release
a reference, thereby completing the migration.

As a result, the behaviour will be less surprising and more consistent
with subsystems such as IIO, which also includes the private data in the
allocation of the generic iio_dev struct, but calls device_del() in
iio_device_unregister().

Signed-off-by: Lukas Wunner <lukas@wunner.de>
Link: https://lore.kernel.org/r/272bae2ef08abd21388c98e23729886663d19192.1605121038.git.lukas@wunner.de
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
iommu/vt-d: Avoid panic if iommu init fails in tboot system 2020-11-24T12:29:17+00:00 Zhenzhong Duan zhenzhong.duan@gmail.com 2020-11-10T07:19:08+00:00 58f1657c3a5878dee824bda252a7a76dc78ee4e7 [ Upstream commit 4d213e76a359e540ca786ee937da7f35faa8e5f8 ] "intel_iommu=off" command line is used to disable iommu but iommu is force enabled in a tboot system for security reason. However for better performance on high speed network device, a new option "intel_iommu=tboot_noforce" is introduced to disable the force on. By default kernel should panic if iommu init fail in tboot for security reason, but it's unnecessory if we use "intel_iommu=tboot_noforce,off". Fix the code setting force_on and move intel_iommu_tboot_noforce from tboot code to intel iommu code. Fixes: 7304e8f28bb2 ("iommu/vt-d: Correctly disable Intel IOMMU force on") Signed-off-by: Zhenzhong Duan <zhenzhong.duan@gmail.com> Tested-by: Lukasz Hawrylko <lukasz.hawrylko@linux.intel.com> Acked-by: Lu Baolu <baolu.lu@linux.intel.com> Link: https://lore.kernel.org/r/20201110071908.3133-1-zhenzhong.duan@gmail.com Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 4d213e76a359e540ca786ee937da7f35faa8e5f8 ]

"intel_iommu=off" command line is used to disable iommu but iommu is force
enabled in a tboot system for security reason.

However for better performance on high speed network device, a new option
"intel_iommu=tboot_noforce" is introduced to disable the force on.

By default kernel should panic if iommu init fail in tboot for security
reason, but it's unnecessory if we use "intel_iommu=tboot_noforce,off".

Fix the code setting force_on and move intel_iommu_tboot_noforce
from tboot code to intel iommu code.

Fixes: 7304e8f28bb2 ("iommu/vt-d: Correctly disable Intel IOMMU force on")
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@gmail.com>
Tested-by: Lukasz Hawrylko <lukasz.hawrylko@linux.intel.com>
Acked-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20201110071908.3133-1-zhenzhong.duan@gmail.com
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
iommu/vt-d: Move intel_iommu_gfx_mapped to Intel IOMMU header 2020-11-24T12:29:17+00:00 Andy Shevchenko andriy.shevchenko@linux.intel.com 2020-08-28T16:12:11+00:00 964b02d50bab830c446bf32dff039e9eb637599b [ Upstream commit c7eb900f5f45eeab1ea1bed997a2a12d8b5907bc ] Static analyzer is not happy about intel_iommu_gfx_mapped declaration: .../drivers/iommu/intel/iommu.c:364:5: warning: symbol 'intel_iommu_gfx_mapped' was not declared. Should it be static? Move its declaration to Intel IOMMU header file. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com> Link: https://lore.kernel.org/r/20200828161212.71294-1-andriy.shevchenko@linux.intel.com Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit c7eb900f5f45eeab1ea1bed997a2a12d8b5907bc ]

Static analyzer is not happy about intel_iommu_gfx_mapped declaration:

.../drivers/iommu/intel/iommu.c:364:5: warning: symbol 'intel_iommu_gfx_mapped' was not declared. Should it be static?

Move its declaration to Intel IOMMU header file.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20200828161212.71294-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
ip_tunnels: Set tunnel option flag when tunnel metadata is present 2020-11-24T12:29:05+00:00 Yi-Hung Wei yihung.wei@gmail.com 2020-11-11T00:16:40+00:00 ef097e93aca2f1bec3d0a2e632edbefedf7efb4e [ Upstream commit 9c2e14b48119b39446031d29d994044ae958d8fc ] Currently, we may set the tunnel option flag when the size of metadata is zero. For example, we set TUNNEL_GENEVE_OPT in the receive function no matter the geneve option is present or not. As this may result in issues on the tunnel flags consumers, this patch fixes the issue. Related discussion: * https://lore.kernel.org/netdev/1604448694-19351-1-git-send-email-yihung.wei@gmail.com/T/#u Fixes: 256c87c17c53 ("net: check tunnel option type in tunnel flags") Signed-off-by: Yi-Hung Wei <yihung.wei@gmail.com> Link: https://lore.kernel.org/r/1605053800-74072-1-git-send-email-yihung.wei@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 9c2e14b48119b39446031d29d994044ae958d8fc ]

Currently, we may set the tunnel option flag when the size of metadata
is zero.  For example, we set TUNNEL_GENEVE_OPT in the receive function
no matter the geneve option is present or not.  As this may result in
issues on the tunnel flags consumers, this patch fixes the issue.

Related discussion:
* https://lore.kernel.org/netdev/1604448694-19351-1-git-send-email-yihung.wei@gmail.com/T/#u

Fixes: 256c87c17c53 ("net: check tunnel option type in tunnel flags")
Signed-off-by: Yi-Hung Wei <yihung.wei@gmail.com>
Link: https://lore.kernel.org/r/1605053800-74072-1-git-send-email-yihung.wei@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
swiotlb: using SIZE_MAX needs limits.h included 2020-11-24T12:29:04+00:00 Stephen Rothwell sfr@canb.auug.org.au 2020-11-02T01:43:27+00:00 fd278c6359ac7cb8bfe9458858f7760523c440bc [ Upstream commit f51778db088b2407ec177f2f4da0f6290602aa3f ] After merging the drm-misc tree, linux-next build (arm multi_v7_defconfig) failed like this: In file included from drivers/gpu/drm/nouveau/nouveau_ttm.c:26: include/linux/swiotlb.h: In function 'swiotlb_max_mapping_size': include/linux/swiotlb.h:99:9: error: 'SIZE_MAX' undeclared (first use in this function) 99 | return SIZE_MAX; | ^~~~~~~~ include/linux/swiotlb.h:7:1: note: 'SIZE_MAX' is defined in header '<stdint.h>'; did you forget to '#include <stdint.h>'? 6 | #include <linux/init.h> +++ |+#include <stdint.h> 7 | #include <linux/types.h> include/linux/swiotlb.h:99:9: note: each undeclared identifier is reported only once for each function it appears in 99 | return SIZE_MAX; | ^~~~~~~~ Caused by commit abe420bfae52 ("swiotlb: Introduce swiotlb_max_mapping_size()") but only exposed by commit "drm/nouveu: fix swiotlb include" Fix it by including linux/limits.h as appropriate. Fixes: abe420bfae52 ("swiotlb: Introduce swiotlb_max_mapping_size()") Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Link: https://lore.kernel.org/r/20201102124327.2f82b2a7@canb.auug.org.au Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit f51778db088b2407ec177f2f4da0f6290602aa3f ]

After merging the drm-misc tree, linux-next build (arm
multi_v7_defconfig) failed like this:

In file included from drivers/gpu/drm/nouveau/nouveau_ttm.c:26:
include/linux/swiotlb.h: In function 'swiotlb_max_mapping_size':
include/linux/swiotlb.h:99:9: error: 'SIZE_MAX' undeclared (first use in this function)
   99 |  return SIZE_MAX;
      |         ^~~~~~~~
include/linux/swiotlb.h:7:1: note: 'SIZE_MAX' is defined in header '<stdint.h>'; did you forget to '#include <stdint.h>'?
    6 | #include <linux/init.h>
  +++ |+#include <stdint.h>
    7 | #include <linux/types.h>
include/linux/swiotlb.h:99:9: note: each undeclared identifier is reported only once for each function it appears in
   99 |  return SIZE_MAX;
      |         ^~~~~~~~

Caused by commit

  abe420bfae52 ("swiotlb: Introduce swiotlb_max_mapping_size()")

but only exposed by commit "drm/nouveu: fix swiotlb include"

Fix it by including linux/limits.h as appropriate.

Fixes: abe420bfae52 ("swiotlb: Introduce swiotlb_max_mapping_size()")
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Link: https://lore.kernel.org/r/20201102124327.2f82b2a7@canb.auug.org.au
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Exempt multicast addresses from five-second neighbor lifetime 2020-11-24T12:28:56+00:00 Jeff Dike jdike@akamai.com 2020-11-13T01:58:15+00:00 e5fe052c065d8074106bc8b68aed88deffe9c5cf [ Upstream commit 8cf8821e15cd553339a5b48ee555a0439c2b2742 ] Commit 58956317c8de ("neighbor: Improve garbage collection") guarantees neighbour table entries a five-second lifetime. Processes which make heavy use of multicast can fill the neighour table with multicast addresses in five seconds. At that point, neighbour entries can't be GC-ed because they aren't five seconds old yet, the kernel log starts to fill up with "neighbor table overflow!" messages, and sends start to fail. This patch allows multicast addresses to be thrown out before they've lived out their five seconds. This makes room for non-multicast addresses and makes messages to all addresses more reliable in these circumstances. Fixes: 58956317c8de ("neighbor: Improve garbage collection") Signed-off-by: Jeff Dike <jdike@akamai.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/20201113015815.31397-1-jdike@akamai.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 8cf8821e15cd553339a5b48ee555a0439c2b2742 ]

Commit 58956317c8de ("neighbor: Improve garbage collection")
guarantees neighbour table entries a five-second lifetime.  Processes
which make heavy use of multicast can fill the neighour table with
multicast addresses in five seconds.  At that point, neighbour entries
can't be GC-ed because they aren't five seconds old yet, the kernel
log starts to fill up with "neighbor table overflow!" messages, and
sends start to fail.

This patch allows multicast addresses to be thrown out before they've
lived out their five seconds.  This makes room for non-multicast
addresses and makes messages to all addresses more reliable in these
circumstances.

Fixes: 58956317c8de ("neighbor: Improve garbage collection")
Signed-off-by: Jeff Dike <jdike@akamai.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20201113015815.31397-1-jdike@akamai.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net/mlx5: Fix a race when moving command interface to events mode 2020-11-22T09:14:11+00:00 Eran Ben Elisha eranbe@mellanox.com 2020-03-18T19:44:32+00:00 7db82a5a4c15b89fa800ce2cf5d04cc0ae30279c commit d43b7007dbd1195a5b6b83213e49b1516aaf6f5e upstream. After driver creates (via FW command) an EQ for commands, the driver will be informed on new commands completion by EQE. However, due to a race in driver's internal command mode metadata update, some new commands will still be miss-handled by driver as if we are in polling mode. Such commands can get two non forced completion, leading to already freed command entry access. CREATE_EQ command, that maps EQ to the command queue must be posted to the command queue while it is empty and no other command should be posted. Add SW mechanism that once the CREATE_EQ command is about to be executed, all other commands will return error without being sent to the FW. Allow sending other commands only after successfully changing the driver's internal command mode metadata. We can safely return error to all other commands while creating the command EQ, as all other commands might be sent from the user/application during driver load. Application can rerun them later after driver's load was finished. Fixes: e126ba97dba9 ("mlx5: Add driver for Mellanox Connect-IB adapters") Signed-off-by: Eran Ben Elisha <eranbe@mellanox.com> Signed-off-by: Moshe Shemesh <moshe@mellanox.com> Signed-off-by: Saeed Mahameed <saeedm@mellanox.com> Cc: Timo Rothenpieler <timo@rothenpieler.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit d43b7007dbd1195a5b6b83213e49b1516aaf6f5e upstream.

After driver creates (via FW command) an EQ for commands, the driver will
be informed on new commands completion by EQE. However, due to a race in
driver's internal command mode metadata update, some new commands will
still be miss-handled by driver as if we are in polling mode. Such commands
can get two non forced completion, leading to already freed command entry
access.

CREATE_EQ command, that maps EQ to the command queue must be posted to the
command queue while it is empty and no other command should be posted.

Add SW mechanism that once the CREATE_EQ command is about to be executed,
all other commands will return error without being sent to the FW. Allow
sending other commands only after successfully changing the driver's
internal command mode metadata.
We can safely return error to all other commands while creating the command
EQ, as all other commands might be sent from the user/application during
driver load. Application can rerun them later after driver's load was
finished.

Fixes: e126ba97dba9 ("mlx5: Add driver for Mellanox Connect-IB adapters")
Signed-off-by: Eran Ben Elisha <eranbe@mellanox.com>
Signed-off-by: Moshe Shemesh <moshe@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Cc: Timo Rothenpieler <timo@rothenpieler.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
SUNRPC: Fix general protection fault in trace_rpc_xdr_overflow() 2020-11-18T18:20:26+00:00 Chuck Lever chuck.lever@oracle.com 2020-10-23T14:41:07+00:00 dfcb33773877f31a40ba0583e622935ef105c90b [ Upstream commit d321ff589c16d8c2207485a6d7fbdb14e873d46e ] The TP_fast_assign() section is careful enough not to dereference xdr->rqst if it's NULL. The TP_STRUCT__entry section is not. Fixes: 5582863f450c ("SUNRPC: Add XDR overflow trace event") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit d321ff589c16d8c2207485a6d7fbdb14e873d46e ]

The TP_fast_assign() section is careful enough not to dereference
xdr->rqst if it's NULL. The TP_STRUCT__entry section is not.

Fixes: 5582863f450c ("SUNRPC: Add XDR overflow trace event")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
bpf: Don't rely on GCC __attribute__((optimize)) to disable GCSE 2020-11-18T18:20:26+00:00 Ard Biesheuvel ardb@kernel.org 2020-10-28T17:15:05+00:00 d2e61c5202e63fd591023525965a7379ba493385 [ Upstream commit 080b6f40763565f65ebb9540219c71ce885cf568 ] Commit 3193c0836 ("bpf: Disable GCC -fgcse optimization for ___bpf_prog_run()") introduced a __no_fgcse macro that expands to a function scope __attribute__((optimize("-fno-gcse"))), to disable a GCC specific optimization that was causing trouble on x86 builds, and was not expected to have any positive effect in the first place. However, as the GCC manual documents, __attribute__((optimize)) is not for production use, and results in all other optimization options to be forgotten for the function in question. This can cause all kinds of trouble, but in one particular reported case, it causes -fno-asynchronous-unwind-tables to be disregarded, resulting in .eh_frame info to be emitted for the function. This reverts commit 3193c0836, and instead, it disables the -fgcse optimization for the entire source file, but only when building for X86 using GCC with CONFIG_BPF_JIT_ALWAYS_ON disabled. Note that the original commit states that CONFIG_RETPOLINE=n triggers the issue, whereas CONFIG_RETPOLINE=y performs better without the optimization, so it is kept disabled in both cases. Fixes: 3193c0836f20 ("bpf: Disable GCC -fgcse optimization for ___bpf_prog_run()") Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Link: https://lore.kernel.org/lkml/CAMuHMdUg0WJHEcq6to0-eODpXPOywLot6UD2=GFHpzoj_hCoBQ@mail.gmail.com/ Link: https://lore.kernel.org/bpf/20201028171506.15682-2-ardb@kernel.org Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 080b6f40763565f65ebb9540219c71ce885cf568 ]

Commit 3193c0836 ("bpf: Disable GCC -fgcse optimization for
___bpf_prog_run()") introduced a __no_fgcse macro that expands to a
function scope __attribute__((optimize("-fno-gcse"))), to disable a
GCC specific optimization that was causing trouble on x86 builds, and
was not expected to have any positive effect in the first place.

However, as the GCC manual documents, __attribute__((optimize))
is not for production use, and results in all other optimization
options to be forgotten for the function in question. This can
cause all kinds of trouble, but in one particular reported case,
it causes -fno-asynchronous-unwind-tables to be disregarded,
resulting in .eh_frame info to be emitted for the function.

This reverts commit 3193c0836, and instead, it disables the -fgcse
optimization for the entire source file, but only when building for
X86 using GCC with CONFIG_BPF_JIT_ALWAYS_ON disabled. Note that the
original commit states that CONFIG_RETPOLINE=n triggers the issue,
whereas CONFIG_RETPOLINE=y performs better without the optimization,
so it is kept disabled in both cases.

Fixes: 3193c0836f20 ("bpf: Disable GCC -fgcse optimization for ___bpf_prog_run()")
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/lkml/CAMuHMdUg0WJHEcq6to0-eODpXPOywLot6UD2=GFHpzoj_hCoBQ@mail.gmail.com/
Link: https://lore.kernel.org/bpf/20201028171506.15682-2-ardb@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
KVM: arm64: ARM_SMCCC_ARCH_WORKAROUND_1 doesn't return SMCCC_RET_NOT_REQUIRED 2020-11-18T18:20:21+00:00 Stephen Boyd swboyd@chromium.org 2020-10-23T15:47:50+00:00 d2cef3bae14b755bc17a29968679b3e95a74909d commit 1de111b51b829bcf01d2e57971f8fd07a665fa3f upstream. According to the SMCCC spec[1](7.5.2 Discovery) the ARM_SMCCC_ARCH_WORKAROUND_1 function id only returns 0, 1, and SMCCC_RET_NOT_SUPPORTED. 0 is "workaround required and safe to call this function" 1 is "workaround not required but safe to call this function" SMCCC_RET_NOT_SUPPORTED is "might be vulnerable or might not be, who knows, I give up!" SMCCC_RET_NOT_SUPPORTED might as well mean "workaround required, except calling this function may not work because it isn't implemented in some cases". Wonderful. We map this SMC call to 0 is SPECTRE_MITIGATED 1 is SPECTRE_UNAFFECTED SMCCC_RET_NOT_SUPPORTED is SPECTRE_VULNERABLE For KVM hypercalls (hvc), we've implemented this function id to return SMCCC_RET_NOT_SUPPORTED, 0, and SMCCC_RET_NOT_REQUIRED. One of those isn't supposed to be there. Per the code we call arm64_get_spectre_v2_state() to figure out what to return for this feature discovery call. 0 is SPECTRE_MITIGATED SMCCC_RET_NOT_REQUIRED is SPECTRE_UNAFFECTED SMCCC_RET_NOT_SUPPORTED is SPECTRE_VULNERABLE Let's clean this up so that KVM tells the guest this mapping: 0 is SPECTRE_MITIGATED 1 is SPECTRE_UNAFFECTED SMCCC_RET_NOT_SUPPORTED is SPECTRE_VULNERABLE Note: SMCCC_RET_NOT_AFFECTED is 1 but isn't part of the SMCCC spec Fixes: c118bbb52743 ("arm64: KVM: Propagate full Spectre v2 workaround state to KVM guests") Signed-off-by: Stephen Boyd <swboyd@chromium.org> Acked-by: Marc Zyngier <maz@kernel.org> Acked-by: Will Deacon <will@kernel.org> Cc: Andre Przywara <andre.przywara@arm.com> Cc: Steven Price <steven.price@arm.com> Cc: Marc Zyngier <maz@kernel.org> Cc: stable@vger.kernel.org Link: https://developer.arm.com/documentation/den0028/latest [1] Link: https://lore.kernel.org/r/20201023154751.1973872-1-swboyd@chromium.org Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Stephen Boyd <swboyd@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 1de111b51b829bcf01d2e57971f8fd07a665fa3f upstream.

According to the SMCCC spec[1](7.5.2 Discovery) the
ARM_SMCCC_ARCH_WORKAROUND_1 function id only returns 0, 1, and
SMCCC_RET_NOT_SUPPORTED.

 0 is "workaround required and safe to call this function"
 1 is "workaround not required but safe to call this function"
 SMCCC_RET_NOT_SUPPORTED is "might be vulnerable or might not be, who knows, I give up!"

SMCCC_RET_NOT_SUPPORTED might as well mean "workaround required, except
calling this function may not work because it isn't implemented in some
cases". Wonderful. We map this SMC call to

 0 is SPECTRE_MITIGATED
 1 is SPECTRE_UNAFFECTED
 SMCCC_RET_NOT_SUPPORTED is SPECTRE_VULNERABLE

For KVM hypercalls (hvc), we've implemented this function id to return
SMCCC_RET_NOT_SUPPORTED, 0, and SMCCC_RET_NOT_REQUIRED. One of those
isn't supposed to be there. Per the code we call
arm64_get_spectre_v2_state() to figure out what to return for this
feature discovery call.

 0 is SPECTRE_MITIGATED
 SMCCC_RET_NOT_REQUIRED is SPECTRE_UNAFFECTED
 SMCCC_RET_NOT_SUPPORTED is SPECTRE_VULNERABLE

Let's clean this up so that KVM tells the guest this mapping:

 0 is SPECTRE_MITIGATED
 1 is SPECTRE_UNAFFECTED
 SMCCC_RET_NOT_SUPPORTED is SPECTRE_VULNERABLE

Note: SMCCC_RET_NOT_AFFECTED is 1 but isn't part of the SMCCC spec

Fixes: c118bbb52743 ("arm64: KVM: Propagate full Spectre v2 workaround state to KVM guests")
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Acked-by: Marc Zyngier <maz@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Cc: Andre Przywara <andre.przywara@arm.com>
Cc: Steven Price <steven.price@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org
Link: https://developer.arm.com/documentation/den0028/latest [1]
Link: https://lore.kernel.org/r/20201023154751.1973872-1-swboyd@chromium.org
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>