linux-stable.git/drivers/firmware, branch v5.8.2 Linux kernel stable tree firmware: qcom_scm: Fix legacy convention SCM accessors 2020-08-19T06:27:08+00:00 Jonathan McDowell noodles@earth.li 2020-07-04T17:23:34+00:00 86caf5d8ac3ee6bd94ddec51524f960317fd06e4 commit b88c28280c3f7097546db93824686db1e7dceee1 upstream. The move to a combined driver for the QCOM SCM hardware changed the io_writel and io_readl helpers to use non-atomic calls, despite the commit message saying that atomic was a better option. This breaks these helpers on hardware that uses the old legacy convention (access fails with a -95 return code). Switch back to using the atomic calls. Observed as a failure routing GPIO interrupts to the Apps processor on an IPQ8064; fix is confirmed as correctly allowing the interrupts to be routed and observed. Reviewed-by: Elliot Berman <eberman@codeaurora.org> Fixes: 57d3b816718c ("firmware: qcom_scm: Remove thin wrappers") Cc: stable@vger.kernel.org Signed-off-by: Jonathan McDowell <noodles@earth.li> Link: https://lore.kernel.org/r/20200704172334.GA759@earth.li Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit b88c28280c3f7097546db93824686db1e7dceee1 upstream.

The move to a combined driver for the QCOM SCM hardware changed the
io_writel and io_readl helpers to use non-atomic calls, despite the
commit message saying that atomic was a better option. This breaks these
helpers on hardware that uses the old legacy convention (access fails
with a -95 return code). Switch back to using the atomic calls.

Observed as a failure routing GPIO interrupts to the Apps processor on
an IPQ8064; fix is confirmed as correctly allowing the interrupts to be
routed and observed.

Reviewed-by: Elliot Berman <eberman@codeaurora.org>
Fixes: 57d3b816718c ("firmware: qcom_scm: Remove thin wrappers")
Cc: stable@vger.kernel.org
Signed-off-by: Jonathan McDowell <noodles@earth.li>
Link: https://lore.kernel.org/r/20200704172334.GA759@earth.li
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
firmware: arm_scmi: Fix SCMI genpd domain probing 2020-08-19T06:26:06+00:00 Cristian Marussi cristian.marussi@arm.com 2020-06-19T22:03:30+00:00 660f9b20f5254ba4185f18e142456e39fc001f5f [ Upstream commit e0f1a30cf184821499eeb67daedd7a3f21bbcb0b ] When, at probe time, an SCMI communication failure inhibits the capacity to query power domains states, such domains should be skipped. Registering partially initialized SCMI power domains with genpd will causes kernel panic. arm-scmi timed out in resp(caller: scmi_power_state_get+0xa4/0xd0) scmi-power-domain scmi_dev.2: failed to get state for domain 9 Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 Mem abort info: ESR = 0x96000006 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 Data abort info: ISV = 0, ISS = 0x00000006 CM = 0, WnR = 0 user pgtable: 4k pages, 48-bit VAs, pgdp=00000009f3691000 [0000000000000000] pgd=00000009f1ca0003, p4d=00000009f1ca0003, pud=00000009f35ea003, pmd=0000000000000000 Internal error: Oops: 96000006 [#1] PREEMPT SMP CPU: 2 PID: 381 Comm: bash Not tainted 5.8.0-rc1-00011-gebd118c2cca8 #2 Hardware name: ARM LTD ARM Juno Development Platform/ARM Juno Development Platform, BIOS EDK II Jan 3 2020 Internal error: Oops: 96000006 [#1] PREEMPT SMP pstate: 80000005 (Nzcv daif -PAN -UAO BTYPE=--) pc : of_genpd_add_provider_onecell+0x98/0x1f8 lr : of_genpd_add_provider_onecell+0x48/0x1f8 Call trace: of_genpd_add_provider_onecell+0x98/0x1f8 scmi_pm_domain_probe+0x174/0x1e8 scmi_dev_probe+0x90/0xe0 really_probe+0xe4/0x448 driver_probe_device+0xfc/0x168 device_driver_attach+0x7c/0x88 bind_store+0xe8/0x128 drv_attr_store+0x2c/0x40 sysfs_kf_write+0x4c/0x60 kernfs_fop_write+0x114/0x230 __vfs_write+0x24/0x50 vfs_write+0xbc/0x1e0 ksys_write+0x70/0xf8 __arm64_sys_write+0x24/0x30 el0_svc_common.constprop.3+0x94/0x160 do_el0_svc+0x2c/0x98 el0_sync_handler+0x148/0x1a8 el0_sync+0x158/0x180 Do not register any power domain that failed to be queried with genpd. Fixes: 898216c97ed2 ("firmware: arm_scmi: add device power domain support using genpd") Link: https://lore.kernel.org/r/20200619220330.12217-1-cristian.marussi@arm.com Signed-off-by: Cristian Marussi <cristian.marussi@arm.com> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit e0f1a30cf184821499eeb67daedd7a3f21bbcb0b ]

When, at probe time, an SCMI communication failure inhibits the capacity
to query power domains states, such domains should be skipped.

Registering partially initialized SCMI power domains with genpd will
causes kernel panic.

 arm-scmi timed out in resp(caller: scmi_power_state_get+0xa4/0xd0)
 scmi-power-domain scmi_dev.2: failed to get state for domain 9
 Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
 Mem abort info:
   ESR = 0x96000006
   EC = 0x25: DABT (current EL), IL = 32 bits
   SET = 0, FnV = 0
   EA = 0, S1PTW = 0
 Data abort info:
   ISV = 0, ISS = 0x00000006
   CM = 0, WnR = 0
 user pgtable: 4k pages, 48-bit VAs, pgdp=00000009f3691000
 [0000000000000000] pgd=00000009f1ca0003, p4d=00000009f1ca0003, pud=00000009f35ea003, pmd=0000000000000000
 Internal error: Oops: 96000006 [#1] PREEMPT SMP
 CPU: 2 PID: 381 Comm: bash Not tainted 5.8.0-rc1-00011-gebd118c2cca8 #2
 Hardware name: ARM LTD ARM Juno Development Platform/ARM Juno Development Platform, BIOS EDK II Jan  3 2020
 Internal error: Oops: 96000006 [#1] PREEMPT SMP
 pstate: 80000005 (Nzcv daif -PAN -UAO BTYPE=--)
 pc : of_genpd_add_provider_onecell+0x98/0x1f8
 lr : of_genpd_add_provider_onecell+0x48/0x1f8
 Call trace:
  of_genpd_add_provider_onecell+0x98/0x1f8
  scmi_pm_domain_probe+0x174/0x1e8
  scmi_dev_probe+0x90/0xe0
  really_probe+0xe4/0x448
  driver_probe_device+0xfc/0x168
  device_driver_attach+0x7c/0x88
  bind_store+0xe8/0x128
  drv_attr_store+0x2c/0x40
  sysfs_kf_write+0x4c/0x60
  kernfs_fop_write+0x114/0x230
  __vfs_write+0x24/0x50
  vfs_write+0xbc/0x1e0
  ksys_write+0x70/0xf8
  __arm64_sys_write+0x24/0x30
  el0_svc_common.constprop.3+0x94/0x160
  do_el0_svc+0x2c/0x98
  el0_sync_handler+0x148/0x1a8
  el0_sync+0x158/0x180

Do not register any power domain that failed to be queried with genpd.

Fixes: 898216c97ed2 ("firmware: arm_scmi: add device power domain support using genpd")
Link: https://lore.kernel.org/r/20200619220330.12217-1-cristian.marussi@arm.com
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
firmware: Fix a reference count leak. 2020-07-29T17:13:50+00:00 Qiushi Wu wu000273@umn.edu 2020-06-13T19:05:33+00:00 fe3c60684377d5ad9b0569b87ed3e26e12c8173b kobject_init_and_add() takes reference even when it fails. If this function returns an error, kobject_put() must be called to properly clean up the memory associated with the object. Callback function fw_cfg_sysfs_release_entry() in kobject_put() can handle the pointer "entry" properly. Signed-off-by: Qiushi Wu <wu000273@umn.edu> Link: https://lore.kernel.org/r/20200613190533.15712-1-wu000273@umn.edu Signed-off-by: Michael S. Tsirkin <mst@redhat.com> 
kobject_init_and_add() takes reference even when it fails.
If this function returns an error, kobject_put() must be called to
properly clean up the memory associated with the object.
Callback function fw_cfg_sysfs_release_entry() in kobject_put()
can handle the pointer "entry" properly.

Signed-off-by: Qiushi Wu <wu000273@umn.edu>
Link: https://lore.kernel.org/r/20200613190533.15712-1-wu000273@umn.edu
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Merge tag 'efi-urgent-2020-07-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into master 2020-07-25T20:18:42+00:00 Linus Torvalds torvalds@linux-foundation.org 2020-07-25T20:18:42+00:00 17baa442864254cb2aadf3a4d668c0f81d2f07c5 Pull EFI fixes from Ingo Molnar: "Various EFI fixes: - Fix the layering violation in the use of the EFI runtime services availability mask in users of the 'efivars' abstraction - Revert build fix for GCC v4.8 which is no longer supported - Clean up some x86 EFI stub details, some of which are borderline bugs that copy around garbage into padding fields - let's fix these out of caution. - Fix build issues while working on RISC-V support - Avoid --whole-archive when linking the stub on arm64" * tag 'efi-urgent-2020-07-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: efi: Revert "efi/x86: Fix build with gcc 4" efi/efivars: Expose RT service availability via efivars abstraction efi/libstub: Move the function prototypes to header file efi/libstub: Fix gcc error around __umoddi3 for 32 bit builds efi/libstub/arm64: link stub lib.a conditionally efi/x86: Only copy upto the end of setup_header efi/x86: Remove unused variables 
Pull EFI fixes from Ingo Molnar:
 "Various EFI fixes:

   - Fix the layering violation in the use of the EFI runtime services
     availability mask in users of the 'efivars' abstraction

   - Revert build fix for GCC v4.8 which is no longer supported

   - Clean up some x86 EFI stub details, some of which are borderline
     bugs that copy around garbage into padding fields - let's fix these
     out of caution.

   - Fix build issues while working on RISC-V support

   - Avoid --whole-archive when linking the stub on arm64"

* tag 'efi-urgent-2020-07-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  efi: Revert "efi/x86: Fix build with gcc 4"
  efi/efivars: Expose RT service availability via efivars abstraction
  efi/libstub: Move the function prototypes to header file
  efi/libstub: Fix gcc error around __umoddi3 for 32 bit builds
  efi/libstub/arm64: link stub lib.a conditionally
  efi/x86: Only copy upto the end of setup_header
  efi/x86: Remove unused variables
Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux into master 2020-07-17T22:27:52+00:00 Linus Torvalds torvalds@linux-foundation.org 2020-07-17T22:27:52+00:00 a570f4198906a88b959ddcc56ddabc634397e810 Pull arm64 fixes from Will Deacon: "A batch of arm64 fixes. Although the diffstat is a bit larger than we'd usually have at this stage, a decent amount of it is the addition of comments describing our syscall tracing behaviour, and also a sweep across all the modular arm64 PMU drivers to make them rebust against unloading and unbinding. There are a couple of minor things kicking around at the moment (CPU errata and module PLTs for very large modules), but I'm not expecting any significant changes now for us in 5.8. - Fix kernel text addresses for relocatable images booting using EFI and with KASLR disabled so that they match the vmlinux ELF binary. - Fix unloading and unbinding of PMU driver modules. - Fix generic mmiowb() when writeX() is called from preemptible context (reported by the riscv folks). - Fix ptrace hardware single-step interactions with signal handlers, system calls and reverse debugging. - Fix reporting of 64-bit x0 register for 32-bit tasks via 'perf_regs'. - Add comments describing syscall entry/exit tracing ABI" * tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: drivers/perf: Prevent forced unbinding of PMU drivers asm-generic/mmiowb: Allow mmiowb_set_pending() when preemptible() arm64: Use test_tsk_thread_flag() for checking TIF_SINGLESTEP arm64: ptrace: Use NO_SYSCALL instead of -1 in syscall_trace_enter() arm64: syscall: Expand the comment about ptrace and syscall(-1) arm64: ptrace: Add a comment describing our syscall entry/exit trap ABI arm64: compat: Ensure upper 32 bits of x0 are zero on syscall return arm64: ptrace: Override SPSR.SS when single-stepping is enabled arm64: ptrace: Consistently use pseudo-singlestep exceptions drivers/perf: Fix kernel panic when rmmod PMU modules during perf sampling efi/libstub/arm64: Retain 2MB kernel Image alignment if !KASLR 
Pull arm64 fixes from Will Deacon:
 "A batch of arm64 fixes.

  Although the diffstat is a bit larger than we'd usually have at this
  stage, a decent amount of it is the addition of comments describing
  our syscall tracing behaviour, and also a sweep across all the modular
  arm64 PMU drivers to make them rebust against unloading and unbinding.

  There are a couple of minor things kicking around at the moment (CPU
  errata and module PLTs for very large modules), but I'm not expecting
  any significant changes now for us in 5.8.

   - Fix kernel text addresses for relocatable images booting using EFI
     and with KASLR disabled so that they match the vmlinux ELF binary.

   - Fix unloading and unbinding of PMU driver modules.

   - Fix generic mmiowb() when writeX() is called from preemptible
     context (reported by the riscv folks).

   - Fix ptrace hardware single-step interactions with signal handlers,
     system calls and reverse debugging.

   - Fix reporting of 64-bit x0 register for 32-bit tasks via
     'perf_regs'.

   - Add comments describing syscall entry/exit tracing ABI"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  drivers/perf: Prevent forced unbinding of PMU drivers
  asm-generic/mmiowb: Allow mmiowb_set_pending() when preemptible()
  arm64: Use test_tsk_thread_flag() for checking TIF_SINGLESTEP
  arm64: ptrace: Use NO_SYSCALL instead of -1 in syscall_trace_enter()
  arm64: syscall: Expand the comment about ptrace and syscall(-1)
  arm64: ptrace: Add a comment describing our syscall entry/exit trap ABI
  arm64: compat: Ensure upper 32 bits of x0 are zero on syscall return
  arm64: ptrace: Override SPSR.SS when single-stepping is enabled
  arm64: ptrace: Consistently use pseudo-singlestep exceptions
  drivers/perf: Fix kernel panic when rmmod PMU modules during perf sampling
  efi/libstub/arm64: Retain 2MB kernel Image alignment if !KASLR
efi/libstub/arm64: Retain 2MB kernel Image alignment if !KASLR 2020-07-13T13:08:07+00:00 Will Deacon will@kernel.org 2020-07-09T20:48:41+00:00 7c116db24d944ff04a67c8bd89cb32c5cd0894ff Since commit 82046702e288 ("efi/libstub/arm64: Replace 'preferred' offset with alignment check"), loading a relocatable arm64 kernel at a physical address which is not 2MB aligned and subsequently booting with EFI will leave the Image in-place, relying on the kernel to relocate itself early during boot. In conjunction with commit dd4bc6076587 ("arm64: warn on incorrect placement of the kernel by the bootloader"), which enables CONFIG_RELOCATABLE by default, this effectively means that entering an arm64 kernel loaded at an alignment smaller than 2MB with EFI (e.g. using QEMU) will result in silent relocation at runtime. Unfortunately, this has a subtle but confusing affect for developers trying to inspect the PC value during a crash and comparing it to the symbol addresses in vmlinux using tools such as 'nm' or 'addr2line'; all text addresses will be displaced by a sub-2MB offset, resulting in the wrong symbol being identified in many cases. Passing "nokaslr" on the command line or disabling "CONFIG_RANDOMIZE_BASE" does not help, since the EFI stub only copies the kernel Image to a 2MB boundary if it is not relocatable. Adjust the EFI stub for arm64 so that the minimum Image alignment is 2MB unless KASLR is in use. Cc: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Marc Zyngier <maz@kernel.org> Cc: David Brazdil <dbrazdil@google.com> Acked-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Will Deacon <will@kernel.org> 
Since commit 82046702e288 ("efi/libstub/arm64: Replace 'preferred' offset
with alignment check"), loading a relocatable arm64 kernel at a physical
address which is not 2MB aligned and subsequently booting with EFI will
leave the Image in-place, relying on the kernel to relocate itself early
during boot. In conjunction with commit dd4bc6076587 ("arm64: warn on
incorrect placement of the kernel by the bootloader"), which enables
CONFIG_RELOCATABLE by default, this effectively means that entering an
arm64 kernel loaded at an alignment smaller than 2MB with EFI (e.g. using
QEMU) will result in silent relocation at runtime.

Unfortunately, this has a subtle but confusing affect for developers
trying to inspect the PC value during a crash and comparing it to the
symbol addresses in vmlinux using tools such as 'nm' or 'addr2line';
all text addresses will be displaced by a sub-2MB offset, resulting in
the wrong symbol being identified in many cases. Passing "nokaslr" on
the command line or disabling "CONFIG_RANDOMIZE_BASE" does not help,
since the EFI stub only copies the kernel Image to a 2MB boundary if it
is not relocatable.

Adjust the EFI stub for arm64 so that the minimum Image alignment is 2MB
unless KASLR is in use.

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: David Brazdil <dbrazdil@google.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux 2020-07-10T15:42:17+00:00 Linus Torvalds torvalds@linux-foundation.org 2020-07-10T15:42:17+00:00 f4c8824cbcc64524905f83388eb1139747829756 Pull arm64 fixes from Will Deacon: "An unfortunately large collection of arm64 fixes for -rc5. Some of this is absolutely trivial, but the alternatives, vDSO and CPU errata workaround fixes are significant. At least people are finding and fixing these things, I suppose. - Fix workaround for CPU erratum #1418040 to disable the compat vDSO - Fix Oops when single-stepping with KGDB - Fix memory attributes for hypervisor device mappings at EL2 - Fix memory leak in PSCI and remove useless variable assignment - Fix up some comments and asm labels in our entry code - Fix broken register table formatting in our generated html docs - Fix missing NULL sentinel in CPU errata workaround list - Fix patching of branches in alternative instruction sections" * tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: arm64/alternatives: don't patch up internal branches arm64: Add missing sentinel to erratum_1463225 arm64: Documentation: Fix broken table in generated HTML arm64: kgdb: Fix single-step exception handling oops arm64: entry: Tidy up block comments and label numbers arm64: Rework ARM_ERRATUM_1414080 handling arm64: arch_timer: Disable the compat vdso for cores affected by ARM64_WORKAROUND_1418040 arm64: arch_timer: Allow an workaround descriptor to disable compat vdso arm64: Introduce a way to disable the 32bit vdso arm64: entry: Fix the typo in the comment of el1_dbg() drivers/firmware/psci: Assign @err directly in hotplug_tests() drivers/firmware/psci: Fix memory leakage in alloc_init_cpu_groups() KVM: arm64: Fix definition of PAGE_HYP_DEVICE 
Pull arm64 fixes from Will Deacon:
 "An unfortunately large collection of arm64 fixes for -rc5.

  Some of this is absolutely trivial, but the alternatives, vDSO and CPU
  errata workaround fixes are significant. At least people are finding
  and fixing these things, I suppose.

   - Fix workaround for CPU erratum #1418040 to disable the compat vDSO

   - Fix Oops when single-stepping with KGDB

   - Fix memory attributes for hypervisor device mappings at EL2

   - Fix memory leak in PSCI and remove useless variable assignment

   - Fix up some comments and asm labels in our entry code

   - Fix broken register table formatting in our generated html docs

   - Fix missing NULL sentinel in CPU errata workaround list

   - Fix patching of branches in alternative instruction sections"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64/alternatives: don't patch up internal branches
  arm64: Add missing sentinel to erratum_1463225
  arm64: Documentation: Fix broken table in generated HTML
  arm64: kgdb: Fix single-step exception handling oops
  arm64: entry: Tidy up block comments and label numbers
  arm64: Rework ARM_ERRATUM_1414080 handling
  arm64: arch_timer: Disable the compat vdso for cores affected by ARM64_WORKAROUND_1418040
  arm64: arch_timer: Allow an workaround descriptor to disable compat vdso
  arm64: Introduce a way to disable the 32bit vdso
  arm64: entry: Fix the typo in the comment of el1_dbg()
  drivers/firmware/psci: Assign @err directly in hotplug_tests()
  drivers/firmware/psci: Fix memory leakage in alloc_init_cpu_groups()
  KVM: arm64: Fix definition of PAGE_HYP_DEVICE
efi: Revert "efi/x86: Fix build with gcc 4" 2020-07-09T07:14:29+00:00 Ard Biesheuvel ardb@kernel.org 2020-07-09T06:59:57+00:00 769e0fe1171e95d90ea5a2d6d0b2bdc7d5d2e7b2 This reverts commit 5435f73d5c4a1b75, which is no longer needed now that the minimum GCC version has been bumped to v4.9 Signed-off-by: Ard Biesheuvel <ardb@kernel.org> 
This reverts commit 5435f73d5c4a1b75, which is no longer needed now
that the minimum GCC version has been bumped to v4.9

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
efi/efivars: Expose RT service availability via efivars abstraction 2020-07-09T07:14:29+00:00 Ard Biesheuvel ardb@kernel.org 2020-07-08T10:01:57+00:00 f88814cc2578c121e6edef686365036db72af0ed Commit bf67fad19e493b ("efi: Use more granular check for availability for variable services") introduced a check into the efivarfs, efi-pstore and other drivers that aborts loading of the module if not all three variable runtime services (GetVariable, SetVariable and GetNextVariable) are supported. However, this results in efivarfs being unavailable entirely if only SetVariable support is missing, which is only needed if you want to make any modifications. Also, efi-pstore and the sysfs EFI variable interface could be backed by another implementation of the 'efivars' abstraction, in which case it is completely irrelevant which services are supported by the EFI firmware. So make the generic 'efivars' abstraction dependent on the availibility of the GetVariable and GetNextVariable EFI runtime services, and add a helper 'efivar_supports_writes()' to find out whether the currently active efivars abstraction supports writes (and wire it up to the availability of SetVariable for the generic one). Then, use the efivar_supports_writes() helper to decide whether to permit efivarfs to be mounted read-write, and whether to enable efi-pstore or the sysfs EFI variable interface altogether. Fixes: bf67fad19e493b ("efi: Use more granular check for availability for variable services") Reported-by: Heinrich Schuchardt <xypron.glpk@gmx.de> Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org> Tested-by: Ilias Apalodimas <ilias.apalodimas@linaro.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> 
Commit

  bf67fad19e493b ("efi: Use more granular check for availability for variable services")

introduced a check into the efivarfs, efi-pstore and other drivers that
aborts loading of the module if not all three variable runtime services
(GetVariable, SetVariable and GetNextVariable) are supported. However, this
results in efivarfs being unavailable entirely if only SetVariable support
is missing, which is only needed if you want to make any modifications.
Also, efi-pstore and the sysfs EFI variable interface could be backed by
another implementation of the 'efivars' abstraction, in which case it is
completely irrelevant which services are supported by the EFI firmware.

So make the generic 'efivars' abstraction dependent on the availibility of
the GetVariable and GetNextVariable EFI runtime services, and add a helper
'efivar_supports_writes()' to find out whether the currently active efivars
abstraction supports writes (and wire it up to the availability of
SetVariable for the generic one).

Then, use the efivar_supports_writes() helper to decide whether to permit
efivarfs to be mounted read-write, and whether to enable efi-pstore or the
sysfs EFI variable interface altogether.

Fixes: bf67fad19e493b ("efi: Use more granular check for availability for variable services")
Reported-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Tested-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
efi/libstub: Move the function prototypes to header file 2020-07-09T06:45:09+00:00 Atish Patra atish.patra@wdc.com 2020-07-06T17:25:59+00:00 3230d95cea0515a6acf3f5ff360663de4c40fd07 The prototype of the functions handle_kernel_image & efi_enter_kernel are defined in efi-stub.c which may result in a compiler warnings if -Wmissing-prototypes is set in gcc compiler. Move the prototype to efistub.h to make the compiler happy. Signed-off-by: Atish Patra <atish.patra@wdc.com> Link: https://lore.kernel.org/r/20200706172609.25965-2-atish.patra@wdc.com Signed-off-by: Ard Biesheuvel <ardb@kernel.org> 
The prototype of the functions handle_kernel_image & efi_enter_kernel
are defined in efi-stub.c which may result in a compiler warnings if
-Wmissing-prototypes is set in gcc compiler.

Move the prototype to efistub.h to make the compiler happy.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Link: https://lore.kernel.org/r/20200706172609.25965-2-atish.patra@wdc.com
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>