1. 20 4月, 2019 11 次提交
    • S
      KVM: nVMX: restore host state in nested_vmx_vmexit for VMFail · f35e2a68
      Sean Christopherson 提交于
      [ Upstream commit bd18bffca35397214ae68d85cf7203aca25c3c1d ]
      
      A VMEnter that VMFails (as opposed to VMExits) does not touch host
      state beyond registers that are explicitly noted in the VMFail path,
      e.g. EFLAGS.  Host state does not need to be loaded because VMFail
      is only signaled for consistency checks that occur before the CPU
      starts to load guest state, i.e. there is no need to restore any
      state as nothing has been modified.  But in the case where a VMFail
      is detected by hardware and not by KVM (due to deferring consistency
      checks to hardware), KVM has already loaded some amount of guest
      state.  Luckily, "loaded" only means loaded to KVM's software model,
      i.e. vmcs01 has not been modified.  So, unwind our software model to
      the pre-VMEntry host state.
      
      Not restoring host state in this VMFail path leads to a variety of
      failures because we end up with stale data in vcpu->arch, e.g. CR0,
      CR4, EFER, etc... will all be out of sync relative to vmcs01.  Any
      significant delta in the stale data is all but guaranteed to crash
      L1, e.g. emulation of SMEP, SMAP, UMIP, WP, etc... will be wrong.
      
      An alternative to this "soft" reload would be to load host state from
      vmcs12 as if we triggered a VMExit (as opposed to VMFail), but that is
      wildly inconsistent with respect to the VMX architecture, e.g. an L1
      VMM with separate VMExit and VMFail paths would explode.
      
      Note that this approach does not mean KVM is 100% accurate with
      respect to VMX hardware behavior, even at an architectural level
      (the exact order of consistency checks is microarchitecture specific).
      But 100% emulation accuracy isn't the goal (with this patch), rather
      the goal is to be consistent in the information delivered to L1, e.g.
      a VMExit should not fall-through VMENTER, and a VMFail should not jump
      to HOST_RIP.
      
      This technically reverts commit "5af41573 (KVM: nVMX: Fix mmu
      context after VMLAUNCH/VMRESUME failure)", but retains the core
      aspects of that patch, just in an open coded form due to the need to
      pull state from vmcs01 instead of vmcs12.  Restoring host state
      resolves a variety of issues introduced by commit "4f350c6d
      (kvm: nVMX: Handle deferred early VMLAUNCH/VMRESUME failure properly)",
      which remedied the incorrect behavior of treating VMFail like VMExit
      but in doing so neglected to restore arch state that had been modified
      prior to attempting nested VMEnter.
      
      A sample failure that occurs due to stale vcpu.arch state is a fault
      of some form while emulating an LGDT (due to emulated UMIP) from L1
      after a failed VMEntry to L3, in this case when running the KVM unit
      test test_tpr_threshold_values in L1.  L0 also hits a WARN in this
      case due to a stale arch.cr4.UMIP.
      
      L1:
        BUG: unable to handle kernel paging request at ffffc90000663b9e
        PGD 276512067 P4D 276512067 PUD 276513067 PMD 274efa067 PTE 8000000271de2163
        Oops: 0009 [#1] SMP
        CPU: 5 PID: 12495 Comm: qemu-system-x86 Tainted: G        W         4.18.0-rc2+ #2
        Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
        RIP: 0010:native_load_gdt+0x0/0x10
      
        ...
      
        Call Trace:
         load_fixmap_gdt+0x22/0x30
         __vmx_load_host_state+0x10e/0x1c0 [kvm_intel]
         vmx_switch_vmcs+0x2d/0x50 [kvm_intel]
         nested_vmx_vmexit+0x222/0x9c0 [kvm_intel]
         vmx_handle_exit+0x246/0x15a0 [kvm_intel]
         kvm_arch_vcpu_ioctl_run+0x850/0x1830 [kvm]
         kvm_vcpu_ioctl+0x3a1/0x5c0 [kvm]
         do_vfs_ioctl+0x9f/0x600
         ksys_ioctl+0x66/0x70
         __x64_sys_ioctl+0x16/0x20
         do_syscall_64+0x4f/0x100
         entry_SYSCALL_64_after_hwframe+0x44/0xa9
      
      L0:
        WARNING: CPU: 2 PID: 3529 at arch/x86/kvm/vmx.c:6618 handle_desc+0x28/0x30 [kvm_intel]
        ...
        CPU: 2 PID: 3529 Comm: qemu-system-x86 Not tainted 4.17.2-coffee+ #76
        Hardware name: Intel Corporation Kabylake Client platform/KBL S
        RIP: 0010:handle_desc+0x28/0x30 [kvm_intel]
      
        ...
      
        Call Trace:
         kvm_arch_vcpu_ioctl_run+0x863/0x1840 [kvm]
         kvm_vcpu_ioctl+0x3a1/0x5c0 [kvm]
         do_vfs_ioctl+0x9f/0x5e0
         ksys_ioctl+0x66/0x70
         __x64_sys_ioctl+0x16/0x20
         do_syscall_64+0x49/0xf0
         entry_SYSCALL_64_after_hwframe+0x44/0xa9
      
      Fixes: 5af41573 (KVM: nVMX: Fix mmu context after VMLAUNCH/VMRESUME failure)
      Fixes: 4f350c6d (kvm: nVMX: Handle deferred early VMLAUNCH/VMRESUME failure properly)
      Cc: Jim Mattson <jmattson@google.com>
      Cc: Krish Sadhukhan <krish.sadhukhan@oracle.com>
      Cc: Paolo Bonzini <pbonzini@redhat.com>
      Cc: Radim KrÄmář <rkrcmar@redhat.com>
      Cc: Wanpeng Li <wanpeng.li@hotmail.com>
      Signed-off-by: NSean Christopherson <sean.j.christopherson@intel.com>
      Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      Signed-off-by: NSasha Levin <sashal@kernel.org>
      f35e2a68
    • B
      ARM: samsung: Limit SAMSUNG_PM_CHECK config option to non-Exynos platforms · 360186d8
      Bartlomiej Zolnierkiewicz 提交于
      [ Upstream commit 6862fdf2201ab67cd962dbf0643d37db909f4860 ]
      
      "S3C2410 PM Suspend Memory CRC" feature (controlled by
      SAMSUNG_PM_CHECK config option) is incompatible with highmem
      (uses phys_to_virt() instead of proper mapping) which is used by
      the majority of Exynos boards. The issue manifests itself in OOPS
      on affected boards, i.e. on Odroid-U3 I got the following one:
      
      Unable to handle kernel paging request at virtual address f0000000
      pgd = 1c0f9bb4
      [f0000000] *pgd=00000000
      Internal error: Oops: 5 [#1] PREEMPT SMP ARM
      [<c0458034>] (crc32_le) from [<c0121f8c>] (s3c_pm_makecheck+0x34/0x54)
      [<c0121f8c>] (s3c_pm_makecheck) from [<c0121efc>] (s3c_pm_run_res+0x74/0x8c)
      [<c0121efc>] (s3c_pm_run_res) from [<c0121ecc>] (s3c_pm_run_res+0x44/0x8c)
      [<c0121ecc>] (s3c_pm_run_res) from [<c01210b8>] (exynos_suspend_enter+0x64/0x148)
      [<c01210b8>] (exynos_suspend_enter) from [<c018893c>] (suspend_devices_and_enter+0x9ec/0xe74)
      [<c018893c>] (suspend_devices_and_enter) from [<c0189534>] (pm_suspend+0x770/0xc04)
      [<c0189534>] (pm_suspend) from [<c0186ce8>] (state_store+0x6c/0xcc)
      [<c0186ce8>] (state_store) from [<c09db434>] (kobj_attr_store+0x14/0x20)
      [<c09db434>] (kobj_attr_store) from [<c02fa63c>] (sysfs_kf_write+0x4c/0x50)
      [<c02fa63c>] (sysfs_kf_write) from [<c02f97a4>] (kernfs_fop_write+0xfc/0x1e4)
      [<c02f97a4>] (kernfs_fop_write) from [<c027b198>] (__vfs_write+0x2c/0x140)
      [<c027b198>] (__vfs_write) from [<c027b418>] (vfs_write+0xa4/0x160)
      [<c027b418>] (vfs_write) from [<c027b5d8>] (ksys_write+0x40/0x8c)
      [<c027b5d8>] (ksys_write) from [<c0101000>] (ret_fast_syscall+0x0/0x28)
      
      Add PLAT_S3C24XX, ARCH_S3C64XX and ARCH_S5PV210 dependencies to
      SAMSUNG_PM_CHECK config option to hide it on Exynos platforms.
      Signed-off-by: NBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
      Signed-off-by: NKrzysztof Kozlowski <krzk@kernel.org>
      Signed-off-by: NSasha Levin <sashal@kernel.org>
      360186d8
    • N
      powerpc/pseries: Remove prrn_work workqueue · 6947d853
      Nathan Fontenot 提交于
      [ Upstream commit cd24e457fd8b2d087d9236700c8d2957054598bf ]
      
      When a PRRN event is received we are already running in a worker
      thread. Instead of spawning off another worker thread on the prrn_work
      workqueue to handle the PRRN event we can just call the PRRN handler
      routine directly.
      
      With this update we can also pass the scope variable for the PRRN
      event directly to the handler instead of it being a global variable.
      
      This patch fixes the following oops mnessage we are seeing in PRRN testing:
      
        Oops: Bad kernel stack pointer, sig: 6 [#1]
        SMP NR_CPUS=2048 NUMA pSeries
        Modules linked in: nfsv3 nfs_acl rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd grace sunrpc fscache binfmt_misc reiserfs vfat fat rpadlpar_io(X) rpaphp(X) tcp_diag udp_diag inet_diag unix_diag af_packet_diag netlink_diag af_packet xfs libcrc32c dm_service_time ibmveth(X) ses enclosure scsi_transport_sas rtc_generic btrfs xor raid6_pq sd_mod ibmvscsi(X) scsi_transport_srp ipr(X) libata sg dm_multipath dm_mod scsi_dh_rdac scsi_dh_emc scsi_dh_alua scsi_mod autofs4
        Supported: Yes, External                                                     54
        CPU: 7 PID: 18967 Comm: kworker/u96:0 Tainted: G                 X 4.4.126-94.22-default #1
        Workqueue: pseries hotplug workque pseries_hp_work_fn
        task: c000000775367790 ti: c00000001ebd4000 task.ti: c00000070d140000
        NIP: 0000000000000000 LR: 000000001fb3d050 CTR: 0000000000000000
        REGS: c00000001ebd7d40 TRAP: 0700   Tainted: G                 X  (4.4.126-94.22-default)
        MSR: 8000000102081000 <41,VEC,ME5  CR: 28000002  XER: 20040018   4
        CFAR: 000000001fb3d084 40 419   1                                3
        GPR00: 000000000000000040000000000010007 000000001ffff400 000000041fffe200
        GPR04: 000000000000008050000000000000000 000000001fb15fa8 0000000500000500
        GPR08: 000000000001f40040000000000000001 0000000000000000 000005:5200040002
        GPR12: 00000000000000005c000000007a05400 c0000000000e89f8 000000001ed9f668
        GPR16: 000000001fbeff944000000001fbeff94 000000001fb545e4 0000006000000060
        GPR20: ffffffffffffffff4ffffffffffffffff 0000000000000000 0000000000000000
        GPR24: 00000000000000005400000001fb3c000 0000000000000000 000000001fb1b040
        GPR28: 000000001fb240004000000001fb440d8 0000000000000008 0000000000000000
        NIP [0000000000000000] 5         (null)
        LR [000000001fb3d050] 031fb3d050
        Call Trace:            4
        Instruction dump:      4                                       5:47 12    2
        XXXXXXXX XXXXXXXX XXXXX4XX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX
        XXXXXXXX XXXXXXXX XXXXX5XX XXXXXXXX 60000000 60000000 60000000 60000000
        ---[ end trace aa5627b04a7d9d6b ]---                                       3NMI watchdog: BUG: soft lockup - CPU#27 stuck for 23s! [kworker/27:0:13903]
        Modules linked in: nfsv3 nfs_acl rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd grace sunrpc fscache binfmt_misc reiserfs vfat fat rpadlpar_io(X) rpaphp(X) tcp_diag udp_diag inet_diag unix_diag af_packet_diag netlink_diag af_packet xfs libcrc32c dm_service_time ibmveth(X) ses enclosure scsi_transport_sas rtc_generic btrfs xor raid6_pq sd_mod ibmvscsi(X) scsi_transport_srp ipr(X) libata sg dm_multipath dm_mod scsi_dh_rdac scsi_dh_emc scsi_dh_alua scsi_mod autofs4
        Supported: Yes, External
        CPU: 27 PID: 13903 Comm: kworker/27:0 Tainted: G      D          X 4.4.126-94.22-default #1
        Workqueue: events prrn_work_fn
        task: c000000747cfa390 ti: c00000074712c000 task.ti: c00000074712c000
        NIP: c0000000008002a8 LR: c000000000090770 CTR: 000000000032e088
        REGS: c00000074712f7b0 TRAP: 0901   Tainted: G      D          X  (4.4.126-94.22-default)
        MSR: 8000000100009033 <SF,EE,ME,IR,DR,RI,LE>  CR: 22482044  XER: 20040000
        CFAR: c0000000008002c4 SOFTE: 1
        GPR00: c000000000090770 c00000074712fa30 c000000000f09800 c000000000fa1928 6:02
        GPR04: c000000775f5e000 fffffffffffffffe 0000000000000001 c000000000f42db8
        GPR08: 0000000000000001 0000000080000007 0000000000000000 0000000000000000
        GPR12: 8006210083180000 c000000007a14400
        NIP [c0000000008002a8] _raw_spin_lock+0x68/0xd0
        LR [c000000000090770] mobility_rtas_call+0x50/0x100
        Call Trace:            59                                        5
        [c00000074712fa60] [c000000000090770] mobility_rtas_call+0x50/0x100
        [c00000074712faf0] [c000000000090b08] pseries_devicetree_update+0xf8/0x530
        [c00000074712fc20] [c000000000031ba4] prrn_work_fn+0x34/0x50
        [c00000074712fc40] [c0000000000e0390] process_one_work+0x1a0/0x4e0
        [c00000074712fcd0] [c0000000000e0870] worker_thread+0x1a0/0x6105:57       2
        [c00000074712fd80] [c0000000000e8b18] kthread+0x128/0x150
        [c00000074712fe30] [c0000000000096f8] ret_from_kernel_thread+0x5c/0x64
        Instruction dump:
        2c090000 40c20010 7d40192d 40c2fff0 7c2004ac 2fa90000 40de0018 5:540030   3
        e8010010 ebe1fff8 7c0803a6 4e800020 <7c210b78> e92d0000 89290009 792affe3
      Signed-off-by: NJohn Allen <jallen@linux.ibm.com>
      Signed-off-by: NHaren Myneni <haren@us.ibm.com>
      Signed-off-by: NNathan Fontenot <nfont@linux.vnet.ibm.com>
      Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      Signed-off-by: NSasha Levin <sashal@kernel.org>
      6947d853
    • K
      x86/gart: Exclude GART aperture from kcore · 83e3e89d
      Kairui Song 提交于
      [ Upstream commit ffc8599aa9763f39f6736a79da4d1575e7006f9a ]
      
      On machines where the GART aperture is mapped over physical RAM,
      /proc/kcore contains the GART aperture range. Accessing the GART range via
      /proc/kcore results in a kernel crash.
      
      vmcore used to have the same issue, until it was fixed with commit
      2a3e83c6 ("x86/gart: Exclude GART aperture from vmcore")', leveraging
      existing hook infrastructure in vmcore to let /proc/vmcore return zeroes
      when attempting to read the aperture region, and so it won't read from the
      actual memory.
      
      Apply the same workaround for kcore. First implement the same hook
      infrastructure for kcore, then reuse the hook functions introduced in the
      previous vmcore fix. Just with some minor adjustment, rename some functions
      for more general usage, and simplify the hook infrastructure a bit as there
      is no module usage yet.
      Suggested-by: NBaoquan He <bhe@redhat.com>
      Signed-off-by: NKairui Song <kasong@redhat.com>
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      Reviewed-by: NJiri Bohac <jbohac@suse.cz>
      Acked-by: NBaoquan He <bhe@redhat.com>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Alexey Dobriyan <adobriyan@gmail.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Omar Sandoval <osandov@fb.com>
      Cc: Dave Young <dyoung@redhat.com>
      Link: https://lkml.kernel.org/r/20190308030508.13548-1-kasong@redhat.comSigned-off-by: NSasha Levin <sashal@kernel.org>
      83e3e89d
    • N
      x86/hw_breakpoints: Make default case in hw_breakpoint_arch_parse() return an error · 777cd268
      Nathan Chancellor 提交于
      [ Upstream commit e898e69d6b9475bf123f99b3c5d1a67bb7cb2361 ]
      
      When building with -Wsometimes-uninitialized, Clang warns:
      
      arch/x86/kernel/hw_breakpoint.c:355:2: warning: variable 'align' is used
      uninitialized whenever switch default is taken
      [-Wsometimes-uninitialized]
      
      The default cannot be reached because arch_build_bp_info() initializes
      hw->len to one of the specified cases. Nevertheless the warning is valid
      and returning -EINVAL makes sure that this cannot be broken by future
      modifications.
      Suggested-by: NNick Desaulniers <ndesaulniers@google.com>
      Signed-off-by: NNathan Chancellor <natechancellor@gmail.com>
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      Reviewed-by: NNick Desaulniers <ndesaulniers@google.com>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: clang-built-linux@googlegroups.com
      Link: https://github.com/ClangBuiltLinux/linux/issues/392
      Link: https://lkml.kernel.org/r/20190307212756.4648-1-natechancellor@gmail.comSigned-off-by: NSasha Levin <sashal@kernel.org>
      777cd268
    • M
      x86/cpu/cyrix: Use correct macros for Cyrix calls on Geode processors · 276084f0
      Matthew Whitehead 提交于
      [ Upstream commit 18fb053f9b827bd98cfc64f2a35df8ab19745a1d ]
      
      There are comments in processor-cyrix.h advising you to _not_ make calls
      using the deprecated macros in this style:
      
        setCx86_old(CX86_CCR4, getCx86_old(CX86_CCR4) | 0x80);
      
      This is because it expands the macro into a non-functioning calling
      sequence. The calling order must be:
      
        outb(CX86_CCR2, 0x22);
        inb(0x23);
      
      From the comments:
      
       * When using the old macros a line like
       *   setCx86(CX86_CCR2, getCx86(CX86_CCR2) | 0x88);
       * gets expanded to:
       *  do {
       *    outb((CX86_CCR2), 0x22);
       *    outb((({
       *        outb((CX86_CCR2), 0x22);
       *        inb(0x23);
       *    }) | 0x88), 0x23);
       *  } while (0);
      
      The new macros fix this problem, so use them instead. Tested on an
      actual Geode processor.
      Signed-off-by: NMatthew Whitehead <tedheadster@gmail.com>
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      Cc: luto@kernel.org
      Link: https://lkml.kernel.org/r/1552596361-8967-2-git-send-email-tedheadster@gmail.comSigned-off-by: NSasha Levin <sashal@kernel.org>
      276084f0
    • K
      x86/hyperv: Prevent potential NULL pointer dereference · 16dab291
      Kangjie Lu 提交于
      [ Upstream commit 534c89c22e26b183d838294f0937ee092c82ad3a ]
      
      The page allocation in hv_cpu_init() can fail, but the code does not
      have a check for that.
      
      Add a check and return -ENOMEM when the allocation fails.
      
      [ tglx: Massaged changelog ]
      Signed-off-by: NKangjie Lu <kjlu@umn.edu>
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      Reviewed-by: NMukesh Ojha <mojha@codeaurora.org>
      Acked-by: N"K. Y. Srinivasan" <kys@microsoft.com>
      Cc: pakki001@umn.edu
      Cc: Haiyang Zhang <haiyangz@microsoft.com>
      Cc: Stephen Hemminger <sthemmin@microsoft.com>
      Cc: Sasha Levin <sashal@kernel.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: linux-hyperv@vger.kernel.org
      Link: https://lkml.kernel.org/r/20190314054651.1315-1-kjlu@umn.eduSigned-off-by: NSasha Levin <sashal@kernel.org>
      16dab291
    • A
      x86/hpet: Prevent potential NULL pointer dereference · 30d9b740
      Aditya Pakki 提交于
      [ Upstream commit 2e84f116afca3719c9d0a1a78b47b48f75fd5724 ]
      
      hpet_virt_address may be NULL when ioremap_nocache fail, but the code lacks
      a check.
      
      Add a check to prevent NULL pointer dereference.
      Signed-off-by: NAditya Pakki <pakki001@umn.edu>
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      Cc: kjlu@umn.edu
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Kees Cook <keescook@chromium.org>
      Cc: Joe Perches <joe@perches.com>
      Cc: Nicolai Stange <nstange@suse.de>
      Cc: Roland Dreier <roland@purestorage.com>
      Link: https://lkml.kernel.org/r/20190319021958.17275-1-pakki001@umn.eduSigned-off-by: NSasha Levin <sashal@kernel.org>
      30d9b740
    • M
      x86/mm: Don't leak kernel addresses · ada35b52
      Matteo Croce 提交于
      [ Upstream commit a3151724437f54076cc10bc02b1c4f0003ae36cd ]
      
      Since commit:
      
        ad67b74d ("printk: hash addresses printed with %p")
      
      at boot "____ptrval____" is printed instead of actual addresses:
      
          found SMP MP-table at [mem 0x000f5cc0-0x000f5ccf] mapped at [(____ptrval____)]
      
      Instead of changing the print to "%px", and leaking a kernel addresses,
      just remove the print completely, like in:
      
        071929db ("arm64: Stop printing the virtual memory layout").
      Signed-off-by: NMatteo Croce <mcroce@redhat.com>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Signed-off-by: NIngo Molnar <mingo@kernel.org>
      Signed-off-by: NSasha Levin <sashal@kernel.org>
      ada35b52
    • C
      arc: hsdk_defconfig: Enable CONFIG_BLK_DEV_RAM · 618490ba
      Corentin Labbe 提交于
      [ Upstream commit 0728aeb7ead99a9b0dac2f3c92b3752b4e02ff97 ]
      
      We have now a HSDK device in our kernelci lab, but kernel builded via
      the hsdk_defconfig lacks ramfs supports, so it cannot boot kernelci jobs
      yet.
      
      So this patch enable CONFIG_BLK_DEV_RAM in hsdk_defconfig.
      Signed-off-by: NCorentin Labbe <clabbe@baylibre.com>
      Acked-by: NAlexey Brodkin <abrodkin@synopsys.com>
      Signed-off-by: NVineet Gupta <vgupta@synopsys.com>
      Signed-off-by: NSasha Levin <sashal@kernel.org>
      618490ba
    • E
      ARC: u-boot args: check that magic number is correct · 2296eede
      Eugeniy Paltsev 提交于
      [ Upstream commit edb64bca50cd736c6894cc6081d5263c007ce005 ]
      
      In case of devboards we really often disable bootloader and load
      Linux image in memory via JTAG. Even if kernel tries to verify
      uboot_tag and uboot_arg there is sill a chance that we treat some
      garbage in registers as valid u-boot arguments in JTAG case.
      E.g. it is enough to have '1' in r0 to treat any value in r2 as
      a boot command line.
      
      So check that magic number passed from u-boot is correct and drop
      u-boot arguments otherwise. That helps to reduce the possibility
      of using garbage as u-boot arguments in JTAG case.
      
      We can safely check U-boot magic value (0x0) in linux passed via
      r1 register as U-boot pass it from the beginning. So there is no
      backward-compatibility issues.
      Signed-off-by: NEugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
      Signed-off-by: NVineet Gupta <vgupta@synopsys.com>
      Signed-off-by: NSasha Levin <sashal@kernel.org>
      2296eede
  2. 17 4月, 2019 28 次提交
  3. 06 4月, 2019 1 次提交