> On Oct 11, 2019, at 4:53 AM, Laszlo Ersek <ler...@redhat.com> wrote: > > On 10/11/19 06:59, Andrew Fish via Groups.Io wrote: >> Liming, >> >> Thanks for looking into this! >> >> Can someone also answer my question about the expected behavior of taking an >> exception in OVMF? Is the CpuDeadloop() expected? > > Yes, it is. > > The exception handler dumps the register file and the stack to the > emulated serial port, not to the QEMU debug port. > > When looking for OVMF debug messages, people usually (and rightly) check > wherever the QEMU debug port has been redirected. (Unless they built > OVMF with -D DEBUG_ON_SERIAL_PORT.) However, the exception handler > always dumps the state to the serial port, regardless of > DEBUG_ON_SERIAL_PORT. This can be confusing, as the normally consulted > debug log has no indication of the issue. >
Laszlo, Thanks if I add -serial file:serial.log to the QEMU command line I see the exception in serial.log. Thanks, Andrew Fish > Thanks > Laszlo > >> >> Thanks, >> >> Andrew Fish >> >>> On Oct 10, 2019, at 6:19 PM, Gao, Liming <liming....@intel.com> wrote: >>> >>> Andrew: >>> I verify the change (2de1f611be06ded3a59726a4052a9039be7d459b >>> MdeModulePkg/BdsDxe: Also call PlatformBootManagerWaitCallback on 0) in >>> Emulator. >>> It works, because PCD value is set to 10 in Emulator. >>> >>> Before this change, if TimeOut PCD is zero, BdsEntry doesn’t call >>> PlatformBootManagerWaitCallback(). >>> After this change, if TimeOut PCD is zero, BdsEntry still call >>> PlatformBootManagerWaitCallback(). So, it trigs this issue. I agree your >>> fix. >>> >>> Pete: >>> Will you contribute the patch to fix this hang issue in OVMF? >>> >>> Thanks >>> Liming >>> From: devel@edk2.groups.io [mailto:devel@edk2.groups.io] On Behalf Of >>> Andrew Fish via Groups.Io >>> Sent: Friday, October 11, 2019 5:12 AM >>> To: devel@edk2.groups.io; Pete Batard <p...@akeo.ie> >>> Subject: [edk2-devel] OVMF is crashing for me in master >>> >>> This is my flavor of OVMF: build -p OvmfPkg/OvmfPkgX64.dsc -a X64 -t XCODE5 >>> >>> It looks like I took an exception? Is it expected that an unhandled >>> exception just hang in a dead loop? I would have expected some serial >>> output about the failure? >>> >>> Looks like a divide by zero exception. The exception context has PC and FP >>> so I can manually walk the stack. Yikes I see >>> PlatformBootManagerWaitCallback() will fault if PcdPlatformBootTimeOut is >>> zero? >>> /Volumes/Case/UDK2018(master)>git grep PcdPlatformBootTimeOut -- *.dsc >>> ArmVirtPkg/ArmVirtQemu.dsc:194: >>> gEfiMdePkgTokenSpaceGuid.PcdPlatformBootTimeOut|3 >>> ArmVirtPkg/ArmVirtQemuKernel.dsc:191: >>> gEfiMdePkgTokenSpaceGuid.PcdPlatformBootTimeOut|3 >>> ArmVirtPkg/ArmVirtXen.dsc:122: >>> gEfiMdePkgTokenSpaceGuid.PcdPlatformBootTimeOut|3 >>> EmulatorPkg/EmulatorPkg.dsc:236: >>> gEfiMdePkgTokenSpaceGuid.PcdPlatformBootTimeOut|L"Timeout"|gEfiGlobalVariableGuid|0x0|10 >>> OvmfPkg/OvmfPkgIa32.dsc:541: >>> gEfiMdePkgTokenSpaceGuid.PcdPlatformBootTimeOut|0 >>> OvmfPkg/OvmfPkgIa32X64.dsc:553: >>> gEfiMdePkgTokenSpaceGuid.PcdPlatformBootTimeOut|0 >>> OvmfPkg/OvmfPkgX64.dsc:552: >>> gEfiMdePkgTokenSpaceGuid.PcdPlatformBootTimeOut|0 >>> OvmfPkg/OvmfXen.dsc:470: gEfiMdePkgTokenSpaceGuid.PcdPlatformBootTimeOut|0 >>> UefiPayloadPkg/UefiPayloadPkgIa32.dsc:344: >>> gEfiMdePkgTokenSpaceGuid.PcdPlatformBootTimeOut|3 >>> UefiPayloadPkg/UefiPayloadPkgIa32X64.dsc:345: >>> gEfiMdePkgTokenSpaceGuid.PcdPlatformBootTimeOut|3 >>> >>> >>> OK PcdPlatformBootTimeOut is zero on Ovmf, so how did this ever work? >>> >>> >>> Ahhh gotom.... >>> /Volumes/Case/UDK2018(master)>git blame -L344,344 >>> /Volumes/Case/UDK2018/MdeModulePkg/Universal/BdsDxe/BdsEntry.c >>> 2de1f611be0 (Pete Batard 2019-09-25 23:50:05 +0800 344) >>> PlatformBootManagerWaitCallback (0); >>> >>> >>> This call causes a divide by zero if PcdPlatformBootTimeOut == 0. >>> >>> This fixes my crash: >>> diff --git a/OvmfPkg/Library/PlatformBootManagerLib/BdsPlatform.c >>> b/OvmfPkg/Library/PlatformBootManagerLib/BdsPlatform.c >>> index 70df6b841a..d6ae43e900 100644 >>> --- a/OvmfPkg/Library/PlatformBootManagerLib/BdsPlatform.c >>> +++ b/OvmfPkg/Library/PlatformBootManagerLib/BdsPlatform.c >>> @@ -1634,6 +1634,11 @@ PlatformBootManagerWaitCallback ( >>> UINT16 Timeout; >>> >>> Timeout = PcdGet16 (PcdPlatformBootTimeOut); >>> + if (Timeout == 0) { >>> + Timeout = 100; >>> + } else { >>> + Timeout = (Timeout - TimeoutRemain) * 100 / Timeout; >>> + } >>> >>> Black.Raw = 0x00000000; >>> White.Raw = 0x00FFFFFF; >>> @@ -1643,7 +1648,7 @@ PlatformBootManagerWaitCallback ( >>> Black.Pixel, >>> L"Start boot option", >>> White.Pixel, >>> - (Timeout - TimeoutRemain) * 100 / Timeout, >>> + Timeout, >>> 0 >>> ); >>> } >>> >>> >>> >>> lldb debugger output: >>> >>> (lldb) bt >>> * thread #1, stop reason = signal SIGTRAP >>> * frame #0: 0x0000000007b58a70 CpuDxe.dll:CpuDeadLoop() + 13 at >>> /Volumes/Case/UDK2018/MdePkg/Library/BaseLib/CpuDeadLoop.c:31 >>> frame #1: 0x0000000007b61222 CpuDxe.dll:CommonExceptionHandlerWorker() + >>> 674 at >>> /Volumes/Case/UDK2018/UefiCpuPkg/Library/CpuExceptionHandlerLib/PeiDxeSmmCpuException.c:115 >>> frame #2: 0x0000000007b61624 CpuDxe.dll:CommonExceptionHandler() + 36 at >>> /Volumes/Case/UDK2018/UefiCpuPkg/Library/CpuExceptionHandlerLib/DxeException.c:40 >>> frame #3: 0x0000000007b5ff26 CpuDxe.dll:HasErrorCode() + 230 >>> (lldb) fr sel 1 >>> frame #1: 0x0000000007b61222 CpuDxe.dll:CommonExceptionHandlerWorker() + >>> 674 at >>> /Volumes/Case/UDK2018/UefiCpuPkg/Library/CpuExceptionHandlerLib/PeiDxeSmmCpuException.c:115 >>> 91 (ExternalInterruptHandler[ExceptionType]) (ExceptionType, >>> SystemContext); >>> 92 } else if (ExceptionType < CPU_EXCEPTION_NUM) { >>> 93 // >>> 94 // Get Spinlock to display CPU information >>> 95 // >>> 96 while (!AcquireSpinLockOrFail >>> (&ExceptionHandlerData->DisplayMessageSpinLock)) { >>> 97 CpuPause (); >>> 98 } >>> 99 // >>> 100 // Initialize the serial port before dumping. >>> 101 // >>> 102 SerialPortInitialize (); >>> 103 // >>> 104 // Display ExceptionType, CPU information and Image >>> information >>> 105 // >>> 106 DumpImageAndCpuContent (ExceptionType, SystemContext); >>> 107 // >>> 108 // Release Spinlock of output message >>> 109 // >>> 110 ReleaseSpinLock >>> (&ExceptionHandlerData->DisplayMessageSpinLock); >>> 111 // >>> 112 // Enter a dead loop if needn't to execute old IDT handler >>> further >>> 113 // >>> 114 if (ReservedVectors[ExceptionType].Attribute != >>> EFI_VECTOR_HANDOFF_HOOK_BEFORE) { >>> -> 115 CpuDeadLoop (); >>> 116 } >>> 117 } >>> 118 } >>> 119 >>> (lldb) p ExceptionType >>> (EFI_EXCEPTION_TYPE) $0 = 0 >>> (lldb) p SystemContext.SystemContextX64->Rip >>> (UINT64) $1 = 0x0000000007a9cc38 >>> (lldb) p SystemContext.SystemContextX64->Rbp >>> (UINT64) $2 = 0x0000000007e8fc20 >>> (lldb) efi_backtrace --pc 0x0000000007a9cc38 --frame 0x0000000007e8fc20 >>> --symbols >>> frame 0: 0x07a9cc38 BdsDxe:PlatformBootManagerWaitCallback + 35 at >>> /Volumes/Case/UDK2018/OvmfPkg/Library/PlatformBootManagerLib/BdsPlatform.c:1646:37 >>> frame 1: 0x07a9e744 BdsDxe:BdsWait + 269 at >>> /Volumes/Case/UDK2018/MdeModulePkg/Universal/BdsDxe/BdsEntry.c:344:3 >>> frame 2: 0x07a9dff9 BdsDxe:BdsEntry + 2620 at >>> /Volumes/Case/UDK2018/MdeModulePkg/Universal/BdsDxe/BdsEntry.c:1002:5 >>> frame 3: 0x07eb367d DxeCore:DxeMain + 2680 at >>> /Volumes/Case/UDK2018/MdeModulePkg/Core/Dxe/DxeMain/DxeMain.c:544:3 >>> frame 4: 0x07e943cb DxeCore:_ModuleEntryPoint + 20 at >>> /Volumes/Case/UDK2018/MdePkg/Library/DxeCoreEntryPoint/DxeCoreEntryPoint.c:48:3 >>> frame 5: 0x07edc947 DxeIpl.dll`AsmEnableCache >>> frame 6: 0x07ee1e4e DxeIpl:HandOffToDxeCore + 509 at >>> /Volumes/Case/UDK2018/MdeModulePkg/Core/DxeIplPeim/X64/DxeLoadFunc.c:113:3 >>> frame 7: 0x07ee0604 DxeIpl:DxeLoadCore + 1354 at >>> /Volumes/Case/UDK2018/MdeModulePkg/Core/DxeIplPeim/DxeLoad.c:449:3 >>> frame 8: 0x07eeff2f PeiCore.dll`PeiCore.cold.3 + 847 >>> frame 9: 0x07ee9d04 PeiCore:PeiCore + 163 at >>> /Volumes/Case/UDK2018/MdeModulePkg/Core/Pei/PeiMain/PeiMain.c:502:3 >>> frame 10: 0x0082c387 0x0082c387 >>> frame 11: 0x00825dd7 0x00825dd7 >>> frame 12: 0x0082ad27 0x0082ad27 >>> frame 13: 0x0082b3a8 0x0082b3a8 >>> frame 14: 0x0082bf23 0x0082bf23 >>> frame 15: 0x00825e24 0x00825e24 >>> frame 16: 0x00823af2 0x00823af2 >>> frame 17: 0xfffd1db8 SecMain:SecStartupPhase2 + 67 at >>> /Volumes/Case/UDK2018/OvmfPkg/Sec/SecMain.c:858:3 >>> frame 18: 0xfffd1d67 SecMain:SecCoreStartupWithStack + 420 at >>> /Volumes/Case/UDK2018/OvmfPkg/Sec/SecMain.c:821:3 >>> frame 19: 0xfffd1e14 SecMain:ProcessLibraryConstructorList + 0 at >>> /Volumes/Case/UDK2018/Build/OvmfX64/DEBUG_XCODE5/X64/OvmfPkg/Sec/SecMain/DEBUG/AutoGen.c:201 >>> >>> (lldb) l >>> /Volumes/Case/UDK2018/OvmfPkg/Library/PlatformBootManagerLib/BdsPlatform.c:1646 >>> 1646 (Timeout - TimeoutRemain) * 100 / Timeout, >>> 1647 0 >>> 1648 ); >>> 1649 } >>> 1650 >>> 1651 /** >>> 1652 The function is called when no boot option could be launched, >>> 1653 including platform recovery options and options pointing to >>> applications >>> 1654 built into firmware volumes. >>> 1655 >>> (lldb) l /Volumes/Case/UDK2018/MdeModulePkg/Universal/BdsDxe/BdsEntry.c:344 >>> 344 PlatformBootManagerWaitCallback (0); >>> 345 DEBUG ((EFI_D_INFO, "[Bds]Exit the waiting!\n")); >>> 346 } >>> 347 >>> 348 /** >>> 349 Attempt to boot each boot option in the BootOptions array. >>> 350 >>> 351 @param BootOptions Input boot option array. >>> 352 @param BootOptionCount Input boot option count. >>> 353 @param BootManagerMenu Input boot manager menu. >>> 354 >>> >>> >>> Thanks, >>> >>> Andrew Fish >>> >>> >> >> >> -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. 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