清除栈错误: User 42 panic

本文探讨了在使用多重继承的类AClass时,如何正确处理异常情况下的资源清理问题。特别是当类同时继承自CBase和MClass接口,并且在实例销毁过程中需要调用特定清理方法时的情况。文章详细解释了为什么直接使用CleanupStack::PushL()会导致User42panic的问题,并提出了解决方案——使用CleanupDeleteL()来避免内存泄漏并确保虚拟析构函数被正确调用。

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A C class, CSquare, uses multiple inheritance from CBase and an M class interface, MPolygon. The object is instantiated and the M class interface pushed on to the cleanup stack. The object is later destroyed by a call to PopAndDestroy(). If the pushing was done with CleanupStack::PushL(), the PushL(TAny*) would be used because the pointer is not a CBase pointerThe PushL(TAny*) overload means that User::Free() is invoked on the pointer on cleanup, but this would result in a User 42 panic. That’s because User::Free() can't find the heap information it needs to release the memory to the system when passed an M class pointer to the sub-object of a C class. Even if it could, the virtual destructor of CSquare would not be called, so the best-case scenario would be a memory leak! The solution is to use CleanupDeleteL() to call delete on the M class pointer and invoke the virtual destructor correctly for the CSquare class.

对于同时继承了cbase和m接口的类,如果使用pushL(),将会重载 PushL(TAny*) ,这就意味着异常退出会调用User::Free() 来清除,但free()不能找到内存中需要释放的信息,析构函数不能被调用,从而引发User 42 panic.解决方案就是使用CleanupDeleteL() t来调用m类指针的删除操作以及cbase析构函数。


class MPolygon
    {
 
public:
 
    virtual TInt CalculateNumberOfVerticesL() =0;
    virtual ~MPolygon(){};
 
};
 
class CSquare : public CBase, public MPolygon
    {
public:
    static CSquare* NewL();
    virtual TInt CalculateNumberOfVerticesL();
    virtual ~CSquare(){};
 
private:
    CSquare(){};
 
    };
 
enum TPolygonType { ESquare };
 
static MPolygon* InstantiatePolygonL(TPolygonType aPolygon);
 
MPolygon* InstantiatePolygonL(TPolygonType aPolygon)
    {
    if (ESquare==aPolygon)
        return (CSquare::NewL());
    else
        return (NULL);
    }
 
/*static*/ CSquare* CSquare::NewL()
    {              // No two-phase construct needed here.
    CSquare* me = new(ELeave) CSquare();
    return (me);
    }
 
TInt CSquare::CalculateNumberOfVerticesL()
    {             // Simple implementation, but others may leave.
    return (4);
    }
 
void DoStuffL()
    {
    MPolygon* square = InstantiatePolygonL(ESquare);
    CleanupDeletePushL(square);
 
    // ... Leaving calls go here.
    ASSERT(4==square->CalculateNumberOfVerticesL());
    CleanupStack::PopAndDestroy(square);
    }

[ 0.000000] Booting Linux on physical CPU 0x0000000000 [0x410fd034] [ 0.000000] Linux version 5.15.36-xilinx-v2022.2 (oe-user@oe-host) (aarch64-xilinx-linux-gcc (GCC) 11.2.0, GNU ld (GNU Binutils) 2.37.20210721) #1 SMP Mon Oct 3 07:50:07 UTC 2022 [ 0.000000] Machine model: xlnx,zynqmp [ 0.000000] earlycon: cdns0 at MMIO 0x00000000ff000000 (options '115200n8') [ 0.000000] printk: bootconsole [cdns0] enabled [ 0.000000] efi: UEFI not found. [ 0.000000] Zone ranges: [ 0.000000] DMA32 [mem 0x0000000000000000-0x00000000ffffffff] [ 0.000000] Normal [mem 0x0000000100000000-0x000000097fffffff] [ 0.000000] Movable zone start for each node [ 0.000000] Early memory node ranges [ 0.000000] node 0: [mem 0x0000000000000000-0x000000007fefffff] [ 0.000000] node 0: [mem 0x0000000800000000-0x000000097fffffff] [ 0.000000] Initmem setup node 0 [mem 0x0000000000000000-0x000000097fffffff] [ 0.000000] On node 0, zone Normal: 256 pages in unavailable ranges [ 0.000000] cma: Reserved 256 MiB at 0x000000006b800000 [ 0.000000] psci: probing for conduit method from DT. [ 0.000000] psci: PSCIv1.1 detected in firmware. [ 0.000000] psci: Using standard PSCI v0.2 function IDs [ 0.000000] psci: MIGRATE_INFO_TYPE not supported. [ 0.000000] psci: SMC Calling Convention v1.2 [ 0.000000] percpu: Embedded 18 pages/cpu s34776 r8192 d30760 u73728 [ 0.000000] Detected VIPT I-cache on CPU0 [ 0.000000] CPU features: detected: ARM erratum 845719 [ 0.000000] Built 1 zonelists, mobility grouping on. Total pages: 2064132 [ 0.000000] Kernel command line: earlycon console=ttyPS0,115200 clk_ignore_unused root=/dev/mmcblk0p2 rw rootwait [ 0.000000] Dentry cache hash table entries: 1048576 (order: 11, 8388608 bytes, linear) [ 0.000000] Inode-cache hash table entries: 524288 (order: 10, 4194304 bytes, linear) [ 0.000000] mem auto-init: stack:off, heap alloc:off, heap free:off [ 0.000000] Unable to handle kernel paging request at virtual address ffff00007fc00000 [ 0.000000] Mem abort info: [ 0.000000] ESR = 0x96000047 [ 0.000000] EC = 0x25: DABT (current EL), IL = 32 bits [ 0.000000] SET = 0, FnV = 0 [ 0.000000] EA = 0, S1PTW = 0 [ 0.000000] FSC = 0x07: level 3 translation fault [ 0.000000] Data abort info: [ 0.000000] ISV = 0, ISS = 0x00000047 [ 0.000000] CM = 0, WnR = 1 [ 0.000000] swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000001378000 [ 0.000000] [ffff00007fc00000] pgd=180000097fff8003, p4d=180000097fff8003 [ 0.000000] Unable to handle kernel paging request at virtual address ffff00097fff8008 [ 0.000000] Mem abort info: [ 0.000000] ESR = 0x96000006 [ 0.000000] EC = 0x25: DABT (current EL), IL = 32 bits [ 0.000000] SET = 0, FnV = 0 [ 0.000000] EA = 0, S1PTW = 0 [ 0.000000] FSC = 0x06: level 2 translation fault [ 0.000000] Data abort info: [ 0.000000] ISV = 0, ISS = 0x00000006 [ 0.000000] CM = 0, WnR = 0 [ 0.000000] swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000001378000 [ 0.000000] [ffff00097fff8008] pgd=180000097fff8003, p4d=180000097fff8003 [ 0.000000] Unable to handle kernel paging request at virtual address ffff00097fff8128 [ 0.000000] Mem abort info: [ 0.000000] ESR = 0x96000006 [ 0.000000] EC = 0x25: DABT (current EL), IL = 32 bits [ 0.000000] SET = 0, FnV = 0 [ 0.000000] EA = 0, S1PTW = 0 [ 0.000000] FSC = 0x06: level 2 translation fault [ 0.000000] Data abort info: [ 0.000000] ISV = 0, ISS = 0x00000006 [ 0.000000] CM = 0, WnR = 0 [ 0.000000] swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000001378000 [ 0.000000] [ffff00097fff8128] pgd=180000097fff8003, p4d=180000097fff8003 [ 0.000000] Unable to handle kernel paging request at virtual address ffff00097fff8128 [ 0.000000] Mem abort info: [ 0.000000] ESR = 0x96000006 [ 0.000000] EC = 0x25: DABT (current EL), IL = 32 bits [ 0.000000] SET = 0, FnV = 0 [ 0.000000] EA = 0, S1PTW = 0 [ 0.000000] FSC = 0x06: level 2 translation fault [ 0.000000] Data abort info: [ 0.000000] ISV = 0, ISS = 0x00000006 [ 0.000000] CM = 0, WnR = 0 [ 0.000000] swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000001378000 [ 0.000000] [ffff00097fff8128] pgd=180000097fff8003, p4d=180000097fff8003 [ 0.000000] Unable to handle kernel paging request at virtual address ffff00097fff8128 [ 0.000000] Mem abort info: [ 0.000000] ESR = 0x96000006 [ 0.000000] EC = 0x25: DABT (current EL), IL = 32 bits [ 0.000000] SET = 0, FnV = 0 [ 0.000000] EA = 0, S1PTW = 0 [ 0.000000] FSC = 0x06: level 2 translation fault [ 0.000000] Data abort info: [ 0.000000] ISV = 0, ISS = 0x00000006 [ 0.000000] CM = 0, WnR = 0 [ 0.000000] swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000001378000 [ 0.000000] [ffff00097fff8128] pgd=180000097fff8003, p4d=180000097fff8003 [ 0.000000] Unable to handle kernel paging request at virtual address ffff00097fff8128 [ 0.000000] Mem abort info: [ 0.000000] ESR = 0x96000006 [ 0.000000] EC = 0x25: DABT (current EL), IL = 32 bits [ 0.000000] SET = 0, FnV = 0 [ 0.000000] EA = 0, S1PTW = 0 [ 0.000000] FSC = 0x06: level 2 translation fault [ 0.000000] Data abort info: [ 0.000000] ISV = 0, ISS = 0x00000006 [ 0.000000] CM = 0, WnR = 0 [ 0.000000] swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000001378000 [ 0.000000] [ffff00097fff8128] pgd=180000097fff8003, p4d=180000097fff8003 [ 0.000000] Unable to handle kernel paging request at virtual address ffff00097fff8128 [ 0.000000] Mem abort info: [ 0.000000] ESR = 0x96000006 [ 0.000000] EC = 0x25: DABT (current EL), IL = 32 bits [ 0.000000] SET = 0, FnV = 0 [ 0.000000] EA = 0, S1PTW = 0 [ 0.000000] FSC = 0x06: level 2 translation fault [ 0.000000] Data abort info: [ 0.000000] ISV = 0, ISS = 0x00000006 [ 0.000000] CM = 0, WnR = 0 [ 0.000000] swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000001378000 [ 0.000000] [ffff00097fff8128] pgd=180000097fff8003, p4d=180000097fff8003 [ 0.000000] Unable to handle kernel paging request at virtual address ffff00097fff8128 [ 0.000000] Mem abort info: [ 0.000000] ESR = 0x96000006 [ 0.000000] EC = 0x25: DABT (current EL), IL = 32 bits [ 0.000000] SET = 0, FnV = 0 [ 0.000000] EA = 0, S1PTW = 0 [ 0.000000] FSC = 0x06: level 2 translation fault [ 0.000000] Data abort info: [ 0.000000] ISV = 0, ISS = 0x00000006 [ 0.000000] CM = 0, WnR = 0 [ 0.000000] swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000001378000 [ 0.000000] [ffff00097fff8128] pgd=180000097fff8003, p4d=180000097fff8003 [ 0.000000] Unable to handle kernel paging request at virtual address ffff00097fff8128 [ 0.000000] Mem abort info: [ 0.000000] ESR = 0x96000006 [ 0.000000] EC = 0x25: DABT (current EL), IL = 32 bits [ 0.000000] SET = 0, FnV = 0 [ 0.000000] EA = 0, S1PTW = 0 [ 0.000000] FSC = 0x06: level 2 translation fault [ 0.000000] Data abort info: [ 0.000000] ISV = 0, ISS = 0x00000006 [ 0.000000] CM = 0, WnR = 0 [ 0.000000] swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000001378000 [ 0.000000] [ffff00097fff8128] pgd=180000097fff8003, p4d=180000097fff8003 [ 0.000000] Unable to handle kernel paging request at virtual address ffff00097fff8128 [ 0.000000] Mem abort info: [ 0.000000] ESR = 0x96000006 [ 0.000000] EC = 0x25: DABT (current EL), IL = 32 bits [ 0.000000] SET = 0, FnV = 0 [ 0.000000] EA = 0, S1PTW = 0 [ 0.000000] FSC = 0x06: level 2 translation fault [ 0.000000] Data abort info: [ 0.000000] ISV = 0, ISS = 0x00000006 [ 0.000000] CM = 0, WnR = 0 [ 0.000000] swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000001378000 [ 0.000000] [ffff00097fff8128] pgd=180000097fff8003, p4d=180000097fff8003 [ 0.000000] Unable to handle kernel paging request at virtual address ffff00097fff8128 [ 0.000000] Mem abort info: [ 0.000000] ESR = 0x96000006 [ 0.000000] EC = 0x25: DABT (current EL), IL = 32 bits [ 0.000000] SET = 0, FnV = 0 [ 0.000000] EA = 0, S1PTW = 0 [ 0.000000] FSC = 0x06: level 2 translation fault [ 0.000000] Data abort info: [ 0.000000] ISV = 0, ISS = 0x00000006 [ 0.000000] CM = 0, WnR = 0 [ 0.000000] swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000001378000 [ 0.000000] [ffff00097fff8128] pgd=180000097fff8003, p4d=180000097fff8003 [ 0.000000] Unable to handle kernel paging request at virtual address ffff00097fff8128 [ 0.000000] Mem abort info: [ 0.000000] ESR = 0x96000006 [ 0.000000] EC = 0x25: DABT (current EL), IL = 32 bits [ 0.000000] SET = 0, FnV = 0 [ 0.000000] EA = 0, S1PTW = 0 [ 0.000000] FSC = 0x06: level 2 translation fault [ 0.000000] Data abort info: [ 0.000000] ISV = 0, ISS = 0x00000006 [ 0.000000] CM = 0, WnR = 0 [ 0.000000] swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000001378000 [ 0.000000] [ffff00097fff8128] pgd=180000097fff8003, p4d=180000097fff8003 [ 0.000000] Unable to handle kernel paging request at virtual address ffff00097fff8128 [ 0.000000] Mem abort info: [ 0.000000] ESR = 0x96000006 [ 0.000000] EC = 0x25: DABT (current EL), IL = 32 bits [ 0.000000] SET = 0, FnV = 0 [ 0.000000] EA = 0, S1PTW = 0 [ 0.000000] FSC = 0x06: level 2 translation fault [ 0.000000] Data abort info: [ 0.000000] ISV = 0, ISS = 0x00000006 [ 0.000000] CM = 0, WnR = 0 [ 0.000000] swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000001378000 [ 0.000000] [ffff00097fff8128] pgd=180000097fff8003, p4d=180000097fff8003 [ 0.000000] Unable to handle kernel paging request at virtual address ffff00097fff8128 [ 0.000000] Mem abort info: [ 0.000000] ESR = 0x96000006 [ 0.000000] EC = 0x25: DABT (current EL), IL = 32 bits [ 0.000000] SET = 0, FnV = 0 [ 0.000000] EA = 0, S1PTW = 0 [ 0.000000] FSC = 0x06: level 2 translation fault [ 0.000000] Data abort info: [ 0.000000] ISV = 0, ISS = 0x00000006 [ 0.000000] CM = 0, WnR = 0 [ 0.000000] swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000001378000 [ 0.000000] [ffff00097fff8128] pgd=180000097fff8003, p4d=180000097fff8003 [ 0.000000] Unable to handle kernel paging request at virtual address ffff00097fff8128 [ 0.000000] Mem abort info: [ 0.000000] ESR = 0x96000006 [ 0.000000] EC = 0x25: DABT (current EL), IL = 32 bits [ 0.000000] SET = 0, FnV = 0 [ 0.000000] EA = 0, S1PTW = 0 [ 0.000000] FSC = 0x06: level 2 translation fault [ 0.000000] Data abort info: [ 0.000000] ISV = 0, ISS = 0x00000006 [ 0.000000] CM = 0, WnR = 0 [ 0.000000] swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000001378000 [ 0.000000] [ffff00097fff8128] pgd=180000097fff8003, p4d=180000097fff8003 [ 0.000000] Unable to handle kernel paging request at virtual address ffff00097fff8128 [ 0.000000] Mem abort info: [ 0.000000] ESR = 0x96000006 [ 0.000000] EC = 0x25: DABT (current EL), IL = 32 bits [ 0.000000] SET = 0, FnV = 0 [ 0.000000] EA = 0, S1PTW = 0 [ 0.000000] FSC = 0x06: level 2 translation fault [ 0.000000] Data abort info: [ 0.000000] ISV = 0, ISS = 0x00000006 [ 0.000000] CM = 0, WnR = 0 [ 0.000000] swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000001378000 [ 0.000000] [ffff00097fff8128] pgd=180000097fff8003, p4d=180000097fff8003 [ 0.000000] Unable to handle kernel paging request at virtual address ffff00097fff8128 [ 0.000000] Mem abort info: [ 0.000000] ESR = 0x96000006 [ 0.000000] EC = 0x25: DABT (current EL), IL = 32 bits [ 0.000000] SET = 0, FnV = 0 [ 0.000000] EA = 0, S1PTW = 0 [ 0.000000] FSC = 0x06: level 2 translation fault [ 0.000000] Data abort info: [ 0.000000] ISV = 0, ISS = 0x00000006 [ 0.000000] CM = 0, WnR = 0 [ 0.000000] swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000001378000 [ 0.000000] [ffff00097fff8128] pgd=180000097fff8003, p4d=180000097fff8003 [ 0.000000] Unable to handle kernel paging request at virtual address ffff00097fff8128 [ 0.000000] Mem abort info: [ 0.000000] ESR = 0x96000006 [ 0.000000] EC = 0x25: DABT (current EL), IL = 32 bits [ 0.000000] SET = 0, FnV = 0 [ 0.000000] EA = 0, S1PTW = 0 [ 0.000000] FSC = 0x06: level 2 translation fault [ 0.000000] Data abort info: [ 0.000000] ISV = 0, ISS = 0x00000006 [ 0.000000] CM = 0, WnR = 0 [ 0.000000] swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000001378000 [ 0.000000] [ffff00097fff8128] pgd=180000097fff8003, p4d=180000097fff8003 [ 0.000000] Unable to handle kernel paging request at virtual address ffff00097fff8128 [ 0.000000] Mem abort info: [ 0.000000] ESR = 0x96000006 [ 0.000000] EC = 0x25: DABT (current EL), IL = 32 bits [ 0.000000] SET = 0, FnV = 0 [ 0.000000] EA = 0, S1PTW = 0 [ 0.000000] FSC = 0x06: level 2 translation fault [ 0.000000] Data abort info: [ 0.000000] ISV = 0, ISS = 0x00000006 [ 0.000000] CM = 0, WnR = 0 [ 0.000000] swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000001378000 [ 0.000000] [ffff00097fff8128] pgd=180000097fff8003, p4d=180000097fff8003 [ 0.000000] Unable to handle kernel paging request at virtual address ffff00097fff8128 [ 0.000000] Mem abort info: [ 0.000000] ESR = 0x96000006 [ 0.000000] EC = 0x25: DABT (current EL), IL = 32 bits [ 0.000000] SET = 0, FnV = 0 [ 0.000000] EA = 0, S1PTW = 0 [ 0.000000] FSC = 0x06: level 2 translation fault [ 0.000000] Data abort info: [ 0.000000] ISV = 0, ISS = 0x00000006 [ 0.000000] CM = 0, WnR = 0 [ 0.000000] swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000001378000 [ 0.000000] [ffff00097fff8128] pgd=180000097fff8003, p4d=180000097fff8003 [ 0.000000] Unable to handle kernel paging request at virtual address ffff00097fff8128 [ 0.000000] Mem abort info: [ 0.000000] ESR = 0x96000006 [ 0.000000] EC = 0x25: DABT (current EL), IL = 32 bits [ 0.000000] SET = 0, FnV = 0 [ 0.000000] EA = 0, S1PTW = 0 [ 0.000000] FSC = 0x06: level 2 translation fault [ 0.000000] Data abort info: [ 0.000000] ISV = 0, ISS = 0x00000006 [ 0.000000] CM = 0, WnR = 0 [ 0.000000] swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000001378000 [ 0.000000] [ffff00097fff8128] pgd=180000097fff8003, p4d=180000097fff8003 [ 0.000000] Unable to handle kernel paging request at virtual address ffff00097fff8128 [ 0.000000] Mem abort info: [ 0.000000] ESR = 0x96000006 [ 0.000000] EC = 0x25: DABT (current EL), IL = 32 bits [ 0.000000] SET = 0, FnV = 0 [ 0.000000] EA = 0, S1PTW = 0 [ 0.000000] FSC = 0x06: level 2 translation fault [ 0.000000] Data abort info: [ 0.000000] ISV = 0, ISS = 0x00000006 [ 0.000000] CM = 0, WnR = 0 [ 0.000000] swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000001378000 [ 0.000000] [ffff00097fff8128] pgd=180000097fff8003, p4d=180000097fff8003 [ 0.000000] Unable to handle kernel paging request at virtual address ffff00097fff8128 [ 0.000000] Mem abort info: [ 0.000000] ESR = 0x96000006 [ 0.000000] EC = 0x25: DABT (current EL), IL = 32 bits [ 0.000000] SET = 0, FnV = 0 [ 0.000000] EA = 0, S1PTW = 0 [ 0.000000] FSC = 0x06: level 2 translation fault [ 0.000000] Data abort info: [ 0.000000] ISV = 0, ISS = 0x00000006 [ 0.000000] CM = 0, WnR = 0 [ 0.000000] swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000001378000 [ 0.000000] [ffff00097fff8128] pgd=180000097fff8003, p4d=180000097fff8003 [ 0.000000] Unable to handle kernel paging request at virtual address ffff00097fff8128 [ 0.000000] Mem abort info: [ 0.000000] ESR = 0x96000006 [ 0.000000] EC = 0x25: DABT (current EL), IL = 32 bits [ 0.000000] SET = 0, FnV = 0 [ 0.000000] EA = 0, S1PTW = 0 [ 0.000000] FSC = 0x06: level 2 translation fault [ 0.000000] Data abort info: [ 0.000000] ISV = 0, ISS = 0x00000006 [ 0.000000] CM = 0, WnR = 0 [ 0.000000] swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000001378000 [ 0.000000] [ffff00097fff8128] pgd=180000097fff8003, p4d=180000097fff8003 [ 0.000000] Insufficient stack space to handle exception! [ 0.000000] ESR: 0x96000006 -- DABT (current EL) [ 0.000000] FAR: 0xffff00097fff8128 [ 0.000000] Task stack: [0xffff8000093a0000..0xffff8000093a4000] [ 0.000000] IRQ stack: [0x0000000000000000..0x0000000000004000] [ 0.000000] Overflow stack: [0xffff00097ef6c2b0..0xffff00097ef6d2b0] [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 5.15.36-xilinx-v2022.2 #1 [ 0.000000] Hardware name: xlnx,zynqmp (DT) [ 0.000000] pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 0.000000] pc : show_pte+0x18c/0x238 [ 0.000000] lr : show_pte+0x15c/0x238 [ 0.000000] sp : ffff8000093a0020 [ 0.000000] x29: ffff8000093a0020 x28: ffff8000093b4e80 x27: 000000007fc8d978 [ 0.000000] x26: 0000000000000000 x25: 0000000000000000 x24: ffff00097efb6f80 [ 0.000000] x23: ffff800009107000 x22: ffff800009178000 x21: 0000000000000128 [ 0.000000] x20: ffff00097fff8000 x19: ffff00097fff8128 x18: ffffffffffffffff [ 0.000000] x17: 3030666666662073 x16: 736572646461206c x15: ffff8000094a7030 [ 0.000000] x14: 0000000000000010 x13: ffff8000093c6128 x12: 00000000000003ba [ 0.000000] x11: 000000000000013e x10: ffff8000093c6128 x9 : ffff8000093c6128 [ 0.000000] x8 : 00000000fffff7ff x7 : ffff8000093f2128 x6 : ffff8000093f2128 [ 0.000000] x5 : 0000000000005ff4 x4 : 40000000fffff93e x3 : 0000000000000000 [ 0.000000] x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff8000090037e8 [ 0.000000] Kernel panic - not syncing: kernel stack overflow zynqmp板卡内核打印这个错误如何解决
07-03
内容概要:本文围绕直流微电网中带有恒功率负载(CPL)的DC/DC升压转换器的稳定控制问题展开研究,提出了一种复合预设性能控制策略。首先,通过精确反馈线性化技术将非线性不确定的DC转换器系统转化为Brunovsky标准型,然后利用非线性扰动观测器评估负载功率的动态变化和输出电压的调节精度。基于反步设计方法,设计了具有预设性能的复合非线性控制器,确保输出电压跟踪误差始终在预定义误差范围内。文章还对比了多种DC/DC转换器控制技术如脉冲调整技术、反馈线性化、滑模控制(SMC)、主动阻尼法和基于无源性的控制,并分析了它们的优缺点。最后,通过数值仿真验证了所提控制器的有效性和优越性。 适合人群:从事电力电子、自动控制领域研究的学者和工程师,以及对先进控制算法感兴趣的研究生及以上学历人员。 使用场景及目标:①适用于需要精确控制输出电压并处理恒功率负载的应用场景;②旨在实现快速稳定的电压跟踪,同时保证系统的鲁棒性和抗干扰能力;③为DC微电网中的功率转换系统提供兼顾瞬态性能和稳态精度的解决方案。 其他说明:文中不仅提供了详细的理论推导和算法实现,还通过Python代码演示了控制策略的具体实现过程,便于读者理解和实践。此外,文章还讨论了不同控制方法的特点和适用范围,为实际工程项目提供了有价值的参考。
内容概要:该论文介绍了一种名为偏振敏感强度衍射断层扫描(PS-IDT)的新型无参考三维偏振敏感计算成像技术。PS-IDT通过多角度圆偏振光照射样品,利用矢量多层光束传播模型(MSBP)和梯度下降算法迭代重建样品的三维各向异性分布。该技术无需干涉参考光或机械扫描,能够处理多重散射样品,并通过强度测量实现3D成像。文中展示了对马铃薯淀粉颗粒和缓步类动物等样品的成功成像实验,并提供了Python代码实现,包括系统初始化、前向传播、多层传播、重建算法以及数字体模验证等模块。 适用人群:具备一定光学成像和编程基础的研究人员,尤其是从事生物医学成像、材料科学成像领域的科研工作者。 使用场景及目标:①研究复杂散射样品(如生物组织、复合材料)的三维各向异性结构;②开发新型偏振敏感成像系统,提高成像分辨率和对比度;③验证和优化计算成像算法,应用于实际样品的高精度成像。 其他说明:PS-IDT技术相比传统偏振成像方法具有明显优势,如无需干涉装置、无需机械扫描、可处理多重散射等。然而,该技术也面临计算复杂度高、需要多角度数据采集等挑战。文中还提出了改进方向,如采用更高数值孔径(NA)物镜、引入深度学习超分辨率技术等,以进一步提升成像质量和效率。此外,文中提供的Python代码框架为研究人员提供了实用的工具,便于理解和应用该技术。
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