yaffs文件系统加载时出现Oops

来源：互联网发布：python dict items 编辑：程序博客网时间：2024/05/22 15:20

yaffs文件系统代码整合到kernel 2.6.32后编译出现如下warning：

fs/yaffs2/yaffs_vfs.c:1063:warning: initialization from incompatible pointer type

fs/yaffs2/yaffs_vfs.c:1192:warning: initialization from incompatible pointer type

fs/yaffs2/yaffs_vfs.c:1674:warning: initialization from incompatible pointer type

同时将其烧录进入mini2440开发板并启动开发板时出现如下Oops：

Unable tohandle kernel paging request at virtual address 72630012

pgd = c0004000

[72630012]*pgd=00000000

Internal error: Oops: 3 [#1]

last sysfs file:

Modules linked in:

CPU: 0 Not tainted (2.6.32.2 #18)

PC is at yaffs_getxattr+0x2c/0x84

LR is atget_vfs_caps_from_disk+0x50/0xec

pc :[<c0144bf8>] lr :[<c0162620>] psr: 60000013

sp : c3823ec8 ip : c0144bcc fp : c03de0ac

r10: c3823f80 r9 : 00000002 r8 : c340c880

r7 : 00000014 r6 : 7263000a r5 : c3823ee4 r4 : c3823f0c

r3 : 00000014 r2 : f0000010 r1 : c0387303 r0 : c340c880

Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment kernel

Control:c000717f Table: 30004000 DAC: 00000017

Process swapper(pid: 1, stack limit = 0xc3822270)

Stack: (0xc3823ec8to 0xc3824000)

3ec0: c3823f0c c340c880 c340e9c0c3804580 c340c880 c0162620

3ee0: 00001000c007c3d4 c39b6000 c007c424 00000000 c39b6000 c39a9d80 c3982800

3f00: 00000002c0162768 00000001 00000000 00000000 00000000 00000000 00000000

3f20: 00000000c3982800 c03de130 00000002 c3982800 00000000 c3823f80 c0091d4c

3f40: c398280000000000 c03de0a8 c0092360 c04c8082 00000000 c03de130 c0403840

3f60: c03de0a8c04c8082 c03de130 00000000 00000000 00000000 00000000 c002b9f8

3f80: 0000000000000000 00000000 00000000 00000000 00000000 00000000 00000000

3fa0: 0000000000000000 00000000 00000000 00000000 00000000 00000000 00000000

3fc0: 0000000000000000 00000002 c0403840 c00224e4 00000000 00000000 c0028588

3fe0: c0403840c0008438 00000000 00000000 00000000 c0029868 ffffefff fdffbfff

[<c0144bf8>](yaffs_getxattr+0x2c/0x84) from [<c0162620>](get_vfs_caps_from_disk+0x50/0xec)

[<c0162620>](get_vfs_caps_from_disk+0x50/0xec) from [<c0162768>](cap_bprm_set_creds+0xac/0x350)

[<c0162768>](cap_bprm_set_creds+0xac/0x350) from [<c0091d4c>](prepare_binprm+0xc4/0x108)

[<c0091d4c>](prepare_binprm+0xc4/0x108) from [<c0092360>] (do_execve+0x15c/0x2e4)

[<c0092360>](do_execve+0x15c/0x2e4) from [<c002b9f8>] (kernel_execve+0x34/0x84)

[<c002b9f8>](kernel_execve+0x34/0x84) from [<c0028588>] (init_post+0x98/0xf4)

[<c0028588>](init_post+0x98/0xf4) from [<c0008438>] (kernel_init+0xdc/0x10c)

[<c0008438>](kernel_init+0xdc/0x10c) from [<c0029868>] (kernel_thread_exit+0x0/0x8)

Code: 159f005811a01005 15962030 1b06843d (e5964008)

---[ end trace3cf0c84bc319fd44 ]---

Kernel panic - notsyncing: Attempted to kill init!

由log可以看出Oops出现的位置处于yaffs.o文件中的getxattr位置，错误的机器码是：e5964008

反汇编yaffs.o：

arm-linux-objdump-Dz -S yaffs.o > yaffs.dump

vim打开 yaffs.dump 搜索错误机器码（e5964008）所在位置：

此处该机器码出现于两个地方：

第一个地方：

int error = 0;

struct yaffs_dev*dev;

struct yaffs_obj*obj = yaffs_inode_to_obj(inode);

838: e5916128 ldr r6,[r1, #296] ; 0x128

yaffs_trace(YAFFS_TRACE_OS,

83c: e3120002 tst r2,#2

840: 159f0058 ldrne r0,[pc, #88] ; 8a0 <yaffs_getxattr+0x7c>

844: 11a01005 movne r1,r5

848: 15962030 ldrne r2,[r6, #48] ; 0x30

84c: 1bfffffe blne 0<printk>

"yaffs_getxattr \"%s\" from object %d",

name,obj->obj_id);

if (error == 0) {

dev= obj->my_dev;

850: e5964008 ldr r4,[r6, #8]

yaffs_gross_lock(dev);

854: e1a00004 mov r0,r4

858: ebffff2a bl 508<yaffs_gross_lock>

error= yaffs_get_xattrib(obj, name, buff, size);

85c: e1a01005 mov r1,r5

860: e59d3018 ldr r3,[sp, #24]

864: e1a02007 mov r2,r7

868: e1a00006 mov r0,r6

86c: ebfffffe bl 5c0c<yaffs_get_xattrib>

870: e1a05000 mov r5,r0

yaffs_gross_unlock(dev);

874: e1a00004 mov r0,r4

878: ebffff5d bl 5f4<yaffs_gross_unlock>

第二个地方：

struct inode *inode= dentry->d_inode;

int error = 0;

struct yaffs_dev*dev;

struct yaffs_obj*obj = yaffs_inode_to_obj(inode);

7c0: e5936128 ldr r6,[r3, #296] ; 0x128

yaffs_trace(YAFFS_TRACE_OS,

7c4: 159f0050 ldrne r0,[pc, #80] ; 81c <yaffs_listxattr+0x78>

7c8: 15961030 ldrne r1,[r6, #48] ; 0x30

7cc: 1bfffffe blne 0<printk>

"yaffs_listxattrof object %d", obj->obj_id);

if (error == 0) {

dev= obj->my_dev;

7d0: e5964008 ldr r4,[r6, #8]

yaffs_gross_lock(dev);

7d4: e1a00004 mov r0,r4

7d8: ebffff4a bl 508<yaffs_gross_lock>

error= yaffs_list_xattrib(obj, buff, size);

7dc: e1a01005 mov r1,r5

7e0: e1a02007 mov r2,r7

7e4: e1a00006 mov r0,r6

7e8: ebfffffe bl 5bfc<yaffs_list_xattrib>

7ec: e1a05000 mov r5,r0

yaffs_gross_unlock(dev);

7f0: e1a00004 mov r0,r4

7f4: ebffff7e bl 5f4<yaffs_gross_unlock>

结合机器码所在位置的汇编上下文可知错误出现在第一个地方，因为第一个地方有 <yaffs_getxattr+0x7c>标志，正好与Oops所提示出错地址（PC is at yaffs_getxattr+0x2c/0x84）相近，之后可通过上下文推测其对应的C代码位置，如此处可搜索log“yaffs_getxattr”所在位置：

grep "yaffs_getxattr" -nr ./yaffs/ ：

./yaffs/yaffs_vfs.c:991: "yaffs_getxattr\"%s\" from object %d",

由此可定位出C语言位置在yaffs_vfs.c的991行附近：

#ifdefYAFFS_NEW_XATTR

static ssize_tyaffs_getxattr(struct dentry * dentry, struct inode *inode,

constchar *name, void *buff, size_t size)

{

#else

static ssize_tyaffs_getxattr(struct dentry * dentry, const char *name,void *buff, size_tsize)

{

structinode *inode = dentry->d_inode;

#endif

interror = 0;

structyaffs_dev *dev;

structyaffs_obj *obj = yaffs_inode_to_obj(inode);

yaffs_trace(YAFFS_TRACE_OS,

"yaffs_getxattr \"%s\" from object %d",

name,obj->obj_id);

if(error == 0) {

dev= obj->my_dev;

yaffs_gross_lock(dev);

error= yaffs_get_xattrib(obj, name, buff, size);

yaffs_gross_unlock(dev);

}

yaffs_trace(YAFFS_TRACE_OS,"yaffs_getxattr done returning %d", error);

returnerror;

}

此处可分析C语言代码，发现有如下问题YAFFS_NEW_XATTR的定义如下：

#if(LINUX_VERSION_CODE >= KERNEL_VERSION(4, 8, 0))

#define YAFFS_NEW_XATTR 1

#else

#define YAFFS_NEW_GET_LINK 0

#endif

此处可知 YAFFS_NEW_GET_LINK是已经定义的因此如上C语言一定会编译

static ssize_tyaffs_getxattr(struct dentry * dentry, struct inode *inode,

constchar *name, void *buff, size_t size)

而#else永远不会被编译，同时查看2.6.32.2代码include/linux/fs.h

struct inode_operations{

….

ssize_t(*getxattr) (struct dentry *, const char *, void *, size_t);

……

}

该定义与

yaffs_getxattr(structdentry * dentry, struct inode *inode,

constchar *name, void *buff, size_t size)

无法匹配！！！！在结合编译时出现的warning:initialization from incompatible pointer type

可知出错正是此处！

修正：将#ifdef YAFFS_NEW_XATTR

改为：#if (YAFFS_NEW_XATTR > 0)

即可解决该bug ！！！

阅读全文

0 0