a17671
bcff10d535
Once the SD card is removed， MMC core will set the the host->claimer=NULL & host->claimer->task=NULL So sdhci_dump_state shall check this condition To avoid using the host->claimer pointer directly Below shows the parsed call stack and logs: Unable to handle kernel NULL pointer dereference at virtual address 0000 <6> Mem abort info: <6> ESR = 0x96000005 <6> Exception class = DABT (current EL), IL = 32 bits <6> SET = 0, FnV = 0 <6> EA = 0, S1PTW = 0 <6> Data abort info: <6> ISV = 0, ISS = 0x00000005 <6> CM = 0, WnR = 0 <6> user pgtable: 4k pages, 39-bit VAs, pgdp = 000000000e17a57e 6> [0000000000000000] pgd=0000000000000000, pud=0000000000000000 <6> Internal error: Oops: 96000005 [#1] PREEMPT SMP <2> pstate: 60000085 (nZCv daIf -PAN -UAO) <2> pc : sdhci_dumpregs+0xf1c/0x1250 <2> lr : sdhci_dumpregs+0xef0/0x1250 <2> sp : ffffff8008003d60 <2> x29: ffffff8008003dc0 x28: 0000000000000012 <2> x27: ffffffc0f76b47c0 x26: ffffff800aebc038 <2> x25: 0000000003ff100b x24: ffffffc0f76b47b8 <2> x23: ffffff800aebc058 x22: 0000000000000000 <2> x21: 0000000000000003 x20: ffffffc0f76b4000 <2> x19: ffffffc0f76b4780 x18: 0000000000000090 <2> x17: ffffff800abb8598 x16: 3030303030307830 <2> x15: 0000000000000040 x14: 0000000000000048 <2> x13: 0000000000000008 x12: 0000000000000000 <2> x11: 0000000000000001 x10: 0000000000000007 <2> x9 : 7c9075bd256d4900 x8 : 0000000000000000 <2> x7 : 0000000000000000 x6 : ffffff800a35f428 <2> x5 : 0000000000000000 x4 : 000000000000000c <2> x3 : 0000000000000000 x2 : 000000000c0a4680 <2> x1 : ffffffc0f764c100 x0 : ffffff800994b313 Call stack:- -012|sdhci_dump_state(inline) -012|sdhci_dumpregs([X19] host = 0xFFFFFFC0F76B4780 = end+0x40ECFA2780) -013|sdhci_data_irq(inline) -013|sdhci_irq() -014|__read_once_size(inline) -014|static_key_count(inline) -014|static_key_false(inline) -014|trace_irq_handler_exit(inline) -014|__handle_irq_event_percpu() -015|handle_irq_event_percpu(inline) -015|handle_irq_event([X19] desc = 0xFFFFFFC0FA892200 = end+0x40F0180200) -016|cond_unmask_eoi_irq(inline) -016|handle_fasteoi_irq([X21] desc = 0xFFFFFFC0FA892200 = end+0x40F0180200) -017|__handle_domain_irq([X20] domain = 0xFFFFFFC005FF9800 = end+0x3FFB8E7800, ?, [X22] lookup = TRUE, [X ---|end of frame Instruction set:- NSX:FFFFFF8008B04A98|F942CA88 ldr x8,[x20,#0x590] ; x8,[mmc,#1424] -->>x8 = 0xFFFFFFC0F76B4000+0x590 = 0xFFFFFFC0F76B4590 (correct address) NSX:FFFFFF8008B04A9C|F0007220 adrp x0,0xFFFFFF800994B000 NSX:FFFFFF8008B04AA0|B9432662 ldr w2,[x19,#0x324] ; w2,[host,#804] NSX:FFFFFF8008B04AA4|910C4C00 add x0,x0,#0x313 ; x0,x0,#787 NSX:FFFFFF8008B04AA8|394CA264 ldrb w4,[x19,#0x328] ; w4,[host,#808] NSX:FFFFFF8008B04AAC|F9400108 ldr x8,[x8] ---->> point of crash //x8=0x0 Change-Id: I9f8edc96c2da93caf423a78610dead0d30921542 Signed-off-by: a17671 <a17671@motorola.com> Reviewed-on: https://gerrit.mot.com/1635488 SLTApproved: Slta Waiver SME-Granted: SME Approvals Granted Tested-by: Jira Key Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com> Submit-Approved: Jira Key
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.