Messages in this thread | | | Subject | Re: [Fastboot] [PATCH] Kdump(x86): add note type NT_KDUMPINFO to kernel core dumps | From | (Eric W. Biederman) | Date | Wed, 21 Sep 2005 08:28:32 -0600 |
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Vivek Goyal <vgoyal@in.ibm.com> writes:
> o This patch adds a new note type NT_KDUMPINFO. This note is added with > kernel core dumps generated by kdump. > > o This note mainly communicates the information required by kernel dump > analysis tool "crash" to analyze the kernel core dump. As of now it contains > the pointer to task struct of panicing task and page size. Page size is > irrelevant for i386 but is required for architectures like ia64 and ppc64. > > o gdb is not affected by this change as gdb need not to parse this note.
A couple of things. - The name of your note is terribly generic, so it seems a poor choice.
- Why do we need to capture the page size at the time of the crash? Isn't the page size a compile time option? Won't sys_getpagesize() get you this information before the crash? Why do we need the kernels page size at all?
- Why do you avoid storing the current task on the other cpus?
- Can't we derive the current task from the existing register information already captured. If not would a little extra debug information captured at compile time be better?
- You don't address the issue of architectural control registers. So you are going to need another note at some point. (Not necessarily a bad thing).
> +/* > + * NT_KDUMPINFO can be used to communicate additional information required for > + * kernel core dumps. Additional information includes kernel configuration > + * variables like page size and any other relevant data required by > + * debugger (crash in this case). > +*/ > +struct elf_kdumpinfo > +{ > + char page_shift; /* Page size */ > + struct task_struct *panic_tsk; /* Pointer to panic task_struct */ > +}; > +
> #define NT_TASKSTRUCT 4 > #define NT_AUXV 6 > #define NT_PRXFPREG 0x46e62b7f /* copied from gdb5.1/include/elf/common.h */ > - > +#define NT_KDUMPINFO 7 /* Used for kernel core dumps */ > - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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