Messages in this thread | | | Date | Tue, 14 Dec 2004 17:25:23 -0200 | From | Fabiano Ramos <> | Subject | help with access_process_vm |
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Hi all.
I am trying to write/read to/from a process image (to be more specific, replace an instruction with a 0xCC trap) from within a debug handler. I mean, a debug handler will be fired (via eflags) and I want to make sure the process will stop again at a given address.
My new handler, called do_debug_new replaces the old do_debug. From inside it, I do something like
task = current; .... access_process_vm(task, addr, &oldvalue, sizeof(oldvalue), 0); newvalue= oldvalue; ptr = (char *) &newvalue; *ptr = 0xCC; access_process_vm(task, addr, &newvalue, sizeof(newvalue), 1); ....
But the first time a call access_process_vm, dmesg shows me: Debug: sleeping function called from invalid context at include/linux/rwsem.h:43 in_atomic():0, irqs_disabled():1 [<c01145ac>] __might_sleep+0x8c/0xa0 [<c011c69b>] access_process_vm+0x4b/0x1d0 [<c010c830>] do_debug_new+0xd0/0x190 [<c038c755>] schedule+0x275/0x460 [<c0105c2d>] error_code+0x2d/0x40
What I am missing? Do I need some syncronization? Can the debug handler run in the context of a process that was not the one that caused the debug trap?
Thanks a lot Fabiano - 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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