On 4/1/2014 3:34 PM, Kees Cook wrote: > On Mon, Mar 24, 2014 at 3:47 AM, Jon Medhurst (Tixy) <t...@linaro.org> wrote: >> On Sun, 2014-03-23 at 16:21 -0600, Kees Cook wrote: >>> For this stage, how about I make this "depends on KEXEC=n && >>> KPROBES=n"? >> >> There's also ftrace (CONFIG_DYNAMIC_FTRACE I believe) which modifies >> kernel code with a call to probe_kernel_write(), which GDB uses as well. >> >> And grepping for the patch_text() function also shows >> __arch_jump_label_transform() modifies kernel code. Not sure how and >> when that gets used. > > Right, so, I'm trying to fix ftrace now, and I've hit a wall. It is as > if changes to the kernel text PMD aren't being noticed after the > kernel is running. Does anyone know why this might be happening? > > Code and details here: > https://lkml.org/lkml/2014/4/1/674 > > -Kees >
We had a flush_tlb_kernel_page after the pmd_flush in our out of tree code which makes the text writeable in __patch_text. Laura -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
