14d260f94f
commit 01039fb8e90c9cb684430414bff70cea9eb168c5 upstream. This commit fixes a kernel oops because of a write in some read-only memory: [ 9.068287] Unable to handle kernel write to read-only memory at virtual address ffff800009240ad8 ..snip.. [ 9.138790] Internal error: Oops: 9600004f [#1] PREEMPT SMP ..snip.. [ 9.269161] Call trace: [ 9.276271] __memcpy+0x5c/0x230 [ 9.278531] snprintf+0x58/0x80 [ 9.282002] qcom_cpufreq_msm8939_name_version+0xb4/0x190 [ 9.284869] qcom_cpufreq_probe+0xc8/0x39c ..snip.. The following line defines a pointer that point to a char buffer stored in read-only memory: char *pvs_name = "speedXX-pvsXX-vXX"; This pointer is meant to hold a template "speedXX-pvsXX-vXX" where the XX values get overridden by the qcom_cpufreq_krait_name_version function. Since the template is actually stored in read-only memory, when the function executes the following call we get an oops: snprintf(*pvs_name, sizeof("speedXX-pvsXX-vXX"), "speed%d-pvs%d-v%d", speed, pvs, pvs_ver); To fix this issue, we instead store the template name onto the stack by using the following syntax: char pvs_name_buffer[] = "speedXX-pvsXX-vXX"; Because the `pvs_name` needs to be able to be assigned to NULL, the template buffer is stored in the pvs_name_buffer and not under the pvs_name variable. Cc: v5.7+ <stable@vger.kernel.org> # v5.7+ Fixes: a8811ec764f9 ("cpufreq: qcom: Add support for krait based socs") Signed-off-by: Fabien Parent <fabien.parent@linaro.org> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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.
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.