Re: [PATCH] x86/microcode: allow non-root reading of microcode version and processor flags
On Mon, Aug 27, 2018 at 04:05:35PM +0800, Jacek Tomaka wrote: > On Mon, Aug 27, 2018 at 3:52 PM, Borislav Petkov wrote: > > > Your From: is Jacek Tomaka and your SOB is different. > > Which one should I use? > Please use my SOB: Jacek Tomaka > > > (Having a single email address for both is easier...) > Sorry about the trouble. No worries, applied. Thx. -- Regards/Gruss, Boris. ECO tip #101: Trim your mails when you reply. --
Re: [PATCH] x86/microcode: allow non-root reading of microcode version and processor flags
On Mon, Aug 27, 2018 at 3:52 PM, Borislav Petkov wrote: > Your From: is Jacek Tomaka and your SOB is different. > Which one should I use? Please use my SOB: Jacek Tomaka > (Having a single email address for both is easier...) Sorry about the trouble. Regards. Jacek Tomaka
Re: [PATCH] x86/microcode: allow non-root reading of microcode version and processor flags
On Sat, Aug 25, 2018 at 11:50:39AM +0800, Jacek Tomaka wrote: > /sys/devices/system/cpu/cpuX/microcode > > Before: > -r processor_flags > -r version > > After: > -r--r--r-- processor_flags > -r--r--r-- version > > Microcode version has been already readable for non root users via > /proc/cpuinfo. However it is easier to access it from > /sys/devices/system/cpu/cpuX/microcode/version > > Reported-by: Tim Burgess > Signed-off-by: Jacek Tomaka Your From: is Jacek Tomaka and your SOB is different. Which one should I use? (Having a single email address for both is easier...) -- Regards/Gruss, Boris. ECO tip #101: Trim your mails when you reply. --
Re: [PATCH] x86/microcode: allow non-root reading of microcode version and processor flags
On Mon, Aug 27, 2018 at 01:01:41PM +0800, Jacek Tomaka wrote: > Not sure if you are leaning towards removing microcode/version interface > altogether or you are writing your thoughts to justify merging this patch. The latter. We cannot *ever* remove sysfs files. Never. -- Regards/Gruss, Boris. ECO tip #101: Trim your mails when you reply. --
Re: [PATCH] x86/microcode: allow non-root reading of microcode version and processor flags
On Sun, Aug 26, 2018 at 08:23:48PM +0800, Jacek Tomaka wrote:
> I am trying to get microcode version from user space. Reading it
> from /proc/cpuinfo requires greping/awking to extract the bits of
> information that are readily available in microcode/version.
If the only reason is because you find it hard to grep/awk, I won't
take it.
> Any reason why the same piece of information has different access
> permissions, depending on the way it is accessed?
I don't see any particular reason in the original commit which added it:
9a4b9efa1d39 ("[PATCH] x86 microcode: add sysfs and hotplug support")
except maybe because the reload interface is root-only so making the
others root-only too, made sense.
However, we've made the microcode revision available to everyone in
/proc/cpuinfo, in the meantime, so I guess there's no point in keeping
the version file root-only anymore. And I guess the processor flags too,
while we're at it.
--
Regards/Gruss,
Boris.
ECO tip #101: Trim your mails when you reply.
--
Re: [PATCH] x86/microcode: allow non-root reading of microcode version and processor flags
> On 26 Aug 2018, at 7:52 pm, Boris Petkov wrote: > >> On August 25, 2018 6:50:39 AM GMT+03:00, Jacek Tomaka >> wrote: >> /sys/devices/system/cpu/cpuX/microcode >> >> Before: >> -r processor_flags >> -r version >> >> After: >> -r--r--r-- processor_flags >> -r--r--r-- version >> >> Microcode version has been already readable for non root users via >> /proc/cpuinfo. However it is easier to access it from >> /sys/devices/system/cpu/cpuX/microcode/version > > Easier than /proc/cpuinfo?! Sorry, not really. Why not? > You'd need to elaborate in greater detail what exactly you're trying to > achieve. I am trying to get microcode version from user space. Reading it from /proc/cpuinfo requires greping/awking to extract the bits of information that are readily available in microcode/version. Any reason why the same piece of information has different access permissions, depending on the way it is accessed? Regards. Jacek Tomaka
Re: [PATCH] x86/microcode: allow non-root reading of microcode version and processor flags
On August 25, 2018 6:50:39 AM GMT+03:00, Jacek Tomaka wrote: >/sys/devices/system/cpu/cpuX/microcode > >Before: >-r processor_flags >-r version > >After: >-r--r--r-- processor_flags >-r--r--r-- version > >Microcode version has been already readable for non root users via >/proc/cpuinfo. However it is easier to access it from >/sys/devices/system/cpu/cpuX/microcode/version Easier than /proc/cpuinfo?! Sorry, not really. You'd need to elaborate in greater detail what exactly you're trying to achieve. -- Sent from a small device: formatting sux and brevity is inevitable.
[PATCH] x86/microcode: allow non-root reading of microcode version and processor flags
/sys/devices/system/cpu/cpuX/microcode
Before:
-r processor_flags
-r version
After:
-r--r--r-- processor_flags
-r--r--r-- version
Microcode version has been already readable for non root users via
/proc/cpuinfo. However it is easier to access it from
/sys/devices/system/cpu/cpuX/microcode/version
Reported-by: Tim Burgess
Signed-off-by: Jacek Tomaka
---
arch/x86/kernel/cpu/microcode/core.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kernel/cpu/microcode/core.c
b/arch/x86/kernel/cpu/microcode/core.c
index b9bc8a1a58..2637ff09d6 100644
--- a/arch/x86/kernel/cpu/microcode/core.c
+++ b/arch/x86/kernel/cpu/microcode/core.c
@@ -666,8 +666,8 @@ static ssize_t pf_show(struct device *dev,
}
static DEVICE_ATTR_WO(reload);
-static DEVICE_ATTR(version, 0400, version_show, NULL);
-static DEVICE_ATTR(processor_flags, 0400, pf_show, NULL);
+static DEVICE_ATTR(version, 0444, version_show, NULL);
+static DEVICE_ATTR(processor_flags, 0444, pf_show, NULL);
static struct attribute *mc_default_attrs[] = {
&dev_attr_version.attr,
--
2.17.0
