bad_mode() handler is called for invalid or undefined instruction in el1 level or when irq,fiq,sync or error situation happen in el1 or el0 level.
As per latest code, above abnormal situation may not result in panic always due to die() call if user mode is determined at that moment. That will just result in kill of current process and panic will be avoided which it must not.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=200637 Signed-off-by: Hari Vyas hari.vyas@broadcom.com --- arch/arm64/kernel/traps.c | 1 - 1 file changed, 1 deletion(-)
diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c index d399d45..716ee73 100644 --- a/arch/arm64/kernel/traps.c +++ b/arch/arm64/kernel/traps.c @@ -621,7 +621,6 @@ asmlinkage void bad_mode(struct pt_regs *regs, int reason, unsigned int esr) handler[reason], smp_processor_id(), esr, esr_get_class_string(esr));
- die("Oops - bad mode", regs, 0); local_daif_mask(); panic("bad mode"); }
On Tue, Aug 07, 2018 at 04:33:48PM +0530, Hari Vyas wrote:
bad_mode() handler is called for invalid or undefined instruction in el1 level or when irq,fiq,sync or error situation happen in el1 or el0 level.
As per latest code, above abnormal situation may not result in panic always due to die() call if user mode is determined at that moment. That will just result in kill of current process and panic will be avoided which it must not.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=200637 Signed-off-by: Hari Vyas hari.vyas@broadcom.com
arch/arm64/kernel/traps.c | 1 - 1 file changed, 1 deletion(-)
diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c index d399d45..716ee73 100644 --- a/arch/arm64/kernel/traps.c +++ b/arch/arm64/kernel/traps.c @@ -621,7 +621,6 @@ asmlinkage void bad_mode(struct pt_regs *regs, int reason, unsigned int esr) handler[reason], smp_processor_id(), esr, esr_get_class_string(esr));
- die("Oops - bad mode", regs, 0); local_daif_mask(); panic("bad mode");
}
1.9.1
<formletter>
This is not the correct way to submit patches for inclusion in the stable kernel tree. Please read: https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html for how to do this properly.
</formletter>
On Tue, Aug 7, 2018 at 5:57 PM, Greg KH greg@kroah.com wrote:
On Tue, Aug 07, 2018 at 04:33:48PM +0530, Hari Vyas wrote:
bad_mode() handler is called for invalid or undefined instruction in el1 level or when irq,fiq,sync or error situation happen in el1 or el0 level.
As per latest code, above abnormal situation may not result in panic always due to die() call if user mode is determined at that moment. That will just result in kill of current process and panic will be avoided which it must not.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=200637 Signed-off-by: Hari Vyas hari.vyas@broadcom.com
arch/arm64/kernel/traps.c | 1 - 1 file changed, 1 deletion(-)
diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c index d399d45..716ee73 100644 --- a/arch/arm64/kernel/traps.c +++ b/arch/arm64/kernel/traps.c @@ -621,7 +621,6 @@ asmlinkage void bad_mode(struct pt_regs *regs, int reason, unsigned int esr) handler[reason], smp_processor_id(), esr, esr_get_class_string(esr));
die("Oops - bad mode", regs, 0); local_daif_mask(); panic("bad mode");}
1.9.1
<formletter>
This is not the correct way to submit patches for inclusion in the stable kernel tree. Please read: https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html for how to do this properly.
</formletter>
Thanks. Probably my mistake to include stable kernel list for regular minor patch. In any case, will take care about it along with arm maintainers and developers review comments which I am awaiting.
On 08/08/2018 11:18 AM, Hari Vyas wrote:
On Tue, Aug 7, 2018 at 5:57 PM, Greg KH greg@kroah.com wrote:
On Tue, Aug 07, 2018 at 04:33:48PM +0530, Hari Vyas wrote:
bad_mode() handler is called for invalid or undefined instruction in el1 level or when irq,fiq,sync or error situation happen in el1 or el0 level.
As per latest code, above abnormal situation may not result in panic always due to die() call if user mode is determined at that moment. That will just result in kill of current process and panic will be avoided which it must not.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=200637 Signed-off-by: Hari Vyas hari.vyas@broadcom.com
arch/arm64/kernel/traps.c | 1 - 1 file changed, 1 deletion(-)
diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c index d399d45..716ee73 100644 --- a/arch/arm64/kernel/traps.c +++ b/arch/arm64/kernel/traps.c @@ -621,7 +621,6 @@ asmlinkage void bad_mode(struct pt_regs *regs, int reason, unsigned int esr) handler[reason], smp_processor_id(), esr, esr_get_class_string(esr));
die("Oops - bad mode", regs, 0); local_daif_mask(); panic("bad mode");}
1.9.1
<formletter>
This is not the correct way to submit patches for inclusion in the stable kernel tree. Please read: https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html for how to do this properly.
</formletter>
Thanks. Probably my mistake to include stable kernel list for regular minor patch. In any case, will take care about it along with arm maintainers and developers review comments which I am awaiting.
Also, if this is a real fix, then providing an appropriate Fixes: tag would help understand when this broke, and how far back this needs to be backported to. This of course, assumes that your patch is the right course of action.
On Wed, Aug 8, 2018 at 11:53 PM, Florian Fainelli f.fainelli@gmail.com wrote:
On 08/08/2018 11:18 AM, Hari Vyas wrote:
On Tue, Aug 7, 2018 at 5:57 PM, Greg KH greg@kroah.com wrote:
On Tue, Aug 07, 2018 at 04:33:48PM +0530, Hari Vyas wrote:
bad_mode() handler is called for invalid or undefined instruction in el1 level or when irq,fiq,sync or error situation happen in el1 or el0 level.
As per latest code, above abnormal situation may not result in panic always due to die() call if user mode is determined at that moment. That will just result in kill of current process and panic will be avoided which it must not.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=200637 Signed-off-by: Hari Vyas hari.vyas@broadcom.com
arch/arm64/kernel/traps.c | 1 - 1 file changed, 1 deletion(-)
diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c index d399d45..716ee73 100644 --- a/arch/arm64/kernel/traps.c +++ b/arch/arm64/kernel/traps.c @@ -621,7 +621,6 @@ asmlinkage void bad_mode(struct pt_regs *regs, int reason, unsigned int esr) handler[reason], smp_processor_id(), esr, esr_get_class_string(esr));
die("Oops - bad mode", regs, 0); local_daif_mask(); panic("bad mode");}
1.9.1
<formletter>
This is not the correct way to submit patches for inclusion in the stable kernel tree. Please read: https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html for how to do this properly.
</formletter>
Thanks. Probably my mistake to include stable kernel list for regular minor patch. In any case, will take care about it along with arm maintainers and developers review comments which I am awaiting.
Also, if this is a real fix, then providing an appropriate Fixes: tag would help understand when this broke, and how far back this needs to be backported to. This of course, assumes that your patch is the right course of action. --
As far as I know, bad mode was earlier(linux 3.14 onwards) also not resulting in panic always. Trap-exception framework is recently changed some time back but this concern remains same. I am also awaiting a response from ARM maintainers before proceeding. Just to be more clear, this concern was pointed out in one of my previous-and-some-what-relative patch about console-verbose level restoration issue.
Florian
On Fri, Aug 10, 2018 at 10:16 PM, Hari Vyas hari.vyas@broadcom.com wrote:
On Wed, Aug 8, 2018 at 11:53 PM, Florian Fainelli f.fainelli@gmail.com wrote:
On 08/08/2018 11:18 AM, Hari Vyas wrote:
On Tue, Aug 7, 2018 at 5:57 PM, Greg KH greg@kroah.com wrote:
On Tue, Aug 07, 2018 at 04:33:48PM +0530, Hari Vyas wrote:
bad_mode() handler is called for invalid or undefined instruction in el1 level or when irq,fiq,sync or error situation happen in el1 or el0 level.
As per latest code, above abnormal situation may not result in panic always due to die() call if user mode is determined at that moment. That will just result in kill of current process and panic will be avoided which it must not.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=200637 Signed-off-by: Hari Vyas hari.vyas@broadcom.com
arch/arm64/kernel/traps.c | 1 - 1 file changed, 1 deletion(-)
diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c index d399d45..716ee73 100644 --- a/arch/arm64/kernel/traps.c +++ b/arch/arm64/kernel/traps.c @@ -621,7 +621,6 @@ asmlinkage void bad_mode(struct pt_regs *regs, int reason, unsigned int esr) handler[reason], smp_processor_id(), esr, esr_get_class_string(esr));
die("Oops - bad mode", regs, 0); local_daif_mask(); panic("bad mode");}
1.9.1
<formletter>
This is not the correct way to submit patches for inclusion in the stable kernel tree. Please read: https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html for how to do this properly.
</formletter>
Thanks. Probably my mistake to include stable kernel list for regular minor patch. In any case, will take care about it along with arm maintainers and developers review comments which I am awaiting.
Also, if this is a real fix, then providing an appropriate Fixes: tag would help understand when this broke, and how far back this needs to be backported to. This of course, assumes that your patch is the right course of action. --
As far as I know, bad mode was earlier(linux 3.14 onwards) also not resulting in panic always. Trap-exception framework is recently changed some time back but this concern remains same. I am also awaiting a response from ARM maintainers before proceeding. Just to be more clear, this concern was pointed out in one of my previous-and-some-what-relative patch about console-verbose level restoration issue.
Florian
Gentle reminder for Arm maintainers. If concern can be taken care from your side in different ways then bug can be resolved.
Regards, hari
linux-stable-mirror@lists.linaro.org
-
Florian Fainelli -
Greg KH -
Hari Vyas