FAILED: patch "[PATCH] powerpc/ftrace: Pass the correct stack pointer for" failed to apply to 4.9-stable tree

FAILED: patch "[PATCH] powerpc/ftrace: Pass the correct stack pointer for" failed to apply to 4.9-stable tree

[gregkh]

The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

>From a4979a7e71eb8da976cbe4a0a1fa50636e76b04f Mon Sep 17 00:00:00 2001
From: "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>
Date: Thu, 1 Jun 2017 16:18:16 +0530
Subject: [PATCH] powerpc/ftrace: Pass the correct stack pointer for
 DYNAMIC_FTRACE_WITH_REGS

For DYNAMIC_FTRACE_WITH_REGS, we should be passing-in the original set
of registers in pt_regs, to capture the state _before_ ftrace_caller.
However, we are instead passing the stack pointer *after* allocating a
stack frame in ftrace_caller. Fix this by saving the proper value of r1
in pt_regs. Also, use SAVE_10GPRS() to simplify the code.

Fixes: 153086644fd1 ("powerpc/ftrace: Add support for -mprofile-kernel ftrace ABI")
Cc: stable@vger.kernel.org # v4.6+
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

diff --git a/arch/powerpc/kernel/trace/ftrace_64_mprofile.S b/arch/powerpc/kernel/trace/ftrace_64_mprofile.S
index 7c933a99f5d5..fa0921410fa4 100644
--- a/arch/powerpc/kernel/trace/ftrace_64_mprofile.S
+++ b/arch/powerpc/kernel/trace/ftrace_64_mprofile.S
@@ -45,10 +45,14 @@ _GLOBAL(ftrace_caller)
 	stdu	r1,-SWITCH_FRAME_SIZE(r1)
 
 	/* Save all gprs to pt_regs */
-	SAVE_8GPRS(0,r1)
-	SAVE_8GPRS(8,r1)
-	SAVE_8GPRS(16,r1)
-	SAVE_8GPRS(24,r1)
+	SAVE_GPR(0, r1)
+	SAVE_10GPRS(2, r1)
+	SAVE_10GPRS(12, r1)
+	SAVE_10GPRS(22, r1)
+
+	/* Save previous stack pointer (r1) */
+	addi	r8, r1, SWITCH_FRAME_SIZE
+	std	r8, GPR1(r1)
 
 	/* Load special regs for save below */
 	mfmsr   r8
@@ -103,10 +107,10 @@ ftrace_call:
 #endif
 
 	/* Restore gprs */
-	REST_8GPRS(0,r1)
-	REST_8GPRS(8,r1)
-	REST_8GPRS(16,r1)
-	REST_8GPRS(24,r1)
+	REST_GPR(0,r1)
+	REST_10GPRS(2,r1)
+	REST_10GPRS(12,r1)
+	REST_10GPRS(22,r1)
 
 	/* Restore possibly modified LR */
 	ld	r0, _LINK(r1)

Re: FAILED: patch "[PATCH] powerpc/ftrace: Pass the correct stack pointer for" failed to apply to 4.9-stable tree

[Naveen N. Rao]

On 2017/06/26 08:20AM, gregkh@linuxfoundation.org wrote:
> 
> The patch below does not apply to the 4.9-stable tree.
> If someone wants it applied there, or to any other stable or longterm
> tree, then please email the backport, including the original git commit
> id to <stable@vger.kernel.org>.

Michael, Greg,
Here is a version that applies on v4.9 and v4.11. These bits have been
moved under arch/powerpc/kernel/trace and as such needed adjustment to
apply to entry_64.S.

I couldn't test this as I get the below error trying to compile v4.9:
ld: arch/powerpc/boot/zImage.pseries: Not enough room for program headers, try linking with -N
ld: final link failed: Bad value

Michael,
Can you please help test this?


Thanks,
Naveen

-
[PATCH] powerpc/ftrace: Pass the correct stack pointer for DYNAMIC_FTRACE_WITH_REGS

For DYNAMIC_FTRACE_WITH_REGS, we should be passing-in the original set
of registers in pt_regs, to capture the state _before_ ftrace_caller.
However, we are instead passing the stack pointer *after* allocating a
stack frame in ftrace_caller. Fix this by saving the proper value of r1
in pt_regs. Also, use SAVE_10GPRS() to simplify the code.

Fixes: 153086644fd1 ("powerpc/ftrace: Add support for -mprofile-kernel ftrace ABI")
Cc: stable@vger.kernel.org # v4.6+
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---
 arch/powerpc/kernel/entry_64.S | 20 ++++++++++++--------
 1 file changed, 12 insertions(+), 8 deletions(-)

diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 767ef6d68c9e..caa659671599 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -1235,10 +1235,14 @@ _GLOBAL(ftrace_caller)
 	stdu	r1,-SWITCH_FRAME_SIZE(r1)
 
 	/* Save all gprs to pt_regs */
-	SAVE_8GPRS(0,r1)
-	SAVE_8GPRS(8,r1)
-	SAVE_8GPRS(16,r1)
-	SAVE_8GPRS(24,r1)
+	SAVE_GPR(0, r1)
+	SAVE_10GPRS(2, r1)
+	SAVE_10GPRS(12, r1)
+	SAVE_10GPRS(22, r1)
+
+	/* Save previous stack pointer (r1) */
+	addi	r8, r1, SWITCH_FRAME_SIZE
+	std	r8, GPR1(r1)
 
 	/* Load special regs for save below */
 	mfmsr   r8
@@ -1292,10 +1296,10 @@ ftrace_call:
 #endif
 
 	/* Restore gprs */
-	REST_8GPRS(0,r1)
-	REST_8GPRS(8,r1)
-	REST_8GPRS(16,r1)
-	REST_8GPRS(24,r1)
+	REST_GPR(0,r1)
+	REST_10GPRS(2,r1)
+	REST_10GPRS(12,r1)
+	REST_10GPRS(22,r1)
 
 	/* Restore callee's TOC */
 	ld	r2, 24(r1)
-- 
2.13.1

Re: FAILED: patch "[PATCH] powerpc/ftrace: Pass the correct stack pointer for" failed to apply to 4.9-stable tree

[Greg KH]

On Thu, Jun 29, 2017 at 08:58:31PM +0530, Naveen N. Rao wrote:
> On 2017/06/26 08:20AM, gregkh@linuxfoundation.org wrote:
> > 
> > The patch below does not apply to the 4.9-stable tree.
> > If someone wants it applied there, or to any other stable or longterm
> > tree, then please email the backport, including the original git commit
> > id to <stable@vger.kernel.org>.
> 
> Michael, Greg,
> Here is a version that applies on v4.9 and v4.11. These bits have been
> moved under arch/powerpc/kernel/trace and as such needed adjustment to
> apply to entry_64.S.
> 
> I couldn't test this as I get the below error trying to compile v4.9:
> ld: arch/powerpc/boot/zImage.pseries: Not enough room for program headers, try linking with -N
> ld: final link failed: Bad value
> 
> Michael,
> Can you please help test this?


Given a lack of response, this is now deleted from my "to-apply" queue.

thanks,

greg k-h

Re: FAILED: patch "[PATCH] powerpc/ftrace: Pass the correct stack pointer for" failed to apply to 4.9-stable tree

[Michael Ellerman]

Greg KH <gregkh@linuxfoundation.org> writes:

> On Thu, Jun 29, 2017 at 08:58:31PM +0530, Naveen N. Rao wrote:
>> On 2017/06/26 08:20AM, gregkh@linuxfoundation.org wrote:
>> > 
>> > The patch below does not apply to the 4.9-stable tree.
>> > If someone wants it applied there, or to any other stable or longterm
>> > tree, then please email the backport, including the original git commit
>> > id to <stable@vger.kernel.org>.
>> 
>> Michael, Greg,
>> Here is a version that applies on v4.9 and v4.11. These bits have been
>> moved under arch/powerpc/kernel/trace and as such needed adjustment to
>> apply to entry_64.S.
>> 
>> I couldn't test this as I get the below error trying to compile v4.9:
>> ld: arch/powerpc/boot/zImage.pseries: Not enough room for program headers, try linking with -N
>> ld: final link failed: Bad value
>> 
>> Michael,
>> Can you please help test this?
>
>
> Given a lack of response, this is now deleted from my "to-apply" queue.

Yeah fair enough, lost in my inbox unfortunately.

The patch seems correct and boots for me.

Should we resend?

cheers