[meta-freescale] [meta-freescale-layer master][PATCH] linux-qoriq, powerpc: kernel patches for cmp assembly instructions that fail with binutils 2.28

Bob Cochran yocto at mindchasers.com
Mon Apr 3 20:32:55 PDT 2017


linux-qoriq 4.1.35 64b kernel fails to build for vdso64/gettimeofday.S, vdso64/datapage.S, and head_64.S due to incorrectly coded cmp instructions.  Apply two existing kernel patches from upstream, mainline kernel to correct the coding of these instructions.

Built and tested on an e5500 t1040rdb-64b machine

Signed-off-by: Bob Cochran <yocto at mindchasers.com>
---
 ...pc-64e-Convert-cmpi-to-cmpwi-in-head_64.S.patch | 57 ++++++++++++++++++
 ...dso64-Use-double-word-compare-on-pointers.patch | 67 ++++++++++++++++++++++
 recipes-kernel/linux/linux-qoriq_4.1.bb            |  2 +
 3 files changed, 126 insertions(+)
 create mode 100644 recipes-kernel/linux/linux-qoriq/powerpc-64e-Convert-cmpi-to-cmpwi-in-head_64.S.patch
 create mode 100644 recipes-kernel/linux/linux-qoriq/powerpc-vdso64-Use-double-word-compare-on-pointers.patch

diff --git a/recipes-kernel/linux/linux-qoriq/powerpc-64e-Convert-cmpi-to-cmpwi-in-head_64.S.patch b/recipes-kernel/linux/linux-qoriq/powerpc-64e-Convert-cmpi-to-cmpwi-in-head_64.S.patch
new file mode 100644
index 0000000..710b212
--- /dev/null
+++ b/recipes-kernel/linux/linux-qoriq/powerpc-64e-Convert-cmpi-to-cmpwi-in-head_64.S.patch
@@ -0,0 +1,57 @@
+From f87f253bac3ce4a4eb2a60a1ae604d74e65f9042 Mon Sep 17 00:00:00 2001
+From: Nicholas Piggin <npiggin at gmail.com>
+Date: Thu, 24 Nov 2016 00:02:07 +1100
+Subject: [PATCH] powerpc/64e: Convert cmpi to cmpwi in head_64.S
+
+From 80f23935cadb ("powerpc: Convert cmp to cmpd in idle enter sequence"):
+
+  PowerPC's "cmp" instruction has four operands. Normally people write
+  "cmpw" or "cmpd" for the second cmp operand 0 or 1. But, frequently
+  people forget, and write "cmp" with just three operands.
+
+  With older binutils this is silently accepted as if this was "cmpw",
+  while often "cmpd" is wanted. With newer binutils GAS will complain
+  about this for 64-bit code. For 32-bit code it still silently assumes
+  "cmpw" is what is meant.
+
+In this case, cmpwi is called for, so this is just a build fix for
+new toolchains.
+
+Cc: stable at vger.kernel.org # v3.0+
+Signed-off-by: Nicholas Piggin <npiggin at gmail.com>
+Signed-off-by: Michael Ellerman <mpe at ellerman.id.au>
+---
+ arch/powerpc/kernel/head_64.S | 8 ++++----
+ 1 file changed, 4 insertions(+), 4 deletions(-)
+
+diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S
+index 451a8e1..bdb4612 100644
+--- a/arch/powerpc/kernel/head_64.S
++++ b/arch/powerpc/kernel/head_64.S
+@@ -221,9 +221,9 @@ booting_thread_hwid:
+  */
+ _GLOBAL(book3e_start_thread)
+ 	LOAD_REG_IMMEDIATE(r5, MSR_KERNEL)
+-	cmpi	0, r3, 0
++	cmpwi	r3, 0
+ 	beq	10f
+-	cmpi	0, r3, 1
++	cmpwi	r3, 1
+ 	beq	11f
+ 	/* If the thread id is invalid, just exit. */
+ 	b	13f
+@@ -248,9 +248,9 @@ _GLOBAL(book3e_start_thread)
+  * r3 = the thread physical id
+  */
+ _GLOBAL(book3e_stop_thread)
+-	cmpi	0, r3, 0
++	cmpwi	r3, 0
+ 	beq	10f
+-	cmpi	0, r3, 1
++	cmpwi	r3, 1
+ 	beq	10f
+ 	/* If the thread id is invalid, just exit. */
+ 	b	13f
+-- 
+2.7.4
+
diff --git a/recipes-kernel/linux/linux-qoriq/powerpc-vdso64-Use-double-word-compare-on-pointers.patch b/recipes-kernel/linux/linux-qoriq/powerpc-vdso64-Use-double-word-compare-on-pointers.patch
new file mode 100644
index 0000000..9fa40de
--- /dev/null
+++ b/recipes-kernel/linux/linux-qoriq/powerpc-vdso64-Use-double-word-compare-on-pointers.patch
@@ -0,0 +1,67 @@
+From 5045ea37377ce8cca6890d32b127ad6770e6dce5 Mon Sep 17 00:00:00 2001
+From: Anton Blanchard <anton at samba.org>
+Date: Sun, 25 Sep 2016 17:16:53 +1000
+Subject: [PATCH] powerpc/vdso64: Use double word compare on pointers
+
+__kernel_get_syscall_map() and __kernel_clock_getres() use cmpli to
+check if the passed in pointer is non zero. cmpli maps to a 32 bit
+compare on binutils, so we ignore the top 32 bits.
+
+A simple test case can be created by passing in a bogus pointer with
+the bottom 32 bits clear. Using a clk_id that is handled by the VDSO,
+then one that is handled by the kernel shows the problem:
+
+  printf("%d\n", clock_getres(CLOCK_REALTIME, (void *)0x100000000));
+  printf("%d\n", clock_getres(CLOCK_BOOTTIME, (void *)0x100000000));
+
+And we get:
+
+  0
+  -1
+
+The bigger issue is if we pass a valid pointer with the bottom 32 bits
+clear, in this case we will return success but won't write any data
+to the pointer.
+
+I stumbled across this issue because the LLVM integrated assembler
+doesn't accept cmpli with 3 arguments. Fix this by converting them to
+cmpldi.
+
+Fixes: a7f290dad32e ("[PATCH] powerpc: Merge vdso's and add vdso support to 32 bits kernel")
+Cc: stable at vger.kernel.org # v2.6.15+
+Signed-off-by: Anton Blanchard <anton at samba.org>
+Signed-off-by: Michael Ellerman <mpe at ellerman.id.au>
+---
+ arch/powerpc/kernel/vdso64/datapage.S     | 2 +-
+ arch/powerpc/kernel/vdso64/gettimeofday.S | 2 +-
+ 2 files changed, 2 insertions(+), 2 deletions(-)
+
+diff --git a/arch/powerpc/kernel/vdso64/datapage.S b/arch/powerpc/kernel/vdso64/datapage.S
+index 184a6ba..abf17fe 100644
+--- a/arch/powerpc/kernel/vdso64/datapage.S
++++ b/arch/powerpc/kernel/vdso64/datapage.S
+@@ -59,7 +59,7 @@ V_FUNCTION_BEGIN(__kernel_get_syscall_map)
+ 	bl	V_LOCAL_FUNC(__get_datapage)
+ 	mtlr	r12
+ 	addi	r3,r3,CFG_SYSCALL_MAP64
+-	cmpli	cr0,r4,0
++	cmpldi	cr0,r4,0
+ 	crclr	cr0*4+so
+ 	beqlr
+ 	li	r0,NR_syscalls
+diff --git a/arch/powerpc/kernel/vdso64/gettimeofday.S b/arch/powerpc/kernel/vdso64/gettimeofday.S
+index a76b4af..3820213 100644
+--- a/arch/powerpc/kernel/vdso64/gettimeofday.S
++++ b/arch/powerpc/kernel/vdso64/gettimeofday.S
+@@ -145,7 +145,7 @@ V_FUNCTION_BEGIN(__kernel_clock_getres)
+ 	bne	cr0,99f
+ 
+ 	li	r3,0
+-	cmpli	cr0,r4,0
++	cmpldi	cr0,r4,0
+ 	crclr	cr0*4+so
+ 	beqlr
+ 	lis	r5,CLOCK_REALTIME_RES at h
+-- 
+2.7.4
+
diff --git a/recipes-kernel/linux/linux-qoriq_4.1.bb b/recipes-kernel/linux/linux-qoriq_4.1.bb
index 6c2b235..12d12f5 100644
--- a/recipes-kernel/linux/linux-qoriq_4.1.bb
+++ b/recipes-kernel/linux/linux-qoriq_4.1.bb
@@ -15,6 +15,8 @@ SRC_URI = "git://git.freescale.com/ppc/sdk/linux.git;nobranch=1 \
     file://powerpc-fsl-Fix-build-of-the-dtb-embedded-kernel-images.patch \
     file://CVE-2016-2053.patch \
     file://CVE-2016-0758.patch \
+    file://powerpc-64e-Convert-cmpi-to-cmpwi-in-head_64.S.patch \
+    file://powerpc-vdso64-Use-double-word-compare-on-pointers.patch \
 "
 SRCREV = "b14540ee315f79f6a5dfc621e7f4217c8fac7d1c"
 
-- 
2.7.4



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