powerpc: add shim patch needed for follow-on patch

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

2 files changed, 133 insertions, 0 deletions

diff --git a/queue/powerpc-kernel-Use-kprobe-blacklist-for-asm-function.patch b/queue/powerpc-kernel-Use-kprobe-blacklist-for-asm-function.patch
new file mode 100644
index 0000000..6453f71
--- /dev/null
+++ b/queue/powerpc-kernel-Use-kprobe-blacklist-for-asm-function.patch
@@ -0,0 +1,132 @@
+From 6f698df10cb24d466b9a790b9daedb9e7bcd5d2a Mon Sep 17 00:00:00 2001
+From: Nicholas Piggin <npiggin@gmail.com>
+Date: Fri, 16 Sep 2016 20:48:17 +1000
+Subject: [PATCH] powerpc/kernel: Use kprobe blacklist for asm functions
+
+commit 6f698df10cb24d466b9a790b9daedb9e7bcd5d2a upstream.
+
+Rather than forcing the whole function into the ".kprobes.text" section,
+just add the symbol's address to the kprobe blacklist.
+
+This also lets us drop the three versions of the_KPROBE macro, in
+exchange for just one version of _ASM_NOKPROBE_SYMBOL - which is a good
+cleanup.
+
+Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
+Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
+
+diff --git a/arch/powerpc/include/asm/ppc_asm.h b/arch/powerpc/include/asm/ppc_asm.h
+index d5d5b5e348f2..cd39ac127786 100644
+--- a/arch/powerpc/include/asm/ppc_asm.h
++++ b/arch/powerpc/include/asm/ppc_asm.h
+@@ -217,13 +217,6 @@ name: \
+ 	addi r2,r2,(.TOC.-0b)@l; \
+ 	.localentry name,.-name
+ 
+-#define _KPROBE(name) \
+-	.section ".kprobes.text","a"; \
+-	.align 2 ; \
+-	.type name,@function; \
+-	.globl name; \
+-name:
+-
+ #define DOTSYM(a)	a
+ 
+ #else
+@@ -247,20 +240,6 @@ GLUE(.,name):
+ 
+ #define _GLOBAL_TOC(name) _GLOBAL(name)
+ 
+-#define _KPROBE(name) \
+-	.section ".kprobes.text","a"; \
+-	.align 2 ; \
+-	.globl name; \
+-	.globl GLUE(.,name); \
+-	.section ".opd","aw"; \
+-name: \
+-	.quad GLUE(.,name); \
+-	.quad .TOC.@tocbase; \
+-	.quad 0; \
+-	.previous; \
+-	.type GLUE(.,name),@function; \
+-GLUE(.,name):
+-
+ #define DOTSYM(a)	GLUE(.,a)
+ 
+ #endif
+@@ -279,13 +258,22 @@ n:
+ 
+ #define _GLOBAL_TOC(name) _GLOBAL(name)
+ 
+-#define _KPROBE(n)	\
+-	.section ".kprobes.text","a";	\
+-	.globl	n;	\
+-n:
+-
+ #endif
+ 
++/*
++ * __kprobes (the C annotation) puts the symbol into the .kprobes.text
++ * section, which gets emitted at the end of regular text.
++ *
++ * _ASM_NOKPROBE_SYMBOL and NOKPROBE_SYMBOL just adds the symbol to
++ * a blacklist. The former is for core kprobe functions/data, the
++ * latter is for those that incdentially must be excluded from probing
++ * and allows them to be linked at more optimal location within text.
++ */
++#define _ASM_NOKPROBE_SYMBOL(entry)			\
++	.pushsection "_kprobe_blacklist","aw";		\
++	PPC_LONG (entry) ;				\
++	.popsection
++
+ #define FUNC_START(name)	_GLOBAL(name)
+ #define FUNC_END(name)
+ 
+diff --git a/arch/powerpc/kernel/misc_32.S b/arch/powerpc/kernel/misc_32.S
+index d9c912b6e632..03756ffdcd71 100644
+--- a/arch/powerpc/kernel/misc_32.S
++++ b/arch/powerpc/kernel/misc_32.S
+@@ -328,7 +328,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_UNIFIED_ID_CACHE)
+  *
+  * flush_icache_range(unsigned long start, unsigned long stop)
+  */
+-_KPROBE(flush_icache_range)
++_GLOBAL(flush_icache_range)
+ BEGIN_FTR_SECTION
+ 	PURGE_PREFETCHED_INS
+ 	blr				/* for 601, do nothing */
+@@ -358,6 +358,8 @@ END_FTR_SECTION_IFSET(CPU_FTR_COHERENT_ICACHE)
+ 	sync				/* additional sync needed on g4 */
+ 	isync
+ 	blr
++_ASM_NOKPROBE_SYMBOL(flush_icache_range)
++
+ /*
+  * Flush a particular page from the data cache to RAM.
+  * Note: this is necessary because the instruction cache does *not*
+diff --git a/arch/powerpc/kernel/misc_64.S b/arch/powerpc/kernel/misc_64.S
+index cb195157b318..5d7e583f1588 100644
+--- a/arch/powerpc/kernel/misc_64.S
++++ b/arch/powerpc/kernel/misc_64.S
+@@ -66,7 +66,7 @@ PPC64_CACHES:
+  *   flush all bytes from start through stop-1 inclusive
+  */
+ 
+-_KPROBE(flush_icache_range)
++_GLOBAL(flush_icache_range)
+ BEGIN_FTR_SECTION
+ 	PURGE_PREFETCHED_INS
+ 	blr
+@@ -109,7 +109,8 @@ END_FTR_SECTION_IFSET(CPU_FTR_COHERENT_ICACHE)
+ 	bdnz	2b
+ 	isync
+ 	blr
+-	.previous .text
++_ASM_NOKPROBE_SYMBOL(flush_icache_range)
++
+ /*
+  * Like above, but only do the D-cache.
+  *
+-- 
+2.12.0
+
diff --git a/queue/series b/queue/series
index 540c9c0..5eb875a 100644
--- a/queue/series
+++ b/queue/series
@@ -29,6 +29,7 @@ metag-usercopy-Fix-src-fixup-in-from-user-rapf-loops.patch
 metag-usercopy-Add-missing-fixups.patch
 powerpc-Disable-HFSCR-TM-if-TM-is-not-supported.patch
 powerpc-mm-Add-missing-global-TLB-invalidate-if-cxl-.patch
+powerpc-kernel-Use-kprobe-blacklist-for-asm-function.patch
 powerpc-64-Fix-flush_-d-i-cache_range-called-from-mo.patch
 powerpc-Don-t-try-to-fix-up-misaligned-load-with-res.patch
 powerpc-crypto-crc32c-vpmsum-Fix-missing-preempt_dis.patch