This is a note to let you know that I've just added the patch titled
powerpc/64: Fix flush_(d|i)cache_range() called from modules
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
powerpc-64-fix-flush_-d-i-cache_range-called-from-modules.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 8f5f525d5b83f7d76a6baf9c4e94d4bf312ea7f6 Mon Sep 17 00:00:00 2001
From: Oliver O'Halloran <oohall@xxxxxxxxx>
Date: Mon, 3 Apr 2017 13:25:12 +1000
Subject: powerpc/64: Fix flush_(d|i)cache_range() called from modules
From: Oliver O'Halloran <oohall@xxxxxxxxx>
commit 8f5f525d5b83f7d76a6baf9c4e94d4bf312ea7f6 upstream.
When the kernel is compiled to use 64bit ABIv2 the _GLOBAL() macro does
not include a global entry point. A function's global entry point is
used when the function is called from a different TOC context and in the
kernel this typically means a call from a module into the vmlinux (or
vice-versa).
There are a few exported asm functions declared with _GLOBAL() and
calling them from a module will likely crash the kernel since any TOC
relative load will yield garbage.
flush_icache_range() and flush_dcache_range() are both exported to
modules, and use the TOC, so must use _GLOBAL_TOC().
Fixes: 721aeaa9fdf3 ("powerpc: Build little endian ppc64 kernel with ABIv2")
Signed-off-by: Oliver O'Halloran <oohall@xxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/powerpc/kernel/misc_64.S | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
--- a/arch/powerpc/kernel/misc_64.S
+++ b/arch/powerpc/kernel/misc_64.S
@@ -67,6 +67,9 @@ PPC64_CACHES:
*/
_KPROBE(flush_icache_range)
+0: addis r2,r12,(.TOC. - 0b)@ha
+ addi r2, r2,(.TOC. - 0b)@l
+ .localentry flush_icache_range, . - flush_icache_range
BEGIN_FTR_SECTION
PURGE_PREFETCHED_INS
blr
@@ -117,7 +120,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_COHERENT_I
*
* flush all bytes from start to stop-1 inclusive
*/
-_GLOBAL(flush_dcache_range)
+_GLOBAL_TOC(flush_dcache_range)
/*
* Flush the data cache to memory
Patches currently in stable-queue which might be from oohall@xxxxxxxxx are
queue-4.4/powerpc-64-fix-flush_-d-i-cache_range-called-from-modules.patch