The patch below does not apply to the 4.4-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@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>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: [PATCH] powerpc/64: Fix flush_(d|i)cache_range() called from modules
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")
Cc: stable@xxxxxxxxxxxxxxx # v3.16+
Signed-off-by: Oliver O'Halloran <oohall@xxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
diff --git a/arch/powerpc/kernel/misc_64.S b/arch/powerpc/kernel/misc_64.S
index ae179cb1bb3c..c119044cad0d 100644
--- a/arch/powerpc/kernel/misc_64.S
+++ b/arch/powerpc/kernel/misc_64.S
@@ -67,7 +67,7 @@ PPC64_CACHES:
* flush all bytes from start through stop-1 inclusive
*/
-_GLOBAL(flush_icache_range)
+_GLOBAL_TOC(flush_icache_range)
BEGIN_FTR_SECTION
PURGE_PREFETCHED_INS
blr
@@ -120,7 +120,7 @@ EXPORT_SYMBOL(flush_icache_range)
*
* flush all bytes from start to stop-1 inclusive
*/
-_GLOBAL(flush_dcache_range)
+_GLOBAL_TOC(flush_dcache_range)
/*
* Flush the data cache to memory