Patch "powerpc/64: Fix flush_(d|i)cache_range() called from modules" has been added to the 3.18-stable tree

Patch "powerpc/64: Fix flush_(d|i)cache_range() called from modules" has been added to the 3.18-stable tree

[gregkh]

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 3.18-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-3.18 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 8f5f525d5b83f7d76a6baf9c4e94d4bf312ea7f6 Mon Sep 17 00:00:00 2001
From: Oliver O'Halloran <oohall@gmail.com>
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@gmail.com>

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@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


---
 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
@@ -66,6 +66,9 @@ 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
@@ -116,7 +119,7 @@ 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@gmail.com are

queue-3.18/powerpc-64-fix-flush_-d-i-cache_range-called-from-modules.patch