Commit 8f5f525d authored Apr 03, 2017 by Oliver O'Halloran Committed by Michael Ellerman Apr 05, 2017

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: 721aeaa9 ("powerpc: Build little endian ppc64 kernel with ABIv2")
Cc: stable@vger.kernel.org # v3.16+
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

parent 48fe9e94

arch/powerpc/kernel/misc_64.S

+2 −2

Original line number	Diff line number	Diff line
		@@ -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