| From | Ben Hutchings <> | Date | Sun, 16 Jul 2017 14:56:46 +0100 | Subject | [PATCH 3.16 125/178] powerpc/64: Fix flush_(d|i)cache_range() called from modules |
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3.16.46-rc1 review patch. If anyone has any objections, please let me know.
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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: Ben Hutchings <ben@decadent.org.uk> --- arch/powerpc/kernel/misc_64.S | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/arch/powerpc/kernel/misc_64.S +++ b/arch/powerpc/kernel/misc_64.S @@ -65,7 +65,7 @@ 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 @@ -117,7 +117,7 @@ _ASM_NOKPROBE_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
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