From: Oliver O'Halloran oohall@gmail.com
This patch has been added to the 4.1 stable tree. If you have any objections, please let us know.
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[ Upstream commit 8f5f525d5b83f7d76a6baf9c4e94d4bf312ea7f6 ]
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@vger.kernel.org # v3.16+ Signed-off-by: Oliver O'Halloran oohall@gmail.com Signed-off-by: Michael Ellerman mpe@ellerman.id.au Signed-off-by: Sasha Levin alexander.levin@microsoft.com --- arch/powerpc/include/asm/ppc_asm.h | 12 ++++++++++++ arch/powerpc/kernel/misc_64.S | 4 ++-- 2 files changed, 14 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/include/asm/ppc_asm.h b/arch/powerpc/include/asm/ppc_asm.h index dd0fc18d8103..160bb2311bbb 100644 --- a/arch/powerpc/include/asm/ppc_asm.h +++ b/arch/powerpc/include/asm/ppc_asm.h @@ -224,6 +224,16 @@ name: \ .globl name; \ name:
+#define _KPROBE_TOC(name) \ + .section ".kprobes.text","a"; \ + .align 2 ; \ + .type name,@function; \ + .globl name; \ +name: \ +0: addis r2,r12,(.TOC.-0b)@ha; \ + addi r2,r2,(.TOC.-0b)@l; \ + .localentry name,.-name + #define DOTSYM(a) a
#else @@ -261,6 +271,8 @@ name: \ .type GLUE(.,name),@function; \ GLUE(.,name):
+#define _KPROBE_TOC(n) _KPROBE(n) + #define DOTSYM(a) GLUE(.,a)
#endif diff --git a/arch/powerpc/kernel/misc_64.S b/arch/powerpc/kernel/misc_64.S index 4e314b90c75d..25a6f6ae729f 100644 --- 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 */
-_KPROBE(flush_icache_range) +_KPROBE_TOC(flush_icache_range) BEGIN_FTR_SECTION PURGE_PREFETCHED_INS blr @@ -116,7 +116,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_COHERENT_ICACHE) * * flush all bytes from start to stop-1 inclusive */ -_GLOBAL(flush_dcache_range) +_GLOBAL_TOC(flush_dcache_range)
/* * Flush the data cache to memory