From 8cf6ecb18baac867585fe1cba5dde6dbf3b6d29a Mon Sep 17 00:00:00 2001 From: "Nysal Jan K.A." Date: Mon, 28 Apr 2025 18:49:35 +0530 Subject: [PATCH] selftests/mm: fix a build failure on powerpc The compiler is unaware of the size of code generated by the ".rept" assembler directive. This results in the compiler emitting branch instructions where the offset to branch to exceeds the maximum allowed value, resulting in build failures like the following: CC protection_keys /tmp/ccypKWAE.s: Assembler messages: /tmp/ccypKWAE.s:2073: Error: operand out of range (0x0000000000020158 is not between 0xffffffffffff8000 and 0x0000000000007ffc) /tmp/ccypKWAE.s:2509: Error: operand out of range (0x0000000000020130 is not between 0xffffffffffff8000 and 0x0000000000007ffc) Fix the issue by manually adding nop instructions using the preprocessor. Link: https://lkml.kernel.org/r/20250428131937.641989-2-nysal@linux.ibm.com Fixes: 46036188ea1f ("selftests/mm: build with -O2") Reported-by: Madhavan Srinivasan Signed-off-by: Nysal Jan K.A. Tested-by: Venkat Rao Bagalkote Reviewed-by: Donet Tom Tested-by: Donet Tom Cc: Signed-off-by: Andrew Morton --- tools/testing/selftests/mm/pkey-powerpc.h | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/mm/pkey-powerpc.h b/tools/testing/selftests/mm/pkey-powerpc.h index d8ec906b8120..17bf2d1b0192 100644 --- a/tools/testing/selftests/mm/pkey-powerpc.h +++ b/tools/testing/selftests/mm/pkey-powerpc.h @@ -104,8 +104,18 @@ static inline void expect_fault_on_read_execonly_key(void *p1, int pkey) return; } +#define REPEAT_8(s) s s s s s s s s +#define REPEAT_64(s) REPEAT_8(s) REPEAT_8(s) REPEAT_8(s) REPEAT_8(s) \ + REPEAT_8(s) REPEAT_8(s) REPEAT_8(s) REPEAT_8(s) +#define REPEAT_512(s) REPEAT_64(s) REPEAT_64(s) REPEAT_64(s) REPEAT_64(s) \ + REPEAT_64(s) REPEAT_64(s) REPEAT_64(s) REPEAT_64(s) +#define REPEAT_4096(s) REPEAT_512(s) REPEAT_512(s) REPEAT_512(s) REPEAT_512(s) \ + REPEAT_512(s) REPEAT_512(s) REPEAT_512(s) REPEAT_512(s) +#define REPEAT_16384(s) REPEAT_4096(s) REPEAT_4096(s) \ + REPEAT_4096(s) REPEAT_4096(s) + /* 4-byte instructions * 16384 = 64K page */ -#define __page_o_noops() asm(".rept 16384 ; nop; .endr") +#define __page_o_noops() asm(REPEAT_16384("nop\n")) static inline void *malloc_pkey_with_mprotect_subpage(long size, int prot, u16 pkey) {