Commit 8cf6ecb1 authored by Nysal Jan K.A.'s avatar Nysal Jan K.A. Committed by Andrew Morton
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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: 46036188 ("selftests/mm: build with -O2")
Reported-by: default avatarMadhavan Srinivasan <maddy@linux.ibm.com>
Signed-off-by: default avatarNysal Jan K.A. <nysal@linux.ibm.com>
Tested-by: default avatarVenkat Rao Bagalkote <venkat88@linux.ibm.com>
Reviewed-by: default avatarDonet Tom <donettom@linux.ibm.com>
Tested-by: default avatarDonet Tom <donettom@linux.ibm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 22adb528

tools/testing/selftests/mm/pkey-powerpc.h

+11 −1
Original line number Diff line number Diff line
@@ -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)

{