diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S index e6d52845854f..e0bcf9354286 100644 --- a/arch/powerpc/kernel/entry_64.S +++ b/arch/powerpc/kernel/entry_64.S @@ -57,12 +57,18 @@ system_call_common: beq- 1f ld r1,PACAKSAVE(r13) 1: std r10,0(r1) - crclr so std r11,_NIP(r1) std r12,_MSR(r1) std r0,GPR0(r1) std r10,GPR1(r1) ACCOUNT_CPU_USER_ENTRY(r10, r11) + /* + * This "crclr so" clears CR0.SO, which is the error indication on + * return from this system call. There must be no cmp instruction + * between it and the "mfcr r9" below, otherwise if XER.SO is set, + * CR0.SO will get set, causing all system calls to appear to fail. + */ + crclr so std r2,GPR2(r1) std r3,GPR3(r1) std r4,GPR4(r1)