From: Helge Deller <deller@xxxxxx> commit 6e3220ba3323a2c24be834aebf5d6e9f89d0993f upstream. Fix the argument pointer (ap) to point to real-mode memory instead of virtual memory. It's interesting that this issue hasn't shown up earlier, as this could have happened with any 64-bit PDC ROM code. I just noticed it because I suddenly faced a HPMC while trying to execute the 64-bit STI ROM code of an Visualize-FXe graphics card for the STI text console. Signed-off-by: Helge Deller <deller@xxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/parisc/kernel/real2.S | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) --- a/arch/parisc/kernel/real2.S +++ b/arch/parisc/kernel/real2.S @@ -235,9 +235,6 @@ ENTRY_CFI(real64_call_asm) /* save fn */ copy %arg2, %r31 - /* set up the new ap */ - ldo 64(%arg1), %r29 - /* load up the arg registers from the saved arg area */ /* 32-bit calling convention passes first 4 args in registers */ ldd 0*REG_SZ(%arg1), %arg0 /* note overwriting arg0 */ @@ -249,7 +246,9 @@ ENTRY_CFI(real64_call_asm) ldd 7*REG_SZ(%arg1), %r19 ldd 1*REG_SZ(%arg1), %arg1 /* do this one last! */ + /* set up real-mode stack and real-mode ap */ tophys_r1 %sp + ldo -16(%sp), %r29 /* Reference param save area */ b,l rfi_virt2real,%r2 nop