Commit f2025a1d authored May 03, 2023 by Helge Deller Committed by Greg Kroah-Hartman May 17, 2023

parisc: Fix argument pointer in real64_call_asm()



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@gmx.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 78728cd5

arch/parisc/kernel/real2.S

+2 −3

Original line number	Diff line number	Diff line
		@@ -248,9 +248,6 @@ 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 0REG_SZ(%arg1), %arg0 / note overwriting arg0 */
		@@ -262,7 +259,9 @@ ENTRY_CFI(real64_call_asm)
		ldd 7*REG_SZ(%arg1), %r19
		ldd 1REG_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