ldstub [addr], reg incorrectly reads a signed byte from memory which causes
problems in the 32-bit Solaris mutex code. Here the byte value being read is
0xff which is incorrectly sign-extended to 0xffffffff before being written back
to the target register causing lock detection to behave incorrectly.
This fixes the intermittent hangs and MUTEX_HELD warnings issued to the
console when running 32-bit Solaris images under qemu-system-sparc.
With thanks to Joseph Dery for providing a condensed test image to consistently
reproduce the problem on demand, and Martin Husemann for allowing me access to
real hardware for comparison.
Signed-off-by: Mark Cave-Ayland <mark.cave-ayl...@ilande.co.uk>
---
target-sparc/translate.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/target-sparc/translate.c b/target-sparc/translate.c
index 58572c3..7998ff5 100644
--- a/target-sparc/translate.c
+++ b/target-sparc/translate.c
@@ -4670,7 +4670,7 @@ static void disas_sparc_insn(DisasContext * dc, unsigned
int insn)
TCGv r_const;
gen_address_mask(dc, cpu_addr);
- tcg_gen_qemu_ld8s(cpu_val, cpu_addr, dc->mem_idx);
+ tcg_gen_qemu_ld8u(cpu_val, cpu_addr, dc->mem_idx);
r_const = tcg_const_tl(0xff);
tcg_gen_qemu_st8(r_const, cpu_addr, dc->mem_idx);
tcg_temp_free(r_const);
--
1.7.10.4
