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authorMark Cave-Ayland <mark.cave-ayland@ilande.co.uk>2016-04-09 12:25:12 +0100
committerMark Cave-Ayland <mark.cave-ayland@ilande.co.uk>2016-04-11 16:25:07 +0100
commit4553e10360a0713e31647220ed396942f9a6fca0 (patch)
treec7e45993f99ac463c921b27a6ff984bdde26e700
parentdc1ffa66619b3661f17a309b0aa8d65d8d29583f (diff)
target-sparc: fix ldstub sign-extension bug
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-ayland@ilande.co.uk> Reviewed-By: Artyom Tarasenko <atar4qemu@gmail.com> Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
-rw-r--r--target-sparc/translate.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/target-sparc/translate.c b/target-sparc/translate.c
index 58572c34cf..7998ff57bf 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);