We translate gUSA regions atomically in a parallel context.
But in a serial context a gUSA region may be interrupted.
In that case, restart the region as the kernel would.
Signed-off-by: Richard Henderson <r...@twiddle.net>
---
linux-user/signal.c | 23 +++++++++++++++++++++++
1 file changed, 23 insertions(+)
diff --git a/linux-user/signal.c b/linux-user/signal.c
index 3d18d1b..a537778 100644
--- a/linux-user/signal.c
+++ b/linux-user/signal.c
@@ -3471,6 +3471,25 @@ static abi_ulong get_sigframe(struct target_sigaction
*ka,
return (sp - frame_size) & -8ul;
}
+/* Notice when we're in the middle of a gUSA region and reset.
+ Note that this will only occur for !parallel_cpus, as we will
+ translate such sequences differently in a parallel context. */
+static void unwind_gusa(CPUSH4State *regs)
+{
+ /* If the stack pointer is sufficiently negative ... */
+ if ((regs->gregs[15] & 0xc0000000u) == 0xc0000000u
+ /* ... and we haven't completed the sequence ... */
+ && regs->pc < regs->gregs[0]) {
+ /* Reset the PC to before the gUSA region, as computed from
+ R0 = region end, SP = -(region size), plus one more insn
+ that actually sets SP to the region size. */
+ regs->pc = regs->gregs[0] + regs->gregs[15] - 2;
+
+ /* Reset the SP to the saved version in R1. */
+ regs->gregs[15] = regs->gregs[1];
+ }
+}
+
static void setup_sigcontext(struct target_sigcontext *sc,
CPUSH4State *regs, unsigned long mask)
{
@@ -3534,6 +3553,8 @@ static void setup_frame(int sig, struct target_sigaction
*ka,
abi_ulong frame_addr;
int i;
+ unwind_gusa(regs);
+
frame_addr = get_sigframe(ka, regs->gregs[15], sizeof(*frame));
trace_user_setup_frame(regs, frame_addr);
if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) {
@@ -3583,6 +3604,8 @@ static void setup_rt_frame(int sig, struct
target_sigaction *ka,
abi_ulong frame_addr;
int i;
+ unwind_gusa(regs);
+
frame_addr = get_sigframe(ka, regs->gregs[15], sizeof(*frame));
trace_user_setup_rt_frame(regs, frame_addr);
if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) {
--
2.9.4
