commit 02d9f5b6acfa494e756ed8a5b373412e4240afaf
author Richard Henderson <richard.henderson@linaro.org> Fri Oct 27 22:03:08 2023 +0000
committer Richard Henderson <richard.henderson@linaro.org> Mon Oct 30 13:40:35 2023 -0700
tree cded9faa304cb8842c42439b6c8f7866f449c068
parent fd9a38fd437c4c31705071c240f4be11394ca1f8

linux-user: Fix guest signal remapping after adjusting SIGABRT

The arithmetic within the loop was not adjusted properly after SIGRTMIN
was stolen for the guest SIGABRT.  The effect was that the guest libc
could not send itself __SIGRTMIN to wake sleeping threads.

Fixes: 38ee0a7dfb4b ("linux-user: Remap guest SIGABRT")
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1967
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

linux-user/signal.c

diff --git a/linux-user/signal.c b/linux-user/signal.c
index 3b8efec..b35d1e5 100644
--- a/linux-user/signal.c
+++ b/linux-user/signal.c
@@ -536,11 +536,10 @@
     host_to_target_signal_table[SIGABRT] = 0;
     host_to_target_signal_table[hsig++] = TARGET_SIGABRT;
 
-    for (; hsig <= SIGRTMAX; hsig++) {
-        tsig = hsig - SIGRTMIN + TARGET_SIGRTMIN;
-        if (tsig <= TARGET_NSIG) {
-            host_to_target_signal_table[hsig] = tsig;
-        }
+    for (tsig = TARGET_SIGRTMIN;
+         hsig <= SIGRTMAX && tsig <= TARGET_NSIG;
+         hsig++, tsig++) {
+        host_to_target_signal_table[hsig] = tsig;
     }
 
     /* Invert the mapping that has already been assigned. */