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authorPeter Maydell <peter.maydell@linaro.org>2019-07-25 14:16:45 +0100
committerLaurent Vivier <laurent@vivier.eu>2019-07-26 19:24:33 +0200
commit5bfce0b74fbd5d53089bb866919d685c47edad9e (patch)
tree7b352053272100d776034988ef56d2241afba8db /linux-user/signal-common.h
parentfff3159900d2b95613a9cb75fc3703e67a674729 (diff)
linux-user: Make sigaltstack stacks per-thread
The alternate signal stack set up by the sigaltstack syscall is supposed to be per-thread. We were incorrectly implementing it as process-wide. This causes problems for guest binaries that rely on this. Notably the Go runtime does, and so we were seeing crashes caused by races where two guest threads might incorrectly both execute on the same stack simultaneously. Replace the global target_sigaltstack_used with a field sigaltstack_used in the TaskState, and make all the references to the old global instead get a pointer to the TaskState and use the field. Fixes: https://bugs.launchpad.net/qemu/+bug/1696773 Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Tested-by: Laurent Vivier <laurent@vivier.eu> Reviewed-by: Laurent Vivier <laurent@vivier.eu> Message-Id: <20190725131645.19501-1-peter.maydell@linaro.org> Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Diffstat (limited to 'linux-user/signal-common.h')
-rw-r--r--linux-user/signal-common.h1
1 files changed, 0 insertions, 1 deletions
diff --git a/linux-user/signal-common.h b/linux-user/signal-common.h
index 51030a9306..1df1068552 100644
--- a/linux-user/signal-common.h
+++ b/linux-user/signal-common.h
@@ -19,7 +19,6 @@
#ifndef SIGNAL_COMMON_H
#define SIGNAL_COMMON_H
-extern struct target_sigaltstack target_sigaltstack_used;
int on_sig_stack(unsigned long sp);
int sas_ss_flags(unsigned long sp);