svn commit: r367760 - head/sys/powerpc/powerpc

[Alfredo Dal'Ava Junior]

Author: alfredo
Date: Tue Nov 17 12:33:12 2020
New Revision: 367760
URL: https://svnweb.freebsd.org/changeset/base/367760

Log:
  [POWERPC] fix signal race condition
  
  r367416 should have called save_fpu() before kern_sigprocmask to avoid
  race condition
  
  Thanks jhibbits and bdragon for pointing it out
  
  Reviewed by:	jhibbits
  Sponsored by:	Eldorado Research Institute (eldorado.org.br)
  Differential Revision:	https://reviews.freebsd.org/D27241

Modified:
  head/sys/powerpc/powerpc/exec_machdep.c

Modified: head/sys/powerpc/powerpc/exec_machdep.c
==============================================================================
--- head/sys/powerpc/powerpc/exec_machdep.c	Tue Nov 17 12:04:29 2020	(r367759)
+++ head/sys/powerpc/powerpc/exec_machdep.c	Tue Nov 17 12:33:12 2020	(r367760)
@@ -334,8 +334,6 @@ sys_sigreturn(struct thread *td, struct sigreturn_args
 	if (error != 0)
 		return (error);
 
-	kern_sigprocmask(td, SIG_SETMASK, &uc.uc_sigmask, NULL, 0);
-
 	/* 
 	 * Save FPU state if needed. User may have changed it on
 	 * signal handler 
@@ -343,6 +341,8 @@ sys_sigreturn(struct thread *td, struct sigreturn_args
 	if (uc.uc_mcontext.mc_srr1 & PSL_FP)
 		save_fpu(td);
 
+	kern_sigprocmask(td, SIG_SETMASK, &uc.uc_sigmask, NULL, 0);
+
 	CTR3(KTR_SIG, "sigreturn: return td=%p pc=%#x sp=%#x",
 	     td, uc.uc_mcontext.mc_srr0, uc.uc_mcontext.mc_gpr[1]);
 
@@ -836,8 +836,6 @@ freebsd32_sigreturn(struct thread *td, struct freebsd3
 	if (error != 0)
 		return (error);
 
-	kern_sigprocmask(td, SIG_SETMASK, &uc.uc_sigmask, NULL, 0);
-
 	/*
 	 * Save FPU state if needed. User may have changed it on
 	 * signal handler
@@ -845,6 +843,7 @@ freebsd32_sigreturn(struct thread *td, struct freebsd3
 	if (uc.uc_mcontext.mc_srr1 & PSL_FP)
 		save_fpu(td);
 
+	kern_sigprocmask(td, SIG_SETMASK, &uc.uc_sigmask, NULL, 0);
 
 	CTR3(KTR_SIG, "sigreturn: return td=%p pc=%#x sp=%#x",
 	     td, uc.uc_mcontext.mc_srr0, uc.uc_mcontext.mc_gpr[1]);