Fix two and a half oversights in COMPAT_FREEBSD32 related to contexts and

TLS:
o) The mc_tls field used to store the TLS base when doing context gets and
   restores was left a pointer and not converted to a 32-bit integer.  This
   had the bug of not correctly capturing the TLS value desired by the user,
   and the extra nastiness of making the structure the wrong size.
o) The mc_tls field was not being saved by sendsig.  As a result, the TLS base
   would always be set to NULL when restoring from a signal handler.

Thanks to gonzo for helping track down a bunch of other TLS bugs that came out
of tracking these down.

2 files changed, 4 insertions, 3 deletions

diff --git a/sys/mips/include/ucontext.h b/sys/mips/include/ucontext.h
index aafd1dc..a37fe7e 100644
--- a/sys/mips/include/ucontext.h
+++ b/sys/mips/include/ucontext.h
@@ -73,7 +73,7 @@ typedef struct __mcontext32 {
 	int		mc_fpused;
 	int32_t		mc_fpregs[33];
 	int32_t		mc_fpc_eir;
-	void		*mc_tls;
+	int32_t		mc_tls;
 	int		__spare__[8];
 } mcontext32_t;
 
diff --git a/sys/mips/mips/freebsd32_machdep.c b/sys/mips/mips/freebsd32_machdep.c
index 3fe8991..2fc4afe 100644
--- a/sys/mips/mips/freebsd32_machdep.c
+++ b/sys/mips/mips/freebsd32_machdep.c
@@ -222,7 +222,7 @@ get_mcontext32(struct thread *td, mcontext32_t *mcp, int flags)
 	for (i = 0; i < 33; i++)
 		mcp->mc_fpregs[i] = mcp64.mc_fpregs[i];
 	mcp->mc_fpc_eir = mcp64.mc_fpc_eir;
-	mcp->mc_tls = mcp64.mc_tls;
+	mcp->mc_tls = (int32_t)(intptr_t)mcp64.mc_tls;
 
 	return (0);
 }
@@ -244,7 +244,7 @@ set_mcontext32(struct thread *td, const mcontext32_t *mcp)
 	for (i = 0; i < 33; i++)
 		mcp64.mc_fpregs[i] = mcp->mc_fpregs[i];
 	mcp64.mc_fpc_eir = mcp->mc_fpc_eir;
-	mcp64.mc_tls = mcp->mc_tls;
+	mcp64.mc_tls = (void *)(intptr_t)mcp->mc_tls;
 
 	return (set_mcontext(td, &mcp64));
 }
@@ -395,6 +395,7 @@ freebsd32_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
 	sf.sf_uc.uc_mcontext.mc_pc = regs.r_regs[PC];
 	sf.sf_uc.uc_mcontext.mullo = regs.r_regs[MULLO];
 	sf.sf_uc.uc_mcontext.mulhi = regs.r_regs[MULHI];
+	sf.sf_uc.uc_mcontext.mc_tls = (int32_t)(intptr_t)td->td_md.md_tls;
 	sf.sf_uc.uc_mcontext.mc_regs[0] = UCONTEXT_MAGIC;  /* magic number */
 	for (i = 1; i < 32; i++)
 		sf.sf_uc.uc_mcontext.mc_regs[i] = regs.r_regs[i];