diff --git a/linux-user/sparc/signal.c b/linux-user/sparc/signal.c
index d796f50f66..d12adc8e6f 100644
--- a/linux-user/sparc/signal.c
+++ b/linux-user/sparc/signal.c
@@ -247,7 +247,7 @@ long do_sigreturn(CPUSPARCState *env)
 {
     abi_ulong sf_addr;
     struct target_signal_frame *sf;
-    uint32_t up_psr, pc, npc;
+    abi_ulong up_psr, pc, npc;
     target_sigset_t set;
     sigset_t host_set;
     int i;
@@ -349,10 +349,15 @@ typedef abi_ulong target_mc_greg_t;
 typedef target_mc_greg_t target_mc_gregset_t[SPARC_MC_NGREG];
 
 struct target_mc_fq {
-    abi_ulong *mcfq_addr;
+    abi_ulong mcfq_addr;
     uint32_t mcfq_insn;
 };
 
+/*
+ * Note the manual 16-alignment; the kernel gets this because it
+ * includes a "long double qregs[16]" in the mcpu_fregs union,
+ * which we can't do.
+ */
 struct target_mc_fpu {
     union {
         uint32_t sregs[32];
@@ -362,11 +367,11 @@ struct target_mc_fpu {
     abi_ulong mcfpu_fsr;
     abi_ulong mcfpu_fprs;
     abi_ulong mcfpu_gsr;
-    struct target_mc_fq *mcfpu_fq;
+    abi_ulong mcfpu_fq;
     unsigned char mcfpu_qcnt;
     unsigned char mcfpu_qentsz;
     unsigned char mcfpu_enab;
-};
+} __attribute__((aligned(16)));
 typedef struct target_mc_fpu target_mc_fpu_t;
 
 typedef struct {
@@ -377,7 +382,7 @@ typedef struct {
 } target_mcontext_t;
 
 struct target_ucontext {
-    struct target_ucontext *tuc_link;
+    abi_ulong tuc_link;
     abi_ulong tuc_flags;
     target_sigset_t tuc_sigmask;
     target_mcontext_t tuc_mcontext;
@@ -398,7 +403,6 @@ void sparc64_set_context(CPUSPARCState *env)
     struct target_ucontext *ucp;
     target_mc_gregset_t *grp;
     abi_ulong pc, npc, tstate;
-    abi_ulong fp, i7, w_addr;
     unsigned int i;
 
     ucp_addr = env->regwptr[WREG_O0];
@@ -442,6 +446,15 @@ void sparc64_set_context(CPUSPARCState *env)
     __get_user(env->gregs[5], (&(*grp)[SPARC_MC_G5]));
     __get_user(env->gregs[6], (&(*grp)[SPARC_MC_G6]));
     __get_user(env->gregs[7], (&(*grp)[SPARC_MC_G7]));
+
+    /*
+     * Note that unlike the kernel, we didn't need to mess with the
+     * guest register window state to save it into a pt_regs to run
+     * the kernel. So for us the guest's O regs are still in WREG_O*
+     * (unlike the kernel which has put them in UREG_I* in a pt_regs)
+     * and the fp and i7 are still in WREG_I6 and WREG_I7 and don't
+     * need to be written back to userspace memory.
+     */
     __get_user(env->regwptr[WREG_O0], (&(*grp)[SPARC_MC_O0]));
     __get_user(env->regwptr[WREG_O1], (&(*grp)[SPARC_MC_O1]));
     __get_user(env->regwptr[WREG_O2], (&(*grp)[SPARC_MC_O2]));
@@ -451,18 +464,9 @@ void sparc64_set_context(CPUSPARCState *env)
     __get_user(env->regwptr[WREG_O6], (&(*grp)[SPARC_MC_O6]));
     __get_user(env->regwptr[WREG_O7], (&(*grp)[SPARC_MC_O7]));
 
-    __get_user(fp, &(ucp->tuc_mcontext.mc_fp));
-    __get_user(i7, &(ucp->tuc_mcontext.mc_i7));
+    __get_user(env->regwptr[WREG_FP], &(ucp->tuc_mcontext.mc_fp));
+    __get_user(env->regwptr[WREG_I7], &(ucp->tuc_mcontext.mc_i7));
 
-    w_addr = TARGET_STACK_BIAS + env->regwptr[WREG_O6];
-    if (put_user(fp, w_addr + offsetof(struct target_reg_window, ins[6]),
-                 abi_ulong) != 0) {
-        goto do_sigsegv;
-    }
-    if (put_user(i7, w_addr + offsetof(struct target_reg_window, ins[7]),
-                 abi_ulong) != 0) {
-        goto do_sigsegv;
-    }
     /* FIXME this does not match how the kernel handles the FPU in
      * its sparc64_set_context implementation. In particular the FPU
      * is only restored if fenab is non-zero in:
@@ -496,7 +500,6 @@ void sparc64_get_context(CPUSPARCState *env)
     struct target_ucontext *ucp;
     target_mc_gregset_t *grp;
     target_mcontext_t *mcp;
-    abi_ulong fp, i7, w_addr;
     int err;
     unsigned int i;
     target_sigset_t target_set;
@@ -548,6 +551,15 @@ void sparc64_get_context(CPUSPARCState *env)
     __put_user(env->gregs[5], &((*grp)[SPARC_MC_G5]));
     __put_user(env->gregs[6], &((*grp)[SPARC_MC_G6]));
     __put_user(env->gregs[7], &((*grp)[SPARC_MC_G7]));
+
+    /*
+     * Note that unlike the kernel, we didn't need to mess with the
+     * guest register window state to save it into a pt_regs to run
+     * the kernel. So for us the guest's O regs are still in WREG_O*
+     * (unlike the kernel which has put them in UREG_I* in a pt_regs)
+     * and the fp and i7 are still in WREG_I6 and WREG_I7 and don't
+     * need to be fished out of userspace memory.
+     */
     __put_user(env->regwptr[WREG_O0], &((*grp)[SPARC_MC_O0]));
     __put_user(env->regwptr[WREG_O1], &((*grp)[SPARC_MC_O1]));
     __put_user(env->regwptr[WREG_O2], &((*grp)[SPARC_MC_O2]));
@@ -557,18 +569,8 @@ void sparc64_get_context(CPUSPARCState *env)
     __put_user(env->regwptr[WREG_O6], &((*grp)[SPARC_MC_O6]));
     __put_user(env->regwptr[WREG_O7], &((*grp)[SPARC_MC_O7]));
 
-    w_addr = TARGET_STACK_BIAS + env->regwptr[WREG_O6];
-    fp = i7 = 0;
-    if (get_user(fp, w_addr + offsetof(struct target_reg_window, ins[6]),
-                 abi_ulong) != 0) {
-        goto do_sigsegv;
-    }
-    if (get_user(i7, w_addr + offsetof(struct target_reg_window, ins[7]),
-                 abi_ulong) != 0) {
-        goto do_sigsegv;
-    }
-    __put_user(fp, &(mcp->mc_fp));
-    __put_user(i7, &(mcp->mc_i7));
+    __put_user(env->regwptr[WREG_FP], &(mcp->mc_fp));
+    __put_user(env->regwptr[WREG_I7], &(mcp->mc_i7));
 
     {
         uint32_t *dst = ucp->tuc_mcontext.mc_fpregs.mcfpu_fregs.sregs;