s390: add support for vector extension
The vector extension introduces 32 128-bit vector registers and a set of
instruction to operate on the vector registers.
The kernel can control the use of vector registers for the problem state
program with a bit in control register 0. Once enabled for a process the
kernel needs to retain the content of the vector registers on context
switch. The signal frame is extended to include the vector registers.
Two new register sets NT_S390_VXRS_LOW and NT_S390_VXRS_HIGH are added
to the regset interface for the debugger and core dumps.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/kernel/signal.c b/arch/s390/kernel/signal.c
index 469c4c6..0c1a0ff 100644
--- a/arch/s390/kernel/signal.c
+++ b/arch/s390/kernel/signal.c
@@ -31,30 +31,117 @@
#include <asm/switch_to.h>
#include "entry.h"
-typedef struct
+/*
+ * Layout of an old-style signal-frame:
+ * -----------------------------------------
+ * | save area (_SIGNAL_FRAMESIZE) |
+ * -----------------------------------------
+ * | struct sigcontext |
+ * | oldmask |
+ * | _sigregs * |
+ * -----------------------------------------
+ * | _sigregs with |
+ * | _s390_regs_common |
+ * | _s390_fp_regs |
+ * -----------------------------------------
+ * | int signo |
+ * -----------------------------------------
+ * | _sigregs_ext with |
+ * | gprs_high 64 byte (opt) |
+ * | vxrs_low 128 byte (opt) |
+ * | vxrs_high 256 byte (opt) |
+ * | reserved 128 byte (opt) |
+ * -----------------------------------------
+ * | __u16 svc_insn |
+ * -----------------------------------------
+ * The svc_insn entry with the sigreturn system call opcode does not
+ * have a fixed position and moves if gprs_high or vxrs exist.
+ * Future extensions will be added to _sigregs_ext.
+ */
+struct sigframe
{
__u8 callee_used_stack[__SIGNAL_FRAMESIZE];
struct sigcontext sc;
_sigregs sregs;
int signo;
- __u8 retcode[S390_SYSCALL_SIZE];
-} sigframe;
+ _sigregs_ext sregs_ext;
+ __u16 svc_insn; /* Offset of svc_insn is NOT fixed! */
+};
-typedef struct
+/*
+ * Layout of an rt signal-frame:
+ * -----------------------------------------
+ * | save area (_SIGNAL_FRAMESIZE) |
+ * -----------------------------------------
+ * | svc __NR_rt_sigreturn 2 byte |
+ * -----------------------------------------
+ * | struct siginfo |
+ * -----------------------------------------
+ * | struct ucontext_extended with |
+ * | unsigned long uc_flags |
+ * | struct ucontext *uc_link |
+ * | stack_t uc_stack |
+ * | _sigregs uc_mcontext with |
+ * | _s390_regs_common |
+ * | _s390_fp_regs |
+ * | sigset_t uc_sigmask |
+ * | _sigregs_ext uc_mcontext_ext |
+ * | gprs_high 64 byte (opt) |
+ * | vxrs_low 128 byte (opt) |
+ * | vxrs_high 256 byte (opt)|
+ * | reserved 128 byte (opt) |
+ * -----------------------------------------
+ * Future extensions will be added to _sigregs_ext.
+ */
+struct rt_sigframe
{
__u8 callee_used_stack[__SIGNAL_FRAMESIZE];
- __u8 retcode[S390_SYSCALL_SIZE];
+ __u16 svc_insn;
struct siginfo info;
- struct ucontext uc;
-} rt_sigframe;
+ struct ucontext_extended uc;
+};
+
+/* Store registers needed to create the signal frame */
+static void store_sigregs(void)
+{
+ save_access_regs(current->thread.acrs);
+ save_fp_ctl(¤t->thread.fp_regs.fpc);
+#ifdef CONFIG_64BIT
+ if (current->thread.vxrs) {
+ int i;
+
+ save_vx_regs(current->thread.vxrs);
+ for (i = 0; i < __NUM_FPRS; i++)
+ current->thread.fp_regs.fprs[i] =
+ *(freg_t *)(current->thread.vxrs + i);
+ } else
+#endif
+ save_fp_regs(current->thread.fp_regs.fprs);
+}
+
+/* Load registers after signal return */
+static void load_sigregs(void)
+{
+ restore_access_regs(current->thread.acrs);
+ /* restore_fp_ctl is done in restore_sigregs */
+#ifdef CONFIG_64BIT
+ if (current->thread.vxrs) {
+ int i;
+
+ for (i = 0; i < __NUM_FPRS; i++)
+ *(freg_t *)(current->thread.vxrs + i) =
+ current->thread.fp_regs.fprs[i];
+ restore_vx_regs(current->thread.vxrs);
+ } else
+#endif
+ restore_fp_regs(current->thread.fp_regs.fprs);
+}
/* Returns non-zero on fault. */
static int save_sigregs(struct pt_regs *regs, _sigregs __user *sregs)
{
_sigregs user_sregs;
- save_access_regs(current->thread.acrs);
-
/* Copy a 'clean' PSW mask to the user to avoid leaking
information about whether PER is currently on. */
user_sregs.regs.psw.mask = PSW_USER_BITS |
@@ -63,12 +150,6 @@
memcpy(&user_sregs.regs.gprs, ®s->gprs, sizeof(sregs->regs.gprs));
memcpy(&user_sregs.regs.acrs, current->thread.acrs,
sizeof(user_sregs.regs.acrs));
- /*
- * We have to store the fp registers to current->thread.fp_regs
- * to merge them with the emulated registers.
- */
- save_fp_ctl(¤t->thread.fp_regs.fpc);
- save_fp_regs(current->thread.fp_regs.fprs);
memcpy(&user_sregs.fpregs, ¤t->thread.fp_regs,
sizeof(user_sregs.fpregs));
if (__copy_to_user(sregs, &user_sregs, sizeof(_sigregs)))
@@ -107,20 +188,64 @@
memcpy(®s->gprs, &user_sregs.regs.gprs, sizeof(sregs->regs.gprs));
memcpy(¤t->thread.acrs, &user_sregs.regs.acrs,
sizeof(current->thread.acrs));
- restore_access_regs(current->thread.acrs);
memcpy(¤t->thread.fp_regs, &user_sregs.fpregs,
sizeof(current->thread.fp_regs));
- restore_fp_regs(current->thread.fp_regs.fprs);
clear_pt_regs_flag(regs, PIF_SYSCALL); /* No longer in a system call */
return 0;
}
+/* Returns non-zero on fault. */
+static int save_sigregs_ext(struct pt_regs *regs,
+ _sigregs_ext __user *sregs_ext)
+{
+#ifdef CONFIG_64BIT
+ __u64 vxrs[__NUM_VXRS_LOW];
+ int i;
+
+ /* Save vector registers to signal stack */
+ if (current->thread.vxrs) {
+ for (i = 0; i < __NUM_VXRS_LOW; i++)
+ vxrs[i] = *((__u64 *)(current->thread.vxrs + i) + 1);
+ if (__copy_to_user(&sregs_ext->vxrs_low, vxrs,
+ sizeof(sregs_ext->vxrs_low)) ||
+ __copy_to_user(&sregs_ext->vxrs_high,
+ current->thread.vxrs + __NUM_VXRS_LOW,
+ sizeof(sregs_ext->vxrs_high)))
+ return -EFAULT;
+ }
+#endif
+ return 0;
+}
+
+static int restore_sigregs_ext(struct pt_regs *regs,
+ _sigregs_ext __user *sregs_ext)
+{
+#ifdef CONFIG_64BIT
+ __u64 vxrs[__NUM_VXRS_LOW];
+ int i;
+
+ /* Restore vector registers from signal stack */
+ if (current->thread.vxrs) {
+ if (__copy_from_user(vxrs, &sregs_ext->vxrs_low,
+ sizeof(sregs_ext->vxrs_low)) ||
+ __copy_from_user(current->thread.vxrs + __NUM_VXRS_LOW,
+ &sregs_ext->vxrs_high,
+ sizeof(sregs_ext->vxrs_high)))
+ return -EFAULT;
+ for (i = 0; i < __NUM_VXRS_LOW; i++)
+ *((__u64 *)(current->thread.vxrs + i) + 1) = vxrs[i];
+ }
+#endif
+ return 0;
+}
+
SYSCALL_DEFINE0(sigreturn)
{
struct pt_regs *regs = task_pt_regs(current);
- sigframe __user *frame = (sigframe __user *)regs->gprs[15];
+ struct sigframe __user *frame =
+ (struct sigframe __user *) regs->gprs[15];
sigset_t set;
if (__copy_from_user(&set.sig, &frame->sc.oldmask, _SIGMASK_COPY_SIZE))
@@ -128,6 +253,9 @@
set_current_blocked(&set);
if (restore_sigregs(regs, &frame->sregs))
goto badframe;
+ if (restore_sigregs_ext(regs, &frame->sregs_ext))
+ goto badframe;
+ load_sigregs();
return regs->gprs[2];
badframe:
force_sig(SIGSEGV, current);
@@ -137,16 +265,20 @@
SYSCALL_DEFINE0(rt_sigreturn)
{
struct pt_regs *regs = task_pt_regs(current);
- rt_sigframe __user *frame = (rt_sigframe __user *)regs->gprs[15];
+ struct rt_sigframe __user *frame =
+ (struct rt_sigframe __user *)regs->gprs[15];
sigset_t set;
if (__copy_from_user(&set.sig, &frame->uc.uc_sigmask, sizeof(set)))
goto badframe;
set_current_blocked(&set);
- if (restore_sigregs(regs, &frame->uc.uc_mcontext))
- goto badframe;
if (restore_altstack(&frame->uc.uc_stack))
goto badframe;
+ if (restore_sigregs(regs, &frame->uc.uc_mcontext))
+ goto badframe;
+ if (restore_sigregs_ext(regs, &frame->uc.uc_mcontext_ext))
+ goto badframe;
+ load_sigregs();
return regs->gprs[2];
badframe:
force_sig(SIGSEGV, current);
@@ -154,11 +286,6 @@
}
/*
- * Set up a signal frame.
- */
-
-
-/*
* Determine which stack to use..
*/
static inline void __user *
@@ -195,39 +322,63 @@
static int setup_frame(int sig, struct k_sigaction *ka,
sigset_t *set, struct pt_regs * regs)
{
- sigframe __user *frame;
+ struct sigframe __user *frame;
+ struct sigcontext sc;
+ unsigned long restorer;
+ size_t frame_size;
- frame = get_sigframe(ka, regs, sizeof(sigframe));
-
+ /*
+ * gprs_high are only present for a 31-bit task running on
+ * a 64-bit kernel (see compat_signal.c) but the space for
+ * gprs_high need to be allocated if vector registers are
+ * included in the signal frame on a 31-bit system.
+ */
+ frame_size = sizeof(*frame) - sizeof(frame->sregs_ext);
+ if (MACHINE_HAS_VX)
+ frame_size += sizeof(frame->sregs_ext);
+ frame = get_sigframe(ka, regs, frame_size);
if (frame == (void __user *) -1UL)
return -EFAULT;
- if (__copy_to_user(&frame->sc.oldmask, &set->sig, _SIGMASK_COPY_SIZE))
- return -EFAULT;
-
- if (save_sigregs(regs, &frame->sregs))
- return -EFAULT;
- if (__put_user(&frame->sregs, &frame->sc.sregs))
- return -EFAULT;
-
- /* Set up to return from userspace. If provided, use a stub
- already in userspace. */
- if (ka->sa.sa_flags & SA_RESTORER) {
- regs->gprs[14] = (unsigned long)
- ka->sa.sa_restorer | PSW_ADDR_AMODE;
- } else {
- regs->gprs[14] = (unsigned long)
- frame->retcode | PSW_ADDR_AMODE;
- if (__put_user(S390_SYSCALL_OPCODE | __NR_sigreturn,
- (u16 __user *)(frame->retcode)))
- return -EFAULT;
- }
-
/* Set up backchain. */
if (__put_user(regs->gprs[15], (addr_t __user *) frame))
return -EFAULT;
+ /* Create struct sigcontext on the signal stack */
+ memcpy(&sc.oldmask, &set->sig, _SIGMASK_COPY_SIZE);
+ sc.sregs = (_sigregs __user __force *) &frame->sregs;
+ if (__copy_to_user(&frame->sc, &sc, sizeof(frame->sc)))
+ return -EFAULT;
+
+ /* Store registers needed to create the signal frame */
+ store_sigregs();
+
+ /* Create _sigregs on the signal stack */
+ if (save_sigregs(regs, &frame->sregs))
+ return -EFAULT;
+
+ /* Place signal number on stack to allow backtrace from handler. */
+ if (__put_user(regs->gprs[2], (int __user *) &frame->signo))
+ return -EFAULT;
+
+ /* Create _sigregs_ext on the signal stack */
+ if (save_sigregs_ext(regs, &frame->sregs_ext))
+ return -EFAULT;
+
+ /* Set up to return from userspace. If provided, use a stub
+ already in userspace. */
+ if (ka->sa.sa_flags & SA_RESTORER) {
+ restorer = (unsigned long) ka->sa.sa_restorer | PSW_ADDR_AMODE;
+ } else {
+ /* Signal frame without vector registers are short ! */
+ __u16 __user *svc = (void *) frame + frame_size - 2;
+ if (__put_user(S390_SYSCALL_OPCODE | __NR_sigreturn, svc))
+ return -EFAULT;
+ restorer = (unsigned long) svc | PSW_ADDR_AMODE;
+ }
+
/* Set up registers for signal handler */
+ regs->gprs[14] = restorer;
regs->gprs[15] = (unsigned long) frame;
/* Force default amode and default user address space control. */
regs->psw.mask = PSW_MASK_EA | PSW_MASK_BA |
@@ -247,54 +398,69 @@
regs->gprs[5] = regs->int_parm_long;
regs->gprs[6] = task_thread_info(current)->last_break;
}
-
- /* Place signal number on stack to allow backtrace from handler. */
- if (__put_user(regs->gprs[2], (int __user *) &frame->signo))
- return -EFAULT;
return 0;
}
static int setup_rt_frame(struct ksignal *ksig, sigset_t *set,
struct pt_regs *regs)
{
- int err = 0;
- rt_sigframe __user *frame;
+ struct rt_sigframe __user *frame;
+ unsigned long uc_flags, restorer;
+ size_t frame_size;
- frame = get_sigframe(&ksig->ka, regs, sizeof(rt_sigframe));
-
+ frame_size = sizeof(struct rt_sigframe) - sizeof(_sigregs_ext);
+ /*
+ * gprs_high are only present for a 31-bit task running on
+ * a 64-bit kernel (see compat_signal.c) but the space for
+ * gprs_high need to be allocated if vector registers are
+ * included in the signal frame on a 31-bit system.
+ */
+ uc_flags = 0;
+#ifdef CONFIG_64BIT
+ if (MACHINE_HAS_VX) {
+ frame_size += sizeof(_sigregs_ext);
+ if (current->thread.vxrs)
+ uc_flags |= UC_VXRS;
+ }
+#endif
+ frame = get_sigframe(&ksig->ka, regs, frame_size);
if (frame == (void __user *) -1UL)
return -EFAULT;
- if (copy_siginfo_to_user(&frame->info, &ksig->info))
- return -EFAULT;
-
- /* Create the ucontext. */
- err |= __put_user(0, &frame->uc.uc_flags);
- err |= __put_user(NULL, &frame->uc.uc_link);
- err |= __save_altstack(&frame->uc.uc_stack, regs->gprs[15]);
- err |= save_sigregs(regs, &frame->uc.uc_mcontext);
- err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
- if (err)
- return -EFAULT;
-
- /* Set up to return from userspace. If provided, use a stub
- already in userspace. */
- if (ksig->ka.sa.sa_flags & SA_RESTORER) {
- regs->gprs[14] = (unsigned long)
- ksig->ka.sa.sa_restorer | PSW_ADDR_AMODE;
- } else {
- regs->gprs[14] = (unsigned long)
- frame->retcode | PSW_ADDR_AMODE;
- if (__put_user(S390_SYSCALL_OPCODE | __NR_rt_sigreturn,
- (u16 __user *)(frame->retcode)))
- return -EFAULT;
- }
-
/* Set up backchain. */
if (__put_user(regs->gprs[15], (addr_t __user *) frame))
return -EFAULT;
+ /* Set up to return from userspace. If provided, use a stub
+ already in userspace. */
+ if (ksig->ka.sa.sa_flags & SA_RESTORER) {
+ restorer = (unsigned long)
+ ksig->ka.sa.sa_restorer | PSW_ADDR_AMODE;
+ } else {
+ __u16 __user *svc = &frame->svc_insn;
+ if (__put_user(S390_SYSCALL_OPCODE | __NR_rt_sigreturn, svc))
+ return -EFAULT;
+ restorer = (unsigned long) svc | PSW_ADDR_AMODE;
+ }
+
+ /* Create siginfo on the signal stack */
+ if (copy_siginfo_to_user(&frame->info, &ksig->info))
+ return -EFAULT;
+
+ /* Store registers needed to create the signal frame */
+ store_sigregs();
+
+ /* Create ucontext on the signal stack. */
+ if (__put_user(uc_flags, &frame->uc.uc_flags) ||
+ __put_user(NULL, &frame->uc.uc_link) ||
+ __save_altstack(&frame->uc.uc_stack, regs->gprs[15]) ||
+ save_sigregs(regs, &frame->uc.uc_mcontext) ||
+ __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)) ||
+ save_sigregs_ext(regs, &frame->uc.uc_mcontext_ext))
+ return -EFAULT;
+
/* Set up registers for signal handler */
+ regs->gprs[14] = restorer;
regs->gprs[15] = (unsigned long) frame;
/* Force default amode and default user address space control. */
regs->psw.mask = PSW_MASK_EA | PSW_MASK_BA |