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Diffstat (limited to 'arch/mips/kernel/signal.c')
-rw-r--r--arch/mips/kernel/signal.c433
1 files changed, 340 insertions, 93 deletions
diff --git a/arch/mips/kernel/signal.c b/arch/mips/kernel/signal.c
index 6a28c792d862..2fec67bfc457 100644
--- a/arch/mips/kernel/signal.c
+++ b/arch/mips/kernel/signal.c
@@ -21,6 +21,7 @@
#include <linux/wait.h>
#include <linux/ptrace.h>
#include <linux/unistd.h>
+#include <linux/uprobes.h>
#include <linux/compiler.h>
#include <linux/syscalls.h>
#include <linux/uaccess.h>
@@ -38,20 +39,21 @@
#include <asm/vdso.h>
#include <asm/dsp.h>
#include <asm/inst.h>
+#include <asm/msa.h>
#include "signal-common.h"
-static int (*save_fp_context)(struct sigcontext __user *sc);
-static int (*restore_fp_context)(struct sigcontext __user *sc);
-
-extern asmlinkage int _save_fp_context(struct sigcontext __user *sc);
-extern asmlinkage int _restore_fp_context(struct sigcontext __user *sc);
+static int (*save_fp_context)(void __user *sc);
+static int (*restore_fp_context)(void __user *sc);
struct sigframe {
u32 sf_ass[4]; /* argument save space for o32 */
u32 sf_pad[2]; /* Was: signal trampoline */
+
+ /* Matches struct ucontext from its uc_mcontext field onwards */
struct sigcontext sf_sc;
sigset_t sf_mask;
+ unsigned long long sf_extcontext[0];
};
struct rt_sigframe {
@@ -65,43 +67,255 @@ struct rt_sigframe {
* Thread saved context copy to/from a signal context presumed to be on the
* user stack, and therefore accessed with appropriate macros from uaccess.h.
*/
-static int copy_fp_to_sigcontext(struct sigcontext __user *sc)
+static int copy_fp_to_sigcontext(void __user *sc)
{
+ struct mips_abi *abi = current->thread.abi;
+ uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
+ uint32_t __user *csr = sc + abi->off_sc_fpc_csr;
int i;
int err = 0;
+ int inc = test_thread_flag(TIF_32BIT_FPREGS) ? 2 : 1;
- for (i = 0; i < NUM_FPU_REGS; i++) {
+ for (i = 0; i < NUM_FPU_REGS; i += inc) {
err |=
__put_user(get_fpr64(&current->thread.fpu.fpr[i], 0),
- &sc->sc_fpregs[i]);
+ &fpregs[i]);
}
- err |= __put_user(current->thread.fpu.fcr31, &sc->sc_fpc_csr);
+ err |= __put_user(current->thread.fpu.fcr31, csr);
return err;
}
-static int copy_fp_from_sigcontext(struct sigcontext __user *sc)
+static int copy_fp_from_sigcontext(void __user *sc)
{
+ struct mips_abi *abi = current->thread.abi;
+ uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
+ uint32_t __user *csr = sc + abi->off_sc_fpc_csr;
int i;
int err = 0;
+ int inc = test_thread_flag(TIF_32BIT_FPREGS) ? 2 : 1;
u64 fpr_val;
- for (i = 0; i < NUM_FPU_REGS; i++) {
- err |= __get_user(fpr_val, &sc->sc_fpregs[i]);
+ for (i = 0; i < NUM_FPU_REGS; i += inc) {
+ err |= __get_user(fpr_val, &fpregs[i]);
set_fpr64(&current->thread.fpu.fpr[i], 0, fpr_val);
}
- err |= __get_user(current->thread.fpu.fcr31, &sc->sc_fpc_csr);
+ err |= __get_user(current->thread.fpu.fcr31, csr);
return err;
}
/*
+ * Wrappers for the assembly _{save,restore}_fp_context functions.
+ */
+static int save_hw_fp_context(void __user *sc)
+{
+ struct mips_abi *abi = current->thread.abi;
+ uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
+ uint32_t __user *csr = sc + abi->off_sc_fpc_csr;
+
+ return _save_fp_context(fpregs, csr);
+}
+
+static int restore_hw_fp_context(void __user *sc)
+{
+ struct mips_abi *abi = current->thread.abi;
+ uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
+ uint32_t __user *csr = sc + abi->off_sc_fpc_csr;
+
+ return _restore_fp_context(fpregs, csr);
+}
+
+/*
+ * Extended context handling.
+ */
+
+static inline void __user *sc_to_extcontext(void __user *sc)
+{
+ struct ucontext __user *uc;
+
+ /*
+ * We can just pretend the sigcontext is always embedded in a struct
+ * ucontext here, because the offset from sigcontext to extended
+ * context is the same in the struct sigframe case.
+ */
+ uc = container_of(sc, struct ucontext, uc_mcontext);
+ return &uc->uc_extcontext;
+}
+
+static int save_msa_extcontext(void __user *buf)
+{
+ struct msa_extcontext __user *msa = buf;
+ uint64_t val;
+ int i, err;
+
+ if (!thread_msa_context_live())
+ return 0;
+
+ /*
+ * Ensure that we can't lose the live MSA context between checking
+ * for it & writing it to memory.
+ */
+ preempt_disable();
+
+ if (is_msa_enabled()) {
+ /*
+ * There are no EVA versions of the vector register load/store
+ * instructions, so MSA context has to be saved to kernel memory
+ * and then copied to user memory. The save to kernel memory
+ * should already have been done when handling scalar FP
+ * context.
+ */
+ BUG_ON(config_enabled(CONFIG_EVA));
+
+ err = __put_user(read_msa_csr(), &msa->csr);
+ err |= _save_msa_all_upper(&msa->wr);
+
+ preempt_enable();
+ } else {
+ preempt_enable();
+
+ err = __put_user(current->thread.fpu.msacsr, &msa->csr);
+
+ for (i = 0; i < NUM_FPU_REGS; i++) {
+ val = get_fpr64(&current->thread.fpu.fpr[i], 1);
+ err |= __put_user(val, &msa->wr[i]);
+ }
+ }
+
+ err |= __put_user(MSA_EXTCONTEXT_MAGIC, &msa->ext.magic);
+ err |= __put_user(sizeof(*msa), &msa->ext.size);
+
+ return err ? -EFAULT : sizeof(*msa);
+}
+
+static int restore_msa_extcontext(void __user *buf, unsigned int size)
+{
+ struct msa_extcontext __user *msa = buf;
+ unsigned long long val;
+ unsigned int csr;
+ int i, err;
+
+ if (size != sizeof(*msa))
+ return -EINVAL;
+
+ err = get_user(csr, &msa->csr);
+ if (err)
+ return err;
+
+ preempt_disable();
+
+ if (is_msa_enabled()) {
+ /*
+ * There are no EVA versions of the vector register load/store
+ * instructions, so MSA context has to be copied to kernel
+ * memory and later loaded to registers. The same is true of
+ * scalar FP context, so FPU & MSA should have already been
+ * disabled whilst handling scalar FP context.
+ */
+ BUG_ON(config_enabled(CONFIG_EVA));
+
+ write_msa_csr(csr);
+ err |= _restore_msa_all_upper(&msa->wr);
+ preempt_enable();
+ } else {
+ preempt_enable();
+
+ current->thread.fpu.msacsr = csr;
+
+ for (i = 0; i < NUM_FPU_REGS; i++) {
+ err |= __get_user(val, &msa->wr[i]);
+ set_fpr64(&current->thread.fpu.fpr[i], 1, val);
+ }
+ }
+
+ return err;
+}
+
+static int save_extcontext(void __user *buf)
+{
+ int sz;
+
+ sz = save_msa_extcontext(buf);
+ if (sz < 0)
+ return sz;
+ buf += sz;
+
+ /* If no context was saved then trivially return */
+ if (!sz)
+ return 0;
+
+ /* Write the end marker */
+ if (__put_user(END_EXTCONTEXT_MAGIC, (u32 *)buf))
+ return -EFAULT;
+
+ sz += sizeof(((struct extcontext *)NULL)->magic);
+ return sz;
+}
+
+static int restore_extcontext(void __user *buf)
+{
+ struct extcontext ext;
+ int err;
+
+ while (1) {
+ err = __get_user(ext.magic, (unsigned int *)buf);
+ if (err)
+ return err;
+
+ if (ext.magic == END_EXTCONTEXT_MAGIC)
+ return 0;
+
+ err = __get_user(ext.size, (unsigned int *)(buf
+ + offsetof(struct extcontext, size)));
+ if (err)
+ return err;
+
+ switch (ext.magic) {
+ case MSA_EXTCONTEXT_MAGIC:
+ err = restore_msa_extcontext(buf, ext.size);
+ break;
+
+ default:
+ err = -EINVAL;
+ break;
+ }
+
+ if (err)
+ return err;
+
+ buf += ext.size;
+ }
+}
+
+/*
* Helper routines
*/
-static int protected_save_fp_context(struct sigcontext __user *sc)
+int protected_save_fp_context(void __user *sc)
{
+ struct mips_abi *abi = current->thread.abi;
+ uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
+ uint32_t __user *csr = sc + abi->off_sc_fpc_csr;
+ uint32_t __user *used_math = sc + abi->off_sc_used_math;
+ unsigned int used, ext_sz;
int err;
-#ifndef CONFIG_EVA
+
+ used = used_math() ? USED_FP : 0;
+ if (!used)
+ goto fp_done;
+
+ if (!test_thread_flag(TIF_32BIT_FPREGS))
+ used |= USED_FR1;
+ if (test_thread_flag(TIF_HYBRID_FPREGS))
+ used |= USED_HYBRID_FPRS;
+
+ /*
+ * EVA does not have userland equivalents of ldc1 or sdc1, so
+ * save to the kernel FP context & copy that to userland below.
+ */
+ if (config_enabled(CONFIG_EVA))
+ lose_fpu(1);
+
while (1) {
lock_fpu_owner();
if (is_fpu_owner()) {
@@ -114,27 +328,57 @@ static int protected_save_fp_context(struct sigcontext __user *sc)
if (likely(!err))
break;
/* touch the sigcontext and try again */
- err = __put_user(0, &sc->sc_fpregs[0]) |
- __put_user(0, &sc->sc_fpregs[31]) |
- __put_user(0, &sc->sc_fpc_csr);
+ err = __put_user(0, &fpregs[0]) |
+ __put_user(0, &fpregs[31]) |
+ __put_user(0, csr);
if (err)
- break; /* really bad sigcontext */
+ return err; /* really bad sigcontext */
}
-#else
- /*
- * EVA does not have FPU EVA instructions so saving fpu context directly
- * does not work.
- */
- lose_fpu(1);
- err = save_fp_context(sc); /* this might fail */
-#endif
- return err;
+
+fp_done:
+ ext_sz = err = save_extcontext(sc_to_extcontext(sc));
+ if (err < 0)
+ return err;
+ used |= ext_sz ? USED_EXTCONTEXT : 0;
+
+ return __put_user(used, used_math);
}
-static int protected_restore_fp_context(struct sigcontext __user *sc)
+int protected_restore_fp_context(void __user *sc)
{
- int err, tmp __maybe_unused;
-#ifndef CONFIG_EVA
+ struct mips_abi *abi = current->thread.abi;
+ uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
+ uint32_t __user *csr = sc + abi->off_sc_fpc_csr;
+ uint32_t __user *used_math = sc + abi->off_sc_used_math;
+ unsigned int used;
+ int err, sig = 0, tmp __maybe_unused;
+
+ err = __get_user(used, used_math);
+ conditional_used_math(used & USED_FP);
+
+ /*
+ * The signal handler may have used FPU; give it up if the program
+ * doesn't want it following sigreturn.
+ */
+ if (err || !(used & USED_FP))
+ lose_fpu(0);
+ if (err)
+ return err;
+ if (!(used & USED_FP))
+ goto fp_done;
+
+ err = sig = fpcsr_pending(csr);
+ if (err < 0)
+ return err;
+
+ /*
+ * EVA does not have userland equivalents of ldc1 or sdc1, so we
+ * disable the FPU here such that the code below simply copies to
+ * the kernel FP context.
+ */
+ if (config_enabled(CONFIG_EVA))
+ lose_fpu(0);
+
while (1) {
lock_fpu_owner();
if (is_fpu_owner()) {
@@ -147,28 +391,24 @@ static int protected_restore_fp_context(struct sigcontext __user *sc)
if (likely(!err))
break;
/* touch the sigcontext and try again */
- err = __get_user(tmp, &sc->sc_fpregs[0]) |
- __get_user(tmp, &sc->sc_fpregs[31]) |
- __get_user(tmp, &sc->sc_fpc_csr);
+ err = __get_user(tmp, &fpregs[0]) |
+ __get_user(tmp, &fpregs[31]) |
+ __get_user(tmp, csr);
if (err)
break; /* really bad sigcontext */
}
-#else
- /*
- * EVA does not have FPU EVA instructions so restoring fpu context
- * directly does not work.
- */
- lose_fpu(0);
- err = restore_fp_context(sc); /* this might fail */
-#endif
- return err;
+
+fp_done:
+ if (used & USED_EXTCONTEXT)
+ err |= restore_extcontext(sc_to_extcontext(sc));
+
+ return err ?: sig;
}
int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
{
int err = 0;
int i;
- unsigned int used_math;
err |= __put_user(regs->cp0_epc, &sc->sc_pc);
@@ -191,19 +431,38 @@ int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
err |= __put_user(rddsp(DSP_MASK), &sc->sc_dsp);
}
- used_math = !!used_math();
- err |= __put_user(used_math, &sc->sc_used_math);
- if (used_math) {
- /*
- * Save FPU state to signal context. Signal handler
- * will "inherit" current FPU state.
- */
- err |= protected_save_fp_context(sc);
- }
+ /*
+ * Save FPU state to signal context. Signal handler
+ * will "inherit" current FPU state.
+ */
+ err |= protected_save_fp_context(sc);
+
return err;
}
+static size_t extcontext_max_size(void)
+{
+ size_t sz = 0;
+
+ /*
+ * The assumption here is that between this point & the point at which
+ * the extended context is saved the size of the context should only
+ * ever be able to shrink (if the task is preempted), but never grow.
+ * That is, what this function returns is an upper bound on the size of
+ * the extended context for the current task at the current time.
+ */
+
+ if (thread_msa_context_live())
+ sz += sizeof(struct msa_extcontext);
+
+ /* If any context is saved then we'll append the end marker */
+ if (sz)
+ sz += sizeof(((struct extcontext *)NULL)->magic);
+
+ return sz;
+}
+
int fpcsr_pending(unsigned int __user *fpcsr)
{
int err, sig = 0;
@@ -223,21 +482,8 @@ int fpcsr_pending(unsigned int __user *fpcsr)
return err ?: sig;
}
-static int
-check_and_restore_fp_context(struct sigcontext __user *sc)
-{
- int err, sig;
-
- err = sig = fpcsr_pending(&sc->sc_fpc_csr);
- if (err > 0)
- err = 0;
- err |= protected_restore_fp_context(sc);
- return err ?: sig;
-}
-
int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
{
- unsigned int used_math;
unsigned long treg;
int err = 0;
int i;
@@ -265,19 +511,7 @@ int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
for (i = 1; i < 32; i++)
err |= __get_user(regs->regs[i], &sc->sc_regs[i]);
- err |= __get_user(used_math, &sc->sc_used_math);
- conditional_used_math(used_math);
-
- if (used_math) {
- /* restore fpu context if we have used it before */
- if (!err)
- err = check_and_restore_fp_context(sc);
- } else {
- /* signal handler may have used FPU. Give it up. */
- lose_fpu(0);
- }
-
- return err;
+ return err ?: protected_restore_fp_context(sc);
}
void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs,
@@ -285,6 +519,9 @@ void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs,
{
unsigned long sp;
+ /* Leave space for potential extended context */
+ frame_size += extcontext_max_size();
+
/* Default to using normal stack */
sp = regs->regs[29];
@@ -520,7 +757,11 @@ struct mips_abi mips_abi = {
.setup_rt_frame = setup_rt_frame,
.rt_signal_return_offset =
offsetof(struct mips_vdso, rt_signal_trampoline),
- .restart = __NR_restart_syscall
+ .restart = __NR_restart_syscall,
+
+ .off_sc_fpregs = offsetof(struct sigcontext, sc_fpregs),
+ .off_sc_fpc_csr = offsetof(struct sigcontext, sc_fpc_csr),
+ .off_sc_used_math = offsetof(struct sigcontext, sc_used_math),
};
static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
@@ -616,6 +857,9 @@ asmlinkage void do_notify_resume(struct pt_regs *regs, void *unused,
user_exit();
+ if (thread_info_flags & _TIF_UPROBE)
+ uprobe_notify_resume(regs);
+
/* deal with pending signal delivery */
if (thread_info_flags & _TIF_SIGPENDING)
do_signal(regs);
@@ -629,43 +873,46 @@ asmlinkage void do_notify_resume(struct pt_regs *regs, void *unused,
}
#ifdef CONFIG_SMP
-#ifndef CONFIG_EVA
-static int smp_save_fp_context(struct sigcontext __user *sc)
+static int smp_save_fp_context(void __user *sc)
{
return raw_cpu_has_fpu
- ? _save_fp_context(sc)
+ ? save_hw_fp_context(sc)
: copy_fp_to_sigcontext(sc);
}
-static int smp_restore_fp_context(struct sigcontext __user *sc)
+static int smp_restore_fp_context(void __user *sc)
{
return raw_cpu_has_fpu
- ? _restore_fp_context(sc)
+ ? restore_hw_fp_context(sc)
: copy_fp_from_sigcontext(sc);
}
-#endif /* CONFIG_EVA */
#endif
static int signal_setup(void)
{
-#ifndef CONFIG_EVA
+ /*
+ * The offset from sigcontext to extended context should be the same
+ * regardless of the type of signal, such that userland can always know
+ * where to look if it wishes to find the extended context structures.
+ */
+ BUILD_BUG_ON((offsetof(struct sigframe, sf_extcontext) -
+ offsetof(struct sigframe, sf_sc)) !=
+ (offsetof(struct rt_sigframe, rs_uc.uc_extcontext) -
+ offsetof(struct rt_sigframe, rs_uc.uc_mcontext)));
+
#ifdef CONFIG_SMP
/* For now just do the cpu_has_fpu check when the functions are invoked */
save_fp_context = smp_save_fp_context;
restore_fp_context = smp_restore_fp_context;
#else
if (cpu_has_fpu) {
- save_fp_context = _save_fp_context;
- restore_fp_context = _restore_fp_context;
+ save_fp_context = save_hw_fp_context;
+ restore_fp_context = restore_hw_fp_context;
} else {
save_fp_context = copy_fp_to_sigcontext;
restore_fp_context = copy_fp_from_sigcontext;
}
#endif /* CONFIG_SMP */
-#else
- save_fp_context = copy_fp_to_sigcontext;
- restore_fp_context = copy_fp_from_sigcontext;
-#endif
return 0;
}