Patchwork [v2,3/6] linux-user:Signal handling for MIPS64

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Submitter Khansa Butt
Date Oct. 21, 2011, 8:17 a.m.
Message ID <1319185026-17589-4-git-send-email-khansa@kics.edu.pk>
Download mbox | patch
Permalink /patch/120960/
State New
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Khansa Butt - Oct. 21, 2011, 8:17 a.m.
From: Khansa Butt <khansa@kics.edu.pk>


Signed-off-by: Khansa Butt <khansa@kics.edu.pk>
---
 linux-user/signal.c |  438 +++++++++++++++++++++++++++++++++++++++++++++++++--
 1 files changed, 426 insertions(+), 12 deletions(-)

Patch

diff --git a/linux-user/signal.c b/linux-user/signal.c
index 59c3c88..f5f8bba 100644
--- a/linux-user/signal.c
+++ b/linux-user/signal.c
@@ -30,6 +30,8 @@ 
 #include "qemu-common.h"
 #include "target_signal.h"
 
+int sigrt;
+
 //#define DEBUG_SIGNAL
 
 static struct target_sigaltstack target_sigaltstack_used = {
@@ -596,7 +598,11 @@  int do_sigaction(int sig, const struct target_sigaction *act,
     if (act) {
         /* FIXME: This is not threadsafe.  */
         k->_sa_handler = tswapl(act->_sa_handler);
+#if defined(TARGET_MIPS64)
+        k->sa_flags = bswap32(act->sa_flags);
+#else
         k->sa_flags = tswapl(act->sa_flags);
+#endif
 #if !defined(TARGET_MIPS)
         k->sa_restorer = tswapl(act->sa_restorer);
 #endif
@@ -2415,29 +2421,435 @@  void sparc64_get_context(CPUSPARCState *env)
 #endif
 #elif defined(TARGET_ABI_MIPSN64)
 
+struct target_sigcontext {
+    uint32_t   sc_regmask;     /* Unused */
+    uint32_t   sc_status;
+    uint64_t   sc_pc;
+    uint64_t   sc_regs[32];
+    uint64_t   sc_fpregs[32];
+    uint32_t   sc_ownedfp;     /* Unused */
+    uint32_t   sc_fpc_csr;
+    uint32_t   sc_fpc_eir;     /* Unused */
+    uint32_t   sc_used_math;
+    uint32_t   sc_dsp;         /* dsp status, was sc_ssflags */
+    uint32_t   pad0;
+    uint64_t   sc_mdhi;
+    uint64_t   sc_mdlo;
+    target_ulong   sc_hi1;         /* Was sc_cause */
+    target_ulong   sc_lo1;         /* Was sc_badvaddr */
+    target_ulong   sc_hi2;         /* Was sc_sigset[4] */
+    target_ulong   sc_lo2;
+    target_ulong   sc_hi3;
+    target_ulong   sc_lo3;
+};
+
+struct sigframe {
+    uint32_t sf_ass[4];         /* argument save space for o32 */
+    uint32_t sf_code[2];            /* signal trampoline */
+    struct target_sigcontext sf_sc;
+    target_sigset_t sf_mask;
+};
+
+struct target_ucontext {
+    target_ulong tuc_flags;
+    target_ulong tuc_link;
+    target_stack_t tuc_stack;
+    target_ulong pad0;
+    struct target_sigcontext tuc_mcontext;
+    target_sigset_t tuc_sigmask;
+};
+
+struct target_rt_sigframe {
+    uint32_t rs_ass[4];               /* argument save space for o32 */
+    uint32_t rs_code[2];              /* signal trampoline */
+    struct target_siginfo rs_info;
+    struct target_ucontext rs_uc;
+};
+
+/* Install trampoline to jump back from signal handler */
+static inline int install_sigtramp(unsigned int *tramp,   unsigned int syscall)
+{
+    int err;
+
+    /*
+     * Set up the return code ...
+     *
+     *         li      v0, __NR__foo_sigreturn
+     *         syscall
+     */
+
+    err = __put_user(0x24020000 + syscall, tramp + 0);
+    err |= __put_user(0x0000000c          , tramp + 1);
+    /* flush_cache_sigtramp((unsigned long) tramp); */
+    return err;
+}
+
+static inline int
+setup_sigcontext(CPUState *regs, struct target_sigcontext *sc)
+{
+    int err = 0;
+
+    err |= __put_user(regs->active_tc.PC, &sc->sc_pc);
+
+#define save_gp_reg(i) do {                         \
+        err |= __put_user(regs->active_tc.gpr[i], &sc->sc_regs[i]); \
+} while (0)
+    __put_user(0, &sc->sc_regs[0]); save_gp_reg(1); save_gp_reg(2);
+    save_gp_reg(3); save_gp_reg(4); save_gp_reg(5); save_gp_reg(6);
+    save_gp_reg(7); save_gp_reg(8); save_gp_reg(9); save_gp_reg(10);
+    save_gp_reg(11); save_gp_reg(12); save_gp_reg(13); save_gp_reg(14);
+    save_gp_reg(15); save_gp_reg(16); save_gp_reg(17); save_gp_reg(18);
+    save_gp_reg(19); save_gp_reg(20); save_gp_reg(21); save_gp_reg(22);
+    save_gp_reg(23); save_gp_reg(24); save_gp_reg(25); save_gp_reg(26);
+    save_gp_reg(27); save_gp_reg(28); save_gp_reg(29); save_gp_reg(30);
+    save_gp_reg(31);
+#undef save_gp_reg
+
+    err |= __put_user(regs->active_tc.HI[0], &sc->sc_mdhi);
+    err |= __put_user(regs->active_tc.LO[0], &sc->sc_mdlo);
+
+    /* Not used yet, but might be useful if we ever have DSP suppport */
+#if 0
+    if (cpu_has_dsp) {
+        err |= __put_user(mfhi1(), &sc->sc_hi1);
+        err |= __put_user(mflo1(), &sc->sc_lo1);
+        err |= __put_user(mfhi2(), &sc->sc_hi2);
+        err |= __put_user(mflo2(), &sc->sc_lo2);
+        err |= __put_user(mfhi3(), &sc->sc_hi3);
+        err |= __put_user(mflo3(), &sc->sc_lo3);
+        err |= __put_user(rddsp(DSP_MASK), &sc->sc_dsp);
+    }
+    /* same with 64 bit */
+#ifdef CONFIG_64BIT
+    err |= __put_user(regs->hi, &sc->sc_hi[0]);
+    err |= __put_user(regs->lo, &sc->sc_lo[0]);
+    if (cpu_has_dsp) {
+        err |= __put_user(mfhi1(), &sc->sc_hi[1]);
+        err |= __put_user(mflo1(), &sc->sc_lo[1]);
+        err |= __put_user(mfhi2(), &sc->sc_hi[2]);
+        err |= __put_user(mflo2(), &sc->sc_lo[2]);
+        err |= __put_user(mfhi3(), &sc->sc_hi[3]);
+        err |= __put_user(mflo3(), &sc->sc_lo[3]);
+        err |= __put_user(rddsp(DSP_MASK), &sc->sc_dsp);
+    }
+#endif
+#endif
+
+#if 0
+    err |= __put_user(!!used_math(), &sc->sc_used_math);
+
+    if (!used_math())
+        goto out;
+
+    /*
+     * Save FPU state to signal context.  Signal handler will "inherit"
+     * current FPU state.
+     */
+    preempt_disable();
+
+    if (!is_fpu_owner()) {
+        own_fpu();
+        restore_fp(current);
+    }
+    err |= save_fp_context(sc);
+
+    preempt_enable();
+    out:
+#endif
+    return err;
+}
+
+static inline int
+restore_sigcontext(CPUState *regs, struct target_sigcontext *sc)
+{
+    int err = 0;
+
+    err |= __get_user(regs->CP0_EPC, &sc->sc_pc);
+
+    err |= __get_user(regs->active_tc.HI[0], &sc->sc_mdhi);
+    err |= __get_user(regs->active_tc.LO[0], &sc->sc_mdlo);
+
+#define restore_gp_reg(i) do {                               \
+        err |= __get_user(regs->active_tc.gpr[i], &sc->sc_regs[i]);     \
+} while (0)
+    restore_gp_reg(1); restore_gp_reg(2); restore_gp_reg(3);
+    restore_gp_reg(4); restore_gp_reg(5); restore_gp_reg(6);
+    restore_gp_reg(7); restore_gp_reg(8); restore_gp_reg(9);
+    restore_gp_reg(10); restore_gp_reg(11); restore_gp_reg(12);
+    restore_gp_reg(13); restore_gp_reg(14); restore_gp_reg(15);
+    restore_gp_reg(16); restore_gp_reg(17); restore_gp_reg(18);
+    restore_gp_reg(19); restore_gp_reg(20); restore_gp_reg(21);
+    restore_gp_reg(22); restore_gp_reg(23); restore_gp_reg(24);
+    restore_gp_reg(25); restore_gp_reg(26); restore_gp_reg(27);
+    restore_gp_reg(28); restore_gp_reg(29); restore_gp_reg(30);
+    restore_gp_reg(31);
+#undef restore_gp_reg
+
+#if 0
+    if (cpu_has_dsp) {
+        err |= __get_user(treg, &sc->sc_hi1); mthi1(treg);
+        err |= __get_user(treg, &sc->sc_lo1); mtlo1(treg);
+        err |= __get_user(treg, &sc->sc_hi2); mthi2(treg);
+        err |= __get_user(treg, &sc->sc_lo2); mtlo2(treg);
+        err |= __get_user(treg, &sc->sc_hi3); mthi3(treg);
+        err |= __get_user(treg, &sc->sc_lo3); mtlo3(treg);
+        err |= __get_user(treg, &sc->sc_dsp); wrdsp(treg, DSP_MASK);
+    }
+#ifdef CONFIG_64BIT
+    err |= __get_user(regs->hi, &sc->sc_hi[0]);
+    err |= __get_user(regs->lo, &sc->sc_lo[0]);
+    if (cpu_has_dsp) {
+        err |= __get_user(treg, &sc->sc_hi[1]); mthi1(treg);
+        err |= __get_user(treg, &sc->sc_lo[1]); mthi1(treg);
+        err |= __get_user(treg, &sc->sc_hi[2]); mthi2(treg);
+        err |= __get_user(treg, &sc->sc_lo[2]); mthi2(treg);
+        err |= __get_user(treg, &sc->sc_hi[3]); mthi3(treg);
+        err |= __get_user(treg, &sc->sc_lo[3]); mthi3(treg);
+        err |= __get_user(treg, &sc->sc_dsp); wrdsp(treg, DSP_MASK);
+    }
+#endif
+
+    err |= __get_user(used_math, &sc->sc_used_math);
+    conditional_used_math(used_math);
+
+    preempt_disable();
+
+    if (used_math()) {
+        /* restore fpu context if we have used it before */
+        own_fpu();
+        err |= restore_fp_context(sc);
+    } else {
+        /* signal handler may have used FPU.  Give it up. */
+        lose_fpu();
+    }
+
+    preempt_enable();
+#endif
+    return err;
+}
+/*
+ * Determine which stack to use..
+ */
+static inline abi_ulong
+get_sigframe(struct target_sigaction *ka, CPUState *regs, size_t frame_size)
+{
+    unsigned long sp;
+
+    /* Default to using normal stack */
+    sp = regs->active_tc.gpr[29];
+
+    /*
+     * FPU emulator may have it's own trampoline active just
+     * above the user stack, 16-bytes before the next lowest
+     * 16 byte boundary.  Try to avoid trashing it.
+     */
+    sp -= 32;
+
+    /* This is the X/Open sanctioned signal stack switching.  */
+    if ((ka->sa_flags & TARGET_SA_ONSTACK) && (sas_ss_flags(sp) == 0)) {
+        sp = target_sigaltstack_used.ss_sp + target_sigaltstack_used.ss_size;
+    }
+
+    return (sp - frame_size) & ~7;
+}
+
+/* compare linux/arch/mips/kernel/signal.c:setup_frame() */
 static void setup_frame(int sig, struct target_sigaction *ka,
-			target_sigset_t *set, CPUState *env)
+        target_sigset_t *set, CPUState *regs)
 {
-    fprintf(stderr, "setup_frame: not implemented\n");
+    struct sigframe *frame;
+    abi_ulong frame_addr;
+    int i;
+
+    frame_addr = get_sigframe(ka, regs, sizeof(*frame));
+    if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0))
+        goto give_sigsegv;
+
+    install_sigtramp(frame->sf_code, TARGET_NR_rt_sigreturn);
+
+    if (setup_sigcontext(regs, &frame->sf_sc))
+        goto give_sigsegv;
+
+    for (i = 0; i < TARGET_NSIG_WORDS; i++) {
+        if (__put_user(set->sig[i], &frame->sf_mask.sig[i]))
+            goto give_sigsegv;
+    }
+
+    /*
+     * Arguments to signal handler:
+     *
+     *   a0 = signal number
+     *   a1 = 0 (should be cause)
+     *   a2 = pointer to struct sigcontext
+     *
+     * $25 and PC point to the signal handler, $29 points to the
+     * struct sigframe.
+     */
+    regs->active_tc.gpr[4] = sig;
+    regs->active_tc.gpr[5] = 0;
+    regs->active_tc.gpr[6] = frame_addr + offsetof(struct sigframe, sf_sc);
+    regs->active_tc.gpr[29] = frame_addr;
+    regs->active_tc.gpr[31] = frame_addr + offsetof(struct sigframe, sf_code);
+    /* The original kernel code sets CP0_EPC to the handler
+     * since it returns to userland using eret
+     * we cannot do this here, and we must set PC directly */
+    regs->active_tc.PC = regs->active_tc.gpr[25] = ka->_sa_handler;
+    unlock_user_struct(frame, frame_addr, 1);
+    return;
+
+    give_sigsegv:
+    unlock_user_struct(frame, frame_addr, 1);
+    force_sig(TARGET_SIGSEGV/*, current*/);
+    return;
 }
 
-static void setup_rt_frame(int sig, struct target_sigaction *ka,
-                           target_siginfo_t *info,
-			   target_sigset_t *set, CPUState *env)
+long do_sigreturn(CPUState *regs)
 {
-    fprintf(stderr, "setup_rt_frame: not implemented\n");
+    struct sigframe *frame;
+    abi_ulong frame_addr;
+    sigset_t blocked;
+    target_sigset_t target_set;
+    int i;
+
+#if defined(DEBUG_SIGNAL)
+    fprintf(stderr, "do_sigreturn\n");
+#endif
+    frame_addr = regs->active_tc.gpr[29];
+    if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1))
+        goto badframe;
+
+    for (i = 0; i < TARGET_NSIG_WORDS; i++) {
+        if (__get_user(target_set.sig[i], &frame->sf_mask.sig[i]))
+            goto badframe;
+    }
+
+    target_to_host_sigset_internal(&blocked, &target_set);
+    sigprocmask(SIG_SETMASK, &blocked, NULL);
+
+    if (restore_sigcontext(regs, &frame->sf_sc))
+        goto badframe;
+
+#if 0
+    /*
+     * Don't let your children do this ...
+     */
+    __asm__ __volatile__(
+            "move\t$29, %0\n\t"
+            "j\tsyscall_exit"
+            :/* no outputs */
+            : "r" (&regs));
+    /* Unreached */
+#endif
+
+    regs->active_tc.PC = regs->CP0_EPC;
+    /* I am not sure this is right, but it seems to work
+     * maybe a problem with nested signals ? */
+    regs->CP0_EPC = 0;
+    return -TARGET_QEMU_ESIGRETURN;
+
+    badframe:
+    force_sig(TARGET_SIGSEGV/*, current*/);
+    return 0;
 }
 
-long do_sigreturn(CPUState *env)
+static void setup_rt_frame(int sig, struct target_sigaction *ka,
+        target_siginfo_t *info,
+        target_sigset_t *set, CPUState *env)
 {
-    fprintf(stderr, "do_sigreturn: not implemented\n");
-    return -TARGET_ENOSYS;
+    struct target_rt_sigframe *frame;
+    abi_ulong frame_addr;
+    int i;
+
+    frame_addr = get_sigframe(ka, env, sizeof(*frame));
+    if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0))
+        goto give_sigsegv;
+
+    install_sigtramp(frame->rs_code, TARGET_NR_rt_sigreturn);
+
+    copy_siginfo_to_user(&frame->rs_info, info);
+
+    __put_user(0, &frame->rs_uc.tuc_flags);
+    __put_user(0, &frame->rs_uc.tuc_link);
+    __put_user(target_sigaltstack_used.ss_sp, &frame->rs_uc.tuc_stack.ss_sp);
+    __put_user(target_sigaltstack_used.ss_size, &frame->rs_uc.tuc_stack.ss_size);
+    __put_user(sas_ss_flags(get_sp_from_cpustate(env)),
+            &frame->rs_uc.tuc_stack.ss_flags);
+
+    setup_sigcontext(env, &frame->rs_uc.tuc_mcontext);
+
+    for (i = 0; i < TARGET_NSIG_WORDS; i++) {
+        __put_user(set->sig[i], &frame->rs_uc.tuc_sigmask.sig[i]);
+    }
+
+    /*
+     * Arguments to signal handler:
+     *
+     *   a0 = signal number
+     *   a1 = pointer to struct siginfo
+     *   a2 = pointer to struct ucontext
+     *
+     * $25 and PC point to the signal handler, $29 points to the
+     * struct sigframe.
+     */
+    env->active_tc.gpr[4] = sig;
+    env->active_tc.gpr[5] = frame_addr
+            + offsetof(struct target_rt_sigframe, rs_info);
+    env->active_tc.gpr[6] = frame_addr
+            + offsetof(struct target_rt_sigframe, rs_uc);
+    env->active_tc.gpr[29] = frame_addr;
+    env->active_tc.gpr[31] = frame_addr
+            + offsetof(struct target_rt_sigframe, rs_code);
+    /* The original kernel code sets CP0_EPC to the handler
+     * since it returns to userland using eret
+     * we cannot do this here, and we must set PC directly */
+    env->active_tc.PC = env->active_tc.gpr[25] = ka->_sa_handler;
+    unlock_user_struct(frame, frame_addr, 1);
+    return;
+
+    give_sigsegv:
+    unlock_user_struct(frame, frame_addr, 1);
+    force_sig(TARGET_SIGSEGV/*, current*/);
+    return;
 }
 
 long do_rt_sigreturn(CPUState *env)
 {
-    fprintf(stderr, "do_rt_sigreturn: not implemented\n");
-    return -TARGET_ENOSYS;
+    /* This has been done to successfully run signal syscall */
+    if (sigrt == 1)
+        return do_sigreturn(env);
+    else {
+        struct target_rt_sigframe *frame;
+        abi_ulong frame_addr;
+        sigset_t blocked;
+
+#if defined(DEBUG_SIGNAL)
+        fprintf(stderr, "do_rt_sigreturn\n");
+#endif
+        frame_addr = env->active_tc.gpr[29];
+        if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1))
+            goto badframe;
+
+        target_to_host_sigset(&blocked, &frame->rs_uc.tuc_sigmask);
+        sigprocmask(SIG_SETMASK, &blocked, NULL);
+
+        if (restore_sigcontext(env, &frame->rs_uc.tuc_mcontext))
+            goto badframe;
+
+        if (do_sigaltstack(frame_addr +
+                offsetof(struct target_rt_sigframe, rs_uc.tuc_stack),
+                0, get_sp_from_cpustate(env)) == -EFAULT)
+            goto badframe;
+
+        env->active_tc.PC = env->CP0_EPC;
+        /* I am not sure this is right, but it seems to work
+         * maybe a problem with nested signals ? */
+        env->CP0_EPC = 0;
+        return -TARGET_QEMU_ESIGRETURN;
+
+        badframe:
+        force_sig(TARGET_SIGSEGV/*, current*/);
+        return 0;
+    }
 }
 
 #elif defined(TARGET_ABI_MIPSN32)
@@ -5305,8 +5717,10 @@  void process_pending_signals(CPUState *cpu_env)
         /* prepare the stack frame of the virtual CPU */
         if (sa->sa_flags & TARGET_SA_SIGINFO)
             setup_rt_frame(sig, sa, &q->info, &target_old_set, cpu_env);
-        else
+        else {
+            sigrt = 1;
             setup_frame(sig, sa, &target_old_set, cpu_env);
+        }
 	if (sa->sa_flags & TARGET_SA_RESETHAND)
             sa->_sa_handler = TARGET_SIG_DFL;
     }