[Risu,v2,4/9] Implement lib to deal with PPC64 registers

Commit Message

Jose Ricardo Ziviani Nov. 6, 2016, 5:15 p.m. UTC

This library is the initial effort to have PPC64 support for Risu. It
implements functions to initialize, compare and print PPC64 registers.

Signed-off-by: Jose Ricardo Ziviani <[e-mail]>
---
 risu_reginfo_ppc64le.c | 200 +++++++++++++++++++++++++++++++++++++++++++++++++
 risu_reginfo_ppc64le.h |  40 ++++++++++
 2 files changed, 240 insertions(+)
 create mode 100644 risu_reginfo_ppc64le.c
 create mode 100644 risu_reginfo_ppc64le.h

Comments

Peter Maydell Feb. 15, 2017, 6:50 p.m. UTC | #1

On 6 November 2016 at 17:15, Jose Ricardo Ziviani
<[e-mail]> wrote:
> This library is the initial effort to have PPC64 support for Risu. It
> implements functions to initialize, compare and print PPC64 registers.
>
> Signed-off-by: Jose Ricardo Ziviani <[e-mail]>

Hi; I've been looking at refactoring risu to reduce the huge
code duplication between the CPU backends, and I noticed this
weirdness in the PPC code:


> +/* reginfo_is_eq: compare the reginfo structs, returns nonzero if equal */
> +int reginfo_is_eq(struct reginfo *m, struct reginfo *a, ucontext_t *uc)
> +{

> +    for (i = 0; i < 32; i++) {
> +        if (m->vrregs.vrregs[i][0] != a->vrregs.vrregs[i][0] ||
> +                m->vrregs.vrregs[i][1] != a->vrregs.vrregs[i][1] ||
> +                m->vrregs.vrregs[i][2] != a->vrregs.vrregs[i][2] ||
> +                m->vrregs.vrregs[i][3] != a->vrregs.vrregs[i][3]) {
> +
> +            if (uc != NULL && (m->gregs[CCR] & 0x10)) {
> +                uc->uc_mcontext.v_regs->vrregs[i][0] = a->vrregs.vrregs[i][0];
> +                uc->uc_mcontext.v_regs->vrregs[i][1] = a->vrregs.vrregs[i][1];
> +                uc->uc_mcontext.v_regs->vrregs[i][2] = a->vrregs.vrregs[i][2];
> +                uc->uc_mcontext.v_regs->vrregs[i][3] = a->vrregs.vrregs[i][3];
> +                return 1;
> +            }

What is this intended to be doing? reginfo_is_eq() should be
a simple "compare two structures" operation, but here we
take a ucontext_t* (which is something completely different)
and modify it. We don't even necessarily have a ucontext_t
to hand when we're trying to compare reginfo structs...

thanks
-- PMM

Jose Ricardo Ziviani Feb. 15, 2017, 7:28 p.m. UTC | #2

On Wed, Feb 15, 2017 at 06:50:13PM +0000, Peter Maydell wrote:
> On 6 November 2016 at 17:15, Jose Ricardo Ziviani
> <[e-mail]> wrote:
> > This library is the initial effort to have PPC64 support for Risu. It
> > implements functions to initialize, compare and print PPC64 registers.
> >
> > Signed-off-by: Jose Ricardo Ziviani <[e-mail]>
> 
> Hi; I've been looking at refactoring risu to reduce the huge
> code duplication between the CPU backends, and I noticed this
> weirdness in the PPC code:
> 
> 
> > +/* reginfo_is_eq: compare the reginfo structs, returns nonzero if equal */
> > +int reginfo_is_eq(struct reginfo *m, struct reginfo *a, ucontext_t *uc)
> > +{
> 
> > +    for (i = 0; i < 32; i++) {
> > +        if (m->vrregs.vrregs[i][0] != a->vrregs.vrregs[i][0] ||
> > +                m->vrregs.vrregs[i][1] != a->vrregs.vrregs[i][1] ||
> > +                m->vrregs.vrregs[i][2] != a->vrregs.vrregs[i][2] ||
> > +                m->vrregs.vrregs[i][3] != a->vrregs.vrregs[i][3]) {
> > +
> > +            if (uc != NULL && (m->gregs[CCR] & 0x10)) {
> > +                uc->uc_mcontext.v_regs->vrregs[i][0] = a->vrregs.vrregs[i][0];
> > +                uc->uc_mcontext.v_regs->vrregs[i][1] = a->vrregs.vrregs[i][1];
> > +                uc->uc_mcontext.v_regs->vrregs[i][2] = a->vrregs.vrregs[i][2];
> > +                uc->uc_mcontext.v_regs->vrregs[i][3] = a->vrregs.vrregs[i][3];
> > +                return 1;
> > +            }
> 
> What is this intended to be doing? reginfo_is_eq() should be
> a simple "compare two structures" operation, but here we
> take a ucontext_t* (which is something completely different)
> and modify it. We don't even necessarily have a ucontext_t
> to hand when we're trying to compare reginfo structs...

hmmm, good question, it's certainly something I've done for testing but forgot to remove. I'll send a patch removing it.

Thanks!

> 
> thanks
> -- PMM
>

Patch

diff --git a/risu_reginfo_ppc64le.c b/risu_reginfo_ppc64le.c
new file mode 100644
index 0000000..7a54eab
--- /dev/null
+++ b/risu_reginfo_ppc64le.c
@@ -0,0 +1,200 @@ 
+/******************************************************************************
+ * Copyright (c) IBM Corp, 2016
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     Jose Ricardo Ziviani - initial implementation
+ *     based on Claudio Fontana's risu_aarch64.c
+ *     based on Peter Maydell's risu_arm.c
+ *****************************************************************************/
+
+#include <stdio.h>
+#include <ucontext.h>
+#include <string.h>
+#include <math.h>
+
+#include "risu.h"
+#include "risu_reginfo_ppc64le.h"
+
+#define XER 37
+#define CCR 38
+
+/* reginfo_init: initialize with a ucontext */
+void reginfo_init(struct reginfo *ri, ucontext_t *uc)
+{
+    int i;
+    memset(ri, 0, sizeof(*ri));
+
+    ri->faulting_insn = *((uint32_t *)uc->uc_mcontext.regs->nip);
+    ri->nip = uc->uc_mcontext.regs->nip - image_start_address;
+
+    for (i = 0; i < NGREG; i++) {
+        ri->gregs[i] = uc->uc_mcontext.gp_regs[i];
+    }
+
+    for (i = 0; i < NFPREG; i++) {
+        ri->fpregs[i] = uc->uc_mcontext.fp_regs[i];
+    }
+
+    for (i = 0; i < 32; i++) {
+        ri->vrregs.vrregs[i][0] = uc->uc_mcontext.v_regs->vrregs[i][0];
+        ri->vrregs.vrregs[i][1] = uc->uc_mcontext.v_regs->vrregs[i][1];
+        ri->vrregs.vrregs[i][2] = uc->uc_mcontext.v_regs->vrregs[i][2];
+        ri->vrregs.vrregs[i][3] = uc->uc_mcontext.v_regs->vrregs[i][3];
+    }
+    ri->vrregs.vscr = uc->uc_mcontext.v_regs->vscr;
+    ri->vrregs.vrsave = uc->uc_mcontext.v_regs->vrsave;
+}
+
+/* reginfo_is_eq: compare the reginfo structs, returns nonzero if equal */
+int reginfo_is_eq(struct reginfo *m, struct reginfo *a, ucontext_t *uc)
+{
+    int i;
+    for (i = 0; i < 32; i++) {
+        if (i == 1 || i == 13) {
+            continue;
+        }
+
+        if (m->gregs[i] != a->gregs[i]) {
+            return 0;
+        }
+    }
+
+    if (m->gregs[XER] != a->gregs[XER]) {
+        return 0;
+    }
+
+    if ((m->gregs[CCR] & 0x10) != (a->gregs[CCR] & 0x10)) {
+        return 0;
+    }
+
+    for (i = 0; i < 32; i++) {
+        if (isnan(m->fpregs[i]) && isnan(a->fpregs[i])) {
+            continue;
+        }
+
+        if  (m->fpregs[i] != a->fpregs[i]) {
+            return 0;
+        }
+    }
+
+    for (i = 0; i < 32; i++) {
+        if (m->vrregs.vrregs[i][0] != a->vrregs.vrregs[i][0] ||
+                m->vrregs.vrregs[i][1] != a->vrregs.vrregs[i][1] ||
+                m->vrregs.vrregs[i][2] != a->vrregs.vrregs[i][2] ||
+                m->vrregs.vrregs[i][3] != a->vrregs.vrregs[i][3]) {
+
+            if (uc != NULL && (m->gregs[CCR] & 0x10)) {
+                uc->uc_mcontext.v_regs->vrregs[i][0] = a->vrregs.vrregs[i][0];
+                uc->uc_mcontext.v_regs->vrregs[i][1] = a->vrregs.vrregs[i][1];
+                uc->uc_mcontext.v_regs->vrregs[i][2] = a->vrregs.vrregs[i][2];
+                uc->uc_mcontext.v_regs->vrregs[i][3] = a->vrregs.vrregs[i][3];
+                return 1;
+            }
+            return 0;
+        }
+    }
+    return 1;
+}
+
+/* reginfo_dump: print state to a stream, returns nonzero on success */
+void reginfo_dump(struct reginfo *ri, int is_master)
+{
+    int i;
+    if (is_master) {
+        fprintf(stderr, "  faulting insn \e[1;101;37m0x%x\e[0m\n", ri->faulting_insn);
+        fprintf(stderr, "  prev insn     \e[1;101;37m0x%x\e[0m\n", ri->prev_insn);
+        fprintf(stderr, "  prev addr     \e[1;101;37m0x%" PRIx64 "\e[0m\n\n", ri->prev_addr);
+    }
+
+    for (i = 0; i < 16; i++) {
+        fprintf(stderr, "\tr%2d: %16lx\tr%2d: %16lx\n", i, ri->gregs[i],
+                i + 16, ri->gregs[i + 16]);
+    }
+
+    fprintf(stderr, "\n");
+    fprintf(stderr, "\tnip    : %16lx\n", ri->gregs[32]);
+    fprintf(stderr, "\tmsr    : %16lx\n", ri->gregs[33]);
+    fprintf(stderr, "\torig r3: %16lx\n", ri->gregs[34]);
+    fprintf(stderr, "\tctr    : %16lx\n", ri->gregs[35]);
+    fprintf(stderr, "\tlnk    : %16lx\n", ri->gregs[36]);
+    fprintf(stderr, "\txer    : %16lx\n", ri->gregs[37]);
+    fprintf(stderr, "\tccr    : %16lx\n", ri->gregs[38]);
+    fprintf(stderr, "\tmq     : %16lx\n", ri->gregs[39]);
+    fprintf(stderr, "\ttrap   : %16lx\n", ri->gregs[40]);
+    fprintf(stderr, "\tdar    : %16lx\n", ri->gregs[41]);
+    fprintf(stderr, "\tdsisr  : %16lx\n", ri->gregs[42]);
+    fprintf(stderr, "\tresult : %16lx\n", ri->gregs[43]);
+    fprintf(stderr, "\tdscr   : %16lx\n\n", ri->gregs[44]);
+
+    for (i = 0; i < 16; i++) {
+        fprintf(stderr, "\tf%2d: %.4f\tr%2d: %.4f\n", i, ri->fpregs[i],
+                i + 16, ri->fpregs[i + 16]);
+    }
+    fprintf(stderr, "\tfpscr: %f\n\n", ri->fpregs[32]);
+
+    for (i = 0; i < 32; i++) {
+        fprintf(stderr, "vr%02d: %8x, %8x, %8x, %8x\n", i,
+                ri->vrregs.vrregs[i][0], ri->vrregs.vrregs[i][1],
+                ri->vrregs.vrregs[i][2], ri->vrregs.vrregs[i][3]);
+    }
+}
+
+int reginfo_dump_mismatch(struct reginfo *m, struct reginfo *a, FILE *f)
+{
+    int i;
+    for (i = 0; i < 32; i++) {
+        if (i == 1 || i == 13) {
+            continue;
+        }
+
+        if (m->gregs[i] != a->gregs[i]) {
+            fprintf(f, "Mismatch: Register r%d\n", i);
+            fprintf(f, "master: [%lx] - apprentice: [%lx]\n",
+                    m->gregs[i], a->gregs[i]);
+        }
+    }
+
+    if (m->gregs[XER] != a->gregs[XER]) {
+        fprintf(f, "Mismatch: XER\n");
+        fprintf(f, "m: [%lx] != a: [%lx]\n",
+                m->gregs[XER], a->gregs[XER]);
+    }
+
+    if (m->gregs[CCR] != a->gregs[CCR]) {
+        fprintf(f, "Mismatch: Cond. Register\n");
+        fprintf(f, "m: [%lx] != a: [%lx]\n",
+                m->gregs[CCR], a->gregs[CCR]);
+    }
+
+    for (i = 0; i < 32; i++) {
+        if (isnan(m->fpregs[i]) && isnan(a->fpregs[i])) {
+            continue;
+        }
+
+        if  (m->fpregs[i] != a->fpregs[i]) {
+            fprintf(f, "Mismatch: Register r%d\n", i);
+            fprintf(f, "m: [%f] != a: [%f]\n",
+                    m->fpregs[i], a->fpregs[i]);
+        }
+    }
+
+    for (i = 0; i < 32; i++) {
+        if (m->vrregs.vrregs[i][0] != a->vrregs.vrregs[i][0] ||
+                m->vrregs.vrregs[i][1] != a->vrregs.vrregs[i][1] ||
+                m->vrregs.vrregs[i][2] != a->vrregs.vrregs[i][2] ||
+                m->vrregs.vrregs[i][3] != a->vrregs.vrregs[i][3]) {
+
+            fprintf(f, "Mismatch: Register vr%d\n", i);
+            fprintf(f, "m: [%x, %x, %x, %x] != a: [%x, %x, %x, %x]\n",
+                    m->vrregs.vrregs[i][0], m->vrregs.vrregs[i][1],
+                    m->vrregs.vrregs[i][2], m->vrregs.vrregs[i][3],
+                    a->vrregs.vrregs[i][0], a->vrregs.vrregs[i][1],
+                    a->vrregs.vrregs[i][2], a->vrregs.vrregs[i][3]);
+        }
+    }
+    return !ferror(f);
+}
diff --git a/risu_reginfo_ppc64le.h b/risu_reginfo_ppc64le.h
new file mode 100644
index 0000000..f0a3b88
--- /dev/null
+++ b/risu_reginfo_ppc64le.h
@@ -0,0 +1,40 @@ 
+/******************************************************************************
+ * Copyright (c) 2013 Linaro Limited
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     Jose Ricardo Ziviani - initial implementation
+ *     based on Claudio Fontana's risu_reginfo_aarch64
+ *     based on Peter Maydell's risu_arm.c
+ *****************************************************************************/
+
+#ifndef RISU_REGINFO_PPC64LE_H
+#define RISU_REGINFO_PPC64LE_H
+
+struct reginfo
+{
+    uint32_t faulting_insn;
+    uint32_t prev_insn;
+    uint64_t nip;
+    uint64_t prev_addr;
+    gregset_t gregs;
+    fpregset_t fpregs;
+    vrregset_t vrregs;
+};
+
+/* initialize structure from a ucontext */
+void reginfo_init(struct reginfo *ri, ucontext_t *uc);
+
+/* return 1 if structs are equal, 0 otherwise. */
+int reginfo_is_eq(struct reginfo *r1, struct reginfo *r2, ucontext_t *uc);
+
+/* print reginfo state to a stream */
+void reginfo_dump(struct reginfo *ri, int is_master);
+
+/* reginfo_dump_mismatch: print mismatch details to a stream, ret nonzero=ok */
+int reginfo_dump_mismatch(struct reginfo *m, struct reginfo *a, FILE *f);
+
+#endif /* RISU_REGINFO_PPC64LE_H */