Jumbo-commit to enhance 32 bit application support on 64 bit kernels.

This is good enough to be able to run a RELENG_4 gdb binary against
a RELENG_4 application, along with various other tools (eg: 4.x gcore).
We use this at work.

ia32_reg.[ch]: handle the 32 bit register file format, used by ptrace,
	procfs and core dumps.
procfs_*regs.c: vary the format of proc/XXX/*regs depending on the client
	and target application.
procfs_map.c: Don't print a 64 bit value to 32 bit consumers, or their
	sscanf fails.  They expect an unsigned long.
imgact_elf.c: produce a valid 32 bit coredump for 32 bit apps.
sys_process.c: handle 32 bit consumers debugging 32 bit targets.  Note
	that 64 bit consumers can still debug 32 bit targets.

IA64 has got stubs for ia32_reg.c.

Known limitations: a 5.x/6.x gdb uses get/setcontext(), which isn't
implemented in the 32/64 wrapper yet.  We also make a tiny patch to
gdb pacify it over conflicting formats of ld-elf.so.1.

Approved by:	re

1 files changed, 224 insertions, 0 deletions

diff --git a/sys/amd64/ia32/ia32_reg.c b/sys/amd64/ia32/ia32_reg.c
new file mode 100644
index 0000000..4f75e4d
--- /dev/null
+++ b/sys/amd64/ia32/ia32_reg.c
@@ -0,0 +1,224 @@
+/*-
+ * Copyright (c) 2005 Peter Wemm
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/param.h>
+#include <sys/exec.h>
+#include <sys/fcntl.h>
+#include <sys/imgact.h>
+#include <sys/kernel.h>
+#include <sys/lock.h>
+#include <sys/malloc.h>
+#include <sys/mutex.h>
+#include <sys/mman.h>
+#include <sys/namei.h>
+#include <sys/pioctl.h>
+#include <sys/proc.h>
+#include <sys/procfs.h>
+#include <sys/resourcevar.h>
+#include <sys/systm.h>
+#include <sys/signalvar.h>
+#include <sys/stat.h>
+#include <sys/sx.h>
+#include <sys/syscall.h>
+#include <sys/sysctl.h>
+#include <sys/sysent.h>
+#include <sys/vnode.h>
+
+#include <vm/vm.h>
+#include <vm/vm_kern.h>
+#include <vm/vm_param.h>
+#include <vm/pmap.h>
+#include <vm/vm_map.h>
+#include <vm/vm_object.h>
+#include <vm/vm_extern.h>
+
+#include <compat/freebsd32/freebsd32_util.h>
+#include <compat/freebsd32/freebsd32_proto.h>
+#include <machine/fpu.h>
+#include <compat/ia32/ia32_reg.h>
+#include <machine/psl.h>
+#include <machine/segments.h>
+#include <machine/specialreg.h>
+#include <machine/frame.h>
+#include <machine/md_var.h>
+#include <machine/pcb.h>
+#include <machine/cpufunc.h>
+
+#define	CS_SECURE(cs)		(ISPL(cs) == SEL_UPL)
+#define	EFL_SECURE(ef, oef)	((((ef) ^ (oef)) & ~PSL_USERCHANGE) == 0)
+
+int
+fill_regs32(struct thread *td, struct reg32 *regs)
+{
+	struct pcb *pcb;
+	struct trapframe *tp;
+
+	tp = td->td_frame;
+	pcb = td->td_pcb;
+	regs->r_fs = pcb->pcb_fs;
+	regs->r_es = pcb->pcb_es;
+	regs->r_ds = pcb->pcb_ds;
+	regs->r_edi = tp->tf_rdi;
+	regs->r_esi = tp->tf_rsi;
+	regs->r_ebp = tp->tf_rbp;
+	regs->r_ebx = tp->tf_rbx;
+	regs->r_edx = tp->tf_rdx;
+	regs->r_ecx = tp->tf_rcx;
+	regs->r_eax = tp->tf_rax;
+	regs->r_eip = tp->tf_rip;
+	regs->r_cs = tp->tf_cs;
+	regs->r_eflags = tp->tf_rflags;
+	regs->r_esp = tp->tf_rsp;
+	regs->r_ss = tp->tf_ss;
+	regs->r_gs = pcb->pcb_gs;
+	return (0);
+}
+
+int
+set_regs32(struct thread *td, struct reg32 *regs)
+{
+	struct pcb *pcb;
+	struct trapframe *tp;
+
+	tp = td->td_frame;
+	if (!EFL_SECURE(regs->r_eflags, tp->tf_rflags) || !CS_SECURE(regs->r_cs))
+		return (EINVAL);
+	pcb = td->td_pcb;
+	load_fs(regs->r_fs);
+	pcb->pcb_fs = regs->r_fs;
+	load_es(regs->r_es);
+	pcb->pcb_es = regs->r_es;
+	load_ds(regs->r_ds);
+	pcb->pcb_ds = regs->r_ds;
+	tp->tf_rdi = regs->r_edi;
+	tp->tf_rsi = regs->r_esi;
+	tp->tf_rbp = regs->r_ebp;
+	tp->tf_rbx = regs->r_ebx;
+	tp->tf_rdx = regs->r_edx;
+	tp->tf_rcx = regs->r_ecx;
+	tp->tf_rax = regs->r_eax;
+	tp->tf_rip = regs->r_eip;
+	tp->tf_cs = regs->r_cs;
+	tp->tf_rflags = regs->r_eflags;
+	tp->tf_rsp = regs->r_esp;
+	tp->tf_ss = regs->r_ss;
+	load_gs(regs->r_gs);
+	pcb->pcb_gs = regs->r_gs;
+	return (0);
+}
+
+int
+fill_fpregs32(struct thread *td, struct fpreg32 *regs)
+{
+	struct save87 *sv_87 = (struct save87 *)regs;
+	struct env87 *penv_87 = &sv_87->sv_env;
+	struct savefpu *sv_fpu = &td->td_pcb->pcb_save;
+	struct envxmm *penv_xmm = &sv_fpu->sv_env;
+	int i;
+
+	bzero(regs, sizeof(*regs));
+	
+	/* FPU control/status */
+	penv_87->en_cw = penv_xmm->en_cw;
+	penv_87->en_sw = penv_xmm->en_sw;
+	penv_87->en_tw = penv_xmm->en_tw;
+	/*
+	 * XXX for en_fip/fcs/foo/fos, check if the fxsave format
+	 * uses the old-style layout for 32 bit user apps.  If so,
+	 * read the ip and operand segment registers from there.
+	 * For now, use the process's %cs/%ds.
+	 */
+	penv_87->en_fip = penv_xmm->en_rip;
+	penv_87->en_fcs = td->td_frame->tf_cs;
+	penv_87->en_opcode = penv_xmm->en_opcode;
+	penv_87->en_foo = penv_xmm->en_rdp;
+	penv_87->en_fos = td->td_pcb->pcb_ds;
+
+	/* FPU registers */
+	for (i = 0; i < 8; ++i)
+		sv_87->sv_ac[i] = sv_fpu->sv_fp[i].fp_acc;
+
+	return (0);
+}
+
+int
+set_fpregs32(struct thread *td, struct fpreg32 *regs)
+{
+	struct save87 *sv_87 = (struct save87 *)regs;
+	struct env87 *penv_87 = &sv_87->sv_env;
+	struct savefpu *sv_fpu = &td->td_pcb->pcb_save;
+	struct envxmm *penv_xmm = &sv_fpu->sv_env;
+	int i;
+
+	/* FPU control/status */
+	penv_xmm->en_cw = penv_87->en_cw;
+	penv_xmm->en_sw = penv_87->en_sw;
+	penv_xmm->en_tw = penv_87->en_tw;
+	penv_xmm->en_rip = penv_87->en_fip;
+	/* penv_87->en_fcs and en_fos ignored, see above */
+	penv_xmm->en_opcode = penv_87->en_opcode;
+	penv_xmm->en_rdp = penv_87->en_foo;
+
+	/* FPU registers */
+	for (i = 0; i < 8; ++i)
+		sv_fpu->sv_fp[i].fp_acc = sv_87->sv_ac[i];
+	for (i = 8; i < 16; ++i)
+		bzero(&sv_fpu->sv_fp[i].fp_acc, sizeof(sv_fpu->sv_fp[i].fp_acc));
+
+	return (0);
+}
+
+int
+fill_dbregs32(struct thread *td, struct dbreg32 *regs)
+{
+	struct dbreg dr;
+	int err, i;
+
+	err = fill_dbregs(td, &dr);
+	for (i = 0; i < 8; i++)
+		regs->dr[i] = dr.dr[i];
+	for (i = 8; i < 16; i++)
+		regs->dr[i] = 0;
+	return (err);
+}
+
+int
+set_dbregs32(struct thread *td, struct dbreg32 *regs)
+{
+	struct dbreg dr;
+	int i;
+
+	for (i = 0; i < 8; i++)
+		dr.dr[i] = regs->dr[i];
+	for (i = 8; i < 16; i++)
+		dr.dr[i] = 0;
+	return (set_dbregs(td, &dr));
+}