freebsd-skq/sys/x86/xen/pv.c
royger 040f3ac494 xen: fix usage of kern_getenv in PVH code
The value returned by kern_getenv should be freed using freeenv.

Reported by:	Coverity
CID:		1248852
Sponsored by: Citrix Systems R&D
2014-10-22 16:49:00 +00:00

413 lines
11 KiB
C

/*
* Copyright (c) 2004 Christian Limpach.
* Copyright (c) 2004-2006,2008 Kip Macy
* Copyright (c) 2008 The NetBSD Foundation, Inc.
* Copyright (c) 2013 Roger Pau Monné <roger.pau@citrix.com>
* 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_ddb.h"
#include <sys/param.h>
#include <sys/bus.h>
#include <sys/kernel.h>
#include <sys/reboot.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/linker.h>
#include <sys/lock.h>
#include <sys/rwlock.h>
#include <sys/boot.h>
#include <sys/ctype.h>
#include <sys/mutex.h>
#include <sys/smp.h>
#include <vm/vm.h>
#include <vm/vm_extern.h>
#include <vm/vm_kern.h>
#include <vm/vm_page.h>
#include <vm/vm_map.h>
#include <vm/vm_object.h>
#include <vm/vm_pager.h>
#include <vm/vm_param.h>
#include <machine/intr_machdep.h>
#include <x86/apicvar.h>
#include <x86/init.h>
#include <machine/pc/bios.h>
#include <machine/smp.h>
#include <machine/intr_machdep.h>
#include <xen/xen-os.h>
#include <xen/hypervisor.h>
#include <xen/xenstore/xenstorevar.h>
#include <xen/xen_pv.h>
#include <xen/xen_msi.h>
#include <xen/interface/vcpu.h>
#include <dev/xen/timer/timer.h>
#ifdef DDB
#include <ddb/ddb.h>
#endif
/* Native initial function */
extern u_int64_t hammer_time(u_int64_t, u_int64_t);
/* Xen initial function */
uint64_t hammer_time_xen(start_info_t *, uint64_t);
#define MAX_E820_ENTRIES 128
/*--------------------------- Forward Declarations ---------------------------*/
static caddr_t xen_pv_parse_preload_data(u_int64_t);
static void xen_pv_parse_memmap(caddr_t, vm_paddr_t *, int *);
#ifdef SMP
static int xen_pv_start_all_aps(void);
#endif
/*---------------------------- Extern Declarations ---------------------------*/
#ifdef SMP
/* Variables used by amd64 mp_machdep to start APs */
extern struct mtx ap_boot_mtx;
extern void *bootstacks[];
extern char *doublefault_stack;
extern char *nmi_stack;
extern void *dpcpu;
extern int bootAP;
extern char *bootSTK;
#endif
/*
* Placed by the linker at the end of the bss section, which is the last
* section loaded by Xen before loading the symtab and strtab.
*/
extern uint32_t end;
/*-------------------------------- Global Data -------------------------------*/
/* Xen init_ops implementation. */
struct init_ops xen_init_ops = {
.parse_preload_data = xen_pv_parse_preload_data,
.early_clock_source_init = xen_clock_init,
.early_delay = xen_delay,
.parse_memmap = xen_pv_parse_memmap,
#ifdef SMP
.start_all_aps = xen_pv_start_all_aps,
#endif
.msi_init = xen_msi_init,
};
static struct bios_smap xen_smap[MAX_E820_ENTRIES];
/*-------------------------------- Xen PV init -------------------------------*/
/*
* First function called by the Xen PVH boot sequence.
*
* Set some Xen global variables and prepare the environment so it is
* as similar as possible to what native FreeBSD init function expects.
*/
uint64_t
hammer_time_xen(start_info_t *si, uint64_t xenstack)
{
uint64_t physfree;
uint64_t *PT4 = (u_int64_t *)xenstack;
uint64_t *PT3 = (u_int64_t *)(xenstack + PAGE_SIZE);
uint64_t *PT2 = (u_int64_t *)(xenstack + 2 * PAGE_SIZE);
int i;
xen_domain_type = XEN_PV_DOMAIN;
vm_guest = VM_GUEST_XEN;
if ((si == NULL) || (xenstack == 0)) {
xc_printf("ERROR: invalid start_info or xen stack, halting\n");
HYPERVISOR_shutdown(SHUTDOWN_crash);
}
xc_printf("FreeBSD PVH running on %s\n", si->magic);
/* We use 3 pages of xen stack for the boot pagetables */
physfree = xenstack + 3 * PAGE_SIZE - KERNBASE;
/* Setup Xen global variables */
HYPERVISOR_start_info = si;
HYPERVISOR_shared_info =
(shared_info_t *)(si->shared_info + KERNBASE);
/*
* Setup some misc global variables for Xen devices
*
* XXX: Devices that need these specific variables should
* be rewritten to fetch this info by themselves from the
* start_info page.
*/
xen_store = (struct xenstore_domain_interface *)
(ptoa(si->store_mfn) + KERNBASE);
console_page = (char *)(ptoa(si->console.domU.mfn) + KERNBASE);
/*
* Use the stack Xen gives us to build the page tables
* as native FreeBSD expects to find them (created
* by the boot trampoline).
*/
for (i = 0; i < (PAGE_SIZE / sizeof(uint64_t)); i++) {
/*
* Each slot of the level 4 pages points
* to the same level 3 page
*/
PT4[i] = ((uint64_t)&PT3[0]) - KERNBASE;
PT4[i] |= PG_V | PG_RW | PG_U;
/*
* Each slot of the level 3 pages points
* to the same level 2 page
*/
PT3[i] = ((uint64_t)&PT2[0]) - KERNBASE;
PT3[i] |= PG_V | PG_RW | PG_U;
/*
* The level 2 page slots are mapped with
* 2MB pages for 1GB.
*/
PT2[i] = i * (2 * 1024 * 1024);
PT2[i] |= PG_V | PG_RW | PG_PS | PG_U;
}
load_cr3(((uint64_t)&PT4[0]) - KERNBASE);
/* Set the hooks for early functions that diverge from bare metal */
init_ops = xen_init_ops;
apic_ops = xen_apic_ops;
/* Now we can jump into the native init function */
return (hammer_time(0, physfree));
}
/*-------------------------------- PV specific -------------------------------*/
#ifdef SMP
static bool
start_xen_ap(int cpu)
{
struct vcpu_guest_context *ctxt;
int ms, cpus = mp_naps;
const size_t stacksize = KSTACK_PAGES * PAGE_SIZE;
/* allocate and set up an idle stack data page */
bootstacks[cpu] =
(void *)kmem_malloc(kernel_arena, stacksize, M_WAITOK | M_ZERO);
doublefault_stack =
(char *)kmem_malloc(kernel_arena, PAGE_SIZE, M_WAITOK | M_ZERO);
nmi_stack =
(char *)kmem_malloc(kernel_arena, PAGE_SIZE, M_WAITOK | M_ZERO);
dpcpu =
(void *)kmem_malloc(kernel_arena, DPCPU_SIZE, M_WAITOK | M_ZERO);
bootSTK = (char *)bootstacks[cpu] + KSTACK_PAGES * PAGE_SIZE - 8;
bootAP = cpu;
ctxt = malloc(sizeof(*ctxt), M_TEMP, M_WAITOK | M_ZERO);
if (ctxt == NULL)
panic("unable to allocate memory");
ctxt->flags = VGCF_IN_KERNEL;
ctxt->user_regs.rip = (unsigned long) init_secondary;
ctxt->user_regs.rsp = (unsigned long) bootSTK;
/* Set the AP to use the same page tables */
ctxt->ctrlreg[3] = KPML4phys;
if (HYPERVISOR_vcpu_op(VCPUOP_initialise, cpu, ctxt))
panic("unable to initialize AP#%d", cpu);
free(ctxt, M_TEMP);
/* Launch the vCPU */
if (HYPERVISOR_vcpu_op(VCPUOP_up, cpu, NULL))
panic("unable to start AP#%d", cpu);
/* Wait up to 5 seconds for it to start. */
for (ms = 0; ms < 5000; ms++) {
if (mp_naps > cpus)
return (true);
DELAY(1000);
}
return (false);
}
static int
xen_pv_start_all_aps(void)
{
int cpu;
mtx_init(&ap_boot_mtx, "ap boot", NULL, MTX_SPIN);
for (cpu = 1; cpu < mp_ncpus; cpu++) {
/* attempt to start the Application Processor */
if (!start_xen_ap(cpu))
panic("AP #%d failed to start!", cpu);
CPU_SET(cpu, &all_cpus); /* record AP in CPU map */
}
return (mp_naps);
}
#endif /* SMP */
/*
* Functions to convert the "extra" parameters passed by Xen
* into FreeBSD boot options.
*/
static void
xen_pv_set_env(void)
{
char *cmd_line_next, *cmd_line;
size_t env_size;
cmd_line = HYPERVISOR_start_info->cmd_line;
env_size = sizeof(HYPERVISOR_start_info->cmd_line);
/* Skip leading spaces */
for (; isspace(*cmd_line) && (env_size != 0); cmd_line++)
env_size--;
/* Replace ',' with '\0' */
for (cmd_line_next = cmd_line; strsep(&cmd_line_next, ",") != NULL;)
;
init_static_kenv(cmd_line, env_size);
}
static void
xen_pv_set_boothowto(void)
{
int i;
char *env;
/* get equivalents from the environment */
for (i = 0; howto_names[i].ev != NULL; i++) {
if ((env = kern_getenv(howto_names[i].ev)) != NULL) {
boothowto |= howto_names[i].mask;
freeenv(env);
}
}
}
#ifdef DDB
/*
* The way Xen loads the symtab is different from the native boot loader,
* because it's tailored for NetBSD. So we have to adapt and use the same
* method as NetBSD. Portions of the code below have been picked from NetBSD:
* sys/kern/kern_ksyms.c CVS Revision 1.71.
*/
static void
xen_pv_parse_symtab(void)
{
Elf_Ehdr *ehdr;
Elf_Shdr *shdr;
vm_offset_t sym_end;
uint32_t size;
int i, j;
size = end;
sym_end = HYPERVISOR_start_info->mod_start != 0 ?
HYPERVISOR_start_info->mod_start :
HYPERVISOR_start_info->mfn_list;
/*
* Make sure the size is right headed, sym_end is just a
* high boundary, but at least allows us to fail earlier.
*/
if ((vm_offset_t)&end + size > sym_end) {
xc_printf("Unable to load ELF symtab: size mismatch\n");
return;
}
ehdr = (Elf_Ehdr *)(&end + 1);
if (memcmp(ehdr->e_ident, ELFMAG, SELFMAG) ||
ehdr->e_ident[EI_CLASS] != ELF_TARG_CLASS ||
ehdr->e_version > 1) {
xc_printf("Unable to load ELF symtab: invalid symbol table\n");
return;
}
shdr = (Elf_Shdr *)((uint8_t *)ehdr + ehdr->e_shoff);
/* Find the symbol table and the corresponding string table. */
for (i = 1; i < ehdr->e_shnum; i++) {
if (shdr[i].sh_type != SHT_SYMTAB)
continue;
if (shdr[i].sh_offset == 0)
continue;
ksymtab = (uintptr_t)((uint8_t *)ehdr + shdr[i].sh_offset);
ksymtab_size = shdr[i].sh_size;
j = shdr[i].sh_link;
if (shdr[j].sh_offset == 0)
continue; /* Can this happen? */
kstrtab = (uintptr_t)((uint8_t *)ehdr + shdr[j].sh_offset);
break;
}
if (ksymtab == 0 || kstrtab == 0) {
xc_printf(
"Unable to load ELF symtab: could not find symtab or strtab\n");
return;
}
}
#endif
static caddr_t
xen_pv_parse_preload_data(u_int64_t modulep)
{
/* Parse the extra boot information given by Xen */
xen_pv_set_env();
xen_pv_set_boothowto();
#ifdef DDB
xen_pv_parse_symtab();
#endif
return (NULL);
}
static void
xen_pv_parse_memmap(caddr_t kmdp, vm_paddr_t *physmap, int *physmap_idx)
{
struct xen_memory_map memmap;
u_int32_t size;
int rc;
/* Fetch the E820 map from Xen */
memmap.nr_entries = MAX_E820_ENTRIES;
set_xen_guest_handle(memmap.buffer, xen_smap);
rc = HYPERVISOR_memory_op(XENMEM_memory_map, &memmap);
if (rc)
panic("unable to fetch Xen E820 memory map");
size = memmap.nr_entries * sizeof(xen_smap[0]);
bios_add_smap_entries(xen_smap, size, physmap, physmap_idx);
}