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Merged
jeremyhu merged 3 commits into from
Dec 3, 2018
Merged

kexec: fix wrong calculation method of ramdisk_start #119

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6f52019
kexec: fix typo for initrd_addr_max
zchee Oct 21, 2016
8f6044f
kexec: fix wrong calculation method of ramdisk_start
zchee Oct 21, 2016
031f2dd
kexec: Rename "memory" to "lowmem".
zchee Oct 21, 2016
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2 changes: 1 addition & 1 deletion include/xhyve/firmware/kexec.h
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Original file line number Diff line number Diff line change
Expand Up @@ -29,7 +29,7 @@ struct setup_header {
uint8_t ext_loader_ver; /* Extended boot loader version */
uint8_t ext_loader_type; /* Extended boot loader ID */
uint32_t cmd_line_ptr; /* 32-bit pointer to the kernel command line */
uint32_t nitrd_addr_max; /* Highest legal initrd address */
uint32_t initrd_addr_max; /* Highest legal initrd address */
uint32_t kernel_alignment; /* Physical addr alignment required for kernel */
uint8_t relocatable_kernel; /* Whether kernel is relocatable or not */
uint8_t min_alignment; /* Minimum alignment, as a power of two */
Expand Down
50 changes: 33 additions & 17 deletions src/firmware/kexec.c
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Original file line number Diff line number Diff line change
Expand Up @@ -35,6 +35,10 @@
#define ALIGNUP(x, a) (((x - 1) & ~(a - 1)) + a)
#endif

#ifndef ALIGNDOWN
#define ALIGNDOWN(x, a) (-(a) & (x))
#endif

#define BASE_GDT 0x2000ull
#define BASE_ZEROPAGE 0x3000ull
#define BASE_CMDLINE 0x4000ull
Expand All @@ -44,7 +48,7 @@
static struct {
uintptr_t base;
size_t size;
} memory, kernel, ramdisk;
} lowmem, kernel, ramdisk;

static struct {
char *kernel;
Expand All @@ -59,13 +63,13 @@ kexec_load_kernel(char *path, char *cmdline) {
volatile struct zero_page *zp;
FILE *f;

if ((memory.size < (BASE_ZEROPAGE + sizeof(struct zero_page))) ||
if ((lowmem.size < (BASE_ZEROPAGE + sizeof(struct zero_page))) ||
((BASE_ZEROPAGE + sizeof(struct zero_page)) > BASE_CMDLINE))
{
return -1;
}

zp = ((struct zero_page *) (memory.base + ((off_t) BASE_ZEROPAGE)));
zp = ((struct zero_page *) (lowmem.base + ((off_t) BASE_ZEROPAGE)));

memset(((void *) ((uintptr_t) zp)), 0, sizeof(struct zero_page));

Expand Down Expand Up @@ -112,15 +116,15 @@ kexec_load_kernel(char *path, char *cmdline) {

if ((kernel_start < BASE_KERNEL) ||
(kernel_size > kernel_init_size) || /* XXX: always true? */
((kernel_start + kernel_init_size) > memory.size)) /* oom */
((kernel_start + kernel_init_size) > lowmem.size)) /* oom */
{
fclose(f);
return -1;
}

/* copy kernel */
fseek(f, ((long) kernel_offset), SEEK_SET);
if (!fread(((void *) (memory.base + kernel_start)), 1, kernel_size, f)) {
if (!fread(((void *) (lowmem.base + kernel_start)), 1, kernel_size, f)) {
fclose(f);
return -1;
}
Expand All @@ -135,22 +139,22 @@ kexec_load_kernel(char *path, char *cmdline) {
return -1;
}

memcpy(((void *) (memory.base + BASE_CMDLINE)), cmdline, cmdline_len);
memset(((void *) (memory.base + BASE_CMDLINE + cmdline_len)), '\0', 1);
memcpy(((void *) (lowmem.base + BASE_CMDLINE)), cmdline, cmdline_len);
memset(((void *) (lowmem.base + BASE_CMDLINE + cmdline_len)), '\0', 1);
zp->setup_header.cmd_line_ptr = ((uint32_t) BASE_CMDLINE);
zp->ext_cmd_line_ptr = ((uint32_t) (BASE_CMDLINE >> 32));

zp->setup_header.hardware_subarch = 0; /* PC */
zp->setup_header.type_of_loader = 0xd; /* kexec */

mem_k = (memory.size - 0x100000) >> 10; /* assume memory base is at 0 */
mem_k = (lowmem.size - 0x100000) >> 10; /* assume lowmem base is at 0 */
zp->alt_mem_k = (mem_k > 0xffffffff) ? 0xffffffff : ((uint32_t) mem_k);

zp->e820_map[0].addr = 0x0000000000000000;
zp->e820_map[0].size = 0x000000000009fc00;
zp->e820_map[0].type = 1;
zp->e820_map[1].addr = 0x0000000000100000;
zp->e820_map[1].size = (memory.size - 0x0000000000100000);
zp->e820_map[1].size = (lowmem.size - 0x0000000000100000);
zp->e820_map[1].type = 1;
if (xh_vm_get_highmem_size() == 0) {
zp->e820_entries = 2;
Expand All @@ -170,11 +174,12 @@ kexec_load_kernel(char *path, char *cmdline) {
static int
kexec_load_ramdisk(char *path) {
uint64_t ramdisk_start;
uint32_t initrd_max;
volatile struct zero_page *zp;
size_t sz;
FILE *f;

zp = ((struct zero_page *) (memory.base + BASE_ZEROPAGE));
zp = ((struct zero_page *) (lowmem.base + BASE_ZEROPAGE));

if (!(f = fopen(path, "r"))) {;
return -1;
Expand All @@ -184,16 +189,27 @@ kexec_load_ramdisk(char *path) {
sz = (size_t) ftell(f);
fseek(f, 0, SEEK_SET);

ramdisk_start = ALIGNUP((kernel.base + kernel.size), 0x1000ull);
/* highest address for loading the initrd */
if (zp->setup_header.version >= 0x203) {
initrd_max = zp->setup_header.initrd_addr_max;
} else {
initrd_max = 0x37ffffff; /* Hardcoded value for older kernels */
}

if (initrd_max >= lowmem.size) {
initrd_max = ((uint32_t) lowmem.size - 1);
}

ramdisk_start = ALIGNDOWN(initrd_max - sz, 0x1000ull);

if ((ramdisk_start + sz) > memory.size) {
/* not enough memory */
if ((ramdisk_start + sz) > lowmem.size) {
/* not enough lowmem */
fclose(f);
return -1;
}

/* copy ramdisk */
if (!fread(((void *) (memory.base + ramdisk_start)), 1, sz, f)) {
if (!fread(((void *) (lowmem.base + ramdisk_start)), 1, sz, f)) {
fclose(f);
return -1;
}
Expand Down Expand Up @@ -225,8 +241,8 @@ kexec(void)
void *gpa_map;

gpa_map = xh_vm_map_gpa(0, xh_vm_get_lowmem_size());
memory.base = (uintptr_t) gpa_map;
memory.size = xh_vm_get_lowmem_size();
lowmem.base = (uintptr_t) gpa_map;
lowmem.size = xh_vm_get_lowmem_size();

if (kexec_load_kernel(config.kernel,
config.cmdline ? config.cmdline : "auto"))
Expand All @@ -240,7 +256,7 @@ kexec(void)
abort();
}

gdt_entry = ((uint64_t *) (memory.base + BASE_GDT));
gdt_entry = ((uint64_t *) (lowmem.base + BASE_GDT));
gdt_entry[0] = 0x0000000000000000; /* null */
gdt_entry[1] = 0x0000000000000000; /* null */
gdt_entry[2] = 0x00cf9a000000ffff; /* code */
Expand Down