Replace the unsafe read-loops in the x86 kernel image loading
functions with our safe read_file() and read_in_full() wrappers.
This should fix random fails in kernel image loading, especially
from pipes and sockets.
Signed-off-by: Andre Przywara <andre.przyw...@arm.com>
---
x86/kvm.c | 35 ++++++++++++++---------------------
1 file changed, 14 insertions(+), 21 deletions(-)
diff --git a/x86/kvm.c b/x86/kvm.c
index a0204b8..ae430a0 100644
--- a/x86/kvm.c
+++ b/x86/kvm.c
@@ -9,6 +9,7 @@
#include <asm/bootparam.h>
#include <linux/kvm.h>
+#include <linux/kernel.h>
#include <sys/types.h>
#include <sys/ioctl.h>
@@ -209,15 +210,14 @@ static inline void *guest_real_to_host(struct kvm *kvm,
u16 selector, u16 offset
static bool load_flat_binary(struct kvm *kvm, int fd_kernel)
{
void *p;
- int nr;
if (lseek(fd_kernel, 0, SEEK_SET) < 0)
die_perror("lseek");
p = guest_real_to_host(kvm, BOOT_LOADER_SELECTOR, BOOT_LOADER_IP);
- while ((nr = read(fd_kernel, p, 65536)) > 0)
- p += nr;
+ if (read_file(fd_kernel, p, kvm->cfg.ram_size) < 0)
+ die_perror("read");
kvm->arch.boot_selector = BOOT_LOADER_SELECTOR;
kvm->arch.boot_ip = BOOT_LOADER_IP;
@@ -232,12 +232,10 @@ static bool load_bzimage(struct kvm *kvm, int fd_kernel,
int fd_initrd,
const char *kernel_cmdline)
{
struct boot_params *kern_boot;
- unsigned long setup_sects;
struct boot_params boot;
size_t cmdline_size;
- ssize_t setup_size;
+ ssize_t file_size;
void *p;
- int nr;
u16 vidmode;
/*
@@ -248,7 +246,7 @@ static bool load_bzimage(struct kvm *kvm, int fd_kernel,
int fd_initrd,
if (lseek(fd_kernel, 0, SEEK_SET) < 0)
die_perror("lseek");
- if (read(fd_kernel, &boot, sizeof(boot)) != sizeof(boot))
+ if (read_in_full(fd_kernel, &boot, sizeof(boot)) != sizeof(boot))
return false;
if (memcmp(&boot.hdr.header, BZIMAGE_MAGIC, strlen(BZIMAGE_MAGIC)))
@@ -262,20 +260,17 @@ static bool load_bzimage(struct kvm *kvm, int fd_kernel,
int fd_initrd,
if (!boot.hdr.setup_sects)
boot.hdr.setup_sects = BZ_DEFAULT_SETUP_SECTS;
- setup_sects = boot.hdr.setup_sects + 1;
-
- setup_size = setup_sects << 9;
+ file_size = (boot.hdr.setup_sects + 1) << 9;
p = guest_real_to_host(kvm, BOOT_LOADER_SELECTOR, BOOT_LOADER_IP);
+ if (read_in_full(fd_kernel, p, file_size) != file_size)
+ die_perror("kernel setup read");
- /* copy setup.bin to mem*/
- if (read(fd_kernel, p, setup_size) != setup_size)
- die_perror("read");
-
- /* copy vmlinux.bin to BZ_KERNEL_START*/
+ /* read actual kernel image (vmlinux.bin) to BZ_KERNEL_START */
p = guest_flat_to_host(kvm, BZ_KERNEL_START);
-
- while ((nr = read(fd_kernel, p, 65536)) > 0)
- p += nr;
+ file_size = read_file(fd_kernel, p,
+ kvm->cfg.ram_size - BZ_KERNEL_START);
+ if (file_size < 0)
+ die_perror("kernel read");
p = guest_flat_to_host(kvm, BOOT_CMDLINE_OFFSET);
if (kernel_cmdline) {
@@ -287,7 +282,6 @@ static bool load_bzimage(struct kvm *kvm, int fd_kernel,
int fd_initrd,
memcpy(p, kernel_cmdline, cmdline_size - 1);
}
-
/* vidmode should be either specified or set by default */
if (kvm->cfg.vnc || kvm->cfg.sdl || kvm->cfg.gtk) {
if (!kvm->cfg.arch.vidmode)
@@ -326,8 +320,7 @@ static bool load_bzimage(struct kvm *kvm, int fd_kernel,
int fd_initrd,
}
p = guest_flat_to_host(kvm, addr);
- nr = read(fd_initrd, p, initrd_stat.st_size);
- if (nr != initrd_stat.st_size)
+ if (read_in_full(fd_initrd, p, initrd_stat.st_size) < 0)
die("Failed to read initrd");
kern_boot->hdr.ramdisk_image = addr;
--
2.5.1
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