qemu/hw/i386/pci-assign-load-rom.c
Paolo Bonzini 9ed2690354 pci-assign: avoid pointless stat
Just check the errno value after fopen and follow it with fstat.
This shuts up Coverity's complaint about TOC/TOU violation.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2017-01-24 23:26:53 +03:00

89 lines
2.7 KiB
C

/*
* This is splited from hw/i386/kvm/pci-assign.c
*/
#include "qemu/osdep.h"
#include "qapi/error.h"
#include "hw/hw.h"
#include "hw/i386/pc.h"
#include "qemu/error-report.h"
#include "ui/console.h"
#include "hw/loader.h"
#include "monitor/monitor.h"
#include "qemu/range.h"
#include "sysemu/sysemu.h"
#include "hw/pci/pci.h"
#include "hw/pci/pci-assign.h"
/*
* Scan the assigned devices for the devices that have an option ROM, and then
* load the corresponding ROM data to RAM. If an error occurs while loading an
* option ROM, we just ignore that option ROM and continue with the next one.
*/
void *pci_assign_dev_load_option_rom(PCIDevice *dev, struct Object *owner,
int *size, unsigned int domain,
unsigned int bus, unsigned int slot,
unsigned int function)
{
char name[32], rom_file[64];
FILE *fp;
uint8_t val;
struct stat st;
void *ptr = NULL;
/* If loading ROM from file, pci handles it */
if (dev->romfile || !dev->rom_bar) {
return NULL;
}
snprintf(rom_file, sizeof(rom_file),
"/sys/bus/pci/devices/%04x:%02x:%02x.%01x/rom",
domain, bus, slot, function);
/* Write "1" to the ROM file to enable it */
fp = fopen(rom_file, "r+");
if (fp == NULL) {
if (errno != ENOENT) {
error_report("pci-assign: Cannot open %s: %s", rom_file, strerror(errno));
}
return NULL;
}
if (fstat(fileno(fp), &st) == -1) {
error_report("pci-assign: Cannot stat %s: %s", rom_file, strerror(errno));
goto close_rom;
}
val = 1;
if (fwrite(&val, 1, 1, fp) != 1) {
goto close_rom;
}
fseek(fp, 0, SEEK_SET);
snprintf(name, sizeof(name), "%s.rom", object_get_typename(owner));
memory_region_init_ram(&dev->rom, owner, name, st.st_size, &error_abort);
vmstate_register_ram(&dev->rom, &dev->qdev);
ptr = memory_region_get_ram_ptr(&dev->rom);
memset(ptr, 0xff, st.st_size);
if (!fread(ptr, 1, st.st_size, fp)) {
error_report("pci-assign: Cannot read from host %s", rom_file);
error_printf("Device option ROM contents are probably invalid "
"(check dmesg).\nSkip option ROM probe with rombar=0, "
"or load from file with romfile=\n");
goto close_rom;
}
pci_register_bar(dev, PCI_ROM_SLOT, 0, &dev->rom);
dev->has_rom = true;
*size = st.st_size;
close_rom:
/* Write "0" to disable ROM */
fseek(fp, 0, SEEK_SET);
val = 0;
if (!fwrite(&val, 1, 1, fp)) {
DEBUG("%s\n", "Failed to disable pci-sysfs rom file");
}
fclose(fp);
return ptr;
}