On 21/2/24 17:59, Thomas Huth wrote:
On 21/02/2024 17.26, Thomas Huth wrote:
From: Peter Maydell <peter.mayd...@linaro.org>
QEMU has historically used variable length arrays only very rarely.
Variable length arrays are a potential security issue where an
on-stack dynamic allocation isn't correctly size-checked, especially
when the size comes from the guest. (An example problem of this kind
from the past is CVE-2021-3527). Forbidding them entirely is a
defensive measure against further bugs of this kind.
Enable -Wvla to prevent any new uses from sneaking into the codebase.
Signed-off-by: Peter Maydell <peter.mayd...@linaro.org>
Message-ID: <20240125173211.1786196-3-peter.mayd...@linaro.org>
[thuth: rebased to current master branch]
Signed-off-by: Thomas Huth <th...@redhat.com>
---
meson.build | 1 +
1 file changed, 1 insertion(+)
Reviewed-by: Philippe Mathieu-Daudé <phi...@linaro.org>
Tested-by: Philippe Mathieu-Daudé <phi...@linaro.org>
diff --git a/meson.build b/meson.build
index c1dc83e4c0..0ef1654e86 100644
--- a/meson.build
+++ b/meson.build
@@ -592,6 +592,7 @@ warn_flags = [
'-Wstrict-prototypes',
'-Wtype-limits',
'-Wundef',
+ '-Wvla',
'-Wwrite-strings',
# Then disable some undesirable warnings
Sigh, there's a new warning in the latest master branch:
https://gitlab.com/thuth/qemu/-/jobs/6225992174
Caused by commit d65aba828 ("hw/sparc/leon3: implement multiprocessor")...
Clément, Philippe, could this maybe be written in a different way that
does not trigger a -Wvla warning?
Clément, ResetData::entry isn't used, so we can simplify removing
the whole ResetData structure, but I'm not sure this is intended:
-- >8 --
diff --git a/hw/sparc/leon3.c b/hw/sparc/leon3.c
index 4873b59b6c..1ff6b5d63d 100644
--- a/hw/sparc/leon3.c
+++ b/hw/sparc/leon3.c
@@ -68,14 +68,6 @@
#define LEON3_APB_PNP_OFFSET (0x800FF000)
#define LEON3_AHB_PNP_OFFSET (0xFFFFF000)
-typedef struct ResetData {
- struct CPUResetData {
- int id;
- SPARCCPU *cpu;
- } info[MAX_CPUS];
- uint32_t entry; /* save kernel entry in case of reset */
-} ResetData;
-
static uint32_t *gen_store_u32(uint32_t *code, hwaddr addr, uint32_t val)
{
stl_p(code++, 0x82100000); /* mov %g0, %g1 */
@@ -148,17 +140,14 @@ static void write_bootloader(void *ptr, hwaddr
kernel_addr)
static void leon3_cpu_reset(void *opaque)
{
- struct CPUResetData *info = (struct CPUResetData *) opaque;
- int id = info->id;
- ResetData *s = (ResetData *)DO_UPCAST(ResetData, info[id], info);
- CPUState *cpu = CPU(s->info[id].cpu);
+ CPUState *cpu = opaque;
CPUSPARCState *env = cpu_env(cpu);
cpu_reset(cpu);
cpu->halted = cpu->cpu_index != 0;
- env->pc = s->entry;
- env->npc = s->entry + 4;
+ env->pc = LEON3_PROM_OFFSET;
+ env->npc = LEON3_PROM_OFFSET + 4;
}
static void leon3_cache_control_int(CPUSPARCState *env)
@@ -259,7 +248,7 @@ static void leon3_generic_hw_init(MachineState *machine)
ram_addr_t ram_size = machine->ram_size;
const char *bios_name = machine->firmware ?: LEON3_PROM_FILENAME;
const char *kernel_filename = machine->kernel_filename;
- SPARCCPU *cpu;
+ SPARCCPU *cpu[MAX_CPUS];
CPUSPARCState *env;
MemoryRegion *address_space_mem = get_system_memory();
MemoryRegion *prom = g_new(MemoryRegion, 1);
@@ -267,28 +256,22 @@ static void leon3_generic_hw_init(MachineState
*machine)
char *filename;
int bios_size;
int prom_size;
- ResetData *reset_info;
DeviceState *dev, *irqmpdev;
int i;
AHBPnp *ahb_pnp;
APBPnp *apb_pnp;
- reset_info = g_malloc0(sizeof(ResetData));
-
for (i = 0; i < machine->smp.cpus; i++) {
/* Init CPU */
- cpu = SPARC_CPU(object_new(machine->cpu_type));
- qdev_init_gpio_in_named(DEVICE(cpu), leon3_start_cpu,
"start_cpu", 1);
- qdev_init_gpio_in_named(DEVICE(cpu), leon3_set_pil_in, "pil", 1);
- qdev_realize(DEVICE(cpu), NULL, &error_fatal);
- env = &cpu->env;
+ cpu[i] = SPARC_CPU(object_new(machine->cpu_type));
+ qdev_init_gpio_in_named(DEVICE(cpu[i]), leon3_start_cpu,
"start_cpu", 1);
+ qdev_init_gpio_in_named(DEVICE(cpu[i]), leon3_set_pil_in,
"pil", 1);
+ qdev_realize(DEVICE(cpu[i]), NULL, &error_fatal);
+ env = &cpu[i]->env;
cpu_sparc_set_id(env, i);
- /* Reset data */
- reset_info->info[i].id = i;
- reset_info->info[i].cpu = cpu;
- qemu_register_reset(leon3_cpu_reset, &reset_info->info[i]);
+ qemu_register_reset(leon3_cpu_reset, cpu[i]);
}
ahb_pnp = GRLIB_AHB_PNP(qdev_new(TYPE_GRLIB_AHB_PNP));
@@ -312,13 +295,12 @@ static void leon3_generic_hw_init(MachineState
*machine)
sysbus_realize_and_unref(SYS_BUS_DEVICE(irqmpdev), &error_fatal);
for (i = 0; i < machine->smp.cpus; i++) {
- cpu = reset_info->info[i].cpu;
- env = &cpu->env;
+ env = &cpu[i]->env;
qdev_connect_gpio_out_named(irqmpdev, "grlib-start-cpu", i,
- qdev_get_gpio_in_named(DEVICE(cpu),
+ qdev_get_gpio_in_named(DEVICE(cpu[i]),
"start_cpu", 0));
qdev_connect_gpio_out_named(irqmpdev, "grlib-irq", i,
- qdev_get_gpio_in_named(DEVICE(cpu),
+ qdev_get_gpio_in_named(DEVICE(cpu[i]),
"pil", 0));
env->irq_manager = irqmpdev;
env->qemu_irq_ack = leon3_irq_manager;
@@ -396,11 +378,6 @@ static void leon3_generic_hw_init(MachineState
*machine)
* bootloader.
*/
write_bootloader(memory_region_get_ram_ptr(prom), entry);
- reset_info->entry = LEON3_PROM_OFFSET;
- for (i = 0; i < machine->smp.cpus; i++) {
- reset_info->info[i].cpu->env.pc = LEON3_PROM_OFFSET;
- reset_info->info[i].cpu->env.npc = LEON3_PROM_OFFSET + 4;
- }
}
}
---
Regards,
Phil.
