[PATCH] hw/i386/fw_cfg: Use g_new() and g_new0() instead of g_malloc()

[PATCH] hw/i386/fw_cfg: Use g_new() and g_new0() instead of g_malloc()

[Sourish Dutta Sharma]

Replace g_malloc() and g_malloc0() calls that calculate the allocation
size using sizeof() with the type-safe g_new() and g_new0() macros.

This aligns the code with QEMU's coding style guidelines, improving
readability and protecting against potential integer overflow
vulnerabilities when allocating arrays.

Signed-off-by: Sourish Duttta Sharma  <sourishduttasharma770@gmail.com>
---
 hw/i386/fw_cfg.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/hw/i386/fw_cfg.c b/hw/i386/fw_cfg.c
index 5670e8553e..ae1ba3b6a2 100644
--- a/hw/i386/fw_cfg.c
+++ b/hw/i386/fw_cfg.c
@@ -91,7 +91,7 @@ void fw_cfg_build_smbios(PCMachineState *pcms, FWCfgState *fw_cfg,
 
     /* build the array of physical mem area from e820 table */
     nr_e820 = e820_get_table(NULL);
-    mem_array = g_malloc0(sizeof(*mem_array) * nr_e820);
+    mem_array = g_new0(struct smbios_phys_mem_area, nr_e820);
     for (i = 0, array_count = 0; i < nr_e820; i++) {
         uint64_t addr, len;
 
@@ -207,7 +207,7 @@ void fw_cfg_build_feature_control(MachineState *ms, FWCfgState *fw_cfg)
         return;
     }
 
-    val = g_malloc(sizeof(*val));
+    val = g_new(uint64_t, 1);
     *val = cpu_to_le64(feature_control_bits | FEATURE_CONTROL_LOCKED);
     fw_cfg_add_file(fw_cfg, "etc/msr_feature_control", val, sizeof(*val));
 }
-- 
2.51.0

Re: [PATCH] hw/i386/fw_cfg: Use g_new() and g_new0() instead of g_malloc()

[Thomas Huth]

On 24/02/2026 17.00, Sourish Dutta Sharma wrote:
> Replace g_malloc() and g_malloc0() calls that calculate the allocation
> size using sizeof() with the type-safe g_new() and g_new0() macros.
> 
> This aligns the code with QEMU's coding style guidelines, improving
> readability and protecting against potential integer overflow
> vulnerabilities when allocating arrays.
> 
> Signed-off-by: Sourish Duttta Sharma  <sourishduttasharma770@gmail.com>
> ---
>   hw/i386/fw_cfg.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)

  Hi!

Thanks for your patch! FWIW, fw_cfg is not really my turf, but since I was 
looking into malloc() related patches today, I noticed your patch which 
seems to have fallen through the cracks (sorry for this!), so I picked it up 
and added it to my latest pull request.

  Regards,
   Thomas

Re: [PATCH] hw/i386/fw_cfg: Use g_new() and g_new0() instead of g_malloc()

[Michael S. Tsirkin]

On Mon, Apr 27, 2026 at 12:02:57PM +0200, Thomas Huth wrote:
> On 24/02/2026 17.00, Sourish Dutta Sharma wrote:
> > Replace g_malloc() and g_malloc0() calls that calculate the allocation
> > size using sizeof() with the type-safe g_new() and g_new0() macros.
> > 
> > This aligns the code with QEMU's coding style guidelines, improving
> > readability and protecting against potential integer overflow
> > vulnerabilities when allocating arrays.
> > 
> > Signed-off-by: Sourish Duttta Sharma  <sourishduttasharma770@gmail.com>
> > ---
> >   hw/i386/fw_cfg.c | 4 ++--
> >   1 file changed, 2 insertions(+), 2 deletions(-)
> 
>  Hi!
> 
> Thanks for your patch! FWIW, fw_cfg is not really my turf, but since I was
> looking into malloc() related patches today, I noticed your patch which
> seems to have fallen through the cracks (sorry for this!), so I picked it up
> and added it to my latest pull request.
> 
>  Regards,
>   Thomas

Thanks for doing this. FWIW

Reviewed-by: Michael S. Tsirkin <mst@redhat.com>