[PATCH] gpu: nova-core: firmware: fwsec: use zeroed() to zero-pad buffers

[PATCH] gpu: nova-core: firmware: fwsec: use zeroed() to zero-pad buffers

[Thorsten Blum]

Use KVec::zeroed() to allocate the zero-padded microcode buffer and copy
the bootloader code into it. Also use KVVec::zeroed() to initialize the
firmware object's leading zero padding.

Signed-off-by: Thorsten Blum <blum@kernel.org>
---
 drivers/gpu/nova-core/firmware/fwsec/bootloader.rs | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/nova-core/firmware/fwsec/bootloader.rs b/drivers/gpu/nova-core/firmware/fwsec/bootloader.rs
index ec4d92317a93..37dcd4bf4711 100644
--- a/drivers/gpu/nova-core/firmware/fwsec/bootloader.rs
+++ b/drivers/gpu/nova-core/firmware/fwsec/bootloader.rs
@@ -137,10 +137,8 @@ pub(crate) fn new(
                 .align_up(Alignment::new::<{ falcon::MEM_BLOCK_ALIGNMENT }>())
                 .ok_or(EINVAL)?;
 
-            let mut ucode = KVec::with_capacity(aligned_code_size, GFP_KERNEL)?;
-            ucode.extend_from_slice(code, GFP_KERNEL)?;
-            ucode.resize(aligned_code_size, 0, GFP_KERNEL)?;
-
+            let mut ucode = KVec::zeroed(aligned_code_size, GFP_KERNEL)?;
+            ucode[..code.len()].copy_from_slice(code);
             ucode
         };
 
@@ -162,8 +160,7 @@ pub(crate) fn new(
                     .ok_or(EOVERFLOW)?
             };
 
-            let mut firmware_obj = KVVec::new();
-            firmware_obj.extend_with(align_padding, 0u8, GFP_KERNEL)?;
+            let mut firmware_obj = KVVec::zeroed(align_padding, GFP_KERNEL)?;
             firmware_obj.extend_from_slice(firmware.ucode.0.as_slice(), GFP_KERNEL)?;
 
             (

Re: [PATCH] gpu: nova-core: firmware: fwsec: use zeroed() to zero-pad buffers

[Danilo Krummrich]

On Tue Oct 6, 2026 at 12:04 PM CEST, Thorsten Blum wrote:
> -            let mut ucode = KVec::with_capacity(aligned_code_size, GFP_KERNEL)?;
> -            ucode.extend_from_slice(code, GFP_KERNEL)?;
> -            ucode.resize(aligned_code_size, 0, GFP_KERNEL)?;
> -
> +            let mut ucode = KVec::zeroed(aligned_code_size, GFP_KERNEL)?;
> +            ucode[..code.len()].copy_from_slice(code);

I kinda dislike that this is now a potential panic, but it does better express
the intent.

Can you please add a corresponding // PANIC comment?

Thanks,
Danilo

Re: [PATCH] gpu: nova-core: firmware: fwsec: use zeroed() to zero-pad buffers

[Alexandre Courbot]

On Wed Oct 7, 2026 at 7:20 AM JST, Danilo Krummrich wrote:
> On Tue Oct 6, 2026 at 12:04 PM CEST, Thorsten Blum wrote:
>> -            let mut ucode = KVec::with_capacity(aligned_code_size, GFP_KERNEL)?;
>> -            ucode.extend_from_slice(code, GFP_KERNEL)?;
>> -            ucode.resize(aligned_code_size, 0, GFP_KERNEL)?;
>> -
>> +            let mut ucode = KVec::zeroed(aligned_code_size, GFP_KERNEL)?;
>> +            ucode[..code.len()].copy_from_slice(code);
>
> I kinda dislike that this is now a potential panic, but it does better express
> the intent.

IMHO the original code expresses the intent just as well, and avoids
writing the area covered by `code` twice, on top of not introducing a
potential panic site.