Re: [PATCH] arm: Zero/Sign extends for CMSE security

[Torbjorn SVENSSON <torbjorn.svensson@foss.st.com>]

Hi,

On 2024-04-24 17:55, Richard Ball wrote:
> This patch makes the following changes:
> 
> 1) When calling a secure function from non-secure code then any arguments
>     smaller than 32-bits that are passed in registers are zero- or sign-extended.
> 2) After a non-secure function returns into secure code then any return value
>     smaller than 32-bits that is passed in a register is  zero- or sign-extended.
> 
> This patch addresses the following CVE-2024-0151.
> 
> gcc/ChangeLog:
>          PR target/114837
>          * config/arm/arm.cc (cmse_nonsecure_call_inline_register_clear):
>            Add zero/sign extend.
>          (arm_expand_prologue): Add zero/sign extend.
> 
> gcc/testsuite/ChangeLog:
> 
>          * gcc.target/arm/cmse/extend-param.c: New test.
>          * gcc.target/arm/cmse/extend-return.c: New test.

I think it would make sense that there is at least one test case that 
takes 2 or more arguments to ensure that not only the first argument is 
extended. WDYT?


Kind regards,
Torbjörn