Re: [PATCH 2/4] backends/tpmL Avoid using g_alloca()

[Stefan Berger <stefanb@linux.ibm.com>]

On 6/5/25 3:35 PM, Philippe Mathieu-Daudé wrote:
> tpm_emulator_ctrlcmd() is not in hot path.
> Use the heap instead of the stack, removing
> the g_alloca() call.
> 
> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>

Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>

> ---
>   backends/tpm/tpm_emulator.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/backends/tpm/tpm_emulator.c b/backends/tpm/tpm_emulator.c
> index 43d350e895d..4a234ab2c0b 100644
> --- a/backends/tpm/tpm_emulator.c
> +++ b/backends/tpm/tpm_emulator.c
> @@ -129,11 +129,11 @@ static int tpm_emulator_ctrlcmd(TPMEmulator *tpm, unsigned long cmd, void *msg,
>       CharBackend *dev = &tpm->ctrl_chr;
>       uint32_t cmd_no = cpu_to_be32(cmd);
>       ssize_t n = sizeof(uint32_t) + msg_len_in;
> -    uint8_t *buf = NULL;
>       ptm_res res;
>   
>       WITH_QEMU_LOCK_GUARD(&tpm->mutex) {
> -        buf = g_alloca(n);
> +        g_autofree uint8_t *buf = g_malloc(n);
> +
>           memcpy(buf, &cmd_no, sizeof(cmd_no));
>           memcpy(buf + sizeof(cmd_no), msg, msg_len_in);
>