[RFC PATCH] hw/core: ensure kernel_end never gets used undefined

[RFC PATCH] hw/core: ensure kernel_end never gets used undefined

[Alex Bennée]

Really the problem here is the return values of fit_load_[kernel|fdt]() are a
little all over the place. However we don't want to somehow get
through not having set kernel_end and having it just be random unused
data.

The compiler complained on an --enable-gcov build:

  In file included from ../../hw/core/loader-fit.c:20:
  /home/alex/lsrc/qemu.git/include/qemu/osdep.h: In function ‘load_fit’:
  /home/alex/lsrc/qemu.git/include/qemu/osdep.h:486:45: error: ‘kernel_end’ may be used uninitialized [-Werror=maybe-uninitialized]
    486 | #define ROUND_UP(n, d) ROUND_DOWN((n) + (d) - 1, (d))
        |                                             ^
  ../../hw/core/loader-fit.c:270:12: note: ‘kernel_end’ was declared here
    270 |     hwaddr kernel_end;
        |            ^~~~~~~~~~

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
---
 hw/core/loader-fit.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hw/core/loader-fit.c b/hw/core/loader-fit.c
index 9f20007dbb..7ccc9d5fbc 100644
--- a/hw/core/loader-fit.c
+++ b/hw/core/loader-fit.c
@@ -267,7 +267,7 @@ int load_fit(const struct fit_loader *ldr, const char *filename, void *opaque)
     const char *def_cfg_name;
     char path[FIT_LOADER_MAX_PATH];
     int itb_size, configs, cfg_off, off;
-    hwaddr kernel_end;
+    hwaddr kernel_end = 0;
     int ret;
 
     itb = load_device_tree(filename, &itb_size);
-- 
2.39.2

Re: [RFC PATCH] hw/core: ensure kernel_end never gets used undefined

[Aleksandar Rikalo]

On Thu, Jul 4, 2024 at 2:49 PM Alex Bennée <alex.bennee@linaro.org> wrote:
>
> Really the problem here is the return values of fit_load_[kernel|fdt]() are a
> little all over the place. However we don't want to somehow get
> through not having set kernel_end and having it just be random unused
> data.
>
> The compiler complained on an --enable-gcov build:
>
>   In file included from ../../hw/core/loader-fit.c:20:
>   /home/alex/lsrc/qemu.git/include/qemu/osdep.h: In function ‘load_fit’:
>   /home/alex/lsrc/qemu.git/include/qemu/osdep.h:486:45: error: ‘kernel_end’ may be used uninitialized [-Werror=maybe-uninitialized]
>     486 | #define ROUND_UP(n, d) ROUND_DOWN((n) + (d) - 1, (d))
>         |                                             ^
>   ../../hw/core/loader-fit.c:270:12: note: ‘kernel_end’ was declared here
>     270 |     hwaddr kernel_end;
>         |            ^~~~~~~~~~
>
> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
> ---
>  hw/core/loader-fit.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/hw/core/loader-fit.c b/hw/core/loader-fit.c
> index 9f20007dbb..7ccc9d5fbc 100644
> --- a/hw/core/loader-fit.c
> +++ b/hw/core/loader-fit.c
> @@ -267,7 +267,7 @@ int load_fit(const struct fit_loader *ldr, const char *filename, void *opaque)
>      const char *def_cfg_name;
>      char path[FIT_LOADER_MAX_PATH];
>      int itb_size, configs, cfg_off, off;
> -    hwaddr kernel_end;
> +    hwaddr kernel_end = 0;
>      int ret;
>
>      itb = load_device_tree(filename, &itb_size);
> --
> 2.39.2
>

Reviewed-by: Aleksandar Rikalo <arikalo@gmail.com>