Re: [PATCH] scripts: Fix size mismatch of kexec_purgatory_size

From: Dave Young
Date: Wed Jul 06 2016 - 04:45:51 EST


On 07/04/16 at 01:55pm, Tautschnig, Michael wrote:
> bin2c is used to create a valid C file out of a binary file where two
> symbols will be globally defined: <name> and <name>_size. <name> is
> passed as the first parameter of the host binary.
>
> Building using goto-cc reported that the purgatory binary code (the only
> current user of this utility) declares kexec_purgatory_size as 'size_t'
> where bin2c generate <name>_size to be 'int' so in a 64-bit host where
> sizeof(size_t) > sizeof(int) this type mismatch will always yield the
> wrong value for big-endian architectures while for little-endian it will
> be wrong if the object laid in memory directly after
> kexec_purgatory_size contains non-zero value at the time of reading.
>
> This commit changes <name>_size to be size_t instead.
>
> Note:
>
> Another way to fix the problem is to change the type of
> kexec_purgatory_size to be 'int' as there's this check in code:
> (kexec_purgatory_size <= 0)
>
> Signed-off-by: Michael Tautschnig <tautschn@xxxxxxxxxx>
> Cc: Michal Marek <mmarek@xxxxxxxx>
> Cc: Vivek Goyal <vgoyal@xxxxxxxxxx>
> ---
> scripts/basic/bin2c.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/scripts/basic/bin2c.c b/scripts/basic/bin2c.c
> index af187e6..c3d7eef 100644
> --- a/scripts/basic/bin2c.c
> +++ b/scripts/basic/bin2c.c
> @@ -29,7 +29,8 @@ int main(int argc, char *argv[])
> } while (ch != EOF);
>
> if (argc > 1)
> - printf("\t;\n\nconst int %s_size = %d;\n", argv[1], total);
> + printf("\t;\n\n#include <linux/types.h>\n\nconst size_t %s_size = %d;\n",
> + argv[1], total);
>
> return 0;
> }
> --
> 2.7.3.AMZN
>
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Acked-by: Dave Young <dyoung@xxxxxxxxxx>

Thanks
Dave