On Fri, Jan 06, 2017 at 03:16:30PM +0800, JingPiao Chen wrote:
[...]
> +#include "defs.h"
> +#include <ustat.h>
> +
> +SYS_FUNC(ustat)
> +{
> + if (entering(tcp))
> + print_dev_t(tcp->u_arg[0]);
> + else {
> + struct ustat ust;
This structure is personality specific and therefore must be mpersified.
> + tprints(", ");
> + if (umoven_or_printaddr(tcp, tcp->u_arg[1], sizeof(ust), &ust))
> + return 0;
Use umove_or_printaddr.
> + tprintf("{f_tfree=%lld, f_tinode=%llu",
> + sign_extend_unsigned_to_ll(ust.f_tfree));
Why sign extend it and print it as signed? It's the number of free blocks,
it cannot be negative. Inside the kernel, struct kstatfs.f_bfree is
of type u64.
> + zero_extend_signed_to_ull(ust.f_tinode),
> + tprints(", f_fname=");
> + print_quoted_string(ust.f_fname, sizeof(ust.f_fname),
> + QUOTE_0_TERMINATED);
> + tprints(", f_fpack=");
> + print_quoted_string(ust.f_fpack, sizeof(ust.f_fpack),
> + QUOTE_0_TERMINATED);
These fields are guaranteed by kernel to be zero, why bother printing
them at all?
--
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