Hi:
On 2021/1/28 10:19, Yafang Shao wrote:
> Currently the pGp only shows the names of page flags, rather than
> the full information including section, node, zone, last cpupid and
> kasan tag. While it is not easy to parse these information manually
> because there're so many flavors. Let's interpret them in pGp as well.
>
> - Before the patch,
> [ 6312.639698] ERR: Slab 0x000000006d1133b9 objects=33 used=3 fp=0x000000006d0779d1 flags=0x17ffffc0010200(slab|head)
>
> - After the patch,
> [ 6315.235783] ERR: Slab 0x000000006d1133b9 objects=33 used=3 fp=0x000000006d0779d1 flags=0x17ffffc0010200(Node 0x0,Zone 0x2,Lastcpupid 0x1fffff,slab|head)
>
Thanks. This really helps!
> Cc: David Hildenbrand <david@xxxxxxxxxx>
> Signed-off-by: Yafang Shao <laoar.shao@xxxxxxxxx>
> ---
> lib/vsprintf.c | 42 +++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 41 insertions(+), 1 deletion(-)
>
> diff --git a/lib/vsprintf.c b/lib/vsprintf.c
> index 3b53c73580c5..bd809f4f1b82 100644
> --- a/lib/vsprintf.c
> +++ b/lib/vsprintf.c
> @@ -1916,6 +1916,46 @@ char *format_flags(char *buf, char *end, unsigned long flags,
> return buf;
> }
>
> +struct page_flags_layout {
> + int width;
> + int shift;
> + int mask;
> + char *name;
Should we add const for name ?
> +};
> +
> +struct page_flags_layout pfl[] = {
Should we add static const for pfl[] as we won't change its value and use it outside this file ?
> + {SECTIONS_WIDTH, SECTIONS_PGSHIFT, SECTIONS_MASK, "Section "},
> + {NODES_WIDTH, NODES_PGSHIFT, NODES_MASK, "Node "},
> + {ZONES_WIDTH, ZONES_PGSHIFT, ZONES_MASK, "Zone "},
> + {LAST_CPUPID_WIDTH, LAST_CPUPID_PGSHIFT, LAST_CPUPID_MASK, "Lastcpupid "},
> + {KASAN_TAG_WIDTH, KASAN_TAG_PGSHIFT, KASAN_TAG_MASK, "Kasantag "},
> +};
> +
> +static
> +char *format_layout(char *buf, char *end, unsigned long flags)
> +{
> + int i;
> +
> + for (i = 0; i < sizeof(pfl) / sizeof(struct page_flags_layout) && buf < end; i++) {
I think we can use ARRAY_SIZE here.
> + if (pfl[i].width == 0)
> + continue;
> +
> + buf = string(buf, end, pfl[i].name, default_str_spec);
> +
> + if (buf >= end)
> + break;
> + buf = number(buf, end, (flags >> pfl[i].shift) & pfl[i].mask,
> + default_flag_spec);
> +
> + if (buf >= end)
> + break;
> + *buf = ',';
> + buf++;
> + }
> +
> + return buf;
> +}
> +
> static noinline_for_stack
> char *flags_string(char *buf, char *end, void *flags_ptr,
> struct printf_spec spec, const char *fmt)
> @@ -1929,7 +1969,7 @@ char *flags_string(char *buf, char *end, void *flags_ptr,
> switch (fmt[1]) {
> case 'p':
> flags = *(unsigned long *)flags_ptr;
> - /* Remove zone id */
> + buf = format_layout(buf, end, flags & ~((1UL << NR_PAGEFLAGS) - 1));
> flags &= (1UL << NR_PAGEFLAGS) - 1;
> names = pageflag_names;
> break;
>
Many thanks.
