* Re: [Bugme-new] [Bug 11539] New: empty filename in /sys/firmware/acpi/tables
2008-09-11 19:33 ` [Bugme-new] [Bug 11539] New: empty filename in /sys/firmware/acpi/tables Andrew Morton
@ 2008-09-12 1:08 ` Zhang Rui
0 siblings, 0 replies; 2+ messages in thread
From: Zhang Rui @ 2008-09-12 1:08 UTC (permalink / raw)
To: Andrew Morton
Cc: nokos, bugme-daemon, linux-acpi, Bob Moore, Lin Ming, Len Brown
On Thu, 2008-09-11 at 12:33 -0700, Andrew Morton wrote:
> On Thu, 11 Sep 2008 02:59:49 -0700 (PDT)
> bugme-daemon@bugzilla.kernel.org wrote:
>
> > http://bugzilla.kernel.org/show_bug.cgi?id=11539
> >
> > Summary: empty filename in /sys/firmware/acpi/tables
> > Product: ACPI
> > Version: 2.5
> > KernelVersion: 2.6.26
> > Platform: All
> > OS/Version: Linux
> > Tree: Mainline
> > Status: NEW
> > Severity: low
> > Priority: P1
> > Component: Other
> > AssignedTo: acpi_other@kernel-bugs.osdl.org
> > ReportedBy: nokos@gmx.net
> >
> >
> > Hardware Environment:
> > A system with an acpi table with an empty signature
> >
> > Problem Description:
> > Since commit bc45b1d39a925b56796bebf8a397a0491489d85c acpi tables are allowed
> > to have an empty signature and /sys/firmware/acpi/tables uses the signature as
> > filename. Applications using naive recursion through /sys loop forever. A
> > possible solution would be:
> > (replacing the zero length filename with the string "NULL")
> >
Acked-by: Zhang Rui <rui.zhang@intel.com>
thanks,
rui
> > diff a/drivers/acpi/system.c b/drivers/acpi/system.c
> > --- a/drivers/acpi/system.c
> > +++ b/drivers/acpi/system.c
>
> (argh)
>
>
> Please don't submit patches via bugzilla, especially not copy-n-paste
> ones. It gets wordwrapped and tabs get replaced with spaces and
> similar crap. Patches should be submitted via email.
>
> I cleaned this patch up and applied it locally.
>
> Please send a Signed-off-by: for this patch as per
> Documentation/SubmittingPatches, section 12.
>
> This patch fixes what appears to be a regression in 2.6.26 and looks
> like it is applicable to both 2.6.26.x and to 2.6.27. Len, Bob: please
> review asap - I can merge it with your ack if you'd like.
>
>
>
> From: Peter Gruber <nokos@gmx.net>
>
> Taken from http://bugzilla.kernel.org/show_bug.cgi?id=11539
>
> Since commit bc45b1d39a925b56796bebf8a397a0491489d85c acpi tables are
> allowed to have an empty signature and /sys/firmware/acpi/tables uses the
> signature as filename. Applications using naive recursion through /sys
> loop forever. A possible solution would be: (replacing the zero length
> filename with the string "NULL")
>
> Cc: Bob Moore <robert.moore@intel.com>
> Cc: Lin Ming <ming.m.lin@intel.com>
> Cc: Len Brown <len.brown@intel.com>
> Cc: <stable@kernel.org> [2.6.26.x]
> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
> ---
>
> drivers/acpi/system.c | 25 +++++++++++++++++--------
> 1 file changed, 17 insertions(+), 8 deletions(-)
>
> diff -puN drivers/acpi/system.c~acpi-dont-create-empty-filenames-in-sys-firmware-acpi-tables drivers/acpi/system.c
> --- a/drivers/acpi/system.c~acpi-dont-create-empty-filenames-in-sys-firmware-acpi-tables
> +++ a/drivers/acpi/system.c
> @@ -78,9 +78,15 @@ static ssize_t acpi_table_show(struct ko
> container_of(bin_attr, struct acpi_table_attr, attr);
> struct acpi_table_header *table_header = NULL;
> acpi_status status;
> + char name[ACPI_NAME_SIZE];
> +
> + if (strncmp(table_attr->name, "NULL", 4))
> + memcpy(name, table_attr->name, ACPI_NAME_SIZE);
> + else
> + memcpy(name, "\0\0\0\0", 4);
>
> status =
> - acpi_get_table(table_attr->name, table_attr->instance,
> + acpi_get_table(name, table_attr->instance,
> &table_header);
> if (ACPI_FAILURE(status))
> return -ENODEV;
> @@ -95,21 +101,24 @@ static void acpi_table_attr_init(struct
> struct acpi_table_header *header = NULL;
> struct acpi_table_attr *attr = NULL;
>
> - memcpy(table_attr->name, table_header->signature, ACPI_NAME_SIZE);
> + if (table_header->signature[0] != '\0')
> + memcpy(table_attr->name, table_header->signature,
> + ACPI_NAME_SIZE);
> + else
> + memcpy(table_attr->name, "NULL", 4);
>
> list_for_each_entry(attr, &acpi_table_attr_list, node) {
> - if (!memcmp(table_header->signature, attr->name,
> - ACPI_NAME_SIZE))
> + if (!memcmp(table_attr->name, attr->name, ACPI_NAME_SIZE))
> if (table_attr->instance < attr->instance)
> table_attr->instance = attr->instance;
> }
> table_attr->instance++;
>
> if (table_attr->instance > 1 || (table_attr->instance == 1 &&
> - !acpi_get_table(table_header->
> - signature, 2,
> - &header)))
> - sprintf(table_attr->name + 4, "%d", table_attr->instance);
> + !acpi_get_table
> + (table_header->signature, 2, &header)))
> + sprintf(table_attr->name + ACPI_NAME_SIZE, "%d",
> + table_attr->instance);
>
> table_attr->attr.size = 0;
> table_attr->attr.read = acpi_table_show;
> _
>
> --
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