On Thu, 2008-09-11 at 12:33 -0700, Andrew Morton wrote: > On Thu, 11 Sep 2008 02:59:49 -0700 (PDT) > bugme-daemon@xxxxxxxxxxxxxxxxxxx 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@xxxxxxxxxxxxxxxxxxxx > > ReportedBy: nokos@xxxxxxx > > > > > > 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@xxxxxxxxx> 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@xxxxxxx> > > 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@xxxxxxxxx> > Cc: Lin Ming <ming.m.lin@xxxxxxxxx> > Cc: Len Brown <len.brown@xxxxxxxxx> > Cc: <stable@xxxxxxxxxx> [2.6.26.x] > Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > --- > > 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; > _ > > -- > To unsubscribe from this list: send the line "unsubscribe linux-acpi" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
