07 Dec, 2013

1 commit

  • Replace direct inclusions of , and
    , which are incorrect, with
    inclusions and remove some inclusions of those files that aren't
    necessary.

    First of all, , and
    should not be included directly from any files that are built for
    CONFIG_ACPI unset, because that generally leads to build warnings about
    undefined symbols in !CONFIG_ACPI builds. For CONFIG_ACPI set,
    includes those files and for CONFIG_ACPI unset it
    provides stub ACPI symbols to be used in that case.

    Second, there are ordering dependencies between those files that always
    have to be met. Namely, it is required that be included
    prior to so that the acpi_pci_root declarations the
    latter depends on are always there. And which provides
    basic ACPICA type declarations should always be included prior to any other
    ACPI headers in CONFIG_ACPI builds. That also is taken care of including
    as appropriate.

    Signed-off-by: Lv Zheng
    Cc: Greg Kroah-Hartman
    Cc: Matthew Garrett
    Cc: Tony Luck
    Cc: "H. Peter Anvin"
    Acked-by: Bjorn Helgaas (drivers/pci stuff)
    Acked-by: Konrad Rzeszutek Wilk (Xen stuff)
    Signed-off-by: Rafael J. Wysocki

    Lv Zheng
     

01 Nov, 2011

1 commit


29 May, 2011

2 commits

  • With /sys/kernel/debug/acpi/custom_method root can write
    to arbitrary memory and increase his priveleges, even if
    these are restricted.

    -> Make this an own debug .config option and warn about the
    security issue in the config description.

    -> Still keep acpi/debugfs.c which now only creates an empty
    /sys/kernel/debug/acpi directory. There might be other
    users of it later.

    Signed-off-by: Thomas Renninger
    Acked-by: Rafael J. Wysocki
    Acked-by: rui.zhang@intel.com
    Signed-off-by: Len Brown

    Thomas Renninger
     
  • - Move param aml_debug_output to other params into sysfs.c
    - Split acpi_debugfs_init to prepare custom_method to be
    an own .config option and driver.

    Signed-off-by: Thomas Renninger
    Acked-by: Rafael J. Wysocki
    Acked-by: rui.zhang@intel.com
    Signed-off-by: Len Brown

    Thomas Renninger
     

25 Feb, 2011

1 commit

  • File position is not controlled, it may lead to overwrites of arbitrary
    kernel memory. Also the code may kfree() the same pointer multiple
    times.

    One more flaw is still present: if multiple processes open the file then
    all 3 static variables are shared, leading to various race conditions.
    They should be moved to file->private_data.

    Signed-off-by: Vasiliy Kulikov
    Reviewed-by: WANG Cong
    Reviewed-by: Eugene Teo
    Cc: stable@kernel.org
    Signed-off-by: Rafael J. Wysocki

    Vasiliy Kulikov
     

14 Nov, 2010

1 commit

  • Currently we have:

    --w--w--w-. 1 root root 0 2010-11-11 14:56 /sys/kernel/debug/acpi/custom_method

    which is just crazy. Change this to --w-------.

    Signed-off-by: Dave Jones
    Signed-off-by: Len Brown
    Cc: stable@kernel.org (for 2.6.36)
    Signed-off-by: Linus Torvalds

    Dave Jones
     

15 Oct, 2010

1 commit

  • All file_operations should get a .llseek operation so we can make
    nonseekable_open the default for future file operations without a
    .llseek pointer.

    The three cases that we can automatically detect are no_llseek, seq_lseek
    and default_llseek. For cases where we can we can automatically prove that
    the file offset is always ignored, we use noop_llseek, which maintains
    the current behavior of not returning an error from a seek.

    New drivers should normally not use noop_llseek but instead use no_llseek
    and call nonseekable_open at open time. Existing drivers can be converted
    to do the same when the maintainer knows for certain that no user code
    relies on calling seek on the device file.

    The generated code is often incorrectly indented and right now contains
    comments that clarify for each added line why a specific variant was
    chosen. In the version that gets submitted upstream, the comments will
    be gone and I will manually fix the indentation, because there does not
    seem to be a way to do that using coccinelle.

    Some amount of new code is currently sitting in linux-next that should get
    the same modifications, which I will do at the end of the merge window.

    Many thanks to Julia Lawall for helping me learn to write a semantic
    patch that does all this.

    ===== begin semantic patch =====
    // This adds an llseek= method to all file operations,
    // as a preparation for making no_llseek the default.
    //
    // The rules are
    // - use no_llseek explicitly if we do nonseekable_open
    // - use seq_lseek for sequential files
    // - use default_llseek if we know we access f_pos
    // - use noop_llseek if we know we don't access f_pos,
    // but we still want to allow users to call lseek
    //
    @ open1 exists @
    identifier nested_open;
    @@
    nested_open(...)
    {

    }

    @ open exists@
    identifier open_f;
    identifier i, f;
    identifier open1.nested_open;
    @@
    int open_f(struct inode *i, struct file *f)
    {

    }

    @ read disable optional_qualifier exists @
    identifier read_f;
    identifier f, p, s, off;
    type ssize_t, size_t, loff_t;
    expression E;
    identifier func;
    @@
    ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
    {

    }

    @ read_no_fpos disable optional_qualifier exists @
    identifier read_f;
    identifier f, p, s, off;
    type ssize_t, size_t, loff_t;
    @@
    ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
    {
    ... when != off
    }

    @ write @
    identifier write_f;
    identifier f, p, s, off;
    type ssize_t, size_t, loff_t;
    expression E;
    identifier func;
    @@
    ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
    {

    }

    @ write_no_fpos @
    identifier write_f;
    identifier f, p, s, off;
    type ssize_t, size_t, loff_t;
    @@
    ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
    {
    ... when != off
    }

    @ fops0 @
    identifier fops;
    @@
    struct file_operations fops = {
    ...
    };

    @ has_llseek depends on fops0 @
    identifier fops0.fops;
    identifier llseek_f;
    @@
    struct file_operations fops = {
    ...
    .llseek = llseek_f,
    ...
    };

    @ has_read depends on fops0 @
    identifier fops0.fops;
    identifier read_f;
    @@
    struct file_operations fops = {
    ...
    .read = read_f,
    ...
    };

    @ has_write depends on fops0 @
    identifier fops0.fops;
    identifier write_f;
    @@
    struct file_operations fops = {
    ...
    .write = write_f,
    ...
    };

    @ has_open depends on fops0 @
    identifier fops0.fops;
    identifier open_f;
    @@
    struct file_operations fops = {
    ...
    .open = open_f,
    ...
    };

    // use no_llseek if we call nonseekable_open
    ////////////////////////////////////////////
    @ nonseekable1 depends on !has_llseek && has_open @
    identifier fops0.fops;
    identifier nso ~= "nonseekable_open";
    @@
    struct file_operations fops = {
    ... .open = nso, ...
    +.llseek = no_llseek, /* nonseekable */
    };

    @ nonseekable2 depends on !has_llseek @
    identifier fops0.fops;
    identifier open.open_f;
    @@
    struct file_operations fops = {
    ... .open = open_f, ...
    +.llseek = no_llseek, /* open uses nonseekable */
    };

    // use seq_lseek for sequential files
    /////////////////////////////////////
    @ seq depends on !has_llseek @
    identifier fops0.fops;
    identifier sr ~= "seq_read";
    @@
    struct file_operations fops = {
    ... .read = sr, ...
    +.llseek = seq_lseek, /* we have seq_read */
    };

    // use default_llseek if there is a readdir
    ///////////////////////////////////////////
    @ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
    identifier fops0.fops;
    identifier readdir_e;
    @@
    // any other fop is used that changes pos
    struct file_operations fops = {
    ... .readdir = readdir_e, ...
    +.llseek = default_llseek, /* readdir is present */
    };

    // use default_llseek if at least one of read/write touches f_pos
    /////////////////////////////////////////////////////////////////
    @ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
    identifier fops0.fops;
    identifier read.read_f;
    @@
    // read fops use offset
    struct file_operations fops = {
    ... .read = read_f, ...
    +.llseek = default_llseek, /* read accesses f_pos */
    };

    @ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
    identifier fops0.fops;
    identifier write.write_f;
    @@
    // write fops use offset
    struct file_operations fops = {
    ... .write = write_f, ...
    + .llseek = default_llseek, /* write accesses f_pos */
    };

    // Use noop_llseek if neither read nor write accesses f_pos
    ///////////////////////////////////////////////////////////

    @ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
    identifier fops0.fops;
    identifier read_no_fpos.read_f;
    identifier write_no_fpos.write_f;
    @@
    // write fops use offset
    struct file_operations fops = {
    ...
    .write = write_f,
    .read = read_f,
    ...
    +.llseek = noop_llseek, /* read and write both use no f_pos */
    };

    @ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
    identifier fops0.fops;
    identifier write_no_fpos.write_f;
    @@
    struct file_operations fops = {
    ... .write = write_f, ...
    +.llseek = noop_llseek, /* write uses no f_pos */
    };

    @ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
    identifier fops0.fops;
    identifier read_no_fpos.read_f;
    @@
    struct file_operations fops = {
    ... .read = read_f, ...
    +.llseek = noop_llseek, /* read uses no f_pos */
    };

    @ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
    identifier fops0.fops;
    @@
    struct file_operations fops = {
    ...
    +.llseek = noop_llseek, /* no read or write fn */
    };
    ===== End semantic patch =====

    Signed-off-by: Arnd Bergmann
    Cc: Julia Lawall
    Cc: Christoph Hellwig

    Arnd Bergmann
     

15 Aug, 2010

2 commits

  • Introduce module parameter acpi.aml_debug_output.

    With acpi.aml_debug_output set, we can get AML debug object output
    (Store (AAA, Debug)), even with CONFIG_ACPI_DEBUG cleared.

    Together with the runtime custom method mechanism,
    we can debug AML code problems without rebuilding the kernel.

    Signed-off-by: Zhang Rui
    Signed-off-by: Len Brown

    Zhang Rui
     
  • Introduce drivers/acpi/debugfs.c.

    Code for ACPI debugfs I/F,
    i.e. /sys/kernel/debug/acpi/custom_method,
    is moved to this file.

    And make ACPI debugfs always built in,
    even if CONFIG_ACPI_DEBUG is cleared.

    BTW:this adds about 400bytes code to ACPI, when
    CONFIG_ACPI_DEBUG is cleared.

    [uaccess.h build fix from Andrew Morton ]

    Signed-off-by: Zhang Rui
    Signed-off-by: Len Brown

    Zhang Rui