Eric Lee / smarc-fsl-linux-kernel

01 Nov, 2011

1 commit

22 Jul, 2011

1 commit

31 Mar, 2011

1 commit

15 Oct, 2010

1 commit

  • 6038f373a   llseek: automatically add .llseek fop ... Browse Code »

    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
     

30 Mar, 2010

1 commit

  • 5a0e3ad6a   include cleanup: Update gfp.h and slab.h includes to prepare for breaking implic… ... Browse Code »

    …it slab.h inclusion from percpu.h

    percpu.h is included by sched.h and module.h and thus ends up being
    included when building most .c files. percpu.h includes slab.h which
    in turn includes gfp.h making everything defined by the two files
    universally available and complicating inclusion dependencies.

    percpu.h -> slab.h dependency is about to be removed. Prepare for
    this change by updating users of gfp and slab facilities include those
    headers directly instead of assuming availability. As this conversion
    needs to touch large number of source files, the following script is
    used as the basis of conversion.

    http://userweb.kernel.org/~tj/misc/slabh-sweep.py

    The script does the followings.

    * Scan files for gfp and slab usages and update includes such that
    only the necessary includes are there. ie. if only gfp is used,
    gfp.h, if slab is used, slab.h.

    * When the script inserts a new include, it looks at the include
    blocks and try to put the new include such that its order conforms
    to its surrounding. It's put in the include block which contains
    core kernel includes, in the same order that the rest are ordered -
    alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
    doesn't seem to be any matching order.

    * If the script can't find a place to put a new include (mostly
    because the file doesn't have fitting include block), it prints out
    an error message indicating which .h file needs to be added to the
    file.

    The conversion was done in the following steps.

    1. The initial automatic conversion of all .c files updated slightly
    over 4000 files, deleting around 700 includes and adding ~480 gfp.h
    and ~3000 slab.h inclusions. The script emitted errors for ~400
    files.

    2. Each error was manually checked. Some didn't need the inclusion,
    some needed manual addition while adding it to implementation .h or
    embedding .c file was more appropriate for others. This step added
    inclusions to around 150 files.

    3. The script was run again and the output was compared to the edits
    from #2 to make sure no file was left behind.

    4. Several build tests were done and a couple of problems were fixed.
    e.g. lib/decompress_*.c used malloc/free() wrappers around slab
    APIs requiring slab.h to be added manually.

    5. The script was run on all .h files but without automatically
    editing them as sprinkling gfp.h and slab.h inclusions around .h
    files could easily lead to inclusion dependency hell. Most gfp.h
    inclusion directives were ignored as stuff from gfp.h was usually
    wildly available and often used in preprocessor macros. Each
    slab.h inclusion directive was examined and added manually as
    necessary.

    6. percpu.h was updated not to include slab.h.

    7. Build test were done on the following configurations and failures
    were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
    distributed build env didn't work with gcov compiles) and a few
    more options had to be turned off depending on archs to make things
    build (like ipr on powerpc/64 which failed due to missing writeq).

    * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
    * powerpc and powerpc64 SMP allmodconfig
    * sparc and sparc64 SMP allmodconfig
    * ia64 SMP allmodconfig
    * s390 SMP allmodconfig
    * alpha SMP allmodconfig
    * um on x86_64 SMP allmodconfig

    8. percpu.h modifications were reverted so that it could be applied as
    a separate patch and serve as bisection point.

    Given the fact that I had only a couple of failures from tests on step
    6, I'm fairly confident about the coverage of this conversion patch.
    If there is a breakage, it's likely to be something in one of the arch
    headers which should be easily discoverable easily on most builds of
    the specific arch.

    Signed-off-by: Tejun Heo <tj@kernel.org>
    Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
    Cc: Ingo Molnar <mingo@redhat.com>
    Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

    Tejun Heo
     

02 Oct, 2009

1 commit

30 Jul, 2009

3 commits

  • a91d74a3c   lguest: update commentry ... Browse Code »

    Every so often, after code shuffles, I need to go through and unbitrot
    the Lguest Journey (see drivers/lguest/README). Since we now use RCU in
    a simple form in one place I took the opportunity to expand that explanation.

    Signed-off-by: Rusty Russell
    Cc: Ingo Molnar
    Cc: Paul McKenney

    Rusty Russell
     
  • 2e04ef769   lguest: fix comment style ... Browse Code »

    I don't really notice it (except to begrudge the extra vertical
    space), but Ingo does. And he pointed out that one excuse of lguest
    is as a teaching tool, it should set a good example.

    Signed-off-by: Rusty Russell
    Cc: Ingo Molnar

    Rusty Russell
     
  • f29452627   lguest: dereferencing freed mem in add_eventfd() ... Browse Code »

    "new" was freed and then dereferenced. Also the return value wasn't being
    used so I modified the caller as well.

    Compile tested only. Found by smatch (http://repo.or.cz/w/smatch.git).

    regards,
    dan carpenter

    Signed-off-by: Dan Carpenter
    Signed-off-by: Rusty Russell

    Dan Carpenter
     

01 Jul, 2009

1 commit

  • 133890103   eventfd: revised interface and cleanups ... Browse Code »

    Change the eventfd interface to de-couple the eventfd memory context, from
    the file pointer instance.

    Without such change, there is no clean way to racely free handle the
    POLLHUP event sent when the last instance of the file* goes away. Also,
    now the internal eventfd APIs are using the eventfd context instead of the
    file*.

    This patch is required by KVM's IRQfd code, which is still under
    development.

    Signed-off-by: Davide Libenzi
    Cc: Gregory Haskins
    Cc: Rusty Russell
    Cc: Benjamin LaHaise
    Cc: Avi Kivity
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Davide Libenzi
     

12 Jun, 2009

4 commits

  • 5dac051bc   lguest: remove obsolete LHREQ_BREAK call ... Browse Code »

    We no longer need an efficient mechanism to force the Guest back into
    host userspace, as each device is serviced without bothering the main
    Guest process (aka. the Launcher).

    Signed-off-by: Rusty Russell

    Rusty Russell
     
  • df60aeef4   lguest: use eventfds for device notification ... Browse Code »

    Currently, when a Guest wants to perform I/O it calls LHCALL_NOTIFY with
    an address: the main Launcher process returns with this address, and figures
    out what device to run.

    A far nicer model is to let processes bind an eventfd to an address: if we
    find one, we simply signal the eventfd.

    Signed-off-by: Rusty Russell
    Cc: Davide Libenzi

    Rusty Russell
     
  • 9f155a9b3   lguest: allow any process to send interrupts ... Browse Code »

    We currently only allow the Launcher process to send interrupts, but it
    as we already send interrupts from the hrtimer, it's a simple matter of
    extracting that code into a common set_interrupt routine.

    As we switch to a thread per virtqueue, this avoids a bottleneck through the
    main Launcher process.

    Signed-off-by: Rusty Russell

    Rusty Russell
     
  • a6c372de6   lguest: fix lguest wake on guest clock tick, or fd activity ... Browse Code »

    The Launcher could be inside the Guest on another CPU; wake_up_process
    will do nothing because it is "running". kick_process will knock it
    back into our kernel in this case, otherwise we'll miss it until the
    next guest exit.

    Signed-off-by: Rusty Russell

    Rusty Russell
     

30 Jan, 2009

1 commit

30 Dec, 2008

1 commit

02 May, 2008

2 commits

31 Mar, 2008

1 commit

28 Mar, 2008

1 commit

11 Mar, 2008

1 commit

30 Jan, 2008

10 commits

15 Nov, 2007

1 commit

25 Oct, 2007

1 commit

23 Oct, 2007

6 commits

  • 15045275c   Remove old lguest I/O infrrasructure. ... Browse Code »

    This patch gets rid of the old lguest host I/O infrastructure and
    replaces it with a single hypercall "LHCALL_NOTIFY" which takes an
    address.

    The main change is the removal of io.c: that mainly did inter-guest
    I/O, which virtio doesn't yet support.

    Signed-off-by: Rusty Russell

    Rusty Russell
     
  • 47436aa4a   Boot with virtual == physical to get closer to native Linux. ... Browse Code »

    1) This allows us to get alot closer to booting bzImages.

    2) It means we don't have to know page_offset.

    3) The Guest needs to modify the boot pagetables to create the
    PAGE_OFFSET mapping before jumping to C code.

    4) guest_pa() walks the page tables rather than using page_offset.

    5) We don't use page_offset to figure out whether to emulate: it was
    always kinda quesationable, and won't work for instructions done
    before remapping (bzImage unpacking in particular).

    6) We still want the kernel address for tlb flushing: have the initial
    hypercall give us that, too.

    Signed-off-by: Rusty Russell

    Rusty Russell
     
  • d612cde06   Move register setup into i386_core.c ... Browse Code »

    Move setup_regs() to lguest_arch_setup_regs() in i386_core.c given
    that this is very architecture specific.

    Signed-off-by: Jes Sorensen
    Signed-off-by: Rusty Russell

    Jes Sorensen
     
  • 511801dc3   Change example launcher to use unsigned long not u32 ... Browse Code »

    Apply Clue 2x4 to lguest userlandkernel handling code and the
    lguest launcher. Pointers are not to be passed in u32's!

    Basic rule of thumb: Anything passing u32's back and forth should be
    passing unsigned longs to be portable to 64 bit archs.

    For those who forgotten already, I repeat: NO POINTERS IN u32!

    Signed-off-by: Jes Sorensen
    Signed-off-by: Rusty Russell

    Jes Sorensen
     
  • 48245cc07   Remove fixed limit on number of guests, and lguests array. ... Browse Code »

    Back when we had all the Guest state in the switcher, we had a fixed
    array of them. This is no longer necessary.

    If we switch the network code to using random_ether_addr (46 bits is
    enough to avoid clashes), we can get rid of the concept of "guest id"
    altogether.

    Signed-off-by: Rusty Russell

    Rusty Russell
     
  • 3c6b5bfa3   Introduce guest mem offset, static link example launcher ... Browse Code »

    In order to avoid problematic special linking of the Launcher, we give
    the Host an offset: this means we can use any memory region in the
    Launcher as Guest memory rather than insisting on mmap() at 0.

    The result is quite pleasing: a number of casts are replaced with
    simple additions.

    Signed-off-by: Rusty Russell

    Rusty Russell
     

27 Jul, 2007

1 commit