1. 15 10月, 2010 1 次提交
    • A
      llseek: automatically add .llseek fop · 6038f373
      Arnd Bergmann 提交于
      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(...)
      {
      <+...
      nonseekable_open(...)
      ...+>
      }
      
      @ open exists@
      identifier open_f;
      identifier i, f;
      identifier open1.nested_open;
      @@
      int open_f(struct inode *i, struct file *f)
      {
      <+...
      (
      nonseekable_open(...)
      |
      nested_open(...)
      )
      ...+>
      }
      
      @ 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)
      {
      <+...
      (
         *off = E
      |
         *off += E
      |
         func(..., off, ...)
      |
         E = *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)
      {
      <+...
      (
        *off = E
      |
        *off += E
      |
        func(..., off, ...)
      |
        E = *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: NArnd Bergmann <arnd@arndb.de>
      Cc: Julia Lawall <julia@diku.dk>
      Cc: Christoph Hellwig <hch@infradead.org>
      6038f373
  2. 31 8月, 2010 1 次提交
  3. 14 8月, 2010 1 次提交
    • M
      ath5k: disable ASPM L0s for all cards · 6ccf15a1
      Maxim Levitsky 提交于
      Atheros PCIe wireless cards handled by ath5k do require L0s disabled.
      For distributions shipping with CONFIG_PCIEASPM (this will be enabled
      by default in the future in 2.6.36) this will also mean both L1 and L0s
      will be disabled when a pre 1.1 PCIe device is detected. We do know L1
      works correctly even for all ath5k pre 1.1 PCIe devices though but cannot
      currently undue the effect of a blacklist, for details you can read
      pcie_aspm_sanity_check() and see how it adjusts the device link
      capability.
      
      It may be possible in the future to implement some PCI API to allow
      drivers to override blacklists for pre 1.1 PCIe but for now it is
      best to accept that both L0s and L1 will be disabled completely for
      distributions shipping with CONFIG_PCIEASPM rather than having this
      issue present. Motivation for adding this new API will be to help
      with power consumption for some of these devices.
      
      Example of issues you'd see:
      
        - On the Acer Aspire One (AOA150, Atheros Communications Inc. AR5001
          Wireless Network Adapter [168c:001c] (rev 01)) doesn't work well
          with ASPM enabled, the card will eventually stall on heavy traffic
          with often 'unsupported jumbo' warnings appearing. Disabling
          ASPM L0s in ath5k fixes these problems.
      
        - On the same card you would see a storm of RXORN interrupts
          even though medium is idle.
      
      Credit for root causing and fixing the bug goes to Jussi Kivilinna.
      
      Cc: David Quan <David.Quan@atheros.com>
      Cc: Matthew Garrett <mjg59@srcf.ucam.org>
      Cc: Tim Gardner <tim.gardner@canonical.com>
      Cc: Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
      Cc: stable@kernel.org
      Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
      Signed-off-by: NMaxim Levitsky <maximlevitsky@gmail.com>
      Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>
      6ccf15a1
  4. 27 7月, 2010 1 次提交
  5. 15 7月, 2010 3 次提交
    • B
      ath5k: clean up rxlink handling · b3f194e5
      Bruno Randolf 提交于
      There were a few places where the sc->rxlink pointer was set to NULL "just in
      case". This helps nothing - quite to the contrary it is problematic since it
      can create self-linked rx descriptors in the middle of the list of receive
      buffers.
      
      Here is an example how this could happen (thanks Bob!):
      
      cpu 0:                                      cpu 1:
      
      ath5k_rx_stop
                                                  ath5k_tasklet_rx
      sc->rxlink = NULL;   /* just in case */
                                                    // following doesn't link used
                                                    // buffer to prev.
                                                    ath5k_rxbuf_setup()
      
      In the case of ath5k_rx_stop() and ath5k_stop_locked() buffers/descriptors are
      not changed so rxlink should not be changed as well.
      
      In ath5k_intr() we seem to  try to work around a hardware bug, as the comment
      (which is copied 1:1 from the HAL) suggests. I don't see how this could help.
      Also the HAL does not set rxlink in this case (So where does this code come
      from? It has been there since the first import of ath5k). Changed to just
      increment a statistics counter.
      
      After this patch rxlink is only set to NULL before we initialize rx descriptors
      and updated when the descriptors are linked together.
      Signed-off-by: NBruno Randolf <br1@einfach.org>
      Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>
      b3f194e5
    • B
      ath5k: disable tasklets during reset · 450464de
      Bob Copeland 提交于
      Based on a patch from Bruno Randolf, attempting useful
      work while we are resetting the chip just leads to interface
      lockups and bad descriptor data, and possibly DMAing to
      freed buffers.  Let's suspend all tasklets while
      reprogramming the registers in the card to avoid such
      problems.
      
      In the future we can convert the tasklets to threaded
      interrupt handlers to simplify things.
      Signed-off-by: NBob Copeland <me@bobcopeland.com>
      Acked-by: NBruno Randolf <br1@einfach.org>
      Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>
      450464de
    • B
      ath5k: move reset to mac80211 workqueue · 5faaff74
      Bob Copeland 提交于
      We currently trigger a reset via a tasklet when certain error
      conditions are detected so that the card will (eventually)
      restart.  Unfortunately this makes locking complicated since
      reset can also be called in process context (e.g. for channel
      change).  Currently nothing protects against concurrent resets,
      which can be the source of corruption bugs.
      
      Reset takes too long to spinlock the whole thing, so this
      patch moves deferred resets into the mac80211 workqueue to
      enable use of sc->lock mutex.
      Signed-off-by: NBob Copeland <me@bobcopeland.com>
      Acked-by: NBruno Randolf <br1@einfach.org>
      Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>
      5faaff74
  6. 29 6月, 2010 1 次提交
  7. 19 6月, 2010 1 次提交
    • B
      ath5k: initialize ah->ah_current_channel · b6855772
      Bob Copeland 提交于
      ath5k assumes ah_current_channel is always a valid pointer in
      several places, but a newly created interface may not have a
      channel.  To avoid null pointer dereferences, set it up to point
      to the first available channel until later reconfigured.
      
      This fixes the following oops:
      $ rmmod ath5k
      $ insmod ath5k
      $ iw phy0 set distance 11000
      
      BUG: unable to handle kernel NULL pointer dereference at 00000006
      IP: [<d0a1ff24>] ath5k_hw_set_coverage_class+0x74/0x1b0 [ath5k]
      *pde = 00000000
      Oops: 0000 [#1]
      last sysfs file: /sys/devices/pci0000:00/0000:00:0e.0/ieee80211/phy0/index
      Modules linked in: usbhid option usb_storage usbserial usblp evdev lm90
      scx200_acb i2c_algo_bit i2c_dev i2c_core via_rhine ohci_hcd ne2k_pci
      8390 leds_alix2 xt_IMQ imq nf_nat_tftp nf_conntrack_tftp nf_nat_irc nf_cc
      
      Pid: 1597, comm: iw Not tainted (2.6.32.14 #8)
      EIP: 0060:[<d0a1ff24>] EFLAGS: 00010296 CPU: 0
      EIP is at ath5k_hw_set_coverage_class+0x74/0x1b0 [ath5k]
      EAX: 000000c2 EBX: 00000000 ECX: ffffffff EDX: c12d2080
      ESI: 00000019 EDI: cf8c0000 EBP: d0a30edc ESP: cfa09bf4
        DS: 007b ES: 007b FS: 0000 GS: 0000 SS: 0068
      Process iw (pid: 1597, ti=cfa09000 task=cf88a000 task.ti=cfa09000)
      Stack:
        d0a34f35 d0a353f8 d0a30edc 000000fe cf8c0000 00000000 1900063d cfa8c9e0
      <0> cfa8c9e8 cfa8c0c0 cfa8c000 d0a27f0c 199d84b4 cfa8c200 00000010 d09bfdc7
      <0> 00000000 00000000 ffffffff d08e0d28 cf9263c0 00000001 cfa09cc4 00000000
      Call Trace:
        [<d0a27f0c>] ? ath5k_hw_attach+0xc8c/0x3c10 [ath5k]
        [<d09bfdc7>] ? __ieee80211_request_smps+0x1347/0x1580 [mac80211]
        [<d08e0d28>] ? nl80211_send_scan_start+0x7b8/0x4520 [cfg80211]
        [<c10f5db9>] ? nla_parse+0x59/0xc0
        [<c11ca8d9>] ? genl_rcv_msg+0x169/0x1a0
        [<c11ca770>] ? genl_rcv_msg+0x0/0x1a0
        [<c11c7e68>] ? netlink_rcv_skb+0x38/0x90
        [<c11c9649>] ? genl_rcv+0x19/0x30
        [<c11c7c03>] ? netlink_unicast+0x1b3/0x220
        [<c11c893e>] ? netlink_sendmsg+0x26e/0x290
        [<c11a409e>] ? sock_sendmsg+0xbe/0xf0
        [<c1032780>] ? autoremove_wake_function+0x0/0x50
        [<c104d846>] ? __alloc_pages_nodemask+0x106/0x530
        [<c1074933>] ? do_lookup+0x53/0x1b0
        [<c10766f9>] ? __link_path_walk+0x9b9/0x9e0
        [<c11acab0>] ? verify_iovec+0x50/0x90
        [<c11a42b1>] ? sys_sendmsg+0x1e1/0x270
        [<c1048e50>] ? find_get_page+0x10/0x50
        [<c104a96f>] ? filemap_fault+0x5f/0x370
        [<c1059159>] ? __do_fault+0x319/0x370
        [<c11a55b4>] ? sys_socketcall+0x244/0x290
        [<c101962c>] ? do_page_fault+0x1ec/0x270
        [<c1019440>] ? do_page_fault+0x0/0x270
        [<c1002ae5>] ? syscall_call+0x7/0xb
      Code: 00 b8 fe 00 00 00 b9 f8 53 a3 d0 89 5c 24 14 89 7c 24 10 89 44 24
      0c 89 6c 24 08 89 4c 24 04 c7 04 24 35 4f a3 d0 e8 7c 30 60 f0 <0f> b7
      43 06 ba 06 00 00 00 a8 10 75 0e 83 e0 20 83 f8 01 19 d2
      EIP: [<d0a1ff24>] ath5k_hw_set_coverage_class+0x74/0x1b0 [ath5k] SS:ESP
      0068:cfa09bf4
      CR2: 0000000000000006
      ---[ end trace 54f73d6b10ceb87b ]---
      
      Cc: stable@kernel.org
      Reported-by: NSteve Brown <sbrown@cortland.com>
      Signed-off-by: NBob Copeland <me@bobcopeland.com>
      Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>
      b6855772
  8. 17 6月, 2010 17 次提交
  9. 08 6月, 2010 5 次提交
  10. 05 6月, 2010 2 次提交
  11. 03 6月, 2010 7 次提交