From dadc63b85414eb711425e70b4140a640fa74ef09 Mon Sep 17 00:00:00 2001 From: Kyle McMartin Date: Sat, 27 Nov 2010 10:30:59 -0500 Subject: more patches for this tty open race --- kernel.spec | 6 ++- tty-ldisc-fix-open-flag-handling.patch | 54 ++++++++++++++++++++++++ tty-open-hangup-race-fixup.patch | 76 ++++++++++++++++++++++++++++++++++ 3 files changed, 135 insertions(+), 1 deletion(-) create mode 100644 tty-ldisc-fix-open-flag-handling.patch create mode 100644 tty-open-hangup-race-fixup.patch diff --git a/kernel.spec b/kernel.spec index 40ca1897e..aeefb1b6c 100644 --- a/kernel.spec +++ b/kernel.spec @@ -51,7 +51,7 @@ Summary: The Linux kernel # For non-released -rc kernels, this will be prepended with "0.", so # for example a 3 here will become 0.3 # -%global baserelease 1 +%global baserelease 2 %global fedora_build %{baserelease} # base_sublevel is the kernel version we're starting with and patching @@ -701,6 +701,8 @@ Patch12303: dmar-disable-when-ricoh-multifunction.patch Patch12400: tty-dont-allow-reopen-when-ldisc-is-changing.patch Patch12401: debug-tty-print-dev-name.patch +Patch12402: tty-ldisc-fix-open-flag-handling.patch +Patch12403: tty-open-hangup-race-fixup.patch %endif @@ -1293,6 +1295,8 @@ ApplyPatch dmar-disable-when-ricoh-multifunction.patch # rhbz#630464 ApplyPatch tty-dont-allow-reopen-when-ldisc-is-changing.patch ApplyPatch debug-tty-print-dev-name.patch +ApplyPatch tty-ldisc-fix-open-flag-handling.patch +ApplyPatch tty-open-hangup-race-fixup.patch # END OF PATCH APPLICATIONS diff --git a/tty-ldisc-fix-open-flag-handling.patch b/tty-ldisc-fix-open-flag-handling.patch new file mode 100644 index 000000000..4213aebb5 --- /dev/null +++ b/tty-ldisc-fix-open-flag-handling.patch @@ -0,0 +1,54 @@ +From linux-kernel-owner@vger.kernel.org Wed Nov 24 18:28:11 2010 +From: Jiri Slaby +Subject: [PATCH 1/2] TTY: ldisc, fix open flag handling +Date: Thu, 25 Nov 2010 00:27:54 +0100 + +When a concrete ldisc open fails in tty_ldisc_open, we forget to clear +TTY_LDISC_OPEN. This causes a false warning on the next ldisc open: +WARNING: at drivers/char/tty_ldisc.c:445 tty_ldisc_open+0x26/0x38() +Hardware name: System Product Name +Modules linked in: ... +Pid: 5251, comm: a.out Tainted: G W 2.6.32-5-686 #1 +Call Trace: + [] ? warn_slowpath_common+0x5e/0x8a + [] ? warn_slowpath_null+0xa/0xc + [] ? tty_ldisc_open+0x26/0x38 + [] ? tty_set_ldisc+0x218/0x304 +... + +So clear the bit when failing... + +Introduced in c65c9bc3efa (tty: rewrite the ldisc locking) back in +2.6.31-rc1. + +Signed-off-by: Jiri Slaby +Cc: Alan Cox +Reported-by: Sergey Lapin +Tested-by: Sergey Lapin +--- + drivers/tty/tty_ldisc.c | 2 ++ + 1 files changed, 2 insertions(+), 0 deletions(-) + +diff --git a/drivers/tty/tty_ldisc.c b/drivers/tty/tty_ldisc.c +index d8e96b0..4214d58 100644 +--- a/drivers/tty/tty_ldisc.c ++++ b/drivers/tty/tty_ldisc.c +@@ -454,6 +454,8 @@ static int tty_ldisc_open(struct tty_struct *tty, struct tty_ldisc *ld) + /* BTM here locks versus a hangup event */ + WARN_ON(!tty_locked()); + ret = ld->ops->open(tty); ++ if (ret) ++ clear_bit(TTY_LDISC_OPEN, &tty->flags); + return ret; + } + return 0; +-- +1.7.3.1 + + +-- +To unsubscribe from this list: send the line "unsubscribe linux-kernel" in +the body of a message to majordomo@vger.kernel.org +More majordomo info at http://vger.kernel.org/majordomo-info.html +Please read the FAQ at http://www.tux.org/lkml/ + diff --git a/tty-open-hangup-race-fixup.patch b/tty-open-hangup-race-fixup.patch new file mode 100644 index 000000000..cda7f41b3 --- /dev/null +++ b/tty-open-hangup-race-fixup.patch @@ -0,0 +1,76 @@ +From 9e88e8b9915b5e067507a087437d80e6a133d612 Mon Sep 17 00:00:00 2001 +From: Jiri Slaby +Date: Sat, 27 Nov 2010 16:06:46 +0100 +Subject: [PATCH 1/1] TTY: open/hangup race fixup + + +Signed-off-by: Jiri Slaby +--- + drivers/tty/tty_io.c | 10 +++++++++- + include/linux/tty.h | 1 + + 2 files changed, 10 insertions(+), 1 deletions(-) + +diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c +index 878f6d6..35480dd 100644 +--- a/drivers/tty/tty_io.c ++++ b/drivers/tty/tty_io.c +@@ -559,6 +559,9 @@ void __tty_hangup(struct tty_struct *tty) + + tty_lock(); + ++ /* some functions below drop BTM, so we need this bit */ ++ set_bit(TTY_HUPPING, &tty->flags); ++ + /* inuse_filps is protected by the single tty lock, + this really needs to change if we want to flush the + workqueue with the lock held */ +@@ -578,6 +581,10 @@ void __tty_hangup(struct tty_struct *tty) + } + spin_unlock(&tty_files_lock); + ++ /* ++ * it drops BTM and thus races with reopen ++ * we protect the race by TTY_HUPPING ++ */ + tty_ldisc_hangup(tty); + + read_lock(&tasklist_lock); +@@ -615,7 +622,6 @@ void __tty_hangup(struct tty_struct *tty) + tty->session = NULL; + tty->pgrp = NULL; + tty->ctrl_status = 0; +- set_bit(TTY_HUPPED, &tty->flags); + spin_unlock_irqrestore(&tty->ctrl_lock, flags); + + /* Account for the p->signal references we killed */ +@@ -641,6 +647,7 @@ void __tty_hangup(struct tty_struct *tty) + * can't yet guarantee all that. + */ + set_bit(TTY_HUPPED, &tty->flags); ++ clear_bit(TTY_HUPPING, &tty->flags); + tty_ldisc_enable(tty); + + tty_unlock(); +@@ -1311,6 +1318,7 @@ static int tty_reopen(struct tty_struct *tty) + struct tty_driver *driver = tty->driver; + + if (test_bit(TTY_CLOSING, &tty->flags) || ++ test_bit(TTY_HUPPING, &tty->flags) || + test_bit(TTY_LDISC_CHANGING, &tty->flags)) + return -EIO; + +diff --git a/include/linux/tty.h b/include/linux/tty.h +index 032d79f..54e4eaa 100644 +--- a/include/linux/tty.h ++++ b/include/linux/tty.h +@@ -366,6 +366,7 @@ struct tty_file_private { + #define TTY_HUPPED 18 /* Post driver->hangup() */ + #define TTY_FLUSHING 19 /* Flushing to ldisc in progress */ + #define TTY_FLUSHPENDING 20 /* Queued buffer flush pending */ ++#define TTY_HUPPING 21 /* ->hangup() in progress */ + + #define TTY_WRITE_FLUSH(tty) tty_write_flush((tty)) + +-- +1.7.3.1 + -- cgit