From: Ingo Molnar Date: Wed, 13 Feb 2008 19:21:06 +0000 (+0100) Subject: x86: fix "BUG: sleeping function called from invalid context" in print_vma_addr() X-Git-Tag: v2.6.25-rc2~9^2~7 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e8bff74afbdb4ad72bf6135c84289c47cf557892;p=pandora-kernel.git x86: fix "BUG: sleeping function called from invalid context" in print_vma_addr() Jiri Kosina reported the following deadlock scenario with show_unhandled_signals enabled: [ 68.379022] gnome-settings-[2941] trap int3 ip:3d2c840f34 sp:7fff36f5d100 error:0<3>BUG: sleeping function called from invalid context at kernel/rwsem.c:21 [ 68.379039] in_atomic():1, irqs_disabled():0 [ 68.379044] no locks held by gnome-settings-/2941. [ 68.379050] Pid: 2941, comm: gnome-settings- Not tainted 2.6.25-rc1 #30 [ 68.379054] [ 68.379056] Call Trace: [ 68.379061] <#DB> [] ? __debug_show_held_locks+0x13/0x30 [ 68.379109] [] __might_sleep+0xe5/0x110 [ 68.379123] [] down_read+0x20/0x70 [ 68.379137] [] print_vma_addr+0x3a/0x110 [ 68.379152] [] do_trap+0xf5/0x170 [ 68.379168] [] do_int3+0x7b/0xe0 [ 68.379180] [] int3+0x9f/0xd0 [ 68.379203] <> [ 68.379229] in libglib-2.0.so.0.1505.0[3d2c800000+dc000] and tracked it down to: commit 03252919b79891063cf99145612360efbdf9500b Author: Andi Kleen Date: Wed Jan 30 13:33:18 2008 +0100 x86: print which shared library/executable faulted in segfault etc. messages the problem is that we call down_read() from an atomic context. Solve this by returning from print_vma_addr() if the preempt count is elevated. Update preempt_conditional_sti / preempt_conditional_cli to unconditionally lift the preempt count even on !CONFIG_PREEMPT. Reported-by: Jiri Kosina Signed-off-by: Ingo Molnar --- Reading git-diff-tree failed