linux-stable/arch/x86
Daniel Glöckner ab9e18587f x86, math-emu: fix init_fpu for task != current
Impact: fix math-emu related crash while using GDB/ptrace

init_fpu() calls finit to initialize a task's xstate, while finit always
works on the current task. If we use PTRACE_GETFPREGS on another
process and both processes did not already use floating point, we get
a null pointer exception in finit.

This patch creates a new function finit_task that takes a task_struct
parameter. finit becomes a wrapper that simply calls finit_task with
current. On the plus side this avoids many calls to get_current which
would each resolve to an inline assembler mov instruction.

An empty finit_task has been added to i387.h to avoid linker errors in
case the compiler still emits the call in init_fpu when
CONFIG_MATH_EMULATION is not defined.

The declaration of finit in i387.h has been removed as the remaining
code using this function gets its prototype from fpu_proto.h.

Signed-off-by: Daniel Glöckner <dg@emlix.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: "Pallipadi Venkatesh" <venkatesh.pallipadi@intel.com>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Bill Metzenthen <billm@melbpc.org.au>
LKML-Reference: <E1Lew31-0004il-Fg@mailer.emlix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-04 20:33:16 +01:00
..
boot x86 setup: fix asm constraints in vesa_store_edid 2009-01-30 23:55:25 +01:00
configs eeprom: More consistent symbol names 2009-01-26 21:19:57 +01:00
crypto crypto: crc32c-intel - Switch to shash 2008-12-25 11:01:37 +11:00
ia32 x86-64: fix int $0x80 -ENOSYS return 2009-02-06 18:22:29 -08:00
include/asm x86, math-emu: fix init_fpu for task != current 2009-03-04 20:33:16 +01:00
kernel x86, math-emu: fix init_fpu for task != current 2009-03-04 20:33:16 +01:00
kvm KVM: VMX: Flush volatile msrs before emulating rdmsr 2009-02-15 02:47:39 +02:00
lguest lguest: typos fix 2009-01-30 11:34:10 +10:30
lib x86: use early clobbers in usercopy*.c 2009-01-21 09:43:17 +01:00
mach-default x86: Add IRQF_TIMER to legacy x86 timer interrupt descriptors 2009-02-22 10:27:49 -08:00
mach-generic x86: rename all fields of mpc_table mpc_X to X 2009-01-05 14:08:34 +01:00
mach-rdc321x
mach-voyager x86, Voyager: fix compile by lifting the degeneracy of phys_cpu_present_map 2009-02-24 12:50:11 -08:00
math-emu x86, math-emu: fix init_fpu for task != current 2009-03-04 20:33:16 +01:00
mm Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-03-03 14:32:55 -08:00
oprofile x86: oprofile: don't set counter width from cpuid on Core2 2009-03-03 12:04:22 +01:00
pci PCI: irq and pci_ids patch for Intel Tigerpoint DeviceIDs 2009-01-27 09:46:08 -08:00
power x86, hibernate: fix breakage on x86_32 with CONFIG_NUMA set 2008-11-12 23:28:51 +01:00
vdso Merge branch 'for-linus' of git://git390.osdl.marist.edu/pub/scm/linux-2.6 2008-12-28 12:33:21 -08:00
video
xen xen: disable interrupts early, as start_kernel expects 2009-02-25 18:51:57 +01:00
Kconfig x86: enable DMAR by default 2009-02-26 20:59:47 +01:00
Kconfig.cpu x86/Kconfig.cpu: make Kconfig help readable in the console 2009-02-04 22:19:27 +01:00
Kconfig.debug trace: mmiotrace to the tracer menu in Kconfig 2009-02-15 20:03:28 +01:00
Makefile x86, um: ... and asm-x86 move 2008-10-22 22:55:20 -07:00
Makefile_32.cpu