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  1. 19 10月, 2015 1 次提交
  3. 06 10月, 2015 1 次提交
  5. 01 10月, 2015 2 次提交
    • T
      x86/process: Unify 32bit and 64bit implementations of get_wchan() · 7ba78053
      由 Thomas Gleixner 提交于 
      The stack layout and the functionality is identical. Use the 64bit
version for all of x86.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NBorislav Petkov <bp@alien8.de>
Reviewed-by: NDmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Kostya Serebryany <kcc@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: kasan-dev <kasan-dev@googlegroups.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Wolfram Gloger <wmglo@dent.med.uni-muenchen.de>
Link: http://lkml.kernel.org/r/20150930083302.779694618@linutronix.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>
      7ba78053
    • T
      x86/process: Add proper bound checks in 64bit get_wchan() · eddd3826
      由 Thomas Gleixner 提交于 
      Dmitry Vyukov reported the following using trinity and the memory
error detector AddressSanitizer
(https://code.google.com/p/address-sanitizer/wiki/AddressSanitizerForKernel).

[ 124.575597] ERROR: AddressSanitizer: heap-buffer-overflow on
address ffff88002e280000
[ 124.576801] ffff88002e280000 is located 131938492886538 bytes to
the left of 28857600-byte region [ffffffff81282e0a, ffffffff82e0830a)
[ 124.578633] Accessed by thread T10915:
[ 124.579295] inlined in describe_heap_address
./arch/x86/mm/asan/report.c:164
[ 124.579295] #0 ffffffff810dd277 in asan_report_error
./arch/x86/mm/asan/report.c:278
[ 124.580137] #1 ffffffff810dc6a0 in asan_check_region
./arch/x86/mm/asan/asan.c:37
[ 124.581050] #2 ffffffff810dd423 in __tsan_read8 ??:0
[ 124.581893] #3 ffffffff8107c093 in get_wchan
./arch/x86/kernel/process_64.c:444

The address checks in the 64bit implementation of get_wchan() are
wrong in several ways:

 - The lower bound of the stack is not the start of the stack
   page. It's the start of the stack page plus sizeof (struct
   thread_info)

 - The upper bound must be:

       top_of_stack - TOP_OF_KERNEL_STACK_PADDING - 2 * sizeof(unsigned long).

   The 2 * sizeof(unsigned long) is required because the stack pointer
   points at the frame pointer. The layout on the stack is: ... IP FP
   ... IP FP. So we need to make sure that both IP and FP are in the
   bounds.

Fix the bound checks and get rid of the mix of numeric constants, u64
and unsigned long. Making all unsigned long allows us to use the same
function for 32bit as well.

Use READ_ONCE() when accessing the stack. This does not prevent a
concurrent wakeup of the task and the stack changing, but at least it
avoids TOCTOU.

Also check task state at the end of the loop. Again that does not
prevent concurrent changes, but it avoids walking for nothing.

Add proper comments while at it.
Reported-by: NDmitry Vyukov <dvyukov@google.com>
Reported-by: NSasha Levin <sasha.levin@oracle.com>
Based-on-patch-from: Wolfram Gloger <wmglo@dent.med.uni-muenchen.de>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NBorislav Petkov <bp@alien8.de>
Reviewed-by: NDmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Kostya Serebryany <kcc@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: kasan-dev <kasan-dev@googlegroups.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Wolfram Gloger <wmglo@dent.med.uni-muenchen.de>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20150930083302.694788319@linutronix.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>
      eddd3826
  7. 31 7月, 2015 2 次提交
    • A
      x86/ldt: Make modify_ldt() optional · a5b9e5a2
      由 Andy Lutomirski 提交于 
      The modify_ldt syscall exposes a large attack surface and is
unnecessary for modern userspace.  Make it optional.
Signed-off-by: NAndy Lutomirski <luto@kernel.org>
Reviewed-by: NKees Cook <keescook@chromium.org>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jan Beulich <jbeulich@suse.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: security@kernel.org <security@kernel.org>
Cc: xen-devel <xen-devel@lists.xen.org>
Link: http://lkml.kernel.org/r/a605166a771c343fd64802dece77a903507333bd.1438291540.git.luto@kernel.org
[ Made MATH_EMULATION dependent on MODIFY_LDT_SYSCALL. ]
Signed-off-by: NIngo Molnar <mingo@kernel.org>
      a5b9e5a2
    • A
      x86/ldt: Make modify_ldt synchronous · 37868fe1
      由 Andy Lutomirski 提交于 
      modify_ldt() has questionable locking and does not synchronize
threads.  Improve it: redesign the locking and synchronize all
threads' LDTs using an IPI on all modifications.

This will dramatically slow down modify_ldt in multithreaded
programs, but there shouldn't be any multithreaded programs that
care about modify_ldt's performance in the first place.

This fixes some fallout from the CVE-2015-5157 fixes.
Signed-off-by: NAndy Lutomirski <luto@kernel.org>
Reviewed-by: NBorislav Petkov <bp@suse.de>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jan Beulich <jbeulich@suse.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: security@kernel.org <security@kernel.org>
Cc: <stable@vger.kernel.org>
Cc: xen-devel <xen-devel@lists.xen.org>
Link: http://lkml.kernel.org/r/4c6978476782160600471bd865b318db34c7b628.1438291540.git.luto@kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
      37868fe1
  9. 06 7月, 2015 1 次提交
  11. 01 7月, 2015 1 次提交
  13. 19 5月, 2015 5 次提交
    • I
      x86/fpu: Rename fpu-internal.h to fpu/internal.h · 78f7f1e5
      由 Ingo Molnar 提交于 
      This unifies all the FPU related header files under a unified, hiearchical
naming scheme:

 - asm/fpu/types.h:      FPU related data types, needed for 'struct task_struct',
                         widely included in almost all kernel code, and hence kept
                         as small as possible.

 - asm/fpu/api.h:        FPU related 'public' methods exported to other subsystems.

 - asm/fpu/internal.h:   FPU subsystem internal methods

 - asm/fpu/xsave.h:      XSAVE support internal methods

(Also standardize the header guard in asm/fpu/internal.h.)
Reviewed-by: NBorislav Petkov <bp@alien8.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@kernel.org>
      78f7f1e5
    • I
      x86/fpu: Use 'struct fpu' in switch_fpu_finish() · 384a23f9
      由 Ingo Molnar 提交于 
      Migrate this function to pure 'struct fpu' usage.
Reviewed-by: NBorislav Petkov <bp@alien8.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@kernel.org>
      384a23f9
    • I
      x86/fpu: Use 'struct fpu' in switch_fpu_prepare() · cb8818b6
      由 Ingo Molnar 提交于 
      Migrate this function to pure 'struct fpu' usage.
Reviewed-by: NBorislav Petkov <bp@alien8.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@kernel.org>
      cb8818b6
    • I
      x86/fpu: Rename math_state_restore() to fpu__restore() · 3a0aee48
      由 Ingo Molnar 提交于 
      Move to the new fpu__*() namespace.
Reviewed-by: NBorislav Petkov <bp@alien8.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@kernel.org>
      3a0aee48
    • I
      x86/fpu: Fix header file dependencies of fpu-internal.h · f89e32e0
      由 Ingo Molnar 提交于 
      Fix a minor header file dependency bug in asm/fpu-internal.h: it
relies on i387.h but does not include it. All users of fpu-internal.h
included it explicitly.

Also remove unnecessary includes, to reduce compilation time.

This also makes it easier to use it as a standalone header file
for FPU internals, such as an upcoming C module in arch/x86/kernel/fpu/.
Reviewed-by: NBorislav Petkov <bp@alien8.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@kernel.org>
      f89e32e0
  15. 08 5月, 2015 1 次提交
  17. 27 4月, 2015 1 次提交
  19. 25 3月, 2015 1 次提交
    • D
      x86/asm/entry: Get rid of KERNEL_STACK_OFFSET · ef593260
      由 Denys Vlasenko 提交于 
      PER_CPU_VAR(kernel_stack) was set up in a way where it points
five stack slots below the top of stack.

Presumably, it was done to avoid one "sub $5*8,%rsp"
in syscall/sysenter code paths, where iret frame needs to be
created by hand.

Ironically, none of them benefits from this optimization,
since all of them need to allocate additional data on stack
(struct pt_regs), so they still have to perform subtraction.

This patch eliminates KERNEL_STACK_OFFSET.

PER_CPU_VAR(kernel_stack) now points directly to top of stack.
pt_regs allocations are adjusted to allocate iret frame as well.
Hopefully we can merge it later with 32-bit specific
PER_CPU_VAR(cpu_current_top_of_stack) variable...

Net result in generated code is that constants in several insns
are changed.

This change is necessary for changing struct pt_regs creation
in SYSCALL64 code path from MOV to PUSH instructions.
Signed-off-by: NDenys Vlasenko <dvlasenk@redhat.com>
Acked-by: NBorislav Petkov <bp@suse.de>
Acked-by: NAndy Lutomirski <luto@kernel.org>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1426785469-15125-2-git-send-email-dvlasenk@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      ef593260
  21. 23 3月, 2015 1 次提交
    • B
      x86/asm/entry: Fix execve() and sigreturn() syscalls to always return via IRET · 1daeaa31
      由 Brian Gerst 提交于 
      Both the execve() and sigreturn() family of syscalls have the
ability to change registers in ways that may not be compatabile
with the syscall path they were called from.

In particular, SYSRET and SYSEXIT can't handle non-default %cs and %ss,
and some bits in eflags.

These syscalls have stubs that are hardcoded to jump to the IRET path,
and not return to the original syscall path.

The following commit:

   76f5df43 ("Always allocate a complete "struct pt_regs" on the kernel stack")

recently changed this for some 32-bit compat syscalls, but introduced a bug where
execve from a 32-bit program to a 64-bit program would fail because it still returned
via SYSRETL. This caused Wine to fail when built for both 32-bit and 64-bit.

This patch sets TIF_NOTIFY_RESUME for execve() and sigreturn() so
that the IRET path is always taken on exit to userspace.
Signed-off-by: NBrian Gerst <brgerst@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1426978461-32089-1-git-send-email-brgerst@gmail.com
[ Improved the changelog and comments. ]
Signed-off-by: NIngo Molnar <mingo@kernel.org>
      1daeaa31
  23. 17 3月, 2015 3 次提交
    • I
      x86/asm/entry/64: Rename 'old_rsp' to 'rsp_scratch' · c38e5038
      由 Ingo Molnar 提交于 
      Make clear that the usage of PER_CPU(old_rsp) is purely temporary,
by renaming it to 'rsp_scratch'.

Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Will Drewry <wad@chromium.org>
Signed-off-by: NIngo Molnar <mingo@kernel.org>
      c38e5038
    • I
      x86/asm/entry/64: Remove thread_struct::usersp · ac9af498
      由 Ingo Molnar 提交于 
      Nothing uses thread_struct::usersp anymore, so remove it.

Originally-from: Denys Vlasenko <dvlasenk@redhat.com>
Tested-by: NBorislav Petkov <bp@alien8.de>
Acked-by: NBorislav Petkov <bp@alien8.de>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Will Drewry <wad@chromium.org>
Signed-off-by: NIngo Molnar <mingo@kernel.org>
      ac9af498
    • I
      x86/asm/entry/64: Simplify 'old_rsp' usage · 9854dd74
      由 Ingo Molnar 提交于 
      Remove all manipulations of PER_CPU(old_rsp) in C code:

 - it is not used on SYSRET return anymore, and system entries
   are atomic, so updating it from the fork and context switch
   paths is pointless.

 - Tweak a few related comments as well: we no longer have a
   "partial stack frame" on entry, ever.

Based on (split out of) patch from Denys Vlasenko.

Originally-from: Denys Vlasenko <dvlasenk@redhat.com>
Tested-by: NBorislav Petkov <bp@alien8.de>
Acked-by: NBorislav Petkov <bp@alien8.de>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1426599779-8010-2-git-send-email-dvlasenk@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      9854dd74
  25. 10 3月, 2015 1 次提交
  27. 07 3月, 2015 1 次提交
  29. 06 3月, 2015 1 次提交
  31. 25 2月, 2015 1 次提交
  33. 04 2月, 2015 1 次提交
  35. 11 12月, 2014 1 次提交
    • A
      x86_64, switch_to(): Load TLS descriptors before switching DS and ES · f647d7c1
      由 Andy Lutomirski 提交于 
      Otherwise, if buggy user code points DS or ES into the TLS
array, they would be corrupted after a context switch.

This also significantly improves the comments and documents some
gotchas in the code.

Before this patch, the both tests below failed.  With this
patch, the es test passes, although the gsbase test still fails.

 ----- begin es test -----

/*
 * Copyright (c) 2014 Andy Lutomirski
 * GPL v2
 */

static unsigned short GDT3(int idx)
{
	return (idx << 3) | 3;
}

static int create_tls(int idx, unsigned int base)
{
	struct user_desc desc = {
		.entry_number    = idx,
		.base_addr       = base,
		.limit           = 0xfffff,
		.seg_32bit       = 1,
		.contents        = 0, /* Data, grow-up */
		.read_exec_only  = 0,
		.limit_in_pages  = 1,
		.seg_not_present = 0,
		.useable         = 0,
	};

	if (syscall(SYS_set_thread_area, &desc) != 0)
		err(1, "set_thread_area");

	return desc.entry_number;
}

int main()
{
	int idx = create_tls(-1, 0);
	printf("Allocated GDT index %d\n", idx);

	unsigned short orig_es;
	asm volatile ("mov %%es,%0" : "=rm" (orig_es));

	int errors = 0;
	int total = 1000;
	for (int i = 0; i < total; i++) {
		asm volatile ("mov %0,%%es" : : "rm" (GDT3(idx)));
		usleep(100);

		unsigned short es;
		asm volatile ("mov %%es,%0" : "=rm" (es));
		asm volatile ("mov %0,%%es" : : "rm" (orig_es));
		if (es != GDT3(idx)) {
			if (errors == 0)
				printf("[FAIL]\tES changed from 0x%hx to 0x%hx\n",
				       GDT3(idx), es);
			errors++;
		}
	}

	if (errors) {
		printf("[FAIL]\tES was corrupted %d/%d times\n", errors, total);
		return 1;
	} else {
		printf("[OK]\tES was preserved\n");
		return 0;
	}
}

 ----- end es test -----

 ----- begin gsbase test -----

/*
 * gsbase.c, a gsbase test
 * Copyright (c) 2014 Andy Lutomirski
 * GPL v2
 */

static unsigned char *testptr, *testptr2;

static unsigned char read_gs_testvals(void)
{
	unsigned char ret;
	asm volatile ("movb %%gs:%1, %0" : "=r" (ret) : "m" (*testptr));
	return ret;
}

int main()
{
	int errors = 0;

	testptr = mmap((void *)0x200000000UL, 1, PROT_READ | PROT_WRITE,
		       MAP_PRIVATE | MAP_FIXED | MAP_ANONYMOUS, -1, 0);
	if (testptr == MAP_FAILED)
		err(1, "mmap");

	testptr2 = mmap((void *)0x300000000UL, 1, PROT_READ | PROT_WRITE,
		       MAP_PRIVATE | MAP_FIXED | MAP_ANONYMOUS, -1, 0);
	if (testptr2 == MAP_FAILED)
		err(1, "mmap");

	*testptr = 0;
	*testptr2 = 1;

	if (syscall(SYS_arch_prctl, ARCH_SET_GS,
		    (unsigned long)testptr2 - (unsigned long)testptr) != 0)
		err(1, "ARCH_SET_GS");

	usleep(100);

	if (read_gs_testvals() == 1) {
		printf("[OK]\tARCH_SET_GS worked\n");
	} else {
		printf("[FAIL]\tARCH_SET_GS failed\n");
		errors++;
	}

	asm volatile ("mov %0,%%gs" : : "r" (0));

	if (read_gs_testvals() == 0) {
		printf("[OK]\tWriting 0 to gs worked\n");
	} else {
		printf("[FAIL]\tWriting 0 to gs failed\n");
		errors++;
	}

	usleep(100);

	if (read_gs_testvals() == 0) {
		printf("[OK]\tgsbase is still zero\n");
	} else {
		printf("[FAIL]\tgsbase was corrupted\n");
		errors++;
	}

	return errors == 0 ? 0 : 1;
}

 ----- end gsbase test -----
Signed-off-by: NAndy Lutomirski <luto@amacapital.net>
Cc: <stable@vger.kernel.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/509d27c9fec78217691c3dad91cec87e1006b34a.1418075657.git.luto@amacapital.netSigned-off-by: NIngo Molnar <mingo@kernel.org>
      f647d7c1
  37. 03 9月, 2014 2 次提交
  39. 06 5月, 2014 1 次提交
  41. 01 5月, 2014 1 次提交
  43. 13 11月, 2013 2 次提交
    • V
      x86: move fpu_counter into ARCH specific thread_struct · c375f15a
      由 Vineet Gupta 提交于 
      Only a couple of arches (sh/x86) use fpu_counter in task_struct so it can
be moved out into ARCH specific thread_struct, reducing the size of
task_struct for other arches.

Compile tested i386_defconfig + gcc 4.7.3
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>
Acked-by: NIngo Molnar <mingo@kernel.org>
Cc: Paul Mundt <paul.mundt@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      c375f15a
    • J
      x86/dumpstack: Fix printk_address for direct addresses · 5f01c988
      由 Jiri Slaby 提交于 
      Consider a kernel crash in a module, simulated the following way:

 static int my_init(void)
 {
         char *map = (void *)0x5;
         *map = 3;
         return 0;
 }
 module_init(my_init);

When we turn off FRAME_POINTERs, the very first instruction in
that function causes a BUG. The problem is that we print IP in
the BUG report using %pB (from printk_address). And %pB
decrements the pointer by one to fix printing addresses of
functions with tail calls.

This was added in commit 71f9e598 ("x86, dumpstack: Use
%pB format specifier for stack trace") to fix the call stack
printouts.

So instead of correct output:

  BUG: unable to handle kernel NULL pointer dereference at 0000000000000005
  IP: [<ffffffffa01ac000>] my_init+0x0/0x10 [pb173]

We get:

  BUG: unable to handle kernel NULL pointer dereference at 0000000000000005
  IP: [<ffffffffa0152000>] 0xffffffffa0151fff

To fix that, we use %pS only for stack addresses printouts (via
newly added printk_stack_address) and %pB for regs->ip (via
printk_address). I.e. we revert to the old behaviour for all
except call stacks. And since from all those reliable is 1, we
remove that parameter from printk_address.
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: joe@perches.com
Cc: jirislaby@gmail.com
Link: http://lkml.kernel.org/r/1382706418-8435-1-git-send-email-jslaby@suse.czSigned-off-by: NIngo Molnar <mingo@kernel.org>
      5f01c988
  45. 25 9月, 2013 1 次提交
  47. 07 8月, 2013 2 次提交
  49. 26 6月, 2013 1 次提交
  51. 19 6月, 2013 1 次提交
  53. 01 5月, 2013 1 次提交
    • T
      dump_stack: unify debug information printed by show_regs() · a43cb95d
      由 Tejun Heo 提交于 
      show_regs() is inherently arch-dependent but it does make sense to print
generic debug information and some archs already do albeit in slightly
different forms.  This patch introduces a generic function to print debug
information from show_regs() so that different archs print out the same
information and it's much easier to modify what's printed.

show_regs_print_info() prints out the same debug info as dump_stack()
does plus task and thread_info pointers.

* Archs which didn't print debug info now do.

  alpha, arc, blackfin, c6x, cris, frv, h8300, hexagon, ia64, m32r,
  metag, microblaze, mn10300, openrisc, parisc, score, sh64, sparc,
  um, xtensa

* Already prints debug info.  Replaced with show_regs_print_info().
  The printed information is superset of what used to be there.

  arm, arm64, avr32, mips, powerpc, sh32, tile, unicore32, x86

* s390 is special in that it used to print arch-specific information
  along with generic debug info.  Heiko and Martin think that the
  arch-specific extra isn't worth keeping s390 specfic implementation.
  Converted to use the generic version.

Note that now all archs print the debug info before actual register
dumps.

An example BUG() dump follows.

 kernel BUG at /work/os/work/kernel/workqueue.c:4841!
 invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
 Modules linked in:
 CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.9.0-rc1-work+ #7
 Hardware name: empty empty/S3992, BIOS 080011  10/26/2007
 task: ffff88007c85e040 ti: ffff88007c860000 task.ti: ffff88007c860000
 RIP: 0010:[<ffffffff8234a07e>]  [<ffffffff8234a07e>] init_workqueues+0x4/0x6
 RSP: 0000:ffff88007c861ec8  EFLAGS: 00010246
 RAX: ffff88007c861fd8 RBX: ffffffff824466a8 RCX: 0000000000000001
 RDX: 0000000000000046 RSI: 0000000000000001 RDI: ffffffff8234a07a
 RBP: ffff88007c861ec8 R08: 0000000000000000 R09: 0000000000000000
 R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff8234a07a
 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 FS:  0000000000000000(0000) GS:ffff88007dc00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
 CR2: ffff88015f7ff000 CR3: 00000000021f1000 CR4: 00000000000007f0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
 Stack:
  ffff88007c861ef8 ffffffff81000312 ffffffff824466a8 ffff88007c85e650
  0000000000000003 0000000000000000 ffff88007c861f38 ffffffff82335e5d
  ffff88007c862080 ffffffff8223d8c0 ffff88007c862080 ffffffff81c47760
 Call Trace:
  [<ffffffff81000312>] do_one_initcall+0x122/0x170
  [<ffffffff82335e5d>] kernel_init_freeable+0x9b/0x1c8
  [<ffffffff81c47760>] ? rest_init+0x140/0x140
  [<ffffffff81c4776e>] kernel_init+0xe/0xf0
  [<ffffffff81c6be9c>] ret_from_fork+0x7c/0xb0
  [<ffffffff81c47760>] ? rest_init+0x140/0x140
  ...

v2: Typo fix in x86-32.

v3: CPU number dropped from show_regs_print_info() as
    dump_stack_print_info() has been updated to print it.  s390
    specific implementation dropped as requested by s390 maintainers.
Signed-off-by: NTejun Heo <tj@kernel.org>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Acked-by: NJesper Nilsson <jesper.nilsson@axis.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Chris Metcalf <cmetcalf@tilera.com>		[tile bits]
Acked-by: Richard Kuo <rkuo@codeaurora.org>		[hexagon bits]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      a43cb95d
  55. 25 1月, 2013 1 次提交
  57. 29 11月, 2012 1 次提交