- 08 9月, 2016 1 次提交
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由 Andy Lutomirski 提交于
If we get a page fault indicating kernel stack overflow, invoke handle_stack_overflow(). To prevent us from overflowing the stack again while handling the overflow (because we are likely to have very little stack space left), call handle_stack_overflow() on the double-fault stack. Signed-off-by: NAndy Lutomirski <luto@kernel.org> 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: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/6d6cf96b3fb9b4c9aa303817e1dc4de0c7c36487.1472603235.git.luto@kernel.org [ Minor edit. ] Signed-off-by: NIngo Molnar <mingo@kernel.org>
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- 24 8月, 2016 14 次提交
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由 Brian Gerst 提交于
thread_saved_pc() was using a completely bogus method to get the return address. Since switch_to() was previously inlined, there was no sane way to know where on the stack the return address was stored. Now with the frame of a sleeping thread well defined, this can be implemented correctly. Signed-off-by: NBrian Gerst <brgerst@gmail.com> Reviewed-by: NJosh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> 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> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1471106302-10159-7-git-send-email-brgerst@gmail.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Brian Gerst 提交于
Instead of setting up a fake pt_regs context, put the kernel thread function pointer and arg into the unused callee-restored registers of 'struct fork_frame'. Signed-off-by: NBrian Gerst <brgerst@gmail.com> Reviewed-by: NJosh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> 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> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1471106302-10159-6-git-send-email-brgerst@gmail.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Brian Gerst 提交于
Move the low-level context switch code to an out-of-line asm stub instead of using complex inline asm. This allows constructing a new stack frame for the child process to make it seamlessly flow to ret_from_fork without an extra test and branch in __switch_to(). It also improves code generation for __schedule() by using the C calling convention instead of clobbering all registers. Signed-off-by: NBrian Gerst <brgerst@gmail.com> Reviewed-by: NJosh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> 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> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1471106302-10159-5-git-send-email-brgerst@gmail.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Brian Gerst 提交于
Add 'struct inactive_task_frame', which defines the layout of the stack for a sleeping process. For now, the only defined field is the BP register (frame pointer). Signed-off-by: NBrian Gerst <brgerst@gmail.com> Reviewed-by: NJosh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> 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> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1471106302-10159-4-git-send-email-brgerst@gmail.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Brian Gerst 提交于
switch_to() no longer saves EFLAGS, so it's bogus to look for it on the stack. Set it to zero like 32-bit. Signed-off-by: NBrian Gerst <brgerst@gmail.com> Reviewed-by: NJosh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1471106302-10159-3-git-send-email-brgerst@gmail.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Brian Gerst 提交于
Match 64-bit and set gdb_regs[GDB_PC] to zero. thread.ip is always the same point in the scheduler (except for newly forked processes), and will be removed in a future patch. Signed-off-by: NBrian Gerst <brgerst@gmail.com> Reviewed-by: NJosh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1471106302-10159-2-git-send-email-brgerst@gmail.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Josh Poimboeuf 提交于
When function graph tracing is enabled, print_context_stack_bp() can report return_to_handler() as an unreliable address, which is confusing and misleading: return_to_handler() is really only useful as a hint for debugging, whereas print_context_stack_bp() users only care about the actual 'reliable' call path. Signed-off-by: NJosh Poimboeuf <jpoimboe@redhat.com> Acked-by: NSteven Rostedt <rostedt@goodmis.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Byungchul Park <byungchul.park@lge.com> 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: Nilay Vaish <nilayvaish@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/c51aef578d8027791b38d2ad9bac0c7f499fde91.1471607358.git.jpoimboe@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Josh Poimboeuf 提交于
When function graph tracing is enabled for a function, its return address on the stack is replaced with the address of an ftrace handler (return_to_handler). Currently 'return_to_handler' can be reported as reliable. That's not ideal, and can actually be misleading. When saving or dumping the stack, you normally only care about what led up to that point (the call path), rather than what will happen in the future (the return path). That's especially true in the non-oops stack trace case, which isn't used for debugging. For example, in a perf profiling operation, reporting return_to_handler() in the trace would just be confusing. And in the oops case, where debugging is important, "unreliable" is also more appropriate there because it serves as a hint that graph tracing was involved, instead of trying to imply that return_to_handler() was the real caller. Signed-off-by: NJosh Poimboeuf <jpoimboe@redhat.com> Acked-by: NSteven Rostedt <rostedt@goodmis.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Byungchul Park <byungchul.park@lge.com> 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: Nilay Vaish <nilayvaish@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/f8af15749c7d632d3e7f815995831d5b7f82950d.1471607358.git.jpoimboe@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Josh Poimboeuf 提交于
Use the more reliable version of ftrace_graph_ret_addr() so we no longer have to worry about the unwinder getting out of sync with the function graph ret_stack index, which can happen if the unwinder skips any frames before calling ftrace_graph_ret_addr(). This fixes this issue (and several others like it): $ cat /proc/self/stack [<ffffffff810489a2>] save_stack_trace_tsk+0x22/0x40 [<ffffffff81311a89>] proc_pid_stack+0xb9/0x110 [<ffffffff813127c4>] proc_single_show+0x54/0x80 [<ffffffff812be088>] seq_read+0x108/0x3e0 [<ffffffff812923d7>] __vfs_read+0x37/0x140 [<ffffffff812929d9>] vfs_read+0x99/0x140 [<ffffffff81293f28>] SyS_read+0x58/0xc0 [<ffffffff818af97c>] entry_SYSCALL_64_fastpath+0x1f/0xbd [<ffffffffffffffff>] 0xffffffffffffffff $ echo function_graph > /sys/kernel/debug/tracing/current_tracer $ cat /proc/self/stack [<ffffffff818b2428>] return_to_handler+0x0/0x27 [<ffffffff810394cc>] print_context_stack+0xfc/0x100 [<ffffffff818b2428>] return_to_handler+0x0/0x27 [<ffffffff8103891b>] dump_trace+0x12b/0x350 [<ffffffff818b2428>] return_to_handler+0x0/0x27 [<ffffffff810489a2>] save_stack_trace_tsk+0x22/0x40 [<ffffffff818b2428>] return_to_handler+0x0/0x27 [<ffffffff81311a89>] proc_pid_stack+0xb9/0x110 [<ffffffff818b2428>] return_to_handler+0x0/0x27 [<ffffffff813127c4>] proc_single_show+0x54/0x80 [<ffffffff818b2428>] return_to_handler+0x0/0x27 [<ffffffff812be088>] seq_read+0x108/0x3e0 [<ffffffff818b2428>] return_to_handler+0x0/0x27 [<ffffffff812923d7>] __vfs_read+0x37/0x140 [<ffffffff818b2428>] return_to_handler+0x0/0x27 [<ffffffff812929d9>] vfs_read+0x99/0x140 [<ffffffffffffffff>] 0xffffffffffffffff Enabling function graph tracing causes the stack trace to change in two ways: First, the real call addresses are confusingly interspersed with 'return_to_handler' addresses. This issue will be fixed by the next patch. Second, the stack trace is offset by two frames, because the unwinder skipped the first two frames and got out of sync with the ret_stack index. This patch fixes this issue. Signed-off-by: NJosh Poimboeuf <jpoimboe@redhat.com> Acked-by: NSteven Rostedt <rostedt@goodmis.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Byungchul Park <byungchul.park@lge.com> 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: Nilay Vaish <nilayvaish@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/a6d623e36f8d08f9a17bd74d804d201177a23afd.1471607358.git.jpoimboe@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Josh Poimboeuf 提交于
Convert print_context_stack() and print_context_stack_bp() to use the arch-independent ftrace_graph_ret_addr() helper. Signed-off-by: NJosh Poimboeuf <jpoimboe@redhat.com> Acked-by: NSteven Rostedt <rostedt@goodmis.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Byungchul Park <byungchul.park@lge.com> 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: Nilay Vaish <nilayvaish@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/56ec97cafc1bf2e34d1119e6443d897db406da86.1471607358.git.jpoimboe@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Josh Poimboeuf 提交于
Storing this value will help prevent unwinders from getting out of sync with the function graph tracer ret_stack. Now instead of needing a stateful iterator, they can compare the return address pointer to find the right ret_stack entry. Note that an array of 50 ftrace_ret_stack structs is allocated for every task. So when an arch implements this, it will add either 200 or 400 bytes of memory usage per task (depending on whether it's a 32-bit or 64-bit platform). Signed-off-by: NJosh Poimboeuf <jpoimboe@redhat.com> Acked-by: NSteven Rostedt <rostedt@goodmis.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Byungchul Park <byungchul.park@lge.com> 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: Nilay Vaish <nilayvaish@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/a95cfcc39e8f26b89a430c56926af0bb217bc0a1.1471607358.git.jpoimboe@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Josh Poimboeuf 提交于
Make HAVE_FUNCTION_GRAPH_FP_TEST a normal define, independent from kconfig. This removes some config file pollution and simplifies the checking for the fp test. Suggested-by: NSteven Rostedt <rostedt@goodmis.org> Signed-off-by: NJosh Poimboeuf <jpoimboe@redhat.com> Acked-by: NSteven Rostedt <rostedt@goodmis.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Byungchul Park <byungchul.park@lge.com> 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: Nilay Vaish <nilayvaish@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/2c4e5f05054d6d367f702fd153af7a0109dd5c81.1471607358.git.jpoimboe@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Andy Lutomirski 提交于
This allows x86_64 kernels to enable vmapped stacks by setting HAVE_ARCH_VMAP_STACK=y - which enables the CONFIG_VMAP_STACK=y high level Kconfig option. There are a couple of interesting bits: First, x86 lazily faults in top-level paging entries for the vmalloc area. This won't work if we get a page fault while trying to access the stack: the CPU will promote it to a double-fault and we'll die. To avoid this problem, probe the new stack when switching stacks and forcibly populate the pgd entry for the stack when switching mms. Second, once we have guard pages around the stack, we'll want to detect and handle stack overflow. I didn't enable it on x86_32. We'd need to rework the double-fault code a bit and I'm concerned about running out of vmalloc virtual addresses under some workloads. This patch, by itself, will behave somewhat erratically when the stack overflows while RSP is still more than a few tens of bytes above the bottom of the stack. Specifically, we'll get #PF and make it to no_context and them oops without reliably triggering a double-fault, and no_context doesn't know about stack overflows. The next patch will improve that case. Thank you to Nadav and Brian for helping me pay enough attention to the SDM to hopefully get this right. Signed-off-by: NAndy Lutomirski <luto@kernel.org> 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: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Nadav Amit <nadav.amit@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/c88f3e2920b18e6cc621d772a04a62c06869037e.1470907718.git.luto@kernel.org [ Minor edits. ] Signed-off-by: NIngo Molnar <mingo@kernel.org>
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由 Borislav Petkov 提交于
The comment probably meant some old AMD64 incarnation which most likely never saw the light of day. STAR and LSTAR are two different registers and STAR sets CS/SS(DS) selectors for *all* modes, not only 32-bit. So simply remove that comment. Signed-off-by: NBorislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@kernel.org> 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: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20160823172356.15879-1-bp@alien8.deSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 19 8月, 2016 7 次提交
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由 Josh Poimboeuf 提交于
There has been a 64-byte gap at the end of the irq stack for at least 12 years. It predates git history, and I can't find any good reason for it. Remove it. What's the worst that could happen? Signed-off-by: NJosh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Byungchul Park <byungchul.park@lge.com> 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: Nilay Vaish <nilayvaish@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/14f9281c5475cc44af95945ea7546bff2e3836db.1471535549.git.jpoimboe@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Josh Poimboeuf 提交于
On x86_32, when an interrupt happens from kernel space, SS and SP aren't pushed and the existing stack is used. So pt_regs is effectively two words shorter, and the previous stack pointer is normally the memory after the shortened pt_regs, aka '®s->sp'. But in the rare case where the interrupt hits right after the stack pointer has been changed to point to an empty stack, like for example when call_on_stack() is used, the address immediately after the shortened pt_regs is no longer on the stack. In that case, instead of '®s->sp', the previous stack pointer should be retrieved from the beginning of the current stack page. kernel_stack_pointer() wants to do that, but it forgets to dereference the pointer. So instead of returning a pointer to the previous stack, it returns a pointer to the beginning of the current stack. Note that it's probably outside of kernel_stack_pointer()'s scope to be switching stacks at all. The x86_64 version of this function doesn't do it, and it would be better for the caller to do it if necessary. But that's a patch for another day. This just fixes the original intent. Signed-off-by: NJosh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Byungchul Park <byungchul.park@lge.com> 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: Nilay Vaish <nilayvaish@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 0788aa6a ("x86: Prepare removal of previous_esp from i386 thread_info structure") Link: http://lkml.kernel.org/r/472453d6e9f6a2d4ab16aaed4935f43117111566.1471535549.git.jpoimboe@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Josh Poimboeuf 提交于
This zeroed word has no apparent purpose, so remove it. Brian Gerst says: "FYI the word used to be the SS segment selector for the LSS instruction, which isn't needed in 64-bit mode." Signed-off-by: NJosh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Byungchul Park <byungchul.park@lge.com> 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: Nilay Vaish <nilayvaish@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/b056855c295bbb3825b97c1e9f7958539a4d6cf2.1471535549.git.jpoimboe@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Josh Poimboeuf 提交于
When starting the dump of an exception stack, it shows "<<EOE>>" instead of "<EOE>". print_trace_stack() already adds brackets, no need to add them again. Signed-off-by: NJosh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Byungchul Park <byungchul.park@lge.com> 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: Nilay Vaish <nilayvaish@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/77f185fd5b81845869b400aa619415458df6b6cc.1471535549.git.jpoimboe@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Josh Poimboeuf 提交于
The 'stack_start' variable is similar in usage to 'initial_code' and 'initial_gs': they're all stored in head_64.S and they're all updated by SMP and ACPI suspend before starting a CPU. Rename it to 'initial_stack' to be consistent with the others. Signed-off-by: NJosh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Byungchul Park <byungchul.park@lge.com> 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: Nilay Vaish <nilayvaish@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/87063d773a3212051b77e17b0ee427f6582a5050.1471535549.git.jpoimboe@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Josh Poimboeuf 提交于
There is no init_rsp variable. Remove its extern. Signed-off-by: NJosh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Byungchul Park <byungchul.park@lge.com> 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: Nilay Vaish <nilayvaish@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/c183bbecd5730d84e8c6aff3824537c1c1bf3591.1471535549.git.jpoimboe@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Josh Poimboeuf 提交于
There are a bewildering array of options for dumping the stack. Simplify things a little by removing show_trace(), which is unused. Signed-off-by: NJosh Poimboeuf <jpoimboe@redhat.com> Reviewed-by: NAndy Lutomirski <luto@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Byungchul Park <byungchul.park@lge.com> 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: Nilay Vaish <nilayvaish@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/fe02292eac9d409001ec0cf6d06f90ced242570d.1471535549.git.jpoimboe@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 18 8月, 2016 2 次提交
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由 Jiri Olsa 提交于
Frank reported kernel panic when he disabled several cores in BIOS via following option: Core Disable Bitmap(Hex) [0] with number 0xFFE, which leaves 16 CPUs in system (out of 48). The kernel panic below goes along with following messages: smpboot: Max logical packages: 2^M smpboot: APIC(0) Converting physical 0 to logical package 0^M smpboot: APIC(20) Converting physical 1 to logical package 1^M smpboot: APIC(40) Package 2 exceeds logical package map^M smpboot: CPU 8 APICId 40 disabled^M smpboot: APIC(60) Package 3 exceeds logical package map^M smpboot: CPU 12 APICId 60 disabled^M ... general protection fault: 0000 [#1] SMP^M Modules linked in:^M CPU: 15 PID: 1 Comm: swapper/0 Not tainted 4.7.0-rc5+ #1^M Hardware name: SGI UV300/UV300, BIOS SGI UV 300 series BIOS 05/25/2016^M task: ffff8801673e0000 ti: ffff8801673ac000 task.ti: ffff8801673ac000^M RIP: 0010:[<ffffffff81014d54>] [<ffffffff81014d54>] uncore_change_context+0xd4/0x180^M ... [<ffffffff810158ac>] uncore_event_init_cpu+0x6c/0x70^M [<ffffffff81d8c91c>] intel_uncore_init+0x1c2/0x2dd^M [<ffffffff81d8c75a>] ? uncore_cpu_setup+0x17/0x17^M [<ffffffff81002190>] do_one_initcall+0x50/0x190^M [<ffffffff810ab193>] ? parse_args+0x293/0x480^M [<ffffffff81d87365>] kernel_init_freeable+0x1a5/0x249^M [<ffffffff81d86a35>] ? set_debug_rodata+0x12/0x12^M [<ffffffff816dc19e>] kernel_init+0xe/0x110^M [<ffffffff816e93bf>] ret_from_fork+0x1f/0x40^M [<ffffffff816dc190>] ? rest_init+0x80/0x80^M The reason for the panic is wrong value of __max_logical_packages, which lets logical_package_map uninitialized and the uncore code relying on this map being properly initialized (maybe we should add some safety checks there as well). The __max_logical_packages is computed as: DIV_ROUND_UP(total_cpus, ncpus); - ncpus being number of cores With above BIOS setup we get total_cpus == 16 which set __max_logical_packages to 2 (ncpus is 12). Once topology_update_package_map processes CPU with logical pkg over 2 we display above messages and fail to initialize the physical_to_logical_pkg map, which makes the uncore code crash. The fix is to remove logical_package_map bitmap completely and keep and update the logical_packages number instead. After we enumerate all the present CPUs, we check if the enumerated logical packages count is within its computed maximum from BIOS data. If it's not the case, we set this maximum to the new enumerated value and freeze any new addition of logical packages. The freeze is because lot of init code like uncore/rapl/cqm depends on having maximum logical package value set to allocate their data, so we can't change it later on. Prarit Bhargava tested the patch and confirms that it solves the problem: From dmidecode: Core Count: 24 Core Enabled: 24 Thread Count: 48 Orig kernel boot log: [ 0.464981] smpboot: Max logical packages: 19 [ 0.469861] smpboot: APIC(0) Converting physical 0 to logical package 0 [ 0.477261] smpboot: APIC(40) Converting physical 1 to logical package 1 [ 0.484760] smpboot: APIC(80) Converting physical 2 to logical package 2 [ 0.492258] smpboot: APIC(c0) Converting physical 3 to logical package 3 1. nr_cpus=8, should stop enumerating in package 0: [ 0.533664] smpboot: APIC(0) Converting physical 0 to logical package 0 [ 0.539596] smpboot: Max logical packages: 19 2. max_cpus=8, should still enumerate all packages: [ 0.526494] smpboot: APIC(0) Converting physical 0 to logical package 0 [ 0.532428] smpboot: APIC(40) Converting physical 1 to logical package 1 [ 0.538456] smpboot: APIC(80) Converting physical 2 to logical package 2 [ 0.544486] smpboot: APIC(c0) Converting physical 3 to logical package 3 [ 0.550524] smpboot: Max logical packages: 19 3. nr_cpus=49 ( 2 socket + 1 core on 3rd socket), should stop enumerating in package 2: [ 0.521378] smpboot: APIC(0) Converting physical 0 to logical package 0 [ 0.527314] smpboot: APIC(40) Converting physical 1 to logical package 1 [ 0.533345] smpboot: APIC(80) Converting physical 2 to logical package 2 [ 0.539368] smpboot: Max logical packages: 19 4. maxcpus=49, should still enumerate all packages: [ 0.525591] smpboot: APIC(0) Converting physical 0 to logical package 0 [ 0.531525] smpboot: APIC(40) Converting physical 1 to logical package 1 [ 0.537547] smpboot: APIC(80) Converting physical 2 to logical package 2 [ 0.543579] smpboot: APIC(c0) Converting physical 3 to logical package 3 [ 0.549624] smpboot: Max logical packages: 19 5. kdump (nr_cpus=1) works as well. Reported-by: NFrank Ramsay <framsay@redhat.com> Tested-by: NPrarit Bhargava <prarit@redhat.com> Signed-off-by: NJiri Olsa <jolsa@kernel.org> Reviewed-by: NPrarit Bhargava <prarit@redhat.com> Acked-by: NPeter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20160815101700.GA30090@kravaSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Borislav Petkov 提交于
Similar to: efaad554 ("x86/microcode/intel: Fix initrd loading with CONFIG_RANDOMIZE_MEMORY=y") ... fix microcode loading from the initrd on AMD by adding the randomization offset to the microcode patch container within the initrd. Reported-and-tested-by: NBrian Gerst <brgerst@gmail.com> Signed-off-by: NBorislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-tip-commits@vger.kernel.org Link: http://lkml.kernel.org/r/20160817113314.GA19221@nazgul.tnicSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 16 8月, 2016 1 次提交
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由 Rafael J. Wysocki 提交于
The value of temp_level4_pgt is the physical address of the top-level page directory, so use __pa() to compute it. Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: NIngo Molnar <mingo@kernel.org>
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- 12 8月, 2016 3 次提交
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由 Kan Liang 提交于
There are bug reports about miscounting uncore counters on some client machines like Sandybridge, Broadwell and Skylake. It is very likely to be observed on idle systems. This issue is caused by a hardware issue. PERF_GLOBAL_CTL could be cleared after Package C7, and nothing will be count. The related errata (HSD 158) could be found in: www.intel.com/content/dam/www/public/us/en/documents/specification-updates/4th-gen-core-family-desktop-specification-update.pdf This patch tries to work around this issue by re-enabling PERF_GLOBAL_CTL in ->enable_box(). The workaround does not cover all cases. It helps for new events after returning from C7. But it cannot prevent C7, it will still miscount if a counter is already active. There is no drawback in leaving it enabled, so it does not need disable_box() here. Signed-off-by: NKan Liang <kan.liang@intel.com> Cc: <stable@vger.kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Link: http://lkml.kernel.org/r/1470925874-59943-1-git-send-email-kan.liang@intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Kan Liang 提交于
Some uncore boxes' num_counters value for Haswell server and Broadwell server are not correct (too large, off by one). This issue was found by comparing the code with the document. Although there is no bug report from users yet, accessing non-existent counters is dangerous and the behavior is undefined: it may cause miscounting or even crashes. This patch makes them consistent with the uncore document. Reported-by: NLukasz Odzioba <lukasz.odzioba@intel.com> Signed-off-by: NKan Liang <kan.liang@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: <stable@vger.kernel.org> Link: http://lkml.kernel.org/r/1470925820-59847-1-git-send-email-kan.liang@intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Denys Vlasenko 提交于
Since instruction decoder now supports EVEX-encoded instructions, two fixes are needed to correctly handle them in uprobes. Extended bits for MODRM.rm field need to be sanitized just like we do it for VEX3, to avoid encoding wrong register for register-relative access. EVEX has _two_ extended bits: b and x. Theoretically, EVEX.x should be ignored by the CPU (since GPRs go only up to 15, not 31), but let's be paranoid here: proper encoding for register-relative access should have EVEX.x = 1. Secondly, we should fetch vex.vvvv for EVEX too. This is now super easy because instruction decoder populates vex_prefix.bytes[2] for all flavors of (e)vex encodings, even for VEX2. Signed-off-by: NDenys Vlasenko <dvlasenk@redhat.com> Acked-by: NMasami Hiramatsu <mhiramat@kernel.org> Acked-by: NSrikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jim Keniston <jkenisto@us.ibm.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: linux-kernel@vger.kernel.org Cc: <stable@vger.kernel.org> # v4.1+ Fixes: 8a764a87 ("x86/asm/decoder: Create artificial 3rd byte for 2-byte VEX") Link: http://lkml.kernel.org/r/20160811154521.20469-1-dvlasenk@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 11 8月, 2016 10 次提交
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I made a mistake while converting the driver to the hotplug state machine and as a result x2apic_cluster_probe() was accessing cpus_in_cluster before allocating it. This patch fixes it by setting the cpumask after the allocation the memory succeeded. While at it, I marked two functions static which are only used within this file. Reported-by: NLaura Abbott <labbott@redhat.com> Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 6b2c2847 ("x86/x2apic: Convert to CPU hotplug state machine") Link: http://lkml.kernel.org/r/1470924515-9444-1-git-send-email-bigeasy@linutronix.deSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Alex Thorlton 提交于
This problem has actually been in the UV code for a while, but we didn't catch it until recently, because we had been relying on EFI_OLD_MEMMAP to allow our systems to boot for a period of time. We noticed the issue when trying to kexec a recent community kernel, where we hit this NULL pointer dereference in efi_sync_low_kernel_mappings(): [ 0.337515] BUG: unable to handle kernel NULL pointer dereference at 0000000000000880 [ 0.346276] IP: [<ffffffff8105df8d>] efi_sync_low_kernel_mappings+0x5d/0x1b0 The problem doesn't show up with EFI_OLD_MEMMAP because we skip the chunk of setup_efi_state() that sets the efi_loader_signature for the kexec'd kernel. When the kexec'd kernel boots, it won't set EFI_BOOT in setup_arch, so we completely avoid the bug. We always kexec with noefi on the command line, so this shouldn't be an issue, but since we're not actually checking for efi_runtime_disabled in uv_bios_init(), we end up trying to do EFI runtime callbacks when we shouldn't be. This patch just adds a check for efi_runtime_disabled in uv_bios_init() so that we don't map in uv_systab when runtime_disabled == true. Signed-off-by: NAlex Thorlton <athorlton@sgi.com> Signed-off-by: NMatt Fleming <matt@codeblueprint.co.uk> Cc: <stable@vger.kernel.org> # v4.7 Cc: Andy Lutomirski <luto@kernel.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bp@suse.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Travis <travis@sgi.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russ Anderson <rja@sgi.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/1470912120-22831-2-git-send-email-matt@codeblueprint.co.ukSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Andy Lutomirski 提交于
On my Dell XPS 13 9350 with firmware 1.4.4 and SGX on, if I boot Fedora 24's grub2-efi off a hard disk, my first 1MB of RAM looks like: efi: mem00: [Runtime Data |RUN| | | | | | | |WB|WT|WC|UC] range=[0x0000000000000000-0x0000000000000fff] (0MB) efi: mem01: [Boot Data | | | | | | | | |WB|WT|WC|UC] range=[0x0000000000001000-0x0000000000027fff] (0MB) efi: mem02: [Loader Data | | | | | | | | |WB|WT|WC|UC] range=[0x0000000000028000-0x0000000000029fff] (0MB) efi: mem03: [Reserved | | | | | | | | |WB|WT|WC|UC] range=[0x000000000002a000-0x000000000002bfff] (0MB) efi: mem04: [Runtime Data |RUN| | | | | | | |WB|WT|WC|UC] range=[0x000000000002c000-0x000000000002cfff] (0MB) efi: mem05: [Loader Data | | | | | | | | |WB|WT|WC|UC] range=[0x000000000002d000-0x000000000002dfff] (0MB) efi: mem06: [Conventional Memory| | | | | | | | |WB|WT|WC|UC] range=[0x000000000002e000-0x0000000000057fff] (0MB) efi: mem07: [Reserved | | | | | | | | |WB|WT|WC|UC] range=[0x0000000000058000-0x0000000000058fff] (0MB) efi: mem08: [Conventional Memory| | | | | | | | |WB|WT|WC|UC] range=[0x0000000000059000-0x000000000009ffff] (0MB) My EBDA is at 0x2c000, which blocks off everything from 0x2c000 and up, and my trampoline is 0x6000 bytes (6 pages), so it doesn't fit in the loader data range at 0x28000. Without this patch, it panics due to a failure to allocate the trampoline. With this patch, it works: [ +0.001744] Base memory trampoline at [ffff880000001000] 1000 size 24576 Signed-off-by: NAndy Lutomirski <luto@kernel.org> Reviewed-by: NMatt Fleming <matt@codeblueprint.co.uk> 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: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mario Limonciello <mario_limonciello@dell.com> Cc: Matt Fleming <mfleming@suse.de> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/998c77b3bf709f3dfed85cb30701ed1a5d8a438b.1470821230.git.luto@kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Andy Lutomirski 提交于
If reserve_real_mode() fails, panicing immediately means we're doomed. Make it safe to try more than once to allocate the trampoline: - Degrade a failure from panic() to pr_info(). (If we make it to setup_real_mode() without reserving the trampoline, we'll panic them.) - Factor out helpers so that platform code can supply a specific address to try. - Warn if reserve_real_mode() is called after we're done with the memblock allocator. If that were to happen, we would behave unpredictably. Signed-off-by: NAndy Lutomirski <luto@kernel.org> 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: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mario Limonciello <mario_limonciello@dell.com> Cc: Matt Fleming <mfleming@suse.de> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/876e383038f3e9971aa72fd20a4f5da05f9d193d.1470821230.git.luto@kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Andy Lutomirski 提交于
There's no need to run setup_real_mode() as early as we run it. Defer it to the same early_initcall that sets up the page permissions for the real mode code. This should be a code size reduction. More importantly, it give us a longer window in which we can allocate the real mode trampoline. Signed-off-by: NAndy Lutomirski <luto@kernel.org> 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: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mario Limonciello <mario_limonciello@dell.com> Cc: Matt Fleming <mfleming@suse.de> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/fd62f0da4f79357695e9bf3e365623736b05f119.1470821230.git.luto@kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Andy Lutomirski 提交于
The initialization process for trampoline_cr4_features and mmu_cr4_features was confusing. The intent is for mmu_cr4_features and *trampoline_cr4_features to stay in sync, but trampoline_cr4_features is NULL until setup_real_mode() runs. The old code synchronized *trampoline_cr4_features *twice*, once in setup_real_mode() and once in setup_arch(). It also initialized mmu_cr4_features in setup_real_mode(), which causes the actual value of mmu_cr4_features to potentially depend on when setup_real_mode() is called. With this patch, mmu_cr4_features is initialized directly in setup_arch(), and *trampoline_cr4_features is synchronized to mmu_cr4_features when the trampoline is set up. After this patch, it should be safe to defer setup_real_mode(). Signed-off-by: NAndy Lutomirski <luto@kernel.org> 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: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mario Limonciello <mario_limonciello@dell.com> Cc: Matt Fleming <mfleming@suse.de> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/d48a263f9912389b957dd495a7127b009259ffe0.1470821230.git.luto@kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Andy Lutomirski 提交于
reserve_bios_regions() is a quirk that reserves memory that we might otherwise think is available. There's no need to run it so early, and running it before we have the memory map initialized with its non-quirky inputs makes it hard to make reserve_bios_regions() more intelligent. Move it right after we populate the memblock state. Signed-off-by: NAndy Lutomirski <luto@kernel.org> 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: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mario Limonciello <mario_limonciello@dell.com> Cc: Matt Fleming <mfleming@suse.de> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/59f58618911005c799c6c9979ce6ae4881d907c2.1470821230.git.luto@kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Aaron Lu 提交于
Since commit: 52aec330 ("x86/tlb: replace INVALIDATE_TLB_VECTOR by CALL_FUNCTION_VECTOR") the TLB remote shootdown is done through call function vector. That commit didn't take care of irq_tlb_count, which a later commit: fd0f5869 ("x86: Distinguish TLB shootdown interrupts from other functions call interrupts") ... tried to fix. The fix assumes every increase of irq_tlb_count has a corresponding increase of irq_call_count. So the irq_call_count is always bigger than irq_tlb_count and we could substract irq_tlb_count from irq_call_count. Unfortunately this is not true for the smp_call_function_single() case. The IPI is only sent if the target CPU's call_single_queue is empty when adding a csd into it in generic_exec_single. That means if two threads are both adding flush tlb csds to the same CPU's call_single_queue, only one IPI is sent. In other words, the irq_call_count is incremented by 1 but irq_tlb_count is incremented by 2. Over time, irq_tlb_count will be bigger than irq_call_count and the substract will produce a very large irq_call_count value due to overflow. Considering that: 1) it's not worth to send more IPIs for the sake of accurate counting of irq_call_count in generic_exec_single(); 2) it's not easy to tell if the call function interrupt is for TLB shootdown in __smp_call_function_single_interrupt(). Not to exclude TLB shootdown from call function count seems to be the simplest fix and this patch just does that. This bug was found by LKP's cyclic performance regression tracking recently with the vm-scalability test suite. I have bisected to commit: 3dec0ba0 ("mm/rmap: share the i_mmap_rwsem") This commit didn't do anything wrong but revealed the irq_call_count problem. IIUC, the commit makes rwc->remap_one in rmap_walk_file concurrent with multiple threads. When remap_one is try_to_unmap_one(), then multiple threads could queue flush TLB to the same CPU but only one IPI will be sent. Since the commit was added in Linux v3.19, the counting problem only shows up from v3.19 onwards. Signed-off-by: NAaron Lu <aaron.lu@intel.com> Cc: Alex Shi <alex.shi@linaro.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tomoki Sekiyama <tomoki.sekiyama.qu@hitachi.com> Link: http://lkml.kernel.org/r/20160811074430.GA18163@aaronlu.sh.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Dave Hansen 提交于
A recent patch changed the format of a swap PTE. The comment explaining the format of the swap PTE is wrong about the bits used for the swap type field. Amusingly, the ASCII art and the patch description are correct, but the comment itself is wrong. As I was looking at this, I also noticed that the SWP_OFFSET_FIRST_BIT has an off-by-one error. This does not really hurt anything. It just wasted a bit of space in the PTE, giving us 2^59 bytes of addressable space in our swapfiles instead of 2^60. But, it doesn't match with the comments, and it wastes a bit of space, so fix it. Signed-off-by: NDave Hansen <dave.hansen@linux.intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave@sr71.net> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luis R. Rodriguez <mcgrof@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Toshi Kani <toshi.kani@hp.com> Fixes: 00839ee3 ("x86/mm: Move swap offset/type up in PTE to work around erratum") Link: http://lkml.kernel.org/r/20160810172325.E56AD7DA@viggo.jf.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Nicolas Iooss 提交于
debug_putstr() is used to output strings without using printf-like formatting but debug_putstr(v) is defined as early_printk(v) in arch/x86/lib/kaslr.c. This makes clang reports the following warning when building with -Wformat-security: arch/x86/lib/kaslr.c:57:15: warning: format string is not a string literal (potentially insecure) [-Wformat-security] debug_putstr(purpose); ^~~~~~~ Fix this by using "%s" in early_printk(). Signed-off-by: NNicolas Iooss <nicolas.iooss_linux@m4x.org> Acked-by: NKees Cook <keescook@chromium.org> Cc: Andy Lutomirski <luto@kernel.org> 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: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20160806102039.27221-1-nicolas.iooss_linux@m4x.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 10 8月, 2016 2 次提交
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由 Dave Hansen 提交于
The Memory Protection Keys "rights register" (PKRU) is XSAVE-managed, and is saved/restored along with the FPU state. When kernel code accesses FPU regsisters, it does a delicate dance with preempt. Otherwise, the context switching code can get confused as to whether the most up-to-date state is in the registers themselves or in the XSAVE buffer. But, PKRU is not a normal FPU register. Using it does not generate the normal device-not-available (#NM) exceptions which means we can not manage it lazily, and the kernel completley disallows using lazy mode when it is enabled. The dance with preempt *only* occurs when managing the FPU lazily. Since we never manage PKRU lazily, we do not have to do the dance with preempt; we can access it directly. Doing it this way saves a ton of complicated code (and is faster too). Further, the XSAVES reenabling failed to patch a bit of code in fpu__xfeature_set_state() the checked for compacted buffers. That check caused fpu__xfeature_set_state() to silently refuse to work when the kernel is using compacted XSAVE buffers. This broke execute-only and future pkey_mprotect() support when using compact XSAVE buffers. But, removing fpu__xfeature_set_state() gets rid of this issue, in addition to the nice cleanup and speedup. This fixes the same thing as a fix that Sai posted: https://lkml.org/lkml/2016/7/25/637 The fix that he posted is a much more obviously correct, but I think we should just do this instead. Reported-by: NSai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Signed-off-by: NDave Hansen <dave.hansen@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Dave Hansen <dave@sr71.net> 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: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Ravi Shankar <ravi.v.shankar@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yu-Cheng Yu <yu-cheng.yu@intel.com> Link: http://lkml.kernel.org/r/20160727232040.7D060DAD@viggo.jf.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Thomas Garnier 提交于
Add vmemmap in the list of randomized memory regions. The vmemmap region holds a representation of the physical memory (through a struct page array). An attacker could use this region to disclose the kernel memory layout (walking the page linked list). Signed-off-by: NThomas Garnier <thgarnie@google.com> Signed-off-by: NKees Cook <keescook@chromium.org> Cc: Andy Lutomirski <luto@kernel.org> 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: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: kernel-hardening@lists.openwall.com Link: http://lkml.kernel.org/r/1469635196-122447-1-git-send-email-thgarnie@google.com [ Minor edits. ] Signed-off-by: NIngo Molnar <mingo@kernel.org>
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