- 24 11月, 2014 3 次提交
-
-
由 Andy Lutomirski 提交于
It's possible for iretq to userspace to fail. This can happen because of a bad CS, SS, or RIP. Historically, we've handled it by fixing up an exception from iretq to land at bad_iret, which pretends that the failed iret frame was really the hardware part of #GP(0) from userspace. To make this work, there's an extra fixup to fudge the gs base into a usable state. This is suboptimal because it loses the original exception. It's also buggy because there's no guarantee that we were on the kernel stack to begin with. For example, if the failing iret happened on return from an NMI, then we'll end up executing general_protection on the NMI stack. This is bad for several reasons, the most immediate of which is that general_protection, as a non-paranoid idtentry, will try to deliver signals and/or schedule from the wrong stack. This patch throws out bad_iret entirely. As a replacement, it augments the existing swapgs fudge into a full-blown iret fixup, mostly written in C. It's should be clearer and more correct. Signed-off-by: NAndy Lutomirski <luto@amacapital.net> Reviewed-by: NThomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
由 Andy Lutomirski 提交于
On a 32-bit kernel, this has no effect, since there are no IST stacks. On a 64-bit kernel, #SS can only happen in user code, on a failed iret to user space, a canonical violation on access via RSP or RBP, or a genuine stack segment violation in 32-bit kernel code. The first two cases don't need IST, and the latter two cases are unlikely fatal bugs, and promoting them to double faults would be fine. This fixes a bug in which the espfix64 code mishandles a stack segment violation. This saves 4k of memory per CPU and a tiny bit of code. Signed-off-by: NAndy Lutomirski <luto@amacapital.net> Reviewed-by: NThomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
由 Andy Lutomirski 提交于
There's nothing special enough about the espfix64 double fault fixup to justify writing it in assembly. Move it to C. This also fixes a bug: if the double fault came from an IST stack, the old asm code would return to a partially uninitialized stack frame. Fixes: 3891a04aSigned-off-by: NAndy Lutomirski <luto@amacapital.net> Reviewed-by: NThomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
- 14 6月, 2014 1 次提交
-
-
由 Masami Hiramatsu 提交于
This essentially reverts commit: ecd50f71 ("kprobes, x86: Call exception_enter after kprobes handled") since it causes build errors with CONFIG_CONTEXT_TRACKING and that has been made from misunderstandings; context_track_user_*() don't involve much in interrupt context, it just returns if in_interrupt() is true. Instead of changing the do_debug/int3(), this just adds context_track_user_*() to kprobes blacklist, since those are still can be called right before kprobes handles int3 and debug exceptions, and probing those will cause an infinite loop. Reported-by: NFrederic Weisbecker <fweisbec@gmail.com> Signed-off-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Borislav Petkov <bp@suse.de> Cc: Kees Cook <keescook@chromium.org> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Seiji Aguchi <seiji.aguchi@hds.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Kees Cook <keescook@chromium.org> Link: http://lkml.kernel.org/r/20140614064711.7865.45957.stgit@kbuild-fedora.novalocalSigned-off-by: NIngo Molnar <mingo@kernel.org>
-
- 14 5月, 2014 7 次提交
-
-
由 Oleg Nesterov 提交于
If the probed insn triggers a trap, ->si_addr = regs->ip is technically correct, but this is not what the signal handler wants; we need to pass the address of the probed insn, not the address of xol slot. Add the new arch-agnostic helper, uprobe_get_trap_addr(), and change fill_trap_info() and math_error() to use it. !CONFIG_UPROBES case in uprobes.h uses a macro to avoid include hell and ensure that it can be compiled even if an architecture doesn't define instruction_pointer(). Test-case: #include <signal.h> #include <stdio.h> #include <unistd.h> extern void probe_div(void); void sigh(int sig, siginfo_t *info, void *c) { int passed = (info->si_addr == probe_div); printf(passed ? "PASS\n" : "FAIL\n"); _exit(!passed); } int main(void) { struct sigaction sa = { .sa_sigaction = sigh, .sa_flags = SA_SIGINFO, }; sigaction(SIGFPE, &sa, NULL); asm ( "xor %ecx,%ecx\n" ".globl probe_div; probe_div:\n" "idiv %ecx\n" ); return 0; } it fails if probe_div() is probed. Note: show_unhandled_signals users should probably use this helper too, but we need to cleanup them first. Signed-off-by: NOleg Nesterov <oleg@redhat.com> Reviewed-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
-
由 Oleg Nesterov 提交于
Now that DO_ERROR_INFO() doesn't differ from DO_ERROR() we can remove it and use DO_ERROR() instead. Signed-off-by: NOleg Nesterov <oleg@redhat.com>
-
由 Oleg Nesterov 提交于
Move the callsite of fill_trap_info() into do_error_trap() and remove the "siginfo_t *info" argument. This obviously breaks DO_ERROR() which passed info == NULL, we simply change fill_trap_info() to return "siginfo_t *" and add the "default" case which returns SEND_SIG_PRIV. Signed-off-by: NOleg Nesterov <oleg@redhat.com>
-
由 Oleg Nesterov 提交于
Extract the fill-siginfo code from DO_ERROR_INFO() into the new helper, fill_trap_info(). It can calculate si_code and si_addr looking at trapnr, so we can remove these arguments from DO_ERROR_INFO() and simplify the source code. The generated code is the same, __builtin_constant_p(trapnr) == T. Signed-off-by: NOleg Nesterov <oleg@redhat.com>
-
由 Oleg Nesterov 提交于
Move the common code from DO_ERROR() and DO_ERROR_INFO() into the new helper, do_error_trap(). This simplifies define's and shaves 527 bytes from traps.o. Signed-off-by: NOleg Nesterov <oleg@redhat.com>
-
由 Oleg Nesterov 提交于
force_sig() is just force_sig_info(SEND_SIG_PRIV). Imho it should die, we have too many ugly "send signal" helpers. And do_trap() looks just ugly because it uses force_sig_info() or force_sig() depending on info != NULL. Signed-off-by: NOleg Nesterov <oleg@redhat.com>
-
由 Oleg Nesterov 提交于
Trivial, make math_error() static. Signed-off-by: NOleg Nesterov <oleg@redhat.com>
-
- 06 5月, 2014 1 次提交
-
-
由 Andi Kleen 提交于
As requested by Linus add explicit __visible to the asmlinkage users. This marks all functions visible to assembler. Tree sweep for arch/x86/* Signed-off-by: NAndi Kleen <ak@linux.intel.com> Link: http://lkml.kernel.org/r/1398984278-29319-3-git-send-email-andi@firstfloor.orgSigned-off-by: NH. Peter Anvin <hpa@linux.intel.com>
-
- 24 4月, 2014 3 次提交
-
-
由 Masami Hiramatsu 提交于
Use NOKPROBE_SYMBOL macro for protecting functions from kprobes instead of __kprobes annotation under arch/x86. This applies nokprobe_inline annotation for some cases, because NOKPROBE_SYMBOL() will inhibit inlining by referring the symbol address. This just folds a bunch of previous NOKPROBE_SYMBOL() cleanup patches for x86 to one patch. Signed-off-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Link: http://lkml.kernel.org/r/20140417081814.26341.51656.stgit@ltc230.yrl.intra.hitachi.co.jp Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Borislav Petkov <bp@suse.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Fernando Luis Vázquez Cao <fernando_b1@lab.ntt.co.jp> Cc: Gleb Natapov <gleb@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Lebon <jlebon@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Matt Fleming <matt.fleming@intel.com> Cc: Michel Lespinasse <walken@google.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Seiji Aguchi <seiji.aguchi@hds.com> Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Cc: Tejun Heo <tj@kernel.org> Cc: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: NIngo Molnar <mingo@kernel.org>
-
由 Masami Hiramatsu 提交于
Move exception_enter() call after kprobes handler is done. Since the exception_enter() involves many other functions (like printk), it can cause recursive int3/break loop when kprobes probe such functions. Signed-off-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Reviewed-by: NSteven Rostedt <rostedt@goodmis.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Borislav Petkov <bp@suse.de> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Kees Cook <keescook@chromium.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Seiji Aguchi <seiji.aguchi@hds.com> Link: http://lkml.kernel.org/r/20140417081740.26341.10894.stgit@ltc230.yrl.intra.hitachi.co.jpSigned-off-by: NIngo Molnar <mingo@kernel.org>
-
由 Masami Hiramatsu 提交于
To avoid a kernel crash by probing on lockdep code, call kprobe_int3_handler() and kprobe_debug_handler()(which was formerly called post_kprobe_handler()) directly from do_int3 and do_debug. Currently kprobes uses notify_die() to hook the int3/debug exceptoins. Since there is a locking code in notify_die, the lockdep code can be invoked. And because the lockdep involves printk() related things, theoretically, we need to prohibit probing on such code, which means much longer blacklist we'll have. Instead, hooking the int3/debug for kprobes before notify_die() can avoid this problem. Anyway, most of the int3 handlers in the kernel are already called from do_int3 directly, e.g. ftrace_int3_handler, poke_int3_handler, kgdb_ll_trap. Actually only kprobe_exceptions_notify is on the notifier_call_chain. Signed-off-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Reviewed-by: NSteven Rostedt <rostedt@goodmis.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Borislav Petkov <bp@suse.de> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Jonathan Lebon <jlebon@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Seiji Aguchi <seiji.aguchi@hds.com> Link: http://lkml.kernel.org/r/20140417081733.26341.24423.stgit@ltc230.yrl.intra.hitachi.co.jpSigned-off-by: NIngo Molnar <mingo@kernel.org>
-
- 12 12月, 2013 1 次提交
-
-
由 Ingo Molnar 提交于
So I was reading the exception handler generation code and got a real headache looking at the unstructured mess that our DO_ERROR*() generation code is today. Make it more readable. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Link: http://lkml.kernel.org/n/tip-kuabysiykvUJpgus35lhnhvs@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
-
- 13 11月, 2013 1 次提交
-
-
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>
-
- 09 11月, 2013 1 次提交
-
-
由 Seiji Aguchi 提交于
This patch registers exception handlers for tracing to a trace IDT. To implemented it in set_intr_gate(), this patch does followings. - Register the exception handlers to the trace IDT by prepending "trace_" to the handler's names. - Also, newly introduce trace_page_fault() to add tracepoints in a subsequent patch. Signed-off-by: NSeiji Aguchi <seiji.aguchi@hds.com> Link: http://lkml.kernel.org/r/52716DEC.5050204@hds.comSigned-off-by: NH. Peter Anvin <hpa@linux.intel.com>
-
- 25 9月, 2013 1 次提交
-
-
由 Peter Zijlstra 提交于
Rewrite the preempt_count macros in order to extract the 3 basic preempt_count value modifiers: __preempt_count_add() __preempt_count_sub() and the new: __preempt_count_dec_and_test() And since we're at it anyway, replace the unconventional $op_preempt_count names with the more conventional preempt_count_$op. Since these basic operators are equivalent to the previous _notrace() variants, do away with the _notrace() versions. Signed-off-by: NPeter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/n/tip-ewbpdbupy9xpsjhg960zwbv8@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
-
- 23 7月, 2013 1 次提交
-
-
由 Jiri Kosina 提交于
In fd4363ff ("x86: Introduce int3 (breakpoint)-based instruction patching"), the mechanism that was introduced for notifying alternatives code from int3 exception handler that and exception occured was die_notifier. This is however problematic, as early code might be using jump labels even before the notifier registration has been performed, which will then lead to an oops due to unhandled exception. One of such occurences has been encountered by Fengguang: int3: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC Modules linked in: CPU: 1 PID: 0 Comm: swapper/1 Not tainted 3.11.0-rc1-01429-g04bf576 #8 task: ffff88000da1b040 ti: ffff88000da1c000 task.ti: ffff88000da1c000 RIP: 0010:[<ffffffff811098cc>] [<ffffffff811098cc>] ttwu_do_wakeup+0x28/0x225 RSP: 0000:ffff88000dd03f10 EFLAGS: 00000006 RAX: 0000000000000000 RBX: ffff88000dd12940 RCX: ffffffff81769c40 RDX: 0000000000000002 RSI: 0000000000000000 RDI: 0000000000000001 RBP: ffff88000dd03f28 R08: ffffffff8176a8c0 R09: 0000000000000002 R10: ffffffff810ff484 R11: ffff88000dd129e8 R12: ffff88000dbc90c0 R13: ffff88000dbc90c0 R14: ffff88000da1dfd8 R15: ffff88000da1dfd8 FS: 0000000000000000(0000) GS:ffff88000dd00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 00000000ffffffff CR3: 0000000001c88000 CR4: 00000000000006e0 Stack: ffff88000dd12940 ffff88000dbc90c0 ffff88000da1dfd8 ffff88000dd03f48 ffffffff81109e2b ffff88000dd12940 0000000000000000 ffff88000dd03f68 ffffffff81109e9e 0000000000000000 0000000000012940 ffff88000dd03f98 Call Trace: <IRQ> [<ffffffff81109e2b>] ttwu_do_activate.constprop.56+0x6d/0x79 [<ffffffff81109e9e>] sched_ttwu_pending+0x67/0x84 [<ffffffff8110c845>] scheduler_ipi+0x15a/0x2b0 [<ffffffff8104dfb4>] smp_reschedule_interrupt+0x38/0x41 [<ffffffff8173bf5d>] reschedule_interrupt+0x6d/0x80 <EOI> [<ffffffff810ff484>] ? __atomic_notifier_call_chain+0x5/0xc1 [<ffffffff8105cc30>] ? native_safe_halt+0xd/0x16 [<ffffffff81015f10>] default_idle+0x147/0x282 [<ffffffff81017026>] arch_cpu_idle+0x3d/0x5d [<ffffffff81127d6a>] cpu_idle_loop+0x46d/0x5db [<ffffffff81127f5c>] cpu_startup_entry+0x84/0x84 [<ffffffff8104f4f8>] start_secondary+0x3c8/0x3d5 [...] Fix this by directly calling poke_int3_handler() from the int3 exception handler (analogically to what ftrace has been doing already), instead of relying on notifier, registration of which might not have yet been finalized by the time of the first trap. Reported-and-tested-by: NFengguang Wu <fengguang.wu@intel.com> Signed-off-by: NJiri Kosina <jkosina@suse.cz> Acked-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: H. Peter Anvin <hpa@linux.intel.com> Cc: Fengguang Wu <fengguang.wu@intel.com> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/alpine.LNX.2.00.1307231007490.14024@pobox.suse.czSigned-off-by: NIngo Molnar <mingo@kernel.org>
-
- 17 7月, 2013 1 次提交
-
-
由 Kees Cook 提交于
Since the IDT is referenced from a fixmap, make sure it is page aligned. Merge with 32-bit one, since it was already aligned to deal with F00F bug. Since bss is cleared before IDT setup, it can live there. This also moves the other *_idt_table variables into common locations. This avoids the risk of the IDT ever being moved in the bss and having the mapping be offset, resulting in calling incorrect handlers. In the current upstream kernel this is not a manifested bug, but heavily patched kernels (such as those using the PaX patch series) did encounter this bug. The tables other than idt_table technically do not need to be page aligned, at least not at the current time, but using a common declaration avoids mistakes. On 64 bits the table is exactly one page long, anyway. Signed-off-by: NKees Cook <keescook@chromium.org> Link: http://lkml.kernel.org/r/20130716183441.GA14232@www.outflux.netReported-by: NPaX Team <pageexec@gmail.com> Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>
-
- 21 6月, 2013 1 次提交
-
-
由 Seiji Aguchi 提交于
Rename variables for debugging to describe meaning of them precisely. Also, introduce a generic way to switch IDT by checking a current state, debug on/off. Signed-off-by: NSeiji Aguchi <seiji.aguchi@hds.com> Link: http://lkml.kernel.org/r/51C323A8.7050905@hds.comSigned-off-by: NH. Peter Anvin <hpa@linux.intel.com> Cc: Steven Rostedt <rostedt@goodmis.org>
-
- 19 6月, 2013 1 次提交
-
-
由 Rusty Russell 提交于
62edab90 changed the argument to notify_die() from dr6 to &dr6, but weirdly, used PTR_ERR() to cast it to a long. Since dr6 is on the stack, this is an abuse of PTR_ERR(). Cast to long, as per kernel standard. Signed-off-by: NRusty Russell <rusty@rustcorp.com.au> Cc: K.Prasad <prasad@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/1371357768-4968-8-git-send-email-rusty@rustcorp.com.auSigned-off-by: NIngo Molnar <mingo@kernel.org>
-
- 14 5月, 2013 1 次提交
-
-
由 Borislav Petkov 提交于
It is sometimes very helpful to be able to pinpoint the location which causes a double fault before it turns into a triple fault and the machine reboots. We have this for 32-bit already so extend it to 64-bit. On 64-bit we get the register snapshot at #DF time and not from the first exception which actually causes the #DF. It should be close enough, though. [ hpa: and definitely better than nothing, which is what we have now. ] Signed-off-by: NBorislav Petkov <bp@suse.de> Link: http://lkml.kernel.org/r/1368093749-31296-1-git-send-email-bp@alien8.deSigned-off-by: NH. Peter Anvin <hpa@linux.intel.com>
-
- 12 4月, 2013 1 次提交
-
-
由 Kees Cook 提交于
Make a copy of the IDT (as seen via the "sidt" instruction) read-only. This primarily removes the IDT from being a target for arbitrary memory write attacks, and has the added benefit of also not leaking the kernel base offset, if it has been relocated. We already did this on vendor == Intel and family == 5 because of the F0 0F bug -- regardless of if a particular CPU had the F0 0F bug or not. Since the workaround was so cheap, there simply was no reason to be very specific. This patch extends the readonly alias to all CPUs, but does not activate the #PF to #UD conversion code needed to deliver the proper exception in the F0 0F case except on Intel family 5 processors. Signed-off-by: NKees Cook <keescook@chromium.org> Link: http://lkml.kernel.org/r/20130410192422.GA17344@www.outflux.net Cc: Eric Northup <digitaleric@google.com> Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>
-
- 08 3月, 2013 2 次提交
-
-
由 Frederic Weisbecker 提交于
On exception exit, we restore the previous context tracking state based on the regs of the interrupted frame. Iff that frame is in user mode as stated by user_mode() helper, we restore the context tracking user mode. However there is a tiny chunck of low level arch code after we pass through user_enter() and until the CPU eventually resumes userspace. If an exception happens in this tiny area, exception_enter() correctly exits the context tracking user mode but exception_exit() won't restore it because of the value returned by user_mode(regs). As a result we may return to userspace with the wrong context tracking state. To fix this, change exception_enter() to return the context tracking state prior to its call and pass this saved state to exception_exit(). This restores the real context tracking state of the interrupted frame. (May be this patch was suggested to me, I don't recall exactly. If so, sorry for the missing credit). Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Kevin Hilman <khilman@linaro.org> Cc: Mats Liljegren <mats.liljegren@enea.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Namhyung Kim <namhyung.kim@lge.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
-
由 Frederic Weisbecker 提交于
Exceptions handling on context tracking should share common treatment: on entry we exit user mode if the exception triggered in that context. Then on exception exit we return to that previous context. Generalize this to avoid duplication across archs. Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Kevin Hilman <khilman@linaro.org> Cc: Mats Liljegren <mats.liljegren@enea.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Namhyung Kim <namhyung.kim@lge.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
-
- 30 1月, 2013 1 次提交
-
-
由 H. Peter Anvin 提交于
Linear mode (CR0.PG = 0) is mutually exclusive with 64-bit mode; all 64-bit code has to use page tables. This makes it awkward before we have first set up properly all-covering page tables to access objects that are outside the static kernel range. So far we have dealt with that simply by mapping a fixed amount of low memory, but that fails in at least two upcoming use cases: 1. We will support load and run kernel, struct boot_params, ramdisk, command line, etc. above the 4 GiB mark. 2. need to access ramdisk early to get microcode to update that as early possible. We could use early_iomap to access them too, but it will make code to messy and hard to be unified with 32 bit. Hence, set up a #PF table and use a fixed number of buffers to set up page tables on demand. If the buffers fill up then we simply flush them and start over. These buffers are all in __initdata, so it does not increase RAM usage at runtime. Thus, with the help of the #PF handler, we can set the final kernel mapping from blank, and switch to init_level4_pgt later. During the switchover in head_64.S, before #PF handler is available, we use three pages to handle kernel crossing 1G, 512G boundaries with sharing page by playing games with page aliasing: the same page is mapped twice in the higher-level tables with appropriate wraparound. The kernel region itself will be properly mapped; other mappings may be spurious. early_make_pgtable is using kernel high mapping address to access pages to set page table. -v4: Add phys_base offset to make kexec happy, and add init_mapping_kernel() - Yinghai -v5: fix compiling with xen, and add back ident level3 and level2 for xen also move back init_level4_pgt from BSS to DATA again. because we have to clear it anyway. - Yinghai -v6: switch to init_level4_pgt in init_mem_mapping. - Yinghai -v7: remove not needed clear_page for init_level4_page it is with fill 512,8,0 already in head_64.S - Yinghai -v8: we need to keep that handler alive until init_mem_mapping and don't let early_trap_init to trash that early #PF handler. So split early_trap_pf_init out and move it down. - Yinghai -v9: switchover only cover kernel space instead of 1G so could avoid touch possible mem holes. - Yinghai -v11: change far jmp back to far return to initial_code, that is needed to fix failure that is reported by Konrad on AMD systems. - Yinghai Signed-off-by: NYinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/1359058816-7615-12-git-send-email-yinghai@kernel.orgSigned-off-by: NH. Peter Anvin <hpa@linux.intel.com>
-
- 18 12月, 2012 1 次提交
-
-
由 H. Peter Anvin 提交于
Remove support for FPU error reporting via IRQ 13, as opposed to exception 16 (#MF). One last remnant of i386 gone. Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com> Cc: Alan Cox <alan@linux.intel.com>
-
- 01 12月, 2012 1 次提交
-
-
由 Frederic Weisbecker 提交于
Create a new subsystem that probes on kernel boundaries to keep track of the transitions between level contexts with two basic initial contexts: user or kernel. This is an abstraction of some RCU code that use such tracking to implement its userspace extended quiescent state. We need to pull this up from RCU into this new level of indirection because this tracking is also going to be used to implement an "on demand" generic virtual cputime accounting. A necessary step to shutdown the tick while still accounting the cputime. Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Gilad Ben-Yossef <gilad@benyossef.com> Reviewed-by: NSteven Rostedt <rostedt@goodmis.org> [ paulmck: fix whitespace error and email address. ] Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
-
- 26 9月, 2012 3 次提交
-
-
由 Frederic Weisbecker 提交于
Add necessary hooks to x86 exception for userspace RCU extended quiescent state support. This includes traps, page fault, debug exceptions, etc... Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com> Cc: Alessio Igor Bogani <abogani@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Avi Kivity <avi@redhat.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Christoph Lameter <cl@linux.com> Cc: Geoff Levand <geoff@infradead.org> Cc: Gilad Ben Yossef <gilad@benyossef.com> Cc: Hakan Akkan <hakanakkan@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Kevin Hilman <khilman@ti.com> Cc: Max Krasnyansky <maxk@qualcomm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephen Hemminger <shemminger@vyatta.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Sven-Thorsten Dietrich <thebigcorporation@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
-
由 Frederic Weisbecker 提交于
There is some unnatural label based layout in this function. Convert the unnecessary goto to readable conditional blocks. Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Ingo Molnar <mingo@kernel.org>
-
由 Frederic Weisbecker 提交于
Cleanup the label maze in this function. Having a seperate function to first handle the traps that don't generate a signal makes it easier to convert into more readable conditional paths. Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1348577479-2564-1-git-send-email-fweisbec@gmail.com [ Fixed 32-bit build failure. ] Signed-off-by: NIngo Molnar <mingo@kernel.org>
-
- 19 9月, 2012 2 次提交
-
-
由 Suresh Siddha 提交于
Decouple non-lazy/eager fpu restore policy from the existence of the xsave feature. Introduce a synthetic CPUID flag to represent the eagerfpu policy. "eagerfpu=on" boot paramter will enable the policy. Requested-by: NH. Peter Anvin <hpa@zytor.com> Requested-by: NLinus Torvalds <torvalds@linux-foundation.org> Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com> Link: http://lkml.kernel.org/r/1347300665-6209-2-git-send-email-suresh.b.siddha@intel.comSigned-off-by: NH. Peter Anvin <hpa@linux.intel.com>
-
由 Suresh Siddha 提交于
Fundamental model of the current Linux kernel is to lazily init and restore FPU instead of restoring the task state during context switch. This changes that fundamental lazy model to the non-lazy model for the processors supporting xsave feature. Reasons driving this model change are: i. Newer processors support optimized state save/restore using xsaveopt and xrstor by tracking the INIT state and MODIFIED state during context-switch. This is faster than modifying the cr0.TS bit which has serializing semantics. ii. Newer glibc versions use SSE for some of the optimized copy/clear routines. With certain workloads (like boot, kernel-compilation etc), application completes its work with in the first 5 task switches, thus taking upto 5 #DNA traps with the kernel not getting a chance to apply the above mentioned pre-load heuristic. iii. Some xstate features (like AMD's LWP feature) don't honor the cr0.TS bit and thus will not work correctly in the presence of lazy restore. Non-lazy state restore is needed for enabling such features. Some data on a two socket SNB system: * Saved 20K DNA exceptions during boot on a two socket SNB system. * Saved 50K DNA exceptions during kernel-compilation workload. * Improved throughput of the AVX based checksumming function inside the kernel by ~15% as xsave/xrstor is faster than the serializing clts/stts pair. Also now kernel_fpu_begin/end() relies on the patched alternative instructions. So move check_fpu() which uses the kernel_fpu_begin/end() after alternative_instructions(). Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com> Link: http://lkml.kernel.org/r/1345842782-24175-7-git-send-email-suresh.b.siddha@intel.com Merge 32-bit boot fix from, Link: http://lkml.kernel.org/r/1347300665-6209-4-git-send-email-suresh.b.siddha@intel.com Cc: Jim Kukunas <james.t.kukunas@linux.intel.com> Cc: NeilBrown <neilb@suse.de> Cc: Avi Kivity <avi@redhat.com> Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>
-
- 06 6月, 2012 1 次提交
-
-
由 Joe Perches 提交于
Use a more current logging style: - Bare printks should have a KERN_<LEVEL> for consistency's sake - Add pr_fmt where appropriate - Neaten some macro definitions - Convert some Ok output to OK - Use "%s: ", __func__ in pr_fmt for summit - Convert some printks to pr_<level> Message output is not identical in all cases. Signed-off-by: NJoe Perches <joe@perches.com> Cc: levinsasha928@gmail.com Link: http://lkml.kernel.org/r/1337655007.24226.10.camel@joe2Laptop [ merged two similar patches, tidied up the changelog ] Signed-off-by: NIngo Molnar <mingo@kernel.org>
-
- 01 6月, 2012 1 次提交
-
-
由 Steven Rostedt 提交于
When the function tracer starts modifying the code via breakpoints it sets a variable (modifying_ftrace_code) to inform the breakpoint handler to call the ftrace int3 code. But there's no synchronization between setting this code and the handler, thus it is possible for the handler to be called on another CPU before it sees the variable. This will cause a kernel crash as the int3 handler will not know what to do with it. I originally added smp_mb()'s to force the visibility of the variable but H. Peter Anvin suggested that I just make it atomic. [ Added comments as suggested by Peter Zijlstra ] Suggested-by: NH. Peter Anvin <hpa@zytor.com> Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
-
- 18 5月, 2012 1 次提交
-
-
由 Paul Gortmaker 提交于
Hardware with MCA bus is limited to 386 and 486 class machines that are now 20+ years old and typically with less than 32MB of memory. A quick search on the internet, and you see that even the MCA hobbyist/enthusiast community has lost interest in the early 2000 era and never really even moved ahead from the 2.4 kernels to the 2.6 series. This deletes anything remaining related to CONFIG_MCA from core kernel code and from the x86 architecture. There is no point in carrying this any further into the future. One complication to watch for is inadvertently scooping up stuff relating to machine check, since there is overlap in the TLA name space (e.g. arch/x86/boot/mca.c). Cc: Thomas Gleixner <tglx@linutronix.de> Cc: James Bottomley <JBottomley@Parallels.com> Cc: x86@kernel.org Acked-by: NIngo Molnar <mingo@elte.hu> Acked-by: NH. Peter Anvin <hpa@zytor.com> Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
-
- 28 4月, 2012 1 次提交
-
-
由 Steven Rostedt 提交于
This method changes x86 to add a breakpoint to the mcount locations instead of calling stop machine. Now that iret can be handled by NMIs, we perform the following to update code: 1) Add a breakpoint to all locations that will be modified 2) Sync all cores 3) Update all locations to be either a nop or call (except breakpoint op) 4) Sync all cores 5) Remove the breakpoint with the new code. 6) Sync all cores [ Added updates that Masami suggested: Use unlikely(modifying_ftrace_code) in int3 trap to keep kprobes efficient. Don't use NOTIFY_* in ftrace handler in int3 as it is not a notifier. ] Cc: H. Peter Anvin <hpa@zytor.com> Acked-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
-
- 29 3月, 2012 1 次提交
-
-
由 David Howells 提交于
Disintegrate asm/system.h for X86. Signed-off-by: NDavid Howells <dhowells@redhat.com> Acked-by: NH. Peter Anvin <hpa@zytor.com> cc: x86@kernel.org
-