- 07 3月, 2015 2 次提交
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由 Andy Lutomirski 提交于
I broke 32-bit kernels. The implementation of sp0 was correct as far as I can tell, but sp0 was much weirder on x86_32 than I realized. It has the following issues: - Init's sp0 is inconsistent with everything else's: non-init tasks are offset by 8 bytes. (I have no idea why, and the comment is unhelpful.) - vm86 does crazy things to sp0. Fix it up by replacing this_cpu_sp0() with current_top_of_stack() and using a new percpu variable to track the top of the stack on x86_32. Signed-off-by: NAndy 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> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 75182b16 ("x86/asm/entry: Switch all C consumers of kernel_stack to this_cpu_sp0()") Link: http://lkml.kernel.org/r/d09dbe270883433776e0cbee3c7079433349e96d.1425692936.git.luto@amacapital.netSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Andy Lutomirski 提交于
The change: 75182b16 ("x86/asm/entry: Switch all C consumers of kernel_stack to this_cpu_sp0()") had the unintended side effect of changing the return value of current_thread_info() during part of the context switch process. Change it back. This has no effect as far as I can tell -- it's just for consistency. Signed-off-by: NAndy 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> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/9fcaa47dd8487db59eed7a3911b6ae409476763e.1425692936.git.luto@amacapital.netSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 06 3月, 2015 6 次提交
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由 Andy Lutomirski 提交于
This has nothing to do with the init thread or the initial anything. It's just the CPU's TSS. Signed-off-by: NAndy 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> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/a0bd5e26b32a2e1f08ff99017d0997118fbb2485.1425611534.git.luto@amacapital.netSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Andy Lutomirski 提交于
The INIT_TSS is unnecessary. Just define the initial TSS where 'cpu_tss' is defined. While we're at it, merge the 32-bit and 64-bit definitions. The only syntactic change is that 32-bit kernels were computing sp0 as long, but now they compute it as unsigned long. Verified by objdump: the contents and relocations of .data..percpu..shared_aligned are unchanged on 32-bit and 64-bit kernels. Signed-off-by: NAndy 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> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/8fc39fa3f6c5d635e93afbdd1a0fe0678a6d7913.1425611534.git.luto@amacapital.netSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Andy Lutomirski 提交于
It has nothing to do with init -- there's only one TSS per cpu. Other names considered include: - current_tss: Confusing because we never switch the tss. - singleton_tss: Too long. This patch was generated with 's/init_tss/cpu_tss/g'. Followup patches will fix INIT_TSS and INIT_TSS_IST by hand. Signed-off-by: NAndy 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> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/da29fb2a793e4f649d93ce2d1ed320ebe8516262.1425611534.git.luto@amacapital.netSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Andy Lutomirski 提交于
The ia32 sysenter code loaded the top of the kernel stack into rsp by loading kernel_stack and then adjusting it. It can be simplified to just read sp0 directly. This requires the addition of a new asm-offsets entry for sp0. Signed-off-by: NAndy 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> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/88ff9006163d296a0665338585c36d9bfb85235d.1425611534.git.luto@amacapital.netSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Andy Lutomirski 提交于
This will make modifying the semantics of kernel_stack easier. The change to ist_begin_non_atomic() is necessary because sp0 no longer points to the same THREAD_SIZE-aligned region as RSP; it's one byte too high for that. At Denys' suggestion, rather than offsetting it, just check explicitly that we're in the correct range ending at sp0. This has the added benefit that we no longer assume that the thread stack is aligned to THREAD_SIZE. Suggested-by: NDenys Vlasenko <dvlasenk@redhat.com> Signed-off-by: NAndy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/ef8254ad414cbb8034c9a56396eeb24f5dd5b0de.1425611534.git.luto@amacapital.netSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Andy Lutomirski 提交于
We currently store references to the top of the kernel stack in multiple places: kernel_stack (with an offset) and init_tss.x86_tss.sp0 (no offset). The latter is defined by hardware and is a clean canonical way to find the top of the stack. Add an accessor so we can start using it. This needs minor paravirt tweaks. On native, sp0 defines the top of the kernel stack and is therefore always correct. On Xen and lguest, the hypervisor tracks the top of the stack, but we want to start reading sp0 in the kernel. Fixing this is simple: just update our local copy of sp0 as well as the hypervisor's copy on task switches. Signed-off-by: NAndy Lutomirski <luto@amacapital.net> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/8d675581859712bee09a055ed8f785d80dac1eca.1425611534.git.luto@amacapital.netSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 05 3月, 2015 17 次提交
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由 Wang Nan 提交于
As early_trap_init() doesn't use IST, replace set_intr_gate_ist() and set_system_intr_gate_ist() with their standard counterparts. set_intr_gate() requires a trace_debug symbol which we don't have and won't use. This patch separates set_intr_gate() into two parts, and uses base version in early_trap_init(). Reported-by: NAndy Lutomirski <luto@amacapital.net> Signed-off-by: NWang Nan <wangnan0@huawei.com> Acked-by: NAndy Lutomirski <luto@amacapital.net> Cc: <dave.hansen@linux.intel.com> Cc: <lizefan@huawei.com> Cc: <masami.hiramatsu.pt@hitachi.com> Cc: <oleg@redhat.com> Cc: <rostedt@goodmis.org> Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1425010789-13714-1-git-send-email-wangnan0@huawei.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Andy Lutomirski 提交于
'ret_from_fork' checks TIF_IA32 to determine whether 'pt_regs' and the related state make sense for 'ret_from_sys_call'. This is entirely the wrong check. TS_COMPAT would make a little more sense, but there's really no point in keeping this optimization at all. This fixes a return to the wrong user CS if we came from int 0x80 in a 64-bit task. Signed-off-by: NAndy 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> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/4710be56d76ef994ddf59087aad98c000fbab9a4.1424989793.git.luto@amacapital.netSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Denys Vlasenko 提交于
Avoid redundant load of %r11 (it is already loaded a few instructions before). Also simplify %rsp restoration, instead of two steps: add $0x80, %rsp mov 0x18(%rsp), %rsp we can do a simplified single step to restore user-space RSP: mov 0x98(%rsp), %rsp and get the same result. Signed-off-by: NDenys Vlasenko <dvlasenk@redhat.com> Signed-off-by: NAndy Lutomirski <luto@amacapital.net> [ Clarified the changelog. ] Cc: Alexei Starovoitov <ast@plumgrid.com> 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: Thomas Gleixner <tglx@linutronix.de> Cc: Will Drewry <wad@chromium.org> Link: http://lkml.kernel.org/r/1aef69b346a6db0d99cdfb0f5ba83e8c985e27d7.1424989793.git.luto@amacapital.netSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Denys Vlasenko 提交于
The last instance of "mysterious" SS+8 constant is replaced by SIZEOF_PTREGS. Message-Id: <1424822419-10267-1-git-send-email-dvlasenk@redhat.com> Signed-off-by: NDenys Vlasenko <dvlasenk@redhat.com> Signed-off-by: NAndy Lutomirski <luto@amacapital.net> Cc: Alexei Starovoitov <ast@plumgrid.com> 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/d35aeba3059407ac54f472ddcfbea767ff8916ac.1424989793.git.luto@amacapital.netSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Denys Vlasenko 提交于
Constants such as SS+8 or SS+8-RIP are mysterious. In most cases, SS+8 is just meant to be SIZEOF_PTREGS, SS+8-RIP is RIP's offset in the iret frame. This patch changes some of these constants to be less mysterious. No code changes (verified with objdump). Signed-off-by: NDenys Vlasenko <dvlasenk@redhat.com> Signed-off-by: NAndy Lutomirski <luto@amacapital.net> Cc: Alexei Starovoitov <ast@plumgrid.com> 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: Thomas Gleixner <tglx@linutronix.de> Cc: Will Drewry <wad@chromium.org> Link: http://lkml.kernel.org/r/1d20491384773bd606e23a382fac23ddb49b5178.1424989793.git.luto@amacapital.netSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Denys Vlasenko 提交于
Use of a small macro - one with conditional expansion - does more harm than good. It obfuscates code, with minimal code reuse. For example, because of obfuscation it's not obvious that in 'ia32_sysenter_target', we can optimize loading of r9 - currently it is loaded with a detour through ebp. This patch folds the IA32_ARG_FIXUP macro into its callers. No code changes. Signed-off-by: NDenys Vlasenko <dvlasenk@redhat.com> Signed-off-by: NAndy Lutomirski <luto@amacapital.net> Cc: Alexei Starovoitov <ast@plumgrid.com> 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: Will Drewry <wad@chromium.org> Link: http://lkml.kernel.org/r/4da092094cd78734384ac31e0d4ec1d8f69145a2.1424989793.git.luto@amacapital.netSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Denys Vlasenko 提交于
This patch does a lot of cleanup in comments and formatting, but it does not change any code: - Rename 'save_paranoid' to 'paranoid_entry': this makes naming similar to its "non-paranoid" sibling, 'error_entry', and to its counterpart, 'paranoid_exit'. - Use the same CFI annotation atop 'paranoid_entry' and 'error_entry'. - Fix irregular indentation of assembler operands. - Add/fix comments on top of 'paranoid_entry' and 'error_entry'. - Remove stale comment about "oldrax". - Make comments about "no swapgs" flag in ebx more prominent. - Deindent wrongly indented top-level comment atop 'paranoid_exit'. - Indent wrongly deindented comment inside 'error_entry'. Signed-off-by: NDenys Vlasenko <dvlasenk@redhat.com> Signed-off-by: NAndy Lutomirski <luto@amacapital.net> Cc: Alexei Starovoitov <ast@plumgrid.com> 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: Will Drewry <wad@chromium.org> Link: http://lkml.kernel.org/r/4640f9fcd5ea46eb299b1cd6d3f5da3167d2f78d.1424989793.git.luto@amacapital.netSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Denys Vlasenko 提交于
For some odd reason, these two functions are at the very top of the file. "save_paranoid"'s caller is approximately in the middle of it, move it there. Move 'ret_from_fork' to be right after fork/exec helpers. This is a pure block move, nothing is changed in the function bodies. Signed-off-by: NDenys Vlasenko <dvlasenk@redhat.com> Signed-off-by: NAndy Lutomirski <luto@amacapital.net> Cc: Alexei Starovoitov <ast@plumgrid.com> 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: Thomas Gleixner <tglx@linutronix.de> Cc: Will Drewry <wad@chromium.org> Link: http://lkml.kernel.org/r/6446bbfe4094532623a5b83779b7015fec167a9d.1424989793.git.luto@amacapital.netSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Denys Vlasenko 提交于
SYSCALL/SYSRET and SYSENTER/SYSEXIT have weird semantics. Moreover, they differ in 32- and 64-bit mode. What is saved? What is not? Is rsp set? Are interrupts disabled? People tend to not remember these details well enough. This patch adds comments which explain in detail what registers are modified by each of these instructions. The comments are placed immediately before corresponding entry and exit points. Signed-off-by: NDenys Vlasenko <dvlasenk@redhat.com> Signed-off-by: NAndy Lutomirski <luto@amacapital.net> Cc: Alexei Starovoitov <ast@plumgrid.com> 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: Thomas Gleixner <tglx@linutronix.de> Cc: Will Drewry <wad@chromium.org> Link: http://lkml.kernel.org/r/a94b98b63527797c871a81402ff5060b18fa880a.1424989793.git.luto@amacapital.netSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Andy Lutomirski 提交于
Nothing references it anymore. Reported-by: NDenys Vlasenko <vda.linux@googlemail.com> Signed-off-by: NAndy 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> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 96b6352c ("x86_64, entry: Remove the syscall exit audit and schedule optimizations") Link: http://lkml.kernel.org/r/dd2a4d26ecc7a5db61b476727175cd99ae2b32a4.1424989793.git.luto@amacapital.netSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Denys Vlasenko 提交于
ARGOFFSET is zero now, removing it changes no code. A few macros lost "offset" parameter, since it is always zero now too. No code changes - verified with objdump. Signed-off-by: NDenys Vlasenko <dvlasenk@redhat.com> Signed-off-by: NAndy Lutomirski <luto@amacapital.net> Cc: Alexei Starovoitov <ast@plumgrid.com> 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: Thomas Gleixner <tglx@linutronix.de> Cc: Will Drewry <wad@chromium.org> Link: http://lkml.kernel.org/r/8689f937622d9d2db0ab8be82331fa15e4ed4713.1424989793.git.luto@amacapital.netSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Denys Vlasenko 提交于
RESTORE_EXTRA_REGS + RESTORE_C_REGS looks small, but it's a lot of instructions (fourteen). Let's reuse them. Signed-off-by: NDenys Vlasenko <dvlasenk@redhat.com> [ Cleaned up the labels. ] Signed-off-by: NAndy Lutomirski <luto@amacapital.net> Cc: Alexei Starovoitov <ast@plumgrid.com> 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: Will Drewry <wad@chromium.org> Link: http://lkml.kernel.org/r/1421272101-16847-2-git-send-email-dvlasenk@redhat.com Link: http://lkml.kernel.org/r/59d71848cee3ec9eb48c0252e602efd6bd560e3c.1424989793.git.luto@amacapital.netSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Denys Vlasenko 提交于
- Misleading and slightly incorrect comments in "struct pt_regs" are fixed (four instances). - Fix incorrect comment atop EMPTY_FRAME macro. - Explain in more detail what we do with stack layout during hw interrupt. - Correct comments about "partial stack frame" which are no longer true. Signed-off-by: NDenys Vlasenko <dvlasenk@redhat.com> Signed-off-by: NAndy Lutomirski <luto@amacapital.net> Cc: Alexei Starovoitov <ast@plumgrid.com> 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: Will Drewry <wad@chromium.org> Link: http://lkml.kernel.org/r/1423778052-21038-3-git-send-email-dvlasenk@redhat.com Link: http://lkml.kernel.org/r/e1f4429c491fe6ceeddb879dea2786e0f8920f9c.1424989793.git.luto@amacapital.netSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Denys Vlasenko 提交于
The 64-bit entry code was using six stack slots less by not saving/restoring registers which are callee-preserved according to the C ABI, and was not allocating space for them. Only when syscalls needed a complete "struct pt_regs" was the complete area allocated and filled in. As an additional twist, on interrupt entry a "slightly less truncated pt_regs" trick is used, to make nested interrupt stacks easier to unwind. This proved to be a source of significant obfuscation and subtle bugs. For example, 'stub_fork' had to pop the return address, extend the struct, save registers, and push return address back. Ugly. 'ia32_ptregs_common' pops return address and "returns" via jmp insn, throwing a wrench into CPU return stack cache. This patch changes the code to always allocate a complete "struct pt_regs" on the kernel stack. The saving of registers is still done lazily. "Partial pt_regs" trick on interrupt stack is retained. Macros which manipulate "struct pt_regs" on stack are reworked: - ALLOC_PT_GPREGS_ON_STACK allocates the structure. - SAVE_C_REGS saves to it those registers which are clobbered by C code. - SAVE_EXTRA_REGS saves to it all other registers. - Corresponding RESTORE_* and REMOVE_PT_GPREGS_FROM_STACK macros reverse it. 'ia32_ptregs_common', 'stub_fork' and friends lost their ugly dance with the return pointer. LOAD_ARGS32 in ia32entry.S now uses symbolic stack offsets instead of magic numbers. 'error_entry' and 'save_paranoid' now use SAVE_C_REGS + SAVE_EXTRA_REGS instead of having it open-coded yet again. Patch was run-tested: 64-bit executables, 32-bit executables, strace works. Timing tests did not show measurable difference in 32-bit and 64-bit syscalls. Signed-off-by: NDenys Vlasenko <dvlasenk@redhat.com> Signed-off-by: NAndy Lutomirski <luto@amacapital.net> Cc: Alexei Starovoitov <ast@plumgrid.com> 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: Will Drewry <wad@chromium.org> Link: http://lkml.kernel.org/r/1423778052-21038-2-git-send-email-dvlasenk@redhat.com Link: http://lkml.kernel.org/r/b89763d354aa23e670b9bdf3a40ae320320a7c2e.1424989793.git.luto@amacapital.netSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Denys Vlasenko 提交于
Since the last fix of this nature, a few more instances have crept in. Fix them up. No object code changes (constants have the same value). Signed-off-by: NDenys Vlasenko <dvlasenk@redhat.com> Signed-off-by: NAndy Lutomirski <luto@amacapital.net> Cc: Alexei Starovoitov <ast@plumgrid.com> 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: Will Drewry <wad@chromium.org> Link: http://lkml.kernel.org/r/1423778052-21038-1-git-send-email-dvlasenk@redhat.com Link: http://lkml.kernel.org/r/f5e1c4084319a42e5f14d41e2d638949ce66bc08.1424989793.git.luto@amacapital.netSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Denys Vlasenko 提交于
Sequences: pushl_cfi %reg CFI_REL_OFFSET reg, 0 and: popl_cfi %reg CFI_RESTORE reg happen quite often. This patch adds macros which generate them. No assembly changes (verified with objdump -dr vmlinux.o). Signed-off-by: NDenys Vlasenko <dvlasenk@redhat.com> Signed-off-by: NAndy Lutomirski <luto@amacapital.net> Cc: Alexei Starovoitov <ast@plumgrid.com> 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: Will Drewry <wad@chromium.org> Link: http://lkml.kernel.org/r/1421017655-25561-1-git-send-email-dvlasenk@redhat.com Link: http://lkml.kernel.org/r/2202eb90f175cf45d1b2d1c64dbb5676a8ad07ad.1424989793.git.luto@amacapital.netSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Denys Vlasenko 提交于
This is a preparatory patch for change in "struct pt_regs" handling in entry_64.S. trace_hardirqs*() thunks were (ab)using a part of the 'pt_regs' handling code, namely the SAVE_ARGS/RESTORE_ARGS macros, to save/restore registers across C function calls. Since SAVE_ARGS is going to be changed, open-code register saving/restoring here. Incidentally, this removes a bit of dead code: one SAVE_ARGS was used just to emit a CFI annotation, but it also generated unreachable assembly instructions. Take a page from thunk_32.S and use push/pop instructions instead of movq, they are far shorter: 1 or 2 bytes versus 5, and no need for instructions to adjust %rsp: text data bss dec hex filename 333 40 0 373 175 thunk_64_movq.o 104 40 0 144 90 thunk_64_push_pop.o [ This is ugly as sin, but we'll fix up the ugliness in the next patch. I see no point in reordering patches just to avoid an ugly intermediate state. --Andy ] Signed-off-by: NDenys Vlasenko <dvlasenk@redhat.com> Signed-off-by: NAndy Lutomirski <luto@amacapital.net> Cc: Alexei Starovoitov <ast@plumgrid.com> 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: Will Drewry <wad@chromium.org> Link: http://lkml.kernel.org/r/1420927210-19738-4-git-send-email-dvlasenk@redhat.com Link: http://lkml.kernel.org/r/4c979ad604f0f02c5ade3b3da308b53eabd5e198.1424989793.git.luto@amacapital.netSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 04 3月, 2015 3 次提交
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由 Brian Gerst 提交于
The check against lastcomm is racy, and the message it produces isn't necessary. vm86 support can be disabled on a 32-bit kernel also, and doesn't have this message. Switch to sys_ni_syscall instead. Signed-off-by: NBrian Gerst <brgerst@gmail.com> Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1425439896-8322-4-git-send-email-brgerst@gmail.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Brian Gerst 提交于
Combine the 32-bit syscall tables into one file. Signed-off-by: NBrian Gerst <brgerst@gmail.com> Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1425439896-8322-3-git-send-email-brgerst@gmail.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Brian Gerst 提交于
compat_ni_syscall() does the same thing as sys_ni_syscall(). Signed-off-by: NBrian Gerst <brgerst@gmail.com> Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1425439896-8322-2-git-send-email-brgerst@gmail.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 28 2月, 2015 1 次提交
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由 Steven Rostedt 提交于
Commit: 1e02ce4c ("x86: Store a per-cpu shadow copy of CR4") added a shadow CR4 such that reads and writes that do not modify the CR4 execute much faster than always reading the register itself. The change modified cpu_init() in common.c, so that the shadow CR4 gets initialized before anything uses it. Unfortunately, there's two cpu_init()s in common.c. There's one for 64-bit and one for 32-bit. The commit only added the shadow init to the 64-bit path, but the 32-bit path needs the init too. Link: http://lkml.kernel.org/r/20150227125208.71c36402@gandalf.local.home Fixes: 1e02ce4c "x86: Store a per-cpu shadow copy of CR4" Signed-off-by: NSteven Rostedt <rostedt@goodmis.org> Acked-by: NAndy Lutomirski <luto@amacapital.net> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/20150227145019.2bdd4354@gandalf.local.homeSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 26 2月, 2015 1 次提交
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由 Wang Nan 提交于
Before this patch early_trap_init() installs DEBUG_STACK for X86_TRAP_BP and X86_TRAP_DB. However, DEBUG_STACK doesn't work correctly until cpu_init() <-- trap_init(). This patch passes 0 to set_intr_gate_ist() and set_system_intr_gate_ist() instead of DEBUG_STACK to let it use same stack as kernel, and installs DEBUG_STACK for them in trap_init(). As core runs at ring 0 between early_trap_init() and trap_init(), there is no chance to get a bad stack before trap_init(). As NMI is also enabled in trap_init(), we don't need to care about is_debug_stack() and related things used in arch/x86/kernel/nmi.c. Signed-off-by: NWang Nan <wangnan0@huawei.com> Reviewed-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Acked-by: NSteven Rostedt <rostedt@goodmis.org> Cc: <dave.hansen@linux.intel.com> Cc: <lizefan@huawei.com> Cc: <luto@amacapital.net> Cc: <oleg@redhat.com> Link: http://lkml.kernel.org/r/1424929779-13174-1-git-send-email-wangnan0@huawei.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 25 2月, 2015 2 次提交
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由 Andy Lutomirski 提交于
CLONE_SETTLS is expected to write a TLS entry in the GDT for 32-bit callers and to set FSBASE for 64-bit callers. The correct check is is_ia32_task(), which returns true in the context of a 32-bit syscall. TIF_IA32 is set if the task itself has a 32-bit personality, which is not the same thing. Signed-off-by: NAndy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Denys Vlasenko <dvlasenk@redhat.com> Link: http://lkml.kernel.org/r/45e2d0d695393d76406a0c7225b82c76223e0cc5.1424822291.git.luto@amacapital.netSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Andy Lutomirski 提交于
The ability for modified CS and/or SS to be useful has nothing to do with TIF_IA32. Similarly, if there's an exploit involving changing CS or SS, it's exploitable with or without a TIF_IA32 check. So just delete the check. Signed-off-by: NAndy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Denys Vlasenko <dvlasenk@redhat.com> Link: http://lkml.kernel.org/r/71c7ab36456855d11ae07edd4945a7dfe80f9915.1424822291.git.luto@amacapital.netSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 24 2月, 2015 4 次提交
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由 Yannick Guerrini 提交于
Change 'Uknown' to 'Unknown' Signed-off-by: NYannick Guerrini <yguerrini@tomshardware.fr> Cc: trivial@kernel.org Link: http://lkml.kernel.org/r/1424710358-10140-1-git-send-email-yguerrini@tomshardware.frSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Boris Ostrovsky 提交于
Commit 1e02ce4c ("x86: Store a per-cpu shadow copy of CR4") introduced CR4 shadows. These shadows are initialized in early boot code. The commit missed initialization for 64-bit PV(H) guests that this patch adds. Signed-off-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com>
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由 David Vrabel 提交于
Hypercalls submitted by user space tools via the privcmd driver can take a long time (potentially many 10s of seconds) if the hypercall has many sub-operations. A fully preemptible kernel may deschedule such as task in any upcall called from a hypercall continuation. However, in a kernel with voluntary or no preemption, hypercall continuations in Xen allow event handlers to be run but the task issuing the hypercall will not be descheduled until the hypercall is complete and the ioctl returns to user space. These long running tasks may also trigger the kernel's soft lockup detection. Add xen_preemptible_hcall_begin() and xen_preemptible_hcall_end() to bracket hypercalls that may be preempted. Use these in the privcmd driver. When returning from an upcall, call xen_maybe_preempt_hcall() which adds a schedule point if if the current task was within a preemptible hypercall. Since _cond_resched() can move the task to a different CPU, clear and set xen_in_preemptible_hcall around the call. Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com> Reviewed-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>
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由 Boris Ostrovsky 提交于
Commit d524165c ("x86/apic: Check x2apic early") tests X2APIC_ENABLE bit of MSR_IA32_APICBASE when CONFIG_X86_X2APIC is off and panics the kernel when this bit is set. Xen's PV guests will pass this MSR read to the hypervisor which will return its version of the MSR, where this bit might be set. Make sure we clear it before returning MSR value to the caller. Signed-off-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com>
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- 23 2月, 2015 4 次提交
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由 Borislav Petkov 提交于
Make REP_GOOD variant the default after alternatives have run. Signed-off-by: NBorislav Petkov <bp@suse.de>
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由 Borislav Petkov 提交于
Make it execute the ERMS version if support is present and we're in the forward memmove() part and remove the unfolded alternatives section definition. Signed-off-by: NBorislav Petkov <bp@suse.de>
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由 Borislav Petkov 提交于
Make alternatives replace single JMPs instead of whole memset functions, thus decreasing the amount of instructions copied during patching time at boot. While at it, make it use the REP_GOOD version by default which means alternatives NOP out the JMP to the other versions, as REP_GOOD is set by default on the majority of relevant x86 processors. Signed-off-by: NBorislav Petkov <bp@suse.de>
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由 Borislav Petkov 提交于
This is based on a patch originally by hpa. With the current improvements to the alternatives, we can simply use %P1 as a mem8 operand constraint and rely on the toolchain to generate the proper instruction sizes. For example, on 32-bit, where we use an empty old instruction we get: apply_alternatives: feat: 6*32+8, old: (c104648b, len: 4), repl: (c195566c, len: 4) c104648b: alt_insn: 90 90 90 90 c195566c: rpl_insn: 0f 0d 4b 5c ... apply_alternatives: feat: 6*32+8, old: (c18e09b4, len: 3), repl: (c1955948, len: 3) c18e09b4: alt_insn: 90 90 90 c1955948: rpl_insn: 0f 0d 08 ... apply_alternatives: feat: 6*32+8, old: (c1190cf9, len: 7), repl: (c1955a79, len: 7) c1190cf9: alt_insn: 90 90 90 90 90 90 90 c1955a79: rpl_insn: 0f 0d 0d a0 d4 85 c1 all with the proper padding done depending on the size of the replacement instruction the compiler generates. Signed-off-by: NBorislav Petkov <bp@suse.de> Cc: H. Peter Anvin <hpa@linux.intel.com>
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