summaryrefslogtreecommitdiffstats
path: root/arch/x86/power/hibernate_asm_64.S
Commit message (Collapse)AuthorAgeFilesLines
* x86, hibernate: Rename temp_level4_pgt to temp_pgtZhimin Gu2018-10-031-1/+1
| | | | | | | | | | | | | | As 32bit system is not using 4-level page, rename it to temp_pgt so that it can be reused for both 32bit and 64bit hibernation. No functional change. Signed-off-by: Zhimin Gu <kookoo.gu@intel.com> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Chen Yu <yu.c.chen@intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* x86/asm/64: Use 32-bit XOR to zero registersJan Beulich2018-07-031-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | Some Intel CPUs don't recognize 64-bit XORs as zeroing idioms. Zeroing idioms don't require execution bandwidth, as they're being taken care of in the frontend (through register renaming). Use 32-bit XORs instead. Signed-off-by: Jan Beulich <jbeulich@suse.com> Cc: Alok Kataria <akataria@vmware.com> 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: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: davem@davemloft.net Cc: herbert@gondor.apana.org.au Cc: pavel@ucw.cz Cc: rjw@rjwysocki.net Link: http://lkml.kernel.org/r/5B39FF1A02000078001CFB54@prv1-mh.provo.novell.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/power/64: Do not refer to __PAGE_OFFSET from assembly codeRafael J. Wysocki2016-08-031-2/+0Star
| | | | | | | | | | | | | | | | When CONFIG_RANDOMIZE_MEMORY is set on x86-64, __PAGE_OFFSET becomes a variable and using it as a symbol in the image memory restoration assembly code under core_restore_code is not correct any more. To avoid that problem, modify set_up_temporary_mappings() to compute the physical address of the temporary page tables and store it in temp_level4_pgt, so that the value of that variable is ready to be written into CR3. Then, the assembly code doesn't have to worry about converting that value into a physical address and things work regardless of whether or not CONFIG_RANDOMIZE_MEMORY is set. Reported-and-tested-by: Thomas Garnier <thgarnie@google.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* x86/power/64: Fix hibernation return address corruptionJosh Poimboeuf2016-07-291-3/+1Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In kernel bug 150021, a kernel panic was reported when restoring a hibernate image. Only a picture of the oops was reported, so I can't paste the whole thing here. But here are the most interesting parts: kernel tried to execute NX-protected page - exploit attempt? (uid: 0) BUG: unable to handle kernel paging request at ffff8804615cfd78 ... RIP: ffff8804615cfd78 RSP: ffff8804615f0000 RBP: ffff8804615cfdc0 ... Call Trace: do_signal+0x23 exit_to_usermode_loop+0x64 ... The RIP is on the same page as RBP, so it apparently started executing on the stack. The bug was bisected to commit ef0f3ed5a4ac (x86/asm/power: Create stack frames in hibernate_asm_64.S), which in retrospect seems quite dangerous, since that code saves and restores the stack pointer from a global variable ('saved_context'). There are a lot of moving parts in the hibernate save and restore paths, so I don't know exactly what caused the panic. Presumably, a FRAME_END was executed without the corresponding FRAME_BEGIN, or vice versa. That would corrupt the return address on the stack and would be consistent with the details of the above panic. [ rjw: One major problem is that by the time the FRAME_BEGIN in restore_registers() is executed, the stack pointer value may not be valid any more. Namely, the stack area pointed to by it previously may have been overwritten by some image memory contents and that page frame may now be used for whatever different purpose it had been allocated for before hibernation. In that case, the FRAME_BEGIN will corrupt that memory. ] Instead of doing the frame pointer save/restore around the bounds of the affected functions, just do it around the call to swsusp_save(). That has the same effect of ensuring that if swsusp_save() sleeps, the frame pointers will be correct. It's also a much more obviously safe way to do it than the original patch. And objtool still doesn't report any warnings. Fixes: ef0f3ed5a4ac (x86/asm/power: Create stack frames in hibernate_asm_64.S) Link: https://bugzilla.kernel.org/show_bug.cgi?id=150021 Cc: 4.6+ <stable@vger.kernel.org> # 4.6+ Reported-by: Andre Reinke <andre.reinke@mailbox.org> Tested-by: Andre Reinke <andre.reinke@mailbox.org> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Acked-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* x86/power/64: Fix kernel text mapping corruption during image restorationRafael J. Wysocki2016-06-301-31/+24Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Logan Gunthorpe reports that hibernation stopped working reliably for him after commit ab76f7b4ab23 (x86/mm: Set NX on gap between __ex_table and rodata). That turns out to be a consequence of a long-standing issue with the 64-bit image restoration code on x86, which is that the temporary page tables set up by it to avoid page tables corruption when the last bits of the image kernel's memory contents are copied into their original page frames re-use the boot kernel's text mapping, but that mapping may very well get corrupted just like any other part of the page tables. Of course, if that happens, the final jump to the image kernel's entry point will go to nowhere. The exact reason why commit ab76f7b4ab23 matters here is that it sometimes causes a PMD of a large page to be split into PTEs that are allocated dynamically and get corrupted during image restoration as described above. To fix that issue note that the code copying the last bits of the image kernel's memory contents to the page frames occupied by them previoulsy doesn't use the kernel text mapping, because it runs from a special page covered by the identity mapping set up for that code from scratch. Hence, the kernel text mapping is only needed before that code starts to run and then it will only be used just for the final jump to the image kernel's entry point. Accordingly, the temporary page tables set up in swsusp_arch_resume() on x86-64 need to contain the kernel text mapping too. That mapping is only going to be used for the final jump to the image kernel, so it only needs to cover the image kernel's entry point, because the first thing the image kernel does after getting control back is to switch over to its own original page tables. Moreover, the virtual address of the image kernel's entry point in that mapping has to be the same as the one mapped by the image kernel's page tables. With that in mind, modify the x86-64's arch_hibernation_header_save() and arch_hibernation_header_restore() routines to pass the physical address of the image kernel's entry point (in addition to its virtual address) to the boot kernel (a small piece of assembly code involved in passing the entry point's virtual address to the image kernel is not necessary any more after that, so drop it). Update RESTORE_MAGIC too to reflect the image header format change. Next, in set_up_temporary_mappings(), use the physical and virtual addresses of the image kernel's entry point passed in the image header to set up a minimum kernel text mapping (using memory pages that won't be overwritten by the image kernel's memory contents) that will map those addresses to each other as appropriate. This makes the concern about the possible corruption of the original boot kernel text mapping go away and if the the minimum kernel text mapping used for the final jump marks the image kernel's entry point memory as executable, the jump to it is guaraneed to succeed. Fixes: ab76f7b4ab23 (x86/mm: Set NX on gap between __ex_table and rodata) Link: http://marc.info/?l=linux-pm&m=146372852823760&w=2 Reported-by: Logan Gunthorpe <logang@deltatee.com> Reported-and-tested-by: Borislav Petkov <bp@suse.de> Tested-by: Kees Cook <keescook@chromium.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* x86/asm/power: Create stack frames in hibernate_asm_64.SJosh Poimboeuf2016-02-241-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | swsusp_arch_suspend() and restore_registers() are callable non-leaf functions which don't honor CONFIG_FRAME_POINTER, which can result in bad stack traces. Also they aren't annotated as ELF callable functions which can confuse tooling. Create a stack frame for them when CONFIG_FRAME_POINTER is enabled and give them proper ELF function annotations. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Reviewed-by: Borislav Petkov <bp@suse.de> Acked-by: Pavel Machek <pavel@ucw.cz> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Bernd Petrovitsch <bernd@petrovitsch.priv.at> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Chris J Arges <chris.j.arges@canonical.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michal Marek <mmarek@suse.cz> Cc: Namhyung Kim <namhyung@gmail.com> Cc: Pedro Alves <palves@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: live-patching@vger.kernel.org Link: http://lkml.kernel.org/r/bdad00205897dc707aebe9e9e39757085e2bf999.1453405861.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86/asm, x86/power/hibernate: Use local labels in asmBorislav Petkov2015-04-151-4/+4
| | | | | | | | | | | | | | | | | | ... so that they don't appear in the object file and thus in objdump output. They're local anyway and have a meaning only within that file. No functionality change. Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Pavel Machek <pavel@ucw.cz> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-pm@vger.kernel.org Link: http://lkml.kernel.org/r/1428867906-12016-1-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
* x86, gdt, hibernate: Store/load GDT for hibernate path.Konrad Rzeszutek Wilk2013-05-021-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The git commite7a5cd063c7b4c58417f674821d63f5eb6747e37 ("x86-64, gdt: Store/load GDT for ACPI S3 or hibernate/resume path is not needed.") assumes that for the hibernate path the booting kernel and the resuming kernel MUST be the same. That is certainly the case for a 32-bit kernel (see check_image_kernel and CONFIG_ARCH_HIBERNATION_HEADER config option). However for 64-bit kernels it is OK to have a different kernel version (and size of the image) of the booting and resuming kernels. Hence the above mentioned git commit introduces an regression. This patch fixes it by introducing a 'struct desc_ptr gdt_desc' back in the 'struct saved_context'. However instead of having in the 'save_processor_state' and 'restore_processor_state' the store/load_gdt calls, we are only saving the GDT in the save_processor_state. For the restore path the lgdt operation is done in hibernate_asm_[32|64].S in the 'restore_registers' path. The apt reader of this description will recognize that only 64-bit kernels need this treatment, not 32-bit. This patch adds the logic in the 32-bit path to be more similar to 64-bit so that in the future the unification process can take advantage of this. [ hpa: this also reverts an inadvertent on-disk format change ] Suggested-by: "H. Peter Anvin" <hpa@zytor.com> Acked-by: "Rafael J. Wysocki" <rjw@sisk.pl> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Link: http://lkml.kernel.org/r/1367459610-9656-2-git-send-email-konrad.wilk@oracle.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
* x86: use _types.h headers in asm where availableJeremy Fitzhardinge2009-02-131-1/+1
| | | | | | | In general, the only definitions that assembly files can use are in _types.S headers (where available), so convert them. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
* x86 cleanup: suspend_asm_64.S - use X86_CR4_PGE instead of numeric valueCyrill Gorcunov2008-02-191-2/+3
| | | | | | | | | | | By including <asm/processor-flags.h> we're allowed to use X86_CR4_PGE instead of numeric constant. md5 sums of compiled files are differ due to this inclusion but .text section remains the same. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* x86 PM: move 64-bit hibernation files to arch/x86/powerRafael J. Wysocki2008-02-091-0/+146
Move arch/x86/kernel/suspend_64.c to arch/x86/power . Move arch/x86/kernel/suspend_asm_64.S to arch/x86/power as hibernate_asm_64.S . Update purpose and copyright information in arch/x86/power/suspend_64.c and arch/x86/power/hibernate_asm_64.S . Update the Makefiles in arch/x86, arch/x86/kernel and arch/x86/power to reflect the above changes. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>