3901336ed9
After making a change to improve objtool's sibling call detection, it started showing the following warning: arch/x86/kvm/vmx/nested.o: warning: objtool: .fixup+0x15: sibling call from callable instruction with modified stack frame The problem is the ____kvm_handle_fault_on_reboot() macro. It does a fake call by pushing a fake RIP and doing a jump. That tricks the unwinder into printing the function which triggered the exception, rather than the .fixup code. Instead of the hack to make it look like the original function made the call, just change the macro so that the original function actually does make the call. This allows removal of the hack, and also makes objtool happy. I triggered a vmx instruction exception and verified that the stack trace is still sane: kernel BUG at arch/x86/kvm/x86.c:358! invalid opcode: 0000 [#1] SMP PTI CPU: 28 PID: 4096 Comm: qemu-kvm Not tainted 5.2.0+ #16 Hardware name: Lenovo THINKSYSTEM SD530 -[7X2106Z000]-/-[7X2106Z000]-, BIOS -[TEE113Z-1.00]- 07/17/2017 RIP: 0010:kvm_spurious_fault+0x5/0x10 Code: 00 00 00 00 00 8b 44 24 10 89 d2 45 89 c9 48 89 44 24 10 8b 44 24 08 48 89 44 24 08 e9 d4 40 22 00 0f 1f 40 00 0f 1f 44 00 00 <0f> 0b 66 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 41 55 49 89 fd 41 RSP: 0018:ffffbf91c683bd00 EFLAGS: 00010246 RAX: 000061f040000000 RBX: ffff9e159c77bba0 RCX: ffff9e15a5c87000 RDX: 0000000665c87000 RSI: ffff9e15a5c87000 RDI: ffff9e159c77bba0 RBP: 0000000000000000 R08: 0000000000000000 R09: ffff9e15a5c87000 R10: 0000000000000000 R11: fffff8f2d99721c0 R12: ffff9e159c77bba0 R13: ffffbf91c671d960 R14: ffff9e159c778000 R15: 0000000000000000 FS: 00007fa341cbe700(0000) GS:ffff9e15b7400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fdd38356804 CR3: 00000006759de003 CR4: 00000000007606e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: loaded_vmcs_init+0x4f/0xe0 alloc_loaded_vmcs+0x38/0xd0 vmx_create_vcpu+0xf7/0x600 kvm_vm_ioctl+0x5e9/0x980 ? __switch_to_asm+0x40/0x70 ? __switch_to_asm+0x34/0x70 ? __switch_to_asm+0x40/0x70 ? __switch_to_asm+0x34/0x70 ? free_one_page+0x13f/0x4e0 do_vfs_ioctl+0xa4/0x630 ksys_ioctl+0x60/0x90 __x64_sys_ioctl+0x16/0x20 do_syscall_64+0x55/0x1c0 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7fa349b1ee5b Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/64a9b64d127e87b6920a97afde8e96ea76f6524e.1563413318.git.jpoimboe@redhat.com |
||
|---|---|---|
| Documentation | ||
| LICENSES | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
README
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.