linux_dsm_epyc7002/arch/x86/entry
Peter Zijlstra a0d14b8909 x86/mm, tracing: Fix CR2 corruption
Despite the current efforts to read CR2 before tracing happens there still
exist a number of possible holes:

  idtentry page_fault             do_page_fault           has_error_code=1
    call error_entry
      TRACE_IRQS_OFF
        call trace_hardirqs_off*
          #PF // modifies CR2

      CALL_enter_from_user_mode
        __context_tracking_exit()
          trace_user_exit(0)
            #PF // modifies CR2

    call do_page_fault
      address = read_cr2(); /* whoopsie */

And similar for i386.

Fix it by pulling the CR2 read into the entry code, before any of that
stuff gets a chance to run and ruin things.

Reported-by: He Zhe <zhe.he@windriver.com>
Reported-by: Eiichi Tsukata <devel@etsukata.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Cc: bp@alien8.de
Cc: rostedt@goodmis.org
Cc: torvalds@linux-foundation.org
Cc: hpa@zytor.com
Cc: dave.hansen@linux.intel.com
Cc: jgross@suse.com
Cc: joel@joelfernandes.org
Link: https://lkml.kernel.org/r/20190711114336.116812491@infradead.org

Debugged-by: Steven Rostedt <rostedt@goodmis.org>
2019-07-17 23:17:38 +02:00
..
syscalls clone3-v5.3 2019-07-11 10:09:44 -07:00
vdso x86/vdso: Fix flip/flop vdso build bug 2019-07-12 17:35:07 +02:00
vsyscall Merge branch 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2019-07-08 21:48:15 -07:00
calling.h x86/paravirt: Make read_cr2() CALLEE_SAVE 2019-07-17 23:17:37 +02:00
common.c arm64 updates for 5.3: 2019-07-08 09:54:55 -07:00
entry_32.S x86/mm, tracing: Fix CR2 corruption 2019-07-17 23:17:38 +02:00
entry_64_compat.S x86/entry/64/compat: Fix stack switching for XEN PV 2019-01-18 00:39:33 +01:00
entry_64.S x86/mm, tracing: Fix CR2 corruption 2019-07-17 23:17:38 +02:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
syscall_32.c syscalls/x86: Unconditionally enable 'struct pt_regs' based syscalls on x86_64 2018-04-05 16:59:38 +02:00
syscall_64.c syscalls/x86: Unconditionally enable 'struct pt_regs' based syscalls on x86_64 2018-04-05 16:59:38 +02:00
thunk_32.S treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 474 2019-06-19 17:09:11 +02:00
thunk_64.S treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 474 2019-06-19 17:09:11 +02:00