diff options
| author | Jiri Slaby <[email protected]> | 2019-09-06 09:55:49 +0200 |
|---|---|---|
| committer | Borislav Petkov <[email protected]> | 2019-09-06 10:34:15 +0200 |
| commit | 559ceeed62a5121783a8955c63aeb18aaa0ef224 (patch) | |
| tree | bcb93c9ad32ff3c9ee49ac50c80236d915f58b69 | |
| parent | db4e919d9a119b7c54eb5e5ac9bee5d3eb4cb859 (diff) | |
x86/asm/suspend: Get rid of bogus_64_magic
bogus_64_magic is only a dead-end loop. There is no need for an
out-of-order function (and unannotated local label), so just handle it
in-place and also store 0xbad-m-a-g-i-c to %rcx beforehand, in case
someone is inspecting registers.
Here a qemu+gdb example:
Remote debugging using localhost:1235
wakeup_long64 () at arch/x86/kernel/acpi/wakeup_64.S:26
26 jmp 1b
(gdb) info registers
rax 0x123456789abcdef0 1311768467463790320
rbx 0x0 0
rcx 0xbad6d61676963 3286910041024867
^^^^^^^^^^^^^^^
[ bp: Add the gdb example. ]
Signed-off-by: Jiri Slaby <[email protected]>
Signed-off-by: Borislav Petkov <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Len Brown <[email protected]>
Cc: [email protected]
Cc: Pavel Machek <[email protected]>
Cc: "Rafael J. Wysocki" <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: x86-ml <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]
| -rw-r--r-- | arch/x86/kernel/acpi/wakeup_64.S | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/arch/x86/kernel/acpi/wakeup_64.S b/arch/x86/kernel/acpi/wakeup_64.S index b0715c3ac18d..7f9ade13bbcf 100644 --- a/arch/x86/kernel/acpi/wakeup_64.S +++ b/arch/x86/kernel/acpi/wakeup_64.S @@ -18,8 +18,13 @@ ENTRY(wakeup_long64) movq saved_magic, %rax movq $0x123456789abcdef0, %rdx cmpq %rdx, %rax - jne bogus_64_magic + je 2f + /* stop here on a saved_magic mismatch */ + movq $0xbad6d61676963, %rcx +1: + jmp 1b +2: movw $__KERNEL_DS, %ax movw %ax, %ss movw %ax, %ds @@ -37,9 +42,6 @@ ENTRY(wakeup_long64) jmp *%rax ENDPROC(wakeup_long64) -bogus_64_magic: - jmp bogus_64_magic - ENTRY(do_suspend_lowlevel) FRAME_BEGIN subq $8, %rsp |