On Fri, 9 Jan 2026 at 13:09, Ard Biesheuvel <[email protected]> wrote: > > On Fri, 9 Jan 2026 at 12:46, Brian Gerst <[email protected]> wrote: > > > > On Fri, Jan 9, 2026 at 2:59 AM Ard Biesheuvel <[email protected]> wrote: > > > > > > On Fri, 9 Jan 2026 at 06:01, Brian Gerst <[email protected]> wrote: > > > > > > > > On Thu, Jan 8, 2026 at 4:28 AM Ard Biesheuvel <[email protected]> wrote: > > > > > > > > > > Use ordinary RIP-relative references to make the code compatible with > > > > > running the linker in PIE mode. > > > > > > > > > > Note that wakeup_long64() runs in the kernel's ordinary virtual > > > > > mapping > > > > > so there is no need to record the address of .Lresume_point in a > > > > > global > > > > > variable. And fix the comment while at it. > > > > > > > > > > Signed-off-by: Ard Biesheuvel <[email protected]> > > > > > --- > > > > > arch/x86/kernel/acpi/wakeup_64.S | 11 ++++------- > > > > > 1 file changed, 4 insertions(+), 7 deletions(-) > > > > > > > > > > diff --git a/arch/x86/kernel/acpi/wakeup_64.S > > > > > b/arch/x86/kernel/acpi/wakeup_64.S > > > > > index 04f561f75e99..15233a4e1c95 100644 > > > > > --- a/arch/x86/kernel/acpi/wakeup_64.S > > > > > +++ b/arch/x86/kernel/acpi/wakeup_64.S > > > > > @@ -14,7 +14,7 @@ > > > > > > > > > > .code64 > > > > > /* > > > > > - * Hooray, we are in Long 64-bit mode (but still running in > > > > > low memory) > > > > > + * Hooray, we are in Long 64-bit mode > > > > > */ > > > > > SYM_FUNC_START(wakeup_long64) > > > > > ANNOTATE_NOENDBR > > > > > @@ -41,7 +41,7 @@ SYM_FUNC_START(wakeup_long64) > > > > > movq saved_rsi(%rip), %rsi > > > > > movq saved_rbp(%rip), %rbp > > > > > > > > > > - movq saved_rip(%rip), %rax > > > > > + leaq .Lresume_point(%rip), %rax > > > > > ANNOTATE_RETPOLINE_SAFE > > > > > jmp *%rax > > > > > > > > If this is already running on the virtual mapping, this can simply be > > > > changed to a direct jump. > > > > > > > > > > Indeed, but I couldn't figure out how to do so without making objtool > > > unhappy. > > > > I replaced it with a simple "jmp .Lresume_point" and objtool seemed > > fine with it on a defconfig build. What error did you see? > > arch/x86/kernel/acpi/wakeup_64.o: warning: objtool: wakeup_long64() > falls through to next function do_suspend_lowlevel()
Note that this is x86_64_defconfig with CONFIG_X86_KERNEL_IBT disabled.
