Messages in this thread Patch in this message | | | From | Uros Bizjak <> | Subject | [PATCH 1/3] x86/callthunks: Move call thunk template to .S file | Date | Thu, 2 Nov 2023 12:25:46 +0100 |
| |
Currently INCREMENT_CALL_DEPTH explicitly defines %gs: segment register prefix for its percpu variable. This is not compatible with !CONFIG_SMP, which requires non-prefixed percpu variables.
Move call thunk template to its own callthunks-tmpl.S assembly file where PER_CPU_VAR macro from percpu.h can be used to conditionally use %gs: segment register prefix, depending on CONFIG_SMP.
Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Uros Bizjak <ubizjak@gmail.com> --- arch/x86/kernel/Makefile | 2 +- arch/x86/kernel/callthunks-tmpl.S | 11 +++++++++++ arch/x86/kernel/callthunks.c | 10 ---------- 3 files changed, 12 insertions(+), 11 deletions(-) create mode 100644 arch/x86/kernel/callthunks-tmpl.S
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile index 3269a0e23d3a..6b6b68ef4c3b 100644 --- a/arch/x86/kernel/Makefile +++ b/arch/x86/kernel/Makefile @@ -143,7 +143,7 @@ obj-$(CONFIG_AMD_MEM_ENCRYPT) += sev.o obj-$(CONFIG_CFI_CLANG) += cfi.o -obj-$(CONFIG_CALL_THUNKS) += callthunks.o +obj-$(CONFIG_CALL_THUNKS) += callthunks.o callthunks-tmpl.o obj-$(CONFIG_X86_CET) += cet.o diff --git a/arch/x86/kernel/callthunks-tmpl.S b/arch/x86/kernel/callthunks-tmpl.S new file mode 100644 index 000000000000..e82c473bd1b1 --- /dev/null +++ b/arch/x86/kernel/callthunks-tmpl.S @@ -0,0 +1,11 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#include <asm/nospec-branch.h> + + .section .rodata + .global skl_call_thunk_template + .global skl_call_thunk_tail + +skl_call_thunk_template: + INCREMENT_CALL_DEPTH +skl_call_thunk_tail: diff --git a/arch/x86/kernel/callthunks.c b/arch/x86/kernel/callthunks.c index e9ad518a5003..d0922cf94c90 100644 --- a/arch/x86/kernel/callthunks.c +++ b/arch/x86/kernel/callthunks.c @@ -62,16 +62,6 @@ static const struct core_text builtin_coretext = { .name = "builtin", }; -asm ( - ".pushsection .rodata \n" - ".global skl_call_thunk_template \n" - "skl_call_thunk_template: \n" - __stringify(INCREMENT_CALL_DEPTH)" \n" - ".global skl_call_thunk_tail \n" - "skl_call_thunk_tail: \n" - ".popsection \n" -); - extern u8 skl_call_thunk_template[]; extern u8 skl_call_thunk_tail[]; -- 2.41.0
| |