* [PATCH 1/6] x86/entry/vdso: rename vdso_image_* to vdso*_image
2025-10-26 22:12 [PATCH 0/6] x86/entry/vdso: cleanups for vdso build and 32-bit vdso H. Peter Anvin
@ 2025-10-26 22:12 ` H. Peter Anvin
2025-10-26 22:12 ` [PATCH 2/6] x86/entry/vdso: refactor the vdso build H. Peter Anvin
` (4 subsequent siblings)
5 siblings, 0 replies; 10+ messages in thread
From: H. Peter Anvin @ 2025-10-26 22:12 UTC (permalink / raw)
To: H. Peter Anvin, Jason A. Donenfeld, Peter Zijlstra (Intel),
Theodore Ts'o, Thomas Weißschuh, Xin Li, Andrew Cooper,
Andy Lutomirski, Ard Biesheuvel, Borislav Petkov, Brian Gerst,
Dave Hansen, Ingo Molnar, James Morse, Jarkko Sakkinen,
Josh Poimboeuf, Kees Cook, Nam Cao, Oleg Nesterov, Perry Yuan,
Thomas Gleixner, Thomas Huth, Uros Bizjak, linux-kernel,
linux-mm, linux-sgx, x86
The .so files for the vdso are named vdso*.so, and these structures
are image of the corresponding vdso. Naming them accordingly is more
consistent, very slightly more compact (by one character...) and
simplifies the Makefile just a little bit.
Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
---
arch/x86/entry/syscall_32.c | 2 +-
arch/x86/entry/vdso/Makefile | 8 ++++----
arch/x86/entry/vdso/vma.c | 10 +++++-----
arch/x86/include/asm/elf.h | 2 +-
arch/x86/include/asm/vdso.h | 6 +++---
arch/x86/kernel/process_64.c | 6 +++---
arch/x86/kernel/signal_32.c | 4 ++--
7 files changed, 19 insertions(+), 19 deletions(-)
diff --git a/arch/x86/entry/syscall_32.c b/arch/x86/entry/syscall_32.c
index 2b15ea17bb7c..eff33a4e0adc 100644
--- a/arch/x86/entry/syscall_32.c
+++ b/arch/x86/entry/syscall_32.c
@@ -318,7 +318,7 @@ __visible noinstr bool do_fast_syscall_32(struct pt_regs *regs)
* convention. Adjust regs so it looks like we entered using int80.
*/
unsigned long landing_pad = (unsigned long)current->mm->context.vdso +
- vdso_image_32.sym_int80_landing_pad;
+ vdso32_image.sym_int80_landing_pad;
/*
* SYSENTER loses EIP, and even SYSCALL32 needs us to skip forward
diff --git a/arch/x86/entry/vdso/Makefile b/arch/x86/entry/vdso/Makefile
index f247f5f5cb44..7f833026d5b2 100644
--- a/arch/x86/entry/vdso/Makefile
+++ b/arch/x86/entry/vdso/Makefile
@@ -16,9 +16,9 @@ vobjs-$(CONFIG_X86_SGX) += vsgx.o
obj-y += vma.o extable.o
# vDSO images to build:
-obj-$(CONFIG_X86_64) += vdso-image-64.o
-obj-$(CONFIG_X86_X32_ABI) += vdso-image-x32.o
-obj-$(CONFIG_COMPAT_32) += vdso-image-32.o vdso32-setup.o
+obj-$(CONFIG_X86_64) += vdso64-image.o
+obj-$(CONFIG_X86_X32_ABI) += vdsox32-image.o
+obj-$(CONFIG_COMPAT_32) += vdso32-image.o vdso32-setup.o
vobjs := $(addprefix $(obj)/, $(vobjs-y))
vobjs32 := $(addprefix $(obj)/, $(vobjs32-y))
@@ -44,7 +44,7 @@ hostprogs += vdso2c
quiet_cmd_vdso2c = VDSO2C $@
cmd_vdso2c = $(obj)/vdso2c $< $(<:%.dbg=%) $@
-$(obj)/vdso-image-%.c: $(obj)/vdso%.so.dbg $(obj)/vdso%.so $(obj)/vdso2c FORCE
+$(obj)/vdso%-image.c: $(obj)/vdso%.so.dbg $(obj)/vdso%.so $(obj)/vdso2c FORCE
$(call if_changed,vdso2c)
#
diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c
index afe105b2f907..8f98c2d7c7a9 100644
--- a/arch/x86/entry/vdso/vma.c
+++ b/arch/x86/entry/vdso/vma.c
@@ -65,7 +65,7 @@ static vm_fault_t vdso_fault(const struct vm_special_mapping *sm,
static void vdso_fix_landing(const struct vdso_image *image,
struct vm_area_struct *new_vma)
{
- if (in_ia32_syscall() && image == &vdso_image_32) {
+ if (in_ia32_syscall() && image == &vdso32_image) {
struct pt_regs *regs = current_pt_regs();
unsigned long vdso_land = image->sym_int80_landing_pad;
unsigned long old_land_addr = vdso_land +
@@ -230,7 +230,7 @@ static int load_vdso32(void)
if (vdso32_enabled != 1) /* Other values all mean "disabled" */
return 0;
- return map_vdso(&vdso_image_32, 0);
+ return map_vdso(&vdso32_image, 0);
}
int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
@@ -239,7 +239,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
if (!vdso64_enabled)
return 0;
- return map_vdso(&vdso_image_64, 0);
+ return map_vdso(&vdso64_image, 0);
}
return load_vdso32();
@@ -252,7 +252,7 @@ int compat_arch_setup_additional_pages(struct linux_binprm *bprm,
if (IS_ENABLED(CONFIG_X86_X32_ABI) && x32) {
if (!vdso64_enabled)
return 0;
- return map_vdso(&vdso_image_x32, 0);
+ return map_vdso(&vdsox32_image, 0);
}
if (IS_ENABLED(CONFIG_IA32_EMULATION))
@@ -267,7 +267,7 @@ bool arch_syscall_is_vdso_sigreturn(struct pt_regs *regs)
const struct vdso_image *image = current->mm->context.vdso_image;
unsigned long vdso = (unsigned long) current->mm->context.vdso;
- if (in_ia32_syscall() && image == &vdso_image_32) {
+ if (in_ia32_syscall() && image == &vdso32_image) {
if (regs->ip == vdso + image->sym_vdso32_sigreturn_landing_pad ||
regs->ip == vdso + image->sym_vdso32_rt_sigreturn_landing_pad)
return true;
diff --git a/arch/x86/include/asm/elf.h b/arch/x86/include/asm/elf.h
index 6c8fdc96be7e..2ba5f166e58f 100644
--- a/arch/x86/include/asm/elf.h
+++ b/arch/x86/include/asm/elf.h
@@ -361,7 +361,7 @@ else if (IS_ENABLED(CONFIG_IA32_EMULATION)) \
#define VDSO_ENTRY \
((unsigned long)current->mm->context.vdso + \
- vdso_image_32.sym___kernel_vsyscall)
+ vdso32_image.sym___kernel_vsyscall)
struct linux_binprm;
diff --git a/arch/x86/include/asm/vdso.h b/arch/x86/include/asm/vdso.h
index b7253ef3205a..e8afbe9faa5b 100644
--- a/arch/x86/include/asm/vdso.h
+++ b/arch/x86/include/asm/vdso.h
@@ -27,9 +27,9 @@ struct vdso_image {
long sym_vdso32_rt_sigreturn_landing_pad;
};
-extern const struct vdso_image vdso_image_64;
-extern const struct vdso_image vdso_image_x32;
-extern const struct vdso_image vdso_image_32;
+extern const struct vdso_image vdso64_image;
+extern const struct vdso_image vdsox32_image;
+extern const struct vdso_image vdso32_image;
extern int __init init_vdso_image(const struct vdso_image *image);
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 52a5c03c353c..ae00c788962a 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -942,14 +942,14 @@ long do_arch_prctl_64(struct task_struct *task, int option, unsigned long arg2)
#ifdef CONFIG_CHECKPOINT_RESTORE
# ifdef CONFIG_X86_X32_ABI
case ARCH_MAP_VDSO_X32:
- return prctl_map_vdso(&vdso_image_x32, arg2);
+ return prctl_map_vdso(&vdsox32_image, arg2);
# endif
# ifdef CONFIG_IA32_EMULATION
case ARCH_MAP_VDSO_32:
- return prctl_map_vdso(&vdso_image_32, arg2);
+ return prctl_map_vdso(&vdso32_image, arg2);
# endif
case ARCH_MAP_VDSO_64:
- return prctl_map_vdso(&vdso_image_64, arg2);
+ return prctl_map_vdso(&vdso64_image, arg2);
#endif
#ifdef CONFIG_ADDRESS_MASKING
case ARCH_GET_UNTAG_MASK:
diff --git a/arch/x86/kernel/signal_32.c b/arch/x86/kernel/signal_32.c
index 42bbc42bd350..e55cf19e68fe 100644
--- a/arch/x86/kernel/signal_32.c
+++ b/arch/x86/kernel/signal_32.c
@@ -282,7 +282,7 @@ int ia32_setup_frame(struct ksignal *ksig, struct pt_regs *regs)
/* Return stub is in 32bit vsyscall page */
if (current->mm->context.vdso)
restorer = current->mm->context.vdso +
- vdso_image_32.sym___kernel_sigreturn;
+ vdso32_image.sym___kernel_sigreturn;
else
restorer = &frame->retcode;
}
@@ -368,7 +368,7 @@ int ia32_setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
restorer = ksig->ka.sa.sa_restorer;
else
restorer = current->mm->context.vdso +
- vdso_image_32.sym___kernel_rt_sigreturn;
+ vdso32_image.sym___kernel_rt_sigreturn;
unsafe_put_user(ptr_to_compat(restorer), &frame->pretcode, Efault);
/*
--
2.51.1
^ permalink raw reply [flat|nested] 10+ messages in thread* [PATCH 2/6] x86/entry/vdso: refactor the vdso build
2025-10-26 22:12 [PATCH 0/6] x86/entry/vdso: cleanups for vdso build and 32-bit vdso H. Peter Anvin
2025-10-26 22:12 ` [PATCH 1/6] x86/entry/vdso: rename vdso_image_* to vdso*_image H. Peter Anvin
@ 2025-10-26 22:12 ` H. Peter Anvin
2025-10-26 22:12 ` [PATCH 3/6] x86/entry/vdso32: remove int80_landing_pad H. Peter Anvin
` (3 subsequent siblings)
5 siblings, 0 replies; 10+ messages in thread
From: H. Peter Anvin @ 2025-10-26 22:12 UTC (permalink / raw)
To: H. Peter Anvin, Jason A. Donenfeld, Peter Zijlstra (Intel),
Theodore Ts'o, Thomas Weißschuh, Xin Li, Andrew Cooper,
Andy Lutomirski, Ard Biesheuvel, Borislav Petkov, Brian Gerst,
Dave Hansen, Ingo Molnar, James Morse, Jarkko Sakkinen,
Josh Poimboeuf, Kees Cook, Nam Cao, Oleg Nesterov, Perry Yuan,
Thomas Gleixner, Thomas Huth, Uros Bizjak, linux-kernel,
linux-mm, linux-sgx, x86
- Separate out the vdso sources into common, vdso32, and vdso64
directories.
- Move the vdso2c tool to arch/x86/tools.
- Build the 32- and 64-bit vdsos in their respective subdirectories;
this greatly simplifies the build flags handling.
- Unify the mangling of Makefile flags between the 32- and 64-bit
vdso code as much as possible; all common rules are put in
arch/x86/entry/vdso/common/Makefile.include. The remaining
is very simple for 32 bits; the 64-bit one is only slightly more
complicated because it contains the x32 generation rule.
- Define __DISABLE_EXPORTS when building the vdso. This need seems to
have been masked by different ordering compile flags before.
- Change CONFIG_X86_64 to BUILD_VDSO32_64 in vdso32/system_call.S,
to make it compatible with including fake_32bit_build.h.
- The -fcf-protection= option was "leaking" from the kernel build,
for reasons that was not clear to me. Futhermore, several
distributions ship with it set to a default value other than
"-fcf-protection=none". This universally sets it to
"-fcf-protection=branch" if supported; this match how user space is
compiled for most distributions, and de facto how the vdso had been
built with most distribution gcc until now.
Note that this patch may seem large, but the vast majority of it is
simply code movement.
Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
---
arch/x86/Makefile | 2 +-
arch/x86/entry/vdso/.gitignore | 11 +-
arch/x86/entry/vdso/Makefile | 162 +-----------------
arch/x86/entry/vdso/common/Makefile.include | 83 +++++++++
.../entry/vdso/{vdso-note.S => common/note.S} | 5 +-
.../entry/vdso/{ => common}/vclock_gettime.c | 0
.../entry/vdso/{ => common}/vdso-layout.lds.S | 0
arch/x86/entry/vdso/{ => common}/vgetcpu.c | 0
arch/x86/entry/vdso/vdso32/Makefile | 24 +++
arch/x86/entry/vdso/vdso32/note.S | 19 +-
arch/x86/entry/vdso/vdso32/system_call.S | 2 +-
arch/x86/entry/vdso/vdso32/vclock_gettime.c | 5 +-
arch/x86/entry/vdso/vdso32/vdso32.lds.S | 2 +-
arch/x86/entry/vdso/vdso32/vgetcpu.c | 4 +-
arch/x86/entry/vdso/vdso64/Makefile | 45 +++++
arch/x86/entry/vdso/vdso64/note.S | 1 +
arch/x86/entry/vdso/vdso64/vclock_gettime.c | 1 +
.../vdso/{vdso.lds.S => vdso64/vdso64.lds.S} | 2 +-
.../x86/entry/vdso/{ => vdso64}/vdsox32.lds.S | 2 +-
arch/x86/entry/vdso/vdso64/vgetcpu.c | 1 +
.../vdso/{ => vdso64}/vgetrandom-chacha.S | 0
arch/x86/entry/vdso/{ => vdso64}/vgetrandom.c | 2 +-
arch/x86/entry/vdso/{ => vdso64}/vsgx.S | 0
arch/x86/tools/Makefile | 15 +-
arch/x86/{entry/vdso => tools}/vdso2c.c | 0
arch/x86/{entry/vdso => tools}/vdso2c.h | 0
26 files changed, 188 insertions(+), 200 deletions(-)
create mode 100644 arch/x86/entry/vdso/common/Makefile.include
rename arch/x86/entry/vdso/{vdso-note.S => common/note.S} (62%)
rename arch/x86/entry/vdso/{ => common}/vclock_gettime.c (100%)
rename arch/x86/entry/vdso/{ => common}/vdso-layout.lds.S (100%)
rename arch/x86/entry/vdso/{ => common}/vgetcpu.c (100%)
create mode 100644 arch/x86/entry/vdso/vdso32/Makefile
create mode 100644 arch/x86/entry/vdso/vdso64/Makefile
create mode 100644 arch/x86/entry/vdso/vdso64/note.S
create mode 100644 arch/x86/entry/vdso/vdso64/vclock_gettime.c
rename arch/x86/entry/vdso/{vdso.lds.S => vdso64/vdso64.lds.S} (94%)
rename arch/x86/entry/vdso/{ => vdso64}/vdsox32.lds.S (92%)
create mode 100644 arch/x86/entry/vdso/vdso64/vgetcpu.c
rename arch/x86/entry/vdso/{ => vdso64}/vgetrandom-chacha.S (100%)
rename arch/x86/entry/vdso/{ => vdso64}/vgetrandom.c (91%)
rename arch/x86/entry/vdso/{ => vdso64}/vsgx.S (100%)
rename arch/x86/{entry/vdso => tools}/vdso2c.c (100%)
rename arch/x86/{entry/vdso => tools}/vdso2c.h (100%)
diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index 4db7e4bf69f5..3ab0651ec900 100644
--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile
@@ -250,7 +250,7 @@ endif
archscripts: scripts_basic
- $(Q)$(MAKE) $(build)=arch/x86/tools relocs
+ $(Q)$(MAKE) $(build)=arch/x86/tools relocs vdso2c
###
# Syscall table generation
diff --git a/arch/x86/entry/vdso/.gitignore b/arch/x86/entry/vdso/.gitignore
index 37a6129d597b..eb60859dbcbf 100644
--- a/arch/x86/entry/vdso/.gitignore
+++ b/arch/x86/entry/vdso/.gitignore
@@ -1,8 +1,5 @@
# SPDX-License-Identifier: GPL-2.0-only
-vdso.lds
-vdsox32.lds
-vdso32-syscall-syms.lds
-vdso32-sysenter-syms.lds
-vdso32-int80-syms.lds
-vdso-image-*.c
-vdso2c
+*.lds
+*.so
+*.so.dbg
+vdso*-image.c
diff --git a/arch/x86/entry/vdso/Makefile b/arch/x86/entry/vdso/Makefile
index 7f833026d5b2..987b43fd4cd3 100644
--- a/arch/x86/entry/vdso/Makefile
+++ b/arch/x86/entry/vdso/Makefile
@@ -3,160 +3,10 @@
# Building vDSO images for x86.
#
-# Include the generic Makefile to check the built vDSO:
-include $(srctree)/lib/vdso/Makefile.include
+# Regular kernel objects
+obj-y := vma.o extable.o
+obj-$(CONFIG_COMPAT_32) += vdso32-setup.o
-# Files to link into the vDSO:
-vobjs-y := vdso-note.o vclock_gettime.o vgetcpu.o vgetrandom.o vgetrandom-chacha.o
-vobjs32-y := vdso32/note.o vdso32/system_call.o vdso32/sigreturn.o
-vobjs32-y += vdso32/vclock_gettime.o vdso32/vgetcpu.o
-vobjs-$(CONFIG_X86_SGX) += vsgx.o
-
-# Files to link into the kernel:
-obj-y += vma.o extable.o
-
-# vDSO images to build:
-obj-$(CONFIG_X86_64) += vdso64-image.o
-obj-$(CONFIG_X86_X32_ABI) += vdsox32-image.o
-obj-$(CONFIG_COMPAT_32) += vdso32-image.o vdso32-setup.o
-
-vobjs := $(addprefix $(obj)/, $(vobjs-y))
-vobjs32 := $(addprefix $(obj)/, $(vobjs32-y))
-
-$(obj)/vdso.o: $(obj)/vdso.so
-
-targets += vdso.lds $(vobjs-y)
-targets += vdso32/vdso32.lds $(vobjs32-y)
-
-targets += $(foreach x, 64 x32 32, vdso-image-$(x).c vdso$(x).so vdso$(x).so.dbg)
-
-CPPFLAGS_vdso.lds += -P -C
-
-VDSO_LDFLAGS_vdso.lds = -m elf_x86_64 -soname linux-vdso.so.1 \
- -z max-page-size=4096
-
-$(obj)/vdso64.so.dbg: $(obj)/vdso.lds $(vobjs) FORCE
- $(call if_changed,vdso_and_check)
-
-HOST_EXTRACFLAGS += -I$(srctree)/tools/include -I$(srctree)/include/uapi -I$(srctree)/arch/$(SUBARCH)/include/uapi
-hostprogs += vdso2c
-
-quiet_cmd_vdso2c = VDSO2C $@
- cmd_vdso2c = $(obj)/vdso2c $< $(<:%.dbg=%) $@
-
-$(obj)/vdso%-image.c: $(obj)/vdso%.so.dbg $(obj)/vdso%.so $(obj)/vdso2c FORCE
- $(call if_changed,vdso2c)
-
-#
-# Don't omit frame pointers for ease of userspace debugging, but do
-# optimize sibling calls.
-#
-CFL := $(PROFILING) -mcmodel=small -fPIC -O2 -fasynchronous-unwind-tables -m64 \
- $(filter -g%,$(KBUILD_CFLAGS)) -fno-stack-protector \
- -fno-omit-frame-pointer -foptimize-sibling-calls \
- -DDISABLE_BRANCH_PROFILING -DBUILD_VDSO
-
-ifdef CONFIG_MITIGATION_RETPOLINE
-ifneq ($(RETPOLINE_VDSO_CFLAGS),)
- CFL += $(RETPOLINE_VDSO_CFLAGS)
-endif
-endif
-
-$(vobjs): KBUILD_CFLAGS := $(filter-out $(PADDING_CFLAGS) $(CC_FLAGS_LTO) $(CC_FLAGS_CFI) $(RANDSTRUCT_CFLAGS) $(KSTACK_ERASE_CFLAGS) $(GCC_PLUGINS_CFLAGS) $(RETPOLINE_CFLAGS),$(KBUILD_CFLAGS)) $(CFL)
-$(vobjs): KBUILD_AFLAGS += -DBUILD_VDSO
-
-#
-# vDSO code runs in userspace and -pg doesn't help with profiling anyway.
-#
-CFLAGS_REMOVE_vclock_gettime.o = -pg
-CFLAGS_REMOVE_vdso32/vclock_gettime.o = -pg
-CFLAGS_REMOVE_vgetcpu.o = -pg
-CFLAGS_REMOVE_vdso32/vgetcpu.o = -pg
-CFLAGS_REMOVE_vsgx.o = -pg
-CFLAGS_REMOVE_vgetrandom.o = -pg
-
-#
-# X32 processes use x32 vDSO to access 64bit kernel data.
-#
-# Build x32 vDSO image:
-# 1. Compile x32 vDSO as 64bit.
-# 2. Convert object files to x32.
-# 3. Build x32 VDSO image with x32 objects, which contains 64bit codes
-# so that it can reach 64bit address space with 64bit pointers.
-#
-
-CPPFLAGS_vdsox32.lds = $(CPPFLAGS_vdso.lds)
-VDSO_LDFLAGS_vdsox32.lds = -m elf32_x86_64 -soname linux-vdso.so.1 \
- -z max-page-size=4096
-
-# x32-rebranded versions
-vobjx32s-y := $(vobjs-y:.o=-x32.o)
-
-# same thing, but in the output directory
-vobjx32s := $(addprefix $(obj)/, $(vobjx32s-y))
-
-# Convert 64bit object file to x32 for x32 vDSO.
-quiet_cmd_x32 = X32 $@
- cmd_x32 = $(OBJCOPY) -O elf32-x86-64 $< $@
-
-$(obj)/%-x32.o: $(obj)/%.o FORCE
- $(call if_changed,x32)
-
-targets += vdsox32.lds $(vobjx32s-y)
-
-$(obj)/%.so: OBJCOPYFLAGS := -S --remove-section __ex_table
-$(obj)/%.so: $(obj)/%.so.dbg FORCE
- $(call if_changed,objcopy)
-
-$(obj)/vdsox32.so.dbg: $(obj)/vdsox32.lds $(vobjx32s) FORCE
- $(call if_changed,vdso_and_check)
-
-CPPFLAGS_vdso32/vdso32.lds = $(CPPFLAGS_vdso.lds)
-VDSO_LDFLAGS_vdso32.lds = -m elf_i386 -soname linux-gate.so.1
-
-KBUILD_AFLAGS_32 := $(filter-out -m64,$(KBUILD_AFLAGS)) -DBUILD_VDSO
-$(obj)/vdso32.so.dbg: KBUILD_AFLAGS = $(KBUILD_AFLAGS_32)
-$(obj)/vdso32.so.dbg: asflags-$(CONFIG_X86_64) += -m32
-
-KBUILD_CFLAGS_32 := $(filter-out -m64,$(KBUILD_CFLAGS))
-KBUILD_CFLAGS_32 := $(filter-out -mcmodel=kernel,$(KBUILD_CFLAGS_32))
-KBUILD_CFLAGS_32 := $(filter-out -fno-pic,$(KBUILD_CFLAGS_32))
-KBUILD_CFLAGS_32 := $(filter-out -mfentry,$(KBUILD_CFLAGS_32))
-KBUILD_CFLAGS_32 := $(filter-out $(RANDSTRUCT_CFLAGS),$(KBUILD_CFLAGS_32))
-KBUILD_CFLAGS_32 := $(filter-out $(KSTACK_ERASE_CFLAGS),$(KBUILD_CFLAGS_32))
-KBUILD_CFLAGS_32 := $(filter-out $(GCC_PLUGINS_CFLAGS),$(KBUILD_CFLAGS_32))
-KBUILD_CFLAGS_32 := $(filter-out $(RETPOLINE_CFLAGS),$(KBUILD_CFLAGS_32))
-KBUILD_CFLAGS_32 := $(filter-out $(CC_FLAGS_LTO),$(KBUILD_CFLAGS_32))
-KBUILD_CFLAGS_32 := $(filter-out $(CC_FLAGS_CFI),$(KBUILD_CFLAGS_32))
-KBUILD_CFLAGS_32 := $(filter-out $(PADDING_CFLAGS),$(KBUILD_CFLAGS_32))
-KBUILD_CFLAGS_32 += -m32 -msoft-float -mregparm=0 -fpic
-KBUILD_CFLAGS_32 += -fno-stack-protector
-KBUILD_CFLAGS_32 += $(call cc-option, -foptimize-sibling-calls)
-KBUILD_CFLAGS_32 += -fno-omit-frame-pointer
-KBUILD_CFLAGS_32 += -DDISABLE_BRANCH_PROFILING
-KBUILD_CFLAGS_32 += -DBUILD_VDSO
-
-ifdef CONFIG_MITIGATION_RETPOLINE
-ifneq ($(RETPOLINE_VDSO_CFLAGS),)
- KBUILD_CFLAGS_32 += $(RETPOLINE_VDSO_CFLAGS)
-endif
-endif
-
-$(obj)/vdso32.so.dbg: KBUILD_CFLAGS = $(KBUILD_CFLAGS_32)
-
-$(obj)/vdso32.so.dbg: $(obj)/vdso32/vdso32.lds $(vobjs32) FORCE
- $(call if_changed,vdso_and_check)
-
-#
-# The DSO images are built using a special linker script.
-#
-quiet_cmd_vdso = VDSO $@
- cmd_vdso = $(LD) -o $@ \
- $(VDSO_LDFLAGS) $(VDSO_LDFLAGS_$(filter %.lds,$(^F))) \
- -T $(filter %.lds,$^) $(filter %.o,$^)
-
-VDSO_LDFLAGS = -shared --hash-style=both --build-id=sha1 --no-undefined \
- $(call ld-option, --eh-frame-hdr) -Bsymbolic -z noexecstack
-
-quiet_cmd_vdso_and_check = VDSO $@
- cmd_vdso_and_check = $(cmd_vdso); $(cmd_vdso_check)
+# vDSO directories
+obj-$(CONFIG_X86_64) += vdso64/
+obj-$(CONFIG_COMPAT_32) += vdso32/
diff --git a/arch/x86/entry/vdso/common/Makefile.include b/arch/x86/entry/vdso/common/Makefile.include
new file mode 100644
index 000000000000..e04cff3400f3
--- /dev/null
+++ b/arch/x86/entry/vdso/common/Makefile.include
@@ -0,0 +1,83 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Building vDSO images for x86.
+#
+
+# Include the generic Makefile to check the built vDSO:
+include $(srctree)/lib/vdso/Makefile.include
+
+obj-y += $(foreach x,$(vdsos-y),vdso$(x)-image.o)
+
+targets += $(foreach x,$(vdsos-y),vdso$(x)-image.c vdso$(x).so vdso$(x).so.dbg vdso$(x).lds)
+targets += $(vobjs-y)
+
+# vobjs-y with $(obj)/ prepended
+vobjs := $(addprefix $(obj)/,$(vobjs-y))
+
+# Options for vdso*.lds
+CPPFLAGS_VDSO_LDS := -P -C -I$(src)/..
+$(obj)/%.lds : KBUILD_CPPFLAGS += $(CPPFLAGS_VDSO_LDS)
+
+#
+# Options from KBUILD_[AC]FLAGS that should *NOT* be kept
+#
+flags-remove-y += \
+ -D__KERNEL__ -mcmodel=kernel -mregparm=3 \
+ -fno-pic -fno-PIC -fno-pie fno-PIE \
+ -mfentry -pg \
+ $(RANDSTRUCT_CFLAGS) $(GCC_PLUGIN_CFLAGS) $(KSTACK_ERASE_CFLAGS) \
+ $(RETPOLINE_CFLAGS) $(CC_FLAGS_LTO) $(CC_FLAGS_CFI) \
+ $(PADDING_CFLAGS)
+
+#
+# Don't omit frame pointers for ease of userspace debugging, but do
+# optimize sibling calls.
+#
+flags-y += -D__DISABLE_EXPORTS
+flags-y += -DDISABLE_BRANCH_PROFILING
+flags-y += -DBUILD_VDSO
+flags-y += -I$(src)/.. -I$(srctree)
+flags-y += -O2 -fpic
+flags-y += -fno-stack-protector
+flags-y += -fno-omit-frame-pointer
+flags-y += -foptimize-sibling-calls
+flags-y += -fasynchronous-unwind-tables
+flags-y += $(call cc-option, -fcf-protection=branch)
+flags-$(CONFIG_MITIGATION_RETPOLINE) += $(RETPOLINE_VDSO_CFLAGS)
+
+# These need to be conditional on $(vobjs) as they do not apply to
+# the output vdso*-image.o files which are standard kernel objects.
+$(vobjs) : KBUILD_AFLAGS := \
+ $(filter-out $(flags-remove-y),$(KBUILD_AFLAGS)) $(flags-y)
+$(vobjs) : KBUILD_CFLAGS := \
+ $(filter-out $(flags-remove-y),$(KBUILD_CFLAGS)) $(flags-y)
+
+#
+# The VDSO images are built using a special linker script.
+#
+VDSO_LDFLAGS := -shared --hash-style=both --build-id=sha1 --no-undefined \
+ $(call ld-option, --eh-frame-hdr) -Bsymbolic -z noexecstack
+
+quiet_cmd_vdso = VDSO $@
+ cmd_vdso = $(LD) -o $@ \
+ $(VDSO_LDFLAGS) $(VDSO_LDFLAGS_$*) \
+ -T $(filter %.lds,$^) $(filter %.o,$^)
+quiet_cmd_vdso_and_check = VDSO $@
+ cmd_vdso_and_check = $(cmd_vdso); $(cmd_vdso_check)
+
+$(obj)/vdso%.so.dbg: $(obj)/vdso%.lds FORCE
+ $(call if_changed,vdso_and_check)
+
+$(obj)/%.so: OBJCOPYFLAGS := -S --remove-section __ex_table
+$(obj)/%.so: $(obj)/%.so.dbg FORCE
+ $(call if_changed,objcopy)
+
+VDSO2C = $(objtree)/arch/x86/tools/vdso2c
+
+quiet_cmd_vdso2c = VDSO2C $@
+ cmd_vdso2c = $(VDSO2C) $< $(<:%.dbg=%) $@
+
+$(obj)/%-image.c: $(obj)/%.so.dbg $(obj)/%.so $(VDSO2C) FORCE
+ $(call if_changed,vdso2c)
+
+$(obj)/%-image.o: $(obj)/%-image.c
diff --git a/arch/x86/entry/vdso/vdso-note.S b/arch/x86/entry/vdso/common/note.S
similarity index 62%
rename from arch/x86/entry/vdso/vdso-note.S
rename to arch/x86/entry/vdso/common/note.S
index 79423170118f..2cbd39939dc6 100644
--- a/arch/x86/entry/vdso/vdso-note.S
+++ b/arch/x86/entry/vdso/common/note.S
@@ -1,13 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0 */
/*
* This supplies .note.* sections to go into the PT_NOTE inside the vDSO text.
* Here we can supply some information useful to userland.
*/
#include <linux/build-salt.h>
-#include <linux/uts.h>
#include <linux/version.h>
#include <linux/elfnote.h>
+/* Ideally this would use UTS_NAME, but using a quoted string here
+ doesn't work. Remember to change this when changing the
+ kernel's name. */
ELFNOTE_START(Linux, 0, "a")
.long LINUX_VERSION_CODE
ELFNOTE_END
diff --git a/arch/x86/entry/vdso/vclock_gettime.c b/arch/x86/entry/vdso/common/vclock_gettime.c
similarity index 100%
rename from arch/x86/entry/vdso/vclock_gettime.c
rename to arch/x86/entry/vdso/common/vclock_gettime.c
diff --git a/arch/x86/entry/vdso/vdso-layout.lds.S b/arch/x86/entry/vdso/common/vdso-layout.lds.S
similarity index 100%
rename from arch/x86/entry/vdso/vdso-layout.lds.S
rename to arch/x86/entry/vdso/common/vdso-layout.lds.S
diff --git a/arch/x86/entry/vdso/vgetcpu.c b/arch/x86/entry/vdso/common/vgetcpu.c
similarity index 100%
rename from arch/x86/entry/vdso/vgetcpu.c
rename to arch/x86/entry/vdso/common/vgetcpu.c
diff --git a/arch/x86/entry/vdso/vdso32/Makefile b/arch/x86/entry/vdso/vdso32/Makefile
new file mode 100644
index 000000000000..add6afb484ba
--- /dev/null
+++ b/arch/x86/entry/vdso/vdso32/Makefile
@@ -0,0 +1,24 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# 32-bit vDSO images for x86.
+#
+
+# The vDSOs built in this directory
+vdsos-y := 32
+
+# Files to link into the vDSO:
+vobjs-y := note.o vclock_gettime.o vgetcpu.o
+vobjs-y += system_call.o sigreturn.o
+
+# Compilation flags
+flags-y := -DBUILD_VDSO32 -m32 -mregparm=0
+flags-$(CONFIG_X86_64) += -include $(src)/fake_32bit_build.h
+flags-remove-y := -m64
+
+# The location of this include matters!
+include $(src)/../common/Makefile.include
+
+# Linker options for the vdso
+VDSO_LDFLAGS_32 := -m elf_i386 -soname linux-gate.so.1
+
+$(obj)/vdso32.so.dbg: $(vobjs)
diff --git a/arch/x86/entry/vdso/vdso32/note.S b/arch/x86/entry/vdso/vdso32/note.S
index 2cbd39939dc6..62d8aa51ce99 100644
--- a/arch/x86/entry/vdso/vdso32/note.S
+++ b/arch/x86/entry/vdso/vdso32/note.S
@@ -1,18 +1 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-/*
- * This supplies .note.* sections to go into the PT_NOTE inside the vDSO text.
- * Here we can supply some information useful to userland.
- */
-
-#include <linux/build-salt.h>
-#include <linux/version.h>
-#include <linux/elfnote.h>
-
-/* Ideally this would use UTS_NAME, but using a quoted string here
- doesn't work. Remember to change this when changing the
- kernel's name. */
-ELFNOTE_START(Linux, 0, "a")
- .long LINUX_VERSION_CODE
-ELFNOTE_END
-
-BUILD_SALT
+#include "common/note.S"
diff --git a/arch/x86/entry/vdso/vdso32/system_call.S b/arch/x86/entry/vdso/vdso32/system_call.S
index d33c6513fd2c..2a15634bbe75 100644
--- a/arch/x86/entry/vdso/vdso32/system_call.S
+++ b/arch/x86/entry/vdso/vdso32/system_call.S
@@ -52,7 +52,7 @@ __kernel_vsyscall:
#define SYSENTER_SEQUENCE "movl %esp, %ebp; sysenter"
#define SYSCALL_SEQUENCE "movl %ecx, %ebp; syscall"
-#ifdef CONFIG_X86_64
+#ifdef BUILD_VDSO32_64
/* If SYSENTER (Intel) or SYSCALL32 (AMD) is available, use it. */
ALTERNATIVE_2 "", SYSENTER_SEQUENCE, X86_FEATURE_SYSENTER32, \
SYSCALL_SEQUENCE, X86_FEATURE_SYSCALL32
diff --git a/arch/x86/entry/vdso/vdso32/vclock_gettime.c b/arch/x86/entry/vdso/vdso32/vclock_gettime.c
index 86981decfea8..1481f0021b9f 100644
--- a/arch/x86/entry/vdso/vdso32/vclock_gettime.c
+++ b/arch/x86/entry/vdso/vdso32/vclock_gettime.c
@@ -1,4 +1 @@
-// SPDX-License-Identifier: GPL-2.0
-#define BUILD_VDSO32
-#include "fake_32bit_build.h"
-#include "../vclock_gettime.c"
+#include "common/vclock_gettime.c"
diff --git a/arch/x86/entry/vdso/vdso32/vdso32.lds.S b/arch/x86/entry/vdso/vdso32/vdso32.lds.S
index 8a3be07006bb..8a853543fc0d 100644
--- a/arch/x86/entry/vdso/vdso32/vdso32.lds.S
+++ b/arch/x86/entry/vdso/vdso32/vdso32.lds.S
@@ -11,7 +11,7 @@
#define BUILD_VDSO32
-#include "../vdso-layout.lds.S"
+#include "common/vdso-layout.lds.S"
/* The ELF entry point can be used to set the AT_SYSINFO value. */
ENTRY(__kernel_vsyscall);
diff --git a/arch/x86/entry/vdso/vdso32/vgetcpu.c b/arch/x86/entry/vdso/vdso32/vgetcpu.c
index 3a9791f5e998..00cc8325a020 100644
--- a/arch/x86/entry/vdso/vdso32/vgetcpu.c
+++ b/arch/x86/entry/vdso/vdso32/vgetcpu.c
@@ -1,3 +1 @@
-// SPDX-License-Identifier: GPL-2.0
-#include "fake_32bit_build.h"
-#include "../vgetcpu.c"
+#include "common/vgetcpu.c"
diff --git a/arch/x86/entry/vdso/vdso64/Makefile b/arch/x86/entry/vdso/vdso64/Makefile
new file mode 100644
index 000000000000..245996f34eae
--- /dev/null
+++ b/arch/x86/entry/vdso/vdso64/Makefile
@@ -0,0 +1,45 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# 64-bit vDSO images for x86.
+#
+
+# The vDSOs built in this directory
+vdsos-y := 64
+vdsos-$(CONFIG_X86_X32_ABI) += x32
+
+# Files to link into the vDSO:
+vobjs-y := note.o vclock_gettime.o vgetcpu.o
+vobjs-y += vgetrandom.o vgetrandom-chacha.o
+vobjs-$(CONFIG_X86_SGX) += vsgx.o
+
+# Compilation flags
+flags-y := -DBUILD_VDSO64 -m64 -mcmodel=small
+
+# The location of this include matters!
+include $(src)/../common/Makefile.include
+
+#
+# X32 processes use x32 vDSO to access 64bit kernel data.
+#
+# Build x32 vDSO image:
+# 1. Compile x32 vDSO as 64bit.
+# 2. Convert object files to x32.
+# 3. Build x32 VDSO image with x32 objects, which contains 64bit codes
+# so that it can reach 64bit address space with 64bit pointers.
+#
+
+# Convert 64bit object file to x32 for x32 vDSO.
+quiet_cmd_x32 = X32 $@
+ cmd_x32 = $(OBJCOPY) -O elf32-x86-64 $< $@
+
+$(obj)/%-x32.o: $(obj)/%.o FORCE
+ $(call if_changed,x32)
+
+vobjsx32 = $(patsubst %.o,%-x32.o,$(vobjs))
+
+# Linker options for the vdso
+VDSO_LDFLAGS_64 := -m elf_x86_64 -soname linux-vdso.so.1 -z max-page-size=4096
+VDSO_LDFLAGS_x32 := $(subst elf_x86_64,elf32_x86_64,$(VDSO_LDFLAGS_64))
+
+$(obj)/vdso64.so.dbg: $(vobjs)
+$(obj)/vdsox32.so.dbg: $(vobjsx32)
diff --git a/arch/x86/entry/vdso/vdso64/note.S b/arch/x86/entry/vdso/vdso64/note.S
new file mode 100644
index 000000000000..62d8aa51ce99
--- /dev/null
+++ b/arch/x86/entry/vdso/vdso64/note.S
@@ -0,0 +1 @@
+#include "common/note.S"
diff --git a/arch/x86/entry/vdso/vdso64/vclock_gettime.c b/arch/x86/entry/vdso/vdso64/vclock_gettime.c
new file mode 100644
index 000000000000..1481f0021b9f
--- /dev/null
+++ b/arch/x86/entry/vdso/vdso64/vclock_gettime.c
@@ -0,0 +1 @@
+#include "common/vclock_gettime.c"
diff --git a/arch/x86/entry/vdso/vdso.lds.S b/arch/x86/entry/vdso/vdso64/vdso64.lds.S
similarity index 94%
rename from arch/x86/entry/vdso/vdso.lds.S
rename to arch/x86/entry/vdso/vdso64/vdso64.lds.S
index 0bab5f4af6d1..5ce3f2b6373a 100644
--- a/arch/x86/entry/vdso/vdso.lds.S
+++ b/arch/x86/entry/vdso/vdso64/vdso64.lds.S
@@ -9,7 +9,7 @@
#define BUILD_VDSO64
-#include "vdso-layout.lds.S"
+#include "common/vdso-layout.lds.S"
/*
* This controls what userland symbols we export from the vDSO.
diff --git a/arch/x86/entry/vdso/vdsox32.lds.S b/arch/x86/entry/vdso/vdso64/vdsox32.lds.S
similarity index 92%
rename from arch/x86/entry/vdso/vdsox32.lds.S
rename to arch/x86/entry/vdso/vdso64/vdsox32.lds.S
index 16a8050a4fb6..3dbd20c8dacc 100644
--- a/arch/x86/entry/vdso/vdsox32.lds.S
+++ b/arch/x86/entry/vdso/vdso64/vdsox32.lds.S
@@ -9,7 +9,7 @@
#define BUILD_VDSOX32
-#include "vdso-layout.lds.S"
+#include "common/vdso-layout.lds.S"
/*
* This controls what userland symbols we export from the vDSO.
diff --git a/arch/x86/entry/vdso/vdso64/vgetcpu.c b/arch/x86/entry/vdso/vdso64/vgetcpu.c
new file mode 100644
index 000000000000..00cc8325a020
--- /dev/null
+++ b/arch/x86/entry/vdso/vdso64/vgetcpu.c
@@ -0,0 +1 @@
+#include "common/vgetcpu.c"
diff --git a/arch/x86/entry/vdso/vgetrandom-chacha.S b/arch/x86/entry/vdso/vdso64/vgetrandom-chacha.S
similarity index 100%
rename from arch/x86/entry/vdso/vgetrandom-chacha.S
rename to arch/x86/entry/vdso/vdso64/vgetrandom-chacha.S
diff --git a/arch/x86/entry/vdso/vgetrandom.c b/arch/x86/entry/vdso/vdso64/vgetrandom.c
similarity index 91%
rename from arch/x86/entry/vdso/vgetrandom.c
rename to arch/x86/entry/vdso/vdso64/vgetrandom.c
index 430862b8977c..6a95d36b12d9 100644
--- a/arch/x86/entry/vdso/vgetrandom.c
+++ b/arch/x86/entry/vdso/vdso64/vgetrandom.c
@@ -4,7 +4,7 @@
*/
#include <linux/types.h>
-#include "../../../../lib/vdso/getrandom.c"
+#include "lib/vdso/getrandom.c"
ssize_t __vdso_getrandom(void *buffer, size_t len, unsigned int flags, void *opaque_state, size_t opaque_len)
{
diff --git a/arch/x86/entry/vdso/vsgx.S b/arch/x86/entry/vdso/vdso64/vsgx.S
similarity index 100%
rename from arch/x86/entry/vdso/vsgx.S
rename to arch/x86/entry/vdso/vdso64/vsgx.S
diff --git a/arch/x86/tools/Makefile b/arch/x86/tools/Makefile
index 7278e2545c35..39a183fffd04 100644
--- a/arch/x86/tools/Makefile
+++ b/arch/x86/tools/Makefile
@@ -38,9 +38,14 @@ $(obj)/insn_decoder_test.o: $(srctree)/tools/arch/x86/lib/insn.c $(srctree)/tool
$(obj)/insn_sanity.o: $(srctree)/tools/arch/x86/lib/insn.c $(srctree)/tools/arch/x86/lib/inat.c $(srctree)/tools/arch/x86/include/asm/inat_types.h $(srctree)/tools/arch/x86/include/asm/inat.h $(srctree)/tools/arch/x86/include/asm/insn.h $(objtree)/arch/x86/lib/inat-tables.c
-HOST_EXTRACFLAGS += -I$(srctree)/tools/include
-hostprogs += relocs
-relocs-objs := relocs_32.o relocs_64.o relocs_common.o
-PHONY += relocs
-relocs: $(obj)/relocs
+HOST_EXTRACFLAGS += -I$(srctree)/tools/include -I$(srctree)/include/uapi \
+ -I$(srctree)/arch/$(SUBARCH)/include/uapi
+
+hostprogs += relocs vdso2c
+relocs-objs := relocs_32.o relocs_64.o relocs_common.o
+
+always-y := $(hostprogs)
+
+PHONY += $(hostprogs)
+$(hostprogs): %: $(obj)/%
@:
diff --git a/arch/x86/entry/vdso/vdso2c.c b/arch/x86/tools/vdso2c.c
similarity index 100%
rename from arch/x86/entry/vdso/vdso2c.c
rename to arch/x86/tools/vdso2c.c
diff --git a/arch/x86/entry/vdso/vdso2c.h b/arch/x86/tools/vdso2c.h
similarity index 100%
rename from arch/x86/entry/vdso/vdso2c.h
rename to arch/x86/tools/vdso2c.h
--
2.51.1
^ permalink raw reply [flat|nested] 10+ messages in thread* [PATCH 3/6] x86/entry/vdso32: remove int80_landing_pad
2025-10-26 22:12 [PATCH 0/6] x86/entry/vdso: cleanups for vdso build and 32-bit vdso H. Peter Anvin
2025-10-26 22:12 ` [PATCH 1/6] x86/entry/vdso: rename vdso_image_* to vdso*_image H. Peter Anvin
2025-10-26 22:12 ` [PATCH 2/6] x86/entry/vdso: refactor the vdso build H. Peter Anvin
@ 2025-10-26 22:12 ` H. Peter Anvin
2025-10-28 6:50 ` kernel test robot
2025-10-29 6:54 ` Brian Gerst
2025-10-26 22:12 ` [PATCH 4/6] x86/entry/vdso32: remove SYSCALL_ENTER_KERNEL macro in sigreturn.S H. Peter Anvin
` (2 subsequent siblings)
5 siblings, 2 replies; 10+ messages in thread
From: H. Peter Anvin @ 2025-10-26 22:12 UTC (permalink / raw)
To: H. Peter Anvin, Jason A. Donenfeld, Peter Zijlstra (Intel),
Theodore Ts'o, Thomas Weißschuh, Xin Li, Andrew Cooper,
Andy Lutomirski, Ard Biesheuvel, Borislav Petkov, Brian Gerst,
Dave Hansen, Ingo Molnar, James Morse, Jarkko Sakkinen,
Josh Poimboeuf, Kees Cook, Nam Cao, Oleg Nesterov, Perry Yuan,
Thomas Gleixner, Thomas Huth, Uros Bizjak, linux-kernel,
linux-mm, linux-sgx, x86
There is no fundamental reason for the int80_landing_pad symbol. If ip
falls within the vdso, and the vdso is moved, we should change the ip
accordingly, regardless of mode or location within the vdso. This
*currently* can only happen on 32 bits, but there isn't any reason not
to do so generically.
Note that if this is ever possible from a vdso-internal call, then the
user space stack will also needed to be adjusted (as well as the
shadow stack, if enabled.) Fortunately this is not currently the case.
At the moment, we don't even consider other threads when moving the
vdso. The assumption is that it is only used by process freeze/thaw
for migration, where this is not an issue.
Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
---
arch/x86/entry/vdso/vdso32/system_call.S | 1 -
arch/x86/entry/vdso/vma.c | 16 ++++++----------
arch/x86/tools/vdso2c.c | 1 -
3 files changed, 6 insertions(+), 12 deletions(-)
diff --git a/arch/x86/entry/vdso/vdso32/system_call.S b/arch/x86/entry/vdso/vdso32/system_call.S
index 2a15634bbe75..d14eca4403c5 100644
--- a/arch/x86/entry/vdso/vdso32/system_call.S
+++ b/arch/x86/entry/vdso/vdso32/system_call.S
@@ -62,7 +62,6 @@ __kernel_vsyscall:
/* Enter using int $0x80 */
int $0x80
-SYM_INNER_LABEL(int80_landing_pad, SYM_L_GLOBAL)
/*
* Restore EDX and ECX in case they were clobbered. EBP is not
diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c
index 8f98c2d7c7a9..e7fd7517370f 100644
--- a/arch/x86/entry/vdso/vma.c
+++ b/arch/x86/entry/vdso/vma.c
@@ -65,16 +65,12 @@ static vm_fault_t vdso_fault(const struct vm_special_mapping *sm,
static void vdso_fix_landing(const struct vdso_image *image,
struct vm_area_struct *new_vma)
{
- if (in_ia32_syscall() && image == &vdso32_image) {
- struct pt_regs *regs = current_pt_regs();
- unsigned long vdso_land = image->sym_int80_landing_pad;
- unsigned long old_land_addr = vdso_land +
- (unsigned long)current->mm->context.vdso;
-
- /* Fixing userspace landing - look at do_fast_syscall_32 */
- if (regs->ip == old_land_addr)
- regs->ip = new_vma->vm_start + vdso_land;
- }
+ struct pt_regs *regs = current_pt_regs();
+ unsigned long ipoffset = regs->ip -
+ (unsigned long)current->mm->context.vdso;
+
+ if (ipoffset < image->size)
+ regs->ip = new_vma->vm_start + ipoffset;
}
static int vdso_mremap(const struct vm_special_mapping *sm,
diff --git a/arch/x86/tools/vdso2c.c b/arch/x86/tools/vdso2c.c
index f84e8f8fa5fe..c81bb32b1e6c 100644
--- a/arch/x86/tools/vdso2c.c
+++ b/arch/x86/tools/vdso2c.c
@@ -79,7 +79,6 @@ struct vdso_sym required_syms[] = {
{"__kernel_vsyscall", true},
{"__kernel_sigreturn", true},
{"__kernel_rt_sigreturn", true},
- {"int80_landing_pad", true},
{"vdso32_rt_sigreturn_landing_pad", true},
{"vdso32_sigreturn_landing_pad", true},
};
--
2.51.1
^ permalink raw reply [flat|nested] 10+ messages in thread* Re: [PATCH 3/6] x86/entry/vdso32: remove int80_landing_pad
2025-10-26 22:12 ` [PATCH 3/6] x86/entry/vdso32: remove int80_landing_pad H. Peter Anvin
@ 2025-10-28 6:50 ` kernel test robot
2025-10-29 6:54 ` Brian Gerst
1 sibling, 0 replies; 10+ messages in thread
From: kernel test robot @ 2025-10-28 6:50 UTC (permalink / raw)
To: H. Peter Anvin
Cc: oe-lkp, lkp, linux-kernel, H. Peter Anvin, Jason A. Donenfeld,
Peter Zijlstra (Intel),
Theodore Ts'o, Thomas Weißschuh, Xin Li, Andrew Cooper,
Andy Lutomirski, Ard Biesheuvel, Borislav Petkov, Brian Gerst,
Dave Hansen, Ingo Molnar, James Morse, Jarkko Sakkinen,
Josh Poimboeuf, Kees Cook, Nam Cao, Oleg Nesterov, Perry Yuan,
Thomas Gleixner, Thomas Huth, Uros Bizjak, linux-mm, linux-sgx,
x86, oliver.sang
Hello,
kernel test robot noticed "segfault_at_ip_sp_error" on:
commit: 19009b8428dfbeea0ecf043c063cf3336282eb2b ("[PATCH 3/6] x86/entry/vdso32: remove int80_landing_pad")
url: https://github.com/intel-lab-lkp/linux/commits/H-Peter-Anvin/x86-entry-vdso-rename-vdso_image_-to-vdso-_image/20251027-061505
base: https://git.kernel.org/cgit/linux/kernel/git/tip/tip.git ad74016b919cbad78d203fa1c459ae18e73ce586
patch link: https://lore.kernel.org/all/20251026221208.1938173-4-hpa@zytor.com/
patch subject: [PATCH 3/6] x86/entry/vdso32: remove int80_landing_pad
in testcase: boot
config: i386-randconfig-002-20251027
compiler: gcc-14
test machine: qemu-system-i386 -enable-kvm -cpu SandyBridge -smp 2 -m 4G
(please refer to attached dmesg/kmsg for entire log/backtrace)
+-----------------------------------------------------------+------------+------------+
| | 28c61beafa | 19009b8428 |
+-----------------------------------------------------------+------------+------------+
| boot_successes | 6 | 0 |
| boot_failures | 0 | 6 |
| segfault_at_ip_sp_error | 0 | 6 |
| Kernel_panic-not_syncing:Attempted_to_kill_init!exitcode= | 0 | 6 |
+-----------------------------------------------------------+------------+------------+
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <oliver.sang@intel.com>
| Closes: https://lore.kernel.org/oe-lkp/202510281407.1fbe8f8b-lkp@intel.com
[ 12.230099][ T1] selinux=0
[ 12.230498][ T1] prompt_ramdisk=0
[ 12.230942][ T1] vga=normal
[ 12.231367][ T1] audit=0
[ 12.231748][ T1] ia32_emulation=on
[ 12.246128][ T1] init[1]: segfault at 1 ip 37fad006 sp 3fb8051f error 6 likely on CPU 0 (core 0, socket 0)
[ 12.247169][ T1] Code: Unable to access opcode bytes at 0x37facfdc.
Code starting with the faulting instruction
===========================================
[ 12.247782][ T1] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b
[ 12.248459][ T1] CPU: 0 UID: 0 PID: 1 Comm: init Not tainted 6.18.0-rc1-00004-g19009b8428df #1 PREEMPT(lazy) 515832f7b4d7c2dccd9418532bf066894e2da3fd
[ 12.249461][ T1] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[ 12.250250][ T1] Call Trace:
[ 12.250556][ T1] ? dump_stack_lvl (kbuild/src/consumer/lib/dump_stack.c:122)
[ 12.250943][ T1] ? dump_stack (kbuild/src/consumer/lib/dump_stack.c:130)
[ 12.251324][ T1] ? vpanic (kbuild/src/consumer/kernel/panic.c:404 kbuild/src/consumer/kernel/panic.c:511)
[ 12.251677][ T1] ? panic (kbuild/src/consumer/kernel/panic.c:365)
[ 12.252001][ T1] ? do_exit.cold (kbuild/src/consumer/kernel/exit.c:1027)
The kernel config and materials to reproduce are available at:
https://download.01.org/0day-ci/archive/20251028/202510281407.1fbe8f8b-lkp@intel.com
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
^ permalink raw reply [flat|nested] 10+ messages in thread* Re: [PATCH 3/6] x86/entry/vdso32: remove int80_landing_pad
2025-10-26 22:12 ` [PATCH 3/6] x86/entry/vdso32: remove int80_landing_pad H. Peter Anvin
2025-10-28 6:50 ` kernel test robot
@ 2025-10-29 6:54 ` Brian Gerst
2025-10-29 14:36 ` H. Peter Anvin
1 sibling, 1 reply; 10+ messages in thread
From: Brian Gerst @ 2025-10-29 6:54 UTC (permalink / raw)
To: H. Peter Anvin
Cc: Jason A. Donenfeld, Peter Zijlstra (Intel),
Theodore Ts'o, Thomas Weißschuh, Xin Li, Andrew Cooper,
Andy Lutomirski, Ard Biesheuvel, Borislav Petkov, Dave Hansen,
Ingo Molnar, James Morse, Jarkko Sakkinen, Josh Poimboeuf,
Kees Cook, Nam Cao, Oleg Nesterov, Perry Yuan, Thomas Gleixner,
Thomas Huth, Uros Bizjak, linux-kernel, linux-mm, linux-sgx, x86
On Sun, Oct 26, 2025 at 6:12 PM H. Peter Anvin <hpa@zytor.com> wrote:
>
> There is no fundamental reason for the int80_landing_pad symbol. If ip
> falls within the vdso, and the vdso is moved, we should change the ip
> accordingly, regardless of mode or location within the vdso. This
> *currently* can only happen on 32 bits, but there isn't any reason not
> to do so generically.
>
> Note that if this is ever possible from a vdso-internal call, then the
> user space stack will also needed to be adjusted (as well as the
> shadow stack, if enabled.) Fortunately this is not currently the case.
>
> At the moment, we don't even consider other threads when moving the
> vdso. The assumption is that it is only used by process freeze/thaw
> for migration, where this is not an issue.
>
> Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
> ---
> arch/x86/entry/vdso/vdso32/system_call.S | 1 -
> arch/x86/entry/vdso/vma.c | 16 ++++++----------
> arch/x86/tools/vdso2c.c | 1 -
> 3 files changed, 6 insertions(+), 12 deletions(-)
>
> diff --git a/arch/x86/entry/vdso/vdso32/system_call.S b/arch/x86/entry/vdso/vdso32/system_call.S
> index 2a15634bbe75..d14eca4403c5 100644
> --- a/arch/x86/entry/vdso/vdso32/system_call.S
> +++ b/arch/x86/entry/vdso/vdso32/system_call.S
> @@ -62,7 +62,6 @@ __kernel_vsyscall:
>
> /* Enter using int $0x80 */
> int $0x80
> -SYM_INNER_LABEL(int80_landing_pad, SYM_L_GLOBAL)
This is still needed by do_fast_syscall_32().
Brian Gerst
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH 3/6] x86/entry/vdso32: remove int80_landing_pad
2025-10-29 6:54 ` Brian Gerst
@ 2025-10-29 14:36 ` H. Peter Anvin
0 siblings, 0 replies; 10+ messages in thread
From: H. Peter Anvin @ 2025-10-29 14:36 UTC (permalink / raw)
To: Brian Gerst
Cc: Jason A. Donenfeld, Peter Zijlstra (Intel),
Theodore Ts'o, Thomas Weißschuh, Xin Li, Andrew Cooper,
Andy Lutomirski, Ard Biesheuvel, Borislav Petkov, Dave Hansen,
Ingo Molnar, James Morse, Jarkko Sakkinen, Josh Poimboeuf,
Kees Cook, Nam Cao, Oleg Nesterov, Perry Yuan, Thomas Gleixner,
Thomas Huth, Uros Bizjak, linux-kernel, linux-mm, linux-sgx, x86
On October 28, 2025 11:54:43 PM PDT, Brian Gerst <brgerst@gmail.com> wrote:
>On Sun, Oct 26, 2025 at 6:12 PM H. Peter Anvin <hpa@zytor.com> wrote:
>>
>> There is no fundamental reason for the int80_landing_pad symbol. If ip
>> falls within the vdso, and the vdso is moved, we should change the ip
>> accordingly, regardless of mode or location within the vdso. This
>> *currently* can only happen on 32 bits, but there isn't any reason not
>> to do so generically.
>>
>> Note that if this is ever possible from a vdso-internal call, then the
>> user space stack will also needed to be adjusted (as well as the
>> shadow stack, if enabled.) Fortunately this is not currently the case.
>>
>> At the moment, we don't even consider other threads when moving the
>> vdso. The assumption is that it is only used by process freeze/thaw
>> for migration, where this is not an issue.
>>
>> Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
>> ---
>> arch/x86/entry/vdso/vdso32/system_call.S | 1 -
>> arch/x86/entry/vdso/vma.c | 16 ++++++----------
>> arch/x86/tools/vdso2c.c | 1 -
>> 3 files changed, 6 insertions(+), 12 deletions(-)
>>
>> diff --git a/arch/x86/entry/vdso/vdso32/system_call.S b/arch/x86/entry/vdso/vdso32/system_call.S
>> index 2a15634bbe75..d14eca4403c5 100644
>> --- a/arch/x86/entry/vdso/vdso32/system_call.S
>> +++ b/arch/x86/entry/vdso/vdso32/system_call.S
>> @@ -62,7 +62,6 @@ __kernel_vsyscall:
>>
>> /* Enter using int $0x80 */
>> int $0x80
>> -SYM_INNER_LABEL(int80_landing_pad, SYM_L_GLOBAL)
>
>This is still needed by do_fast_syscall_32().
>
>
>Brian Gerst
>
Yeah, that was a complete brainfart on my part. I'm already reworking the patchset, fixing this and adding more improvements.
^ permalink raw reply [flat|nested] 10+ messages in thread
* [PATCH 4/6] x86/entry/vdso32: remove SYSCALL_ENTER_KERNEL macro in sigreturn.S
2025-10-26 22:12 [PATCH 0/6] x86/entry/vdso: cleanups for vdso build and 32-bit vdso H. Peter Anvin
` (2 preceding siblings ...)
2025-10-26 22:12 ` [PATCH 3/6] x86/entry/vdso32: remove int80_landing_pad H. Peter Anvin
@ 2025-10-26 22:12 ` H. Peter Anvin
2025-10-26 22:12 ` [PATCH 5/6] x86/entry/vdso32: remove open-coded DWARF " H. Peter Anvin
2025-10-26 22:12 ` [PATCH 6/6] x86/entry/vdso32: add endbr32 to system_call.S H. Peter Anvin
5 siblings, 0 replies; 10+ messages in thread
From: H. Peter Anvin @ 2025-10-26 22:12 UTC (permalink / raw)
To: H. Peter Anvin, Jason A. Donenfeld, Peter Zijlstra (Intel),
Theodore Ts'o, Thomas Weißschuh, Xin Li, Andrew Cooper,
Andy Lutomirski, Ard Biesheuvel, Borislav Petkov, Brian Gerst,
Dave Hansen, Ingo Molnar, James Morse, Jarkko Sakkinen,
Josh Poimboeuf, Kees Cook, Nam Cao, Oleg Nesterov, Perry Yuan,
Thomas Gleixner, Thomas Huth, Uros Bizjak, linux-kernel,
linux-mm, linux-sgx, x86
A macro SYSCALL_ENTER_KERNEL was defined in sigreturn.S, with the
ability of overriding it. The override capability, however, is not
used anywhere, and the macro name is potentially confusing because it
seems to imply that sysenter/syscall could be used here, which is NOT
true: the sigreturn system calls MUST use int $0x80.
Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
---
arch/x86/entry/vdso/vdso32/sigreturn.S | 8 ++------
1 file changed, 2 insertions(+), 6 deletions(-)
diff --git a/arch/x86/entry/vdso/vdso32/sigreturn.S b/arch/x86/entry/vdso/vdso32/sigreturn.S
index 1bd068f72d4c..965900c6763b 100644
--- a/arch/x86/entry/vdso/vdso32/sigreturn.S
+++ b/arch/x86/entry/vdso/vdso32/sigreturn.S
@@ -3,10 +3,6 @@
#include <asm/unistd_32.h>
#include <asm/asm-offsets.h>
-#ifndef SYSCALL_ENTER_KERNEL
-#define SYSCALL_ENTER_KERNEL int $0x80
-#endif
-
.text
.globl __kernel_sigreturn
.type __kernel_sigreturn,@function
@@ -16,7 +12,7 @@ __kernel_sigreturn:
.LSTART_sigreturn:
popl %eax /* XXX does this mean it needs unwind info? */
movl $__NR_sigreturn, %eax
- SYSCALL_ENTER_KERNEL
+ int $0x80
.LEND_sigreturn:
SYM_INNER_LABEL(vdso32_sigreturn_landing_pad, SYM_L_GLOBAL)
nop
@@ -28,7 +24,7 @@ SYM_INNER_LABEL(vdso32_sigreturn_landing_pad, SYM_L_GLOBAL)
__kernel_rt_sigreturn:
.LSTART_rt_sigreturn:
movl $__NR_rt_sigreturn, %eax
- SYSCALL_ENTER_KERNEL
+ int $0x80
.LEND_rt_sigreturn:
SYM_INNER_LABEL(vdso32_rt_sigreturn_landing_pad, SYM_L_GLOBAL)
nop
--
2.51.1
^ permalink raw reply [flat|nested] 10+ messages in thread* [PATCH 5/6] x86/entry/vdso32: remove open-coded DWARF in sigreturn.S
2025-10-26 22:12 [PATCH 0/6] x86/entry/vdso: cleanups for vdso build and 32-bit vdso H. Peter Anvin
` (3 preceding siblings ...)
2025-10-26 22:12 ` [PATCH 4/6] x86/entry/vdso32: remove SYSCALL_ENTER_KERNEL macro in sigreturn.S H. Peter Anvin
@ 2025-10-26 22:12 ` H. Peter Anvin
2025-10-26 22:12 ` [PATCH 6/6] x86/entry/vdso32: add endbr32 to system_call.S H. Peter Anvin
5 siblings, 0 replies; 10+ messages in thread
From: H. Peter Anvin @ 2025-10-26 22:12 UTC (permalink / raw)
To: H. Peter Anvin, Jason A. Donenfeld, Peter Zijlstra (Intel),
Theodore Ts'o, Thomas Weißschuh, Xin Li, Andrew Cooper,
Andy Lutomirski, Ard Biesheuvel, Borislav Petkov, Brian Gerst,
Dave Hansen, Ingo Molnar, James Morse, Jarkko Sakkinen,
Josh Poimboeuf, Kees Cook, Nam Cao, Oleg Nesterov, Perry Yuan,
Thomas Gleixner, Thomas Huth, Uros Bizjak, linux-kernel,
linux-mm, linux-sgx, x86
The vdso32 sigreturn.S contains open-coded DWARF bytecode, which
includes a hack for gdb to not try to step back to a previous call
instruction when backtracing from a signal handler.
Neither of those are necessary anymore: the backtracing issue is
handled by ".cfi_entry simple" and ".cfi_signal_frame", both of which
have been supported for a very long time now, which allows the
remaining frame to be built using regular .cfi annotations.
Add a few more register offsets to the signal frame just for good
measure.
Replace the nop on fallthrough of the system call (which should never,
ever happen) with a ud2a trap.
Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
---
arch/x86/entry/vdso/vdso32/sigreturn.S | 146 ++++++-------------------
arch/x86/include/asm/dwarf2.h | 1 +
arch/x86/kernel/asm-offsets.c | 6 +
3 files changed, 39 insertions(+), 114 deletions(-)
diff --git a/arch/x86/entry/vdso/vdso32/sigreturn.S b/arch/x86/entry/vdso/vdso32/sigreturn.S
index 965900c6763b..25b0ac4b4bfe 100644
--- a/arch/x86/entry/vdso/vdso32/sigreturn.S
+++ b/arch/x86/entry/vdso/vdso32/sigreturn.S
@@ -1,136 +1,54 @@
/* SPDX-License-Identifier: GPL-2.0 */
#include <linux/linkage.h>
#include <asm/unistd_32.h>
+#include <asm/dwarf2.h>
#include <asm/asm-offsets.h>
+.macro STARTPROC_SIGNAL_FRAME sc
+ CFI_STARTPROC simple
+ CFI_SIGNAL_FRAME
+ /* -4 as pretcode has already been popped */
+ CFI_DEF_CFA esp, \sc - 4
+ CFI_OFFSET eip, IA32_SIGCONTEXT_ip
+ CFI_OFFSET eax, IA32_SIGCONTEXT_ax
+ CFI_OFFSET ebx, IA32_SIGCONTEXT_bx
+ CFI_OFFSET ecx, IA32_SIGCONTEXT_cx
+ CFI_OFFSET edx, IA32_SIGCONTEXT_dx
+ CFI_OFFSET esp, IA32_SIGCONTEXT_sp
+ CFI_OFFSET ebp, IA32_SIGCONTEXT_bp
+ CFI_OFFSET esi, IA32_SIGCONTEXT_si
+ CFI_OFFSET edi, IA32_SIGCONTEXT_di
+ CFI_OFFSET es, IA32_SIGCONTEXT_es
+ CFI_OFFSET cs, IA32_SIGCONTEXT_cs
+ CFI_OFFSET ss, IA32_SIGCONTEXT_ss
+ CFI_OFFSET ds, IA32_SIGCONTEXT_ds
+ CFI_OFFSET eflags, IA32_SIGCONTEXT_flags
+.endm
+
.text
.globl __kernel_sigreturn
.type __kernel_sigreturn,@function
- nop /* this guy is needed for .LSTARTFDEDLSI1 below (watch for HACK) */
ALIGN
__kernel_sigreturn:
-.LSTART_sigreturn:
- popl %eax /* XXX does this mean it needs unwind info? */
+ STARTPROC_SIGNAL_FRAME IA32_SIGFRAME_sigcontext
+ popl %eax
+ CFI_ADJUST_CFA_OFFSET -4
movl $__NR_sigreturn, %eax
int $0x80
-.LEND_sigreturn:
SYM_INNER_LABEL(vdso32_sigreturn_landing_pad, SYM_L_GLOBAL)
- nop
- .size __kernel_sigreturn,.-.LSTART_sigreturn
+ ud2a
+ CFI_ENDPROC
+ .size __kernel_sigreturn,.-__kernel_sigreturn
.globl __kernel_rt_sigreturn
.type __kernel_rt_sigreturn,@function
ALIGN
__kernel_rt_sigreturn:
-.LSTART_rt_sigreturn:
+ STARTPROC_SIGNAL_FRAME IA32_RT_SIGFRAME_sigcontext
movl $__NR_rt_sigreturn, %eax
int $0x80
-.LEND_rt_sigreturn:
SYM_INNER_LABEL(vdso32_rt_sigreturn_landing_pad, SYM_L_GLOBAL)
- nop
- .size __kernel_rt_sigreturn,.-.LSTART_rt_sigreturn
- .previous
-
- .section .eh_frame,"a",@progbits
-.LSTARTFRAMEDLSI1:
- .long .LENDCIEDLSI1-.LSTARTCIEDLSI1
-.LSTARTCIEDLSI1:
- .long 0 /* CIE ID */
- .byte 1 /* Version number */
- .string "zRS" /* NUL-terminated augmentation string */
- .uleb128 1 /* Code alignment factor */
- .sleb128 -4 /* Data alignment factor */
- .byte 8 /* Return address register column */
- .uleb128 1 /* Augmentation value length */
- .byte 0x1b /* DW_EH_PE_pcrel|DW_EH_PE_sdata4. */
- .byte 0 /* DW_CFA_nop */
- .align 4
-.LENDCIEDLSI1:
- .long .LENDFDEDLSI1-.LSTARTFDEDLSI1 /* Length FDE */
-.LSTARTFDEDLSI1:
- .long .LSTARTFDEDLSI1-.LSTARTFRAMEDLSI1 /* CIE pointer */
- /* HACK: The dwarf2 unwind routines will subtract 1 from the
- return address to get an address in the middle of the
- presumed call instruction. Since we didn't get here via
- a call, we need to include the nop before the real start
- to make up for it. */
- .long .LSTART_sigreturn-1-. /* PC-relative start address */
- .long .LEND_sigreturn-.LSTART_sigreturn+1
- .uleb128 0 /* Augmentation */
- /* What follows are the instructions for the table generation.
- We record the locations of each register saved. This is
- complicated by the fact that the "CFA" is always assumed to
- be the value of the stack pointer in the caller. This means
- that we must define the CFA of this body of code to be the
- saved value of the stack pointer in the sigcontext. Which
- also means that there is no fixed relation to the other
- saved registers, which means that we must use DW_CFA_expression
- to compute their addresses. It also means that when we
- adjust the stack with the popl, we have to do it all over again. */
-
-#define do_cfa_expr(offset) \
- .byte 0x0f; /* DW_CFA_def_cfa_expression */ \
- .uleb128 1f-0f; /* length */ \
-0: .byte 0x74; /* DW_OP_breg4 */ \
- .sleb128 offset; /* offset */ \
- .byte 0x06; /* DW_OP_deref */ \
-1:
-
-#define do_expr(regno, offset) \
- .byte 0x10; /* DW_CFA_expression */ \
- .uleb128 regno; /* regno */ \
- .uleb128 1f-0f; /* length */ \
-0: .byte 0x74; /* DW_OP_breg4 */ \
- .sleb128 offset; /* offset */ \
-1:
-
- do_cfa_expr(IA32_SIGCONTEXT_sp+4)
- do_expr(0, IA32_SIGCONTEXT_ax+4)
- do_expr(1, IA32_SIGCONTEXT_cx+4)
- do_expr(2, IA32_SIGCONTEXT_dx+4)
- do_expr(3, IA32_SIGCONTEXT_bx+4)
- do_expr(5, IA32_SIGCONTEXT_bp+4)
- do_expr(6, IA32_SIGCONTEXT_si+4)
- do_expr(7, IA32_SIGCONTEXT_di+4)
- do_expr(8, IA32_SIGCONTEXT_ip+4)
-
- .byte 0x42 /* DW_CFA_advance_loc 2 -- nop; popl eax. */
-
- do_cfa_expr(IA32_SIGCONTEXT_sp)
- do_expr(0, IA32_SIGCONTEXT_ax)
- do_expr(1, IA32_SIGCONTEXT_cx)
- do_expr(2, IA32_SIGCONTEXT_dx)
- do_expr(3, IA32_SIGCONTEXT_bx)
- do_expr(5, IA32_SIGCONTEXT_bp)
- do_expr(6, IA32_SIGCONTEXT_si)
- do_expr(7, IA32_SIGCONTEXT_di)
- do_expr(8, IA32_SIGCONTEXT_ip)
-
- .align 4
-.LENDFDEDLSI1:
-
- .long .LENDFDEDLSI2-.LSTARTFDEDLSI2 /* Length FDE */
-.LSTARTFDEDLSI2:
- .long .LSTARTFDEDLSI2-.LSTARTFRAMEDLSI1 /* CIE pointer */
- /* HACK: See above wrt unwind library assumptions. */
- .long .LSTART_rt_sigreturn-1-. /* PC-relative start address */
- .long .LEND_rt_sigreturn-.LSTART_rt_sigreturn+1
- .uleb128 0 /* Augmentation */
- /* What follows are the instructions for the table generation.
- We record the locations of each register saved. This is
- slightly less complicated than the above, since we don't
- modify the stack pointer in the process. */
-
- do_cfa_expr(IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_sp)
- do_expr(0, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_ax)
- do_expr(1, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_cx)
- do_expr(2, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_dx)
- do_expr(3, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_bx)
- do_expr(5, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_bp)
- do_expr(6, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_si)
- do_expr(7, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_di)
- do_expr(8, IA32_RT_SIGFRAME_sigcontext-4 + IA32_SIGCONTEXT_ip)
-
- .align 4
-.LENDFDEDLSI2:
+ ud2a
+ CFI_ENDPROC
+ .size __kernel_rt_sigreturn,.-__kernel_rt_sigreturn
.previous
diff --git a/arch/x86/include/asm/dwarf2.h b/arch/x86/include/asm/dwarf2.h
index 302e11b15da8..09c9684d3ad6 100644
--- a/arch/x86/include/asm/dwarf2.h
+++ b/arch/x86/include/asm/dwarf2.h
@@ -20,6 +20,7 @@
#define CFI_RESTORE_STATE .cfi_restore_state
#define CFI_UNDEFINED .cfi_undefined
#define CFI_ESCAPE .cfi_escape
+#define CFI_SIGNAL_FRAME .cfi_signal_frame
#ifndef BUILD_VDSO
/*
diff --git a/arch/x86/kernel/asm-offsets.c b/arch/x86/kernel/asm-offsets.c
index 32ba599a51f8..a7e7df837405 100644
--- a/arch/x86/kernel/asm-offsets.c
+++ b/arch/x86/kernel/asm-offsets.c
@@ -63,8 +63,14 @@ static void __used common(void)
OFFSET(IA32_SIGCONTEXT_bp, sigcontext_32, bp);
OFFSET(IA32_SIGCONTEXT_sp, sigcontext_32, sp);
OFFSET(IA32_SIGCONTEXT_ip, sigcontext_32, ip);
+ OFFSET(IA32_SIGCONTEXT_es, sigcontext_32, es);
+ OFFSET(IA32_SIGCONTEXT_cs, sigcontext_32, cs);
+ OFFSET(IA32_SIGCONTEXT_ss, sigcontext_32, ss);
+ OFFSET(IA32_SIGCONTEXT_ds, sigcontext_32, ds);
+ OFFSET(IA32_SIGCONTEXT_flags, sigcontext_32, flags);
BLANK();
+ OFFSET(IA32_SIGFRAME_sigcontext, sigframe_ia32, sc);
OFFSET(IA32_RT_SIGFRAME_sigcontext, rt_sigframe_ia32, uc.uc_mcontext);
#endif
--
2.51.1
^ permalink raw reply [flat|nested] 10+ messages in thread* [PATCH 6/6] x86/entry/vdso32: add endbr32 to system_call.S
2025-10-26 22:12 [PATCH 0/6] x86/entry/vdso: cleanups for vdso build and 32-bit vdso H. Peter Anvin
` (4 preceding siblings ...)
2025-10-26 22:12 ` [PATCH 5/6] x86/entry/vdso32: remove open-coded DWARF " H. Peter Anvin
@ 2025-10-26 22:12 ` H. Peter Anvin
5 siblings, 0 replies; 10+ messages in thread
From: H. Peter Anvin @ 2025-10-26 22:12 UTC (permalink / raw)
To: H. Peter Anvin, Jason A. Donenfeld, Peter Zijlstra (Intel),
Theodore Ts'o, Thomas Weißschuh, Xin Li, Andrew Cooper,
Andy Lutomirski, Ard Biesheuvel, Borislav Petkov, Brian Gerst,
Dave Hansen, Ingo Molnar, James Morse, Jarkko Sakkinen,
Josh Poimboeuf, Kees Cook, Nam Cao, Oleg Nesterov, Perry Yuan,
Thomas Gleixner, Thomas Huth, Uros Bizjak, linux-kernel,
linux-mm, linux-sgx, x86
*If* the C code is compiled with endbr support, put one at the assembly
system call entry point as well.
Note that no endbr is required at the sigreturn entry points, because
those are logically subroutine returns and invoked via ret
instructions.
Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
---
arch/x86/entry/vdso/vdso32/system_call.S | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/arch/x86/entry/vdso/vdso32/system_call.S b/arch/x86/entry/vdso/vdso32/system_call.S
index d14eca4403c5..0ca7ca1c490b 100644
--- a/arch/x86/entry/vdso/vdso32/system_call.S
+++ b/arch/x86/entry/vdso/vdso32/system_call.S
@@ -8,12 +8,19 @@
#include <asm/cpufeatures.h>
#include <asm/alternative.h>
+.macro CET_ENDBR
+#if defined(__CET__) && (__CET__ & 1)
+ endbr32
+#endif
+.endm
+
.text
.globl __kernel_vsyscall
.type __kernel_vsyscall,@function
ALIGN
__kernel_vsyscall:
CFI_STARTPROC
+ CET_ENDBR
/*
* Reshuffle regs so that all of any of the entry instructions
* will preserve enough state.
--
2.51.1
^ permalink raw reply [flat|nested] 10+ messages in thread