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-rw-r--r--arch/s390/Kconfig4
-rw-r--r--arch/s390/Makefile4
-rw-r--r--arch/s390/boot/Makefile1
-rw-r--r--arch/s390/boot/boot.h4
-rw-r--r--arch/s390/boot/ipl_parm.c6
-rw-r--r--arch/s390/boot/stackprotector.c6
-rw-r--r--arch/s390/boot/startup.c8
-rw-r--r--arch/s390/include/asm/arch-stackprotector.h25
-rw-r--r--arch/s390/include/asm/lowcore.h3
-rw-r--r--arch/s390/include/asm/stackprotector.h16
-rw-r--r--arch/s390/kernel/Makefile2
-rw-r--r--arch/s390/kernel/asm-offsets.c4
-rw-r--r--arch/s390/kernel/entry.S8
-rw-r--r--arch/s390/kernel/module.c9
-rw-r--r--arch/s390/kernel/smp.c3
-rw-r--r--arch/s390/kernel/stackprotector.c156
-rw-r--r--arch/s390/kernel/vdso64/Makefile1
-rw-r--r--arch/s390/kernel/vmlinux.lds.S13
18 files changed, 269 insertions, 4 deletions
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index cb143bf782f8..d83501f829f1 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -69,6 +69,9 @@ config CC_HAS_ASM_AOR_FORMAT_FLAGS
Clang versions before 19.1.0 do not support A,
O, and R inline assembly format flags.
+config CC_HAS_STACKPROTECTOR_GLOBAL
+ def_bool $(cc-option, -mstack-protector-guard=global -mstack-protector-guard-record)
+
config S390
def_bool y
#
@@ -245,6 +248,7 @@ config S390
select HAVE_SAMPLE_FTRACE_DIRECT_MULTI
select HAVE_SETUP_PER_CPU_AREA
select HAVE_SOFTIRQ_ON_OWN_STACK
+ select HAVE_STACKPROTECTOR if CC_HAS_STACKPROTECTOR_GLOBAL
select HAVE_SYSCALL_TRACEPOINTS
select HAVE_VIRT_CPU_ACCOUNTING
select HAVE_VIRT_CPU_ACCOUNTING_IDLE
diff --git a/arch/s390/Makefile b/arch/s390/Makefile
index bf53e7d1487a..f0a670dcce71 100644
--- a/arch/s390/Makefile
+++ b/arch/s390/Makefile
@@ -89,6 +89,10 @@ ifdef CONFIG_EXPOLINE
aflags-y += -DCC_USING_EXPOLINE
endif
+ifeq ($(CONFIG_STACKPROTECTOR),y)
+ KBUILD_CFLAGS += -mstack-protector-guard=global -mstack-protector-guard-record
+endif
+
ifdef CONFIG_FUNCTION_TRACER
ifeq ($(call cc-option,-mfentry -mnop-mcount),)
# make use of hotpatch feature if the compiler supports it
diff --git a/arch/s390/boot/Makefile b/arch/s390/boot/Makefile
index 02f2cf082748..490167faba7a 100644
--- a/arch/s390/boot/Makefile
+++ b/arch/s390/boot/Makefile
@@ -32,6 +32,7 @@ obj-$(CONFIG_RANDOMIZE_BASE) += kaslr.o
obj-y += $(if $(CONFIG_KERNEL_UNCOMPRESSED),,decompressor.o) info.o
obj-$(CONFIG_KERNEL_ZSTD) += clz_ctz.o
obj-$(CONFIG_KMSAN) += kmsan.o
+obj-$(CONFIG_STACKPROTECTOR) += stackprotector.o
obj-all := $(obj-y) piggy.o syms.o
targets := bzImage section_cmp.boot.data section_cmp.boot.preserved.data $(obj-y)
diff --git a/arch/s390/boot/boot.h b/arch/s390/boot/boot.h
index 37d5b097ede5..61a205b489fb 100644
--- a/arch/s390/boot/boot.h
+++ b/arch/s390/boot/boot.h
@@ -28,6 +28,10 @@ struct vmlinux_info {
unsigned long invalid_pg_dir_off;
unsigned long alt_instructions;
unsigned long alt_instructions_end;
+#ifdef CONFIG_STACKPROTECTOR
+ unsigned long stack_prot_start;
+ unsigned long stack_prot_end;
+#endif
#ifdef CONFIG_KASAN
unsigned long kasan_early_shadow_page_off;
unsigned long kasan_early_shadow_pte_off;
diff --git a/arch/s390/boot/ipl_parm.c b/arch/s390/boot/ipl_parm.c
index f584d7da29cb..6bc950b92be7 100644
--- a/arch/s390/boot/ipl_parm.c
+++ b/arch/s390/boot/ipl_parm.c
@@ -3,6 +3,7 @@
#include <linux/init.h>
#include <linux/ctype.h>
#include <linux/pgtable.h>
+#include <asm/arch-stackprotector.h>
#include <asm/abs_lowcore.h>
#include <asm/page-states.h>
#include <asm/machine.h>
@@ -294,6 +295,11 @@ void parse_boot_command_line(void)
cmma_flag = 0;
}
+#ifdef CONFIG_STACKPROTECTOR
+ if (!strcmp(param, "debug_stackprotector"))
+ stack_protector_debug = 1;
+#endif
+
#if IS_ENABLED(CONFIG_KVM)
if (!strcmp(param, "prot_virt")) {
rc = kstrtobool(val, &enabled);
diff --git a/arch/s390/boot/stackprotector.c b/arch/s390/boot/stackprotector.c
new file mode 100644
index 000000000000..68494940c12a
--- /dev/null
+++ b/arch/s390/boot/stackprotector.c
@@ -0,0 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#define boot_fmt(fmt) "stackprot: " fmt
+
+#include "boot.h"
+#include "../kernel/stackprotector.c"
diff --git a/arch/s390/boot/startup.c b/arch/s390/boot/startup.c
index 3fbd25b9498f..f77067dfc2a8 100644
--- a/arch/s390/boot/startup.c
+++ b/arch/s390/boot/startup.c
@@ -20,6 +20,9 @@
#include <asm/uv.h>
#include <asm/abs_lowcore.h>
#include <asm/physmem_info.h>
+#include <asm/stacktrace.h>
+#include <asm/asm-offsets.h>
+#include <asm/arch-stackprotector.h>
#include "decompressor.h"
#include "boot.h"
#include "uv.h"
@@ -477,6 +480,10 @@ static void kaslr_adjust_vmlinux_info(long offset)
vmlinux.invalid_pg_dir_off += offset;
vmlinux.alt_instructions += offset;
vmlinux.alt_instructions_end += offset;
+#ifdef CONFIG_STACKPROTECTOR
+ vmlinux.stack_prot_start += offset;
+ vmlinux.stack_prot_end += offset;
+#endif
#ifdef CONFIG_KASAN
vmlinux.kasan_early_shadow_page_off += offset;
vmlinux.kasan_early_shadow_pte_off += offset;
@@ -622,6 +629,7 @@ void startup_kernel(void)
__apply_alternatives((struct alt_instr *)_vmlinux_info.alt_instructions,
(struct alt_instr *)_vmlinux_info.alt_instructions_end,
ALT_CTX_EARLY);
+ stack_protector_apply_early(text_lma);
/*
* Save KASLR offset for early dumps, before vmcore_info is set.
diff --git a/arch/s390/include/asm/arch-stackprotector.h b/arch/s390/include/asm/arch-stackprotector.h
new file mode 100644
index 000000000000..953627259e91
--- /dev/null
+++ b/arch/s390/include/asm/arch-stackprotector.h
@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef _ASM_S390_ARCH_STACKPROTECTOR_H
+#define _ASM_S390_ARCH_STACKPROTECTOR_H
+
+extern unsigned long __stack_chk_guard;
+extern int stack_protector_debug;
+
+void __stack_protector_apply_early(unsigned long kernel_start);
+int __stack_protector_apply(unsigned long *start, unsigned long *end, unsigned long kernel_start);
+
+static inline void stack_protector_apply_early(unsigned long kernel_start)
+{
+ if (IS_ENABLED(CONFIG_STACKPROTECTOR))
+ __stack_protector_apply_early(kernel_start);
+}
+
+static inline int stack_protector_apply(unsigned long *start, unsigned long *end)
+{
+ if (IS_ENABLED(CONFIG_STACKPROTECTOR))
+ return __stack_protector_apply(start, end, 0);
+ return 0;
+}
+
+#endif /* _ASM_S390_ARCH_STACKPROTECTOR_H */
diff --git a/arch/s390/include/asm/lowcore.h b/arch/s390/include/asm/lowcore.h
index d9c853db9a40..50ffe75adeb4 100644
--- a/arch/s390/include/asm/lowcore.h
+++ b/arch/s390/include/asm/lowcore.h
@@ -100,7 +100,8 @@ struct lowcore {
/* Save areas. */
__u64 save_area[8]; /* 0x0200 */
- __u8 pad_0x0240[0x0280-0x0240]; /* 0x0240 */
+ __u64 stack_canary; /* 0x0240 */
+ __u8 pad_0x0248[0x0280-0x0248]; /* 0x0248 */
__u64 save_area_restart[1]; /* 0x0280 */
__u64 pcpu; /* 0x0288 */
diff --git a/arch/s390/include/asm/stackprotector.h b/arch/s390/include/asm/stackprotector.h
new file mode 100644
index 000000000000..0497850103dd
--- /dev/null
+++ b/arch/s390/include/asm/stackprotector.h
@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef _ASM_S390_STACKPROTECTOR_H
+#define _ASM_S390_STACKPROTECTOR_H
+
+#include <linux/sched.h>
+#include <asm/current.h>
+#include <asm/lowcore.h>
+
+static __always_inline void boot_init_stack_canary(void)
+{
+ current->stack_canary = get_random_canary();
+ get_lowcore()->stack_canary = current->stack_canary;
+}
+
+#endif /* _ASM_S390_STACKPROTECTOR_H */
diff --git a/arch/s390/kernel/Makefile b/arch/s390/kernel/Makefile
index 810000355ac5..ecaee29e724e 100644
--- a/arch/s390/kernel/Makefile
+++ b/arch/s390/kernel/Makefile
@@ -67,7 +67,7 @@ obj-$(CONFIG_KEXEC_CORE) += machine_kexec.o relocate_kernel.o
obj-$(CONFIG_VMCORE_INFO) += vmcore_info.o
obj-$(CONFIG_UPROBES) += uprobes.o
obj-$(CONFIG_JUMP_LABEL) += jump_label.o
-
+obj-$(CONFIG_STACKPROTECTOR) += stackprotector.o
obj-$(CONFIG_KEXEC_FILE) += machine_kexec_file.o kexec_image.o
obj-$(CONFIG_KEXEC_FILE) += kexec_elf.o
obj-$(CONFIG_CERT_STORE) += cert_store.o
diff --git a/arch/s390/kernel/asm-offsets.c b/arch/s390/kernel/asm-offsets.c
index a8915663e917..cfe27f6579e3 100644
--- a/arch/s390/kernel/asm-offsets.c
+++ b/arch/s390/kernel/asm-offsets.c
@@ -21,6 +21,9 @@ int main(void)
OFFSET(__TASK_stack, task_struct, stack);
OFFSET(__TASK_thread, task_struct, thread);
OFFSET(__TASK_pid, task_struct, pid);
+#ifdef CONFIG_STACKPROTECTOR
+ OFFSET(__TASK_stack_canary, task_struct, stack_canary);
+#endif
BLANK();
/* thread struct offsets */
OFFSET(__THREAD_ksp, thread_struct, ksp);
@@ -139,6 +142,7 @@ int main(void)
OFFSET(__LC_CURRENT_PID, lowcore, current_pid);
OFFSET(__LC_LAST_BREAK, lowcore, last_break);
/* software defined ABI-relevant lowcore locations 0xe00 - 0xe20 */
+ OFFSET(__LC_STACK_CANARY, lowcore, stack_canary);
OFFSET(__LC_DUMP_REIPL, lowcore, ipib);
OFFSET(__LC_VMCORE_INFO, lowcore, vmcore_info);
OFFSET(__LC_OS_INFO, lowcore, os_info);
diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
index 1e266c0eae2c..24cc33e668ea 100644
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -162,9 +162,13 @@ SYM_FUNC_START(__switch_to_asm)
stg %r3,__LC_CURRENT(%r13) # store task struct of next
stg %r15,__LC_KERNEL_STACK(%r13) # store end of kernel stack
lg %r15,__THREAD_ksp(%r1,%r3) # load kernel stack of next
- aghi %r3,__TASK_pid
- mvc __LC_CURRENT_PID(4,%r13),0(%r3) # store pid of next
+ aghik %r4,%r3,__TASK_pid
+ mvc __LC_CURRENT_PID(4,%r13),0(%r4) # store pid of next
ALTERNATIVE "nop", "lpp _LPP_OFFSET(%r13)", ALT_FACILITY(40)
+#ifdef CONFIG_STACKPROTECTOR
+ lg %r3,__TASK_stack_canary(%r3)
+ stg %r3,__LC_STACK_CANARY(%r13)
+#endif
lmg %r6,%r15,__SF_GPRS(%r15) # load gprs of next task
BR_EX %r14
SYM_FUNC_END(__switch_to_asm)
diff --git a/arch/s390/kernel/module.c b/arch/s390/kernel/module.c
index 54d99e811a83..9d1f8a50f5a4 100644
--- a/arch/s390/kernel/module.c
+++ b/arch/s390/kernel/module.c
@@ -22,12 +22,14 @@
#include <linux/bug.h>
#include <linux/memory.h>
#include <linux/execmem.h>
+#include <asm/arch-stackprotector.h>
#include <asm/alternative.h>
#include <asm/nospec-branch.h>
#include <asm/facility.h>
#include <asm/ftrace.lds.h>
#include <asm/set_memory.h>
#include <asm/setup.h>
+#include <asm/asm-offsets.h>
#if 0
#define DEBUGP printk
@@ -525,6 +527,13 @@ int module_finalize(const Elf_Ehdr *hdr,
(str_has_prefix(secname, ".s390_return")))
nospec_revert(aseg, aseg + s->sh_size);
+ if (IS_ENABLED(CONFIG_STACKPROTECTOR) &&
+ (str_has_prefix(secname, "__stack_protector_loc"))) {
+ rc = stack_protector_apply(aseg, aseg + s->sh_size);
+ if (rc)
+ break;
+ }
+
#ifdef CONFIG_FUNCTION_TRACER
if (!strcmp(FTRACE_CALLSITE_SECTION, secname)) {
rc = module_alloc_ftrace_hotpatch_trampolines(me, s);
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index 25240be74c21..b7429f30afc1 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -280,6 +280,9 @@ static void pcpu_attach_task(int cpu, struct task_struct *tsk)
lc->hardirq_timer = tsk->thread.hardirq_timer;
lc->softirq_timer = tsk->thread.softirq_timer;
lc->steal_timer = 0;
+#ifdef CONFIG_STACKPROTECTOR
+ lc->stack_canary = tsk->stack_canary;
+#endif
}
static void pcpu_start_fn(int cpu, void (*func)(void *), void *data)
diff --git a/arch/s390/kernel/stackprotector.c b/arch/s390/kernel/stackprotector.c
new file mode 100644
index 000000000000..d4e40483f008
--- /dev/null
+++ b/arch/s390/kernel/stackprotector.c
@@ -0,0 +1,156 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#ifndef pr_fmt
+#define pr_fmt(fmt) "stackprot: " fmt
+#endif
+
+#include <linux/export.h>
+#include <linux/uaccess.h>
+#include <linux/printk.h>
+#include <asm/abs_lowcore.h>
+#include <asm/sections.h>
+#include <asm/machine.h>
+#include <asm/asm-offsets.h>
+#include <asm/arch-stackprotector.h>
+
+#ifdef __DECOMPRESSOR
+
+#define DEBUGP boot_debug
+#define EMERGP boot_emerg
+#define PANIC boot_panic
+
+#else /* __DECOMPRESSOR */
+
+#define DEBUGP pr_debug
+#define EMERGP pr_emerg
+#define PANIC panic
+
+#endif /* __DECOMPRESSOR */
+
+int __bootdata_preserved(stack_protector_debug);
+
+unsigned long __stack_chk_guard;
+EXPORT_SYMBOL(__stack_chk_guard);
+
+struct insn_ril {
+ u8 opc1 : 8;
+ u8 r1 : 4;
+ u8 opc2 : 4;
+ u32 imm;
+} __packed;
+
+/*
+ * Convert a virtual instruction address to a real instruction address. The
+ * decompressor needs to patch instructions within the kernel image based on
+ * their virtual addresses, while dynamic address translation is still
+ * disabled. Therefore a translation from virtual kernel image addresses to
+ * the corresponding physical addresses is required.
+ *
+ * After dynamic address translation is enabled and when the kernel needs to
+ * patch instructions such a translation is not required since the addresses
+ * are identical.
+ */
+static struct insn_ril *vaddress_to_insn(unsigned long vaddress)
+{
+#ifdef __DECOMPRESSOR
+ return (struct insn_ril *)__kernel_pa(vaddress);
+#else
+ return (struct insn_ril *)vaddress;
+#endif
+}
+
+static unsigned long insn_to_vaddress(struct insn_ril *insn)
+{
+#ifdef __DECOMPRESSOR
+ return (unsigned long)__kernel_va(insn);
+#else
+ return (unsigned long)insn;
+#endif
+}
+
+#define INSN_RIL_STRING_SIZE (sizeof(struct insn_ril) * 2 + 1)
+
+static void insn_ril_to_string(char *str, struct insn_ril *insn)
+{
+ u8 *ptr = (u8 *)insn;
+ int i;
+
+ for (i = 0; i < sizeof(*insn); i++)
+ hex_byte_pack(&str[2 * i], ptr[i]);
+ str[2 * i] = 0;
+}
+
+static void stack_protector_dump(struct insn_ril *old, struct insn_ril *new)
+{
+ char ostr[INSN_RIL_STRING_SIZE];
+ char nstr[INSN_RIL_STRING_SIZE];
+
+ insn_ril_to_string(ostr, old);
+ insn_ril_to_string(nstr, new);
+ DEBUGP("%016lx: %s -> %s\n", insn_to_vaddress(old), ostr, nstr);
+}
+
+static int stack_protector_verify(struct insn_ril *insn, unsigned long kernel_start)
+{
+ char istr[INSN_RIL_STRING_SIZE];
+ unsigned long vaddress, offset;
+
+ /* larl */
+ if (insn->opc1 == 0xc0 && insn->opc2 == 0x0)
+ return 0;
+ /* lgrl */
+ if (insn->opc1 == 0xc4 && insn->opc2 == 0x8)
+ return 0;
+ insn_ril_to_string(istr, insn);
+ vaddress = insn_to_vaddress(insn);
+ if (__is_defined(__DECOMPRESSOR)) {
+ offset = (unsigned long)insn - kernel_start + TEXT_OFFSET;
+ EMERGP("Unexpected instruction at %016lx/%016lx: %s\n", vaddress, offset, istr);
+ PANIC("Stackprotector error\n");
+ } else {
+ EMERGP("Unexpected instruction at %016lx: %s\n", vaddress, istr);
+ }
+ return -EINVAL;
+}
+
+int __stack_protector_apply(unsigned long *start, unsigned long *end, unsigned long kernel_start)
+{
+ unsigned long canary, *loc;
+ struct insn_ril *insn, new;
+ int rc;
+
+ /*
+ * Convert LARL/LGRL instructions to LLILF so register R1 contains the
+ * address of the per-cpu / per-process stack canary:
+ *
+ * LARL/LGRL R1,__stack_chk_guard => LLILF R1,__lc_stack_canary
+ */
+ canary = __LC_STACK_CANARY;
+ if (machine_has_relocated_lowcore())
+ canary += LOWCORE_ALT_ADDRESS;
+ for (loc = start; loc < end; loc++) {
+ insn = vaddress_to_insn(*loc);
+ rc = stack_protector_verify(insn, kernel_start);
+ if (rc)
+ return rc;
+ new = *insn;
+ new.opc1 = 0xc0;
+ new.opc2 = 0xf;
+ new.imm = canary;
+ if (stack_protector_debug)
+ stack_protector_dump(insn, &new);
+ s390_kernel_write(insn, &new, sizeof(*insn));
+ }
+ return 0;
+}
+
+#ifdef __DECOMPRESSOR
+void __stack_protector_apply_early(unsigned long kernel_start)
+{
+ unsigned long *start, *end;
+
+ start = (unsigned long *)vmlinux.stack_prot_start;
+ end = (unsigned long *)vmlinux.stack_prot_end;
+ __stack_protector_apply(start, end, kernel_start);
+}
+#endif
diff --git a/arch/s390/kernel/vdso64/Makefile b/arch/s390/kernel/vdso64/Makefile
index d8f0df742809..49ad8dfc7c79 100644
--- a/arch/s390/kernel/vdso64/Makefile
+++ b/arch/s390/kernel/vdso64/Makefile
@@ -32,6 +32,7 @@ KBUILD_CFLAGS_64 := $(filter-out -mno-pic-data-is-text-relative,$(KBUILD_CFLAGS_
KBUILD_CFLAGS_64 := $(filter-out -munaligned-symbols,$(KBUILD_CFLAGS_64))
KBUILD_CFLAGS_64 := $(filter-out -fno-asynchronous-unwind-tables,$(KBUILD_CFLAGS_64))
KBUILD_CFLAGS_64 += -m64 -fPIC -fno-common -fno-builtin -fasynchronous-unwind-tables
+KBUILD_CFLAGS_64 += -fno-stack-protector
ldflags-y := -shared -soname=linux-vdso64.so.1 \
--hash-style=both --build-id=sha1 -T
diff --git a/arch/s390/kernel/vmlinux.lds.S b/arch/s390/kernel/vmlinux.lds.S
index d74d4c52ccd0..d5b67c99a24a 100644
--- a/arch/s390/kernel/vmlinux.lds.S
+++ b/arch/s390/kernel/vmlinux.lds.S
@@ -150,6 +150,15 @@ SECTIONS
*(.altinstr_replacement)
}
+#ifdef CONFIG_STACKPROTECTOR
+ . = ALIGN(8);
+ .stack_prot_table : {
+ __stack_prot_start = .;
+ KEEP(*(__stack_protector_loc))
+ __stack_prot_end = .;
+ }
+#endif
+
/*
* Table with the patch locations to undo expolines
*/
@@ -257,6 +266,10 @@ SECTIONS
QUAD(invalid_pg_dir)
QUAD(__alt_instructions)
QUAD(__alt_instructions_end)
+#ifdef CONFIG_STACKPROTECTOR
+ QUAD(__stack_prot_start)
+ QUAD(__stack_prot_end)
+#endif
#ifdef CONFIG_KASAN
QUAD(kasan_early_shadow_page)
QUAD(kasan_early_shadow_pte)
generated by cgit (git 2.34.1) at 2025-12-04 17:42:24 +0000