summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
Diffstat
-rw-r--r--arch/powerpc/boot/dts/microwatt.dts2
-rw-r--r--arch/powerpc/boot/dts/mpc8315erdb.dts10
-rw-r--r--arch/powerpc/include/asm/ppc_asm.h2
-rw-r--r--arch/powerpc/include/uapi/asm/ioctls.h8
-rw-r--r--arch/powerpc/kernel/eeh.c2
-rw-r--r--arch/powerpc/kernel/vdso/Makefile2
-rw-r--r--arch/x86/Kconfig2
-rw-r--r--arch/x86/include/asm/module.h8
-rw-r--r--arch/x86/include/asm/sighandling.h22
-rw-r--r--arch/x86/include/asm/tdx.h2
-rw-r--r--arch/x86/kernel/alternative.c79
-rw-r--r--arch/x86/kernel/signal_32.c4
-rw-r--r--arch/x86/kernel/signal_64.c4
-rw-r--r--arch/x86/mm/init_32.c3
-rw-r--r--arch/x86/mm/init_64.c3
-rw-r--r--arch/x86/mm/pat/set_memory.c3
-rw-r--r--arch/x86/virt/vmx/tdx/tdx.c5
-rw-r--r--include/linux/execmem.h8
-rw-r--r--include/linux/module.h5
-rw-r--r--mm/execmem.c40
-rw-r--r--tools/testing/selftests/x86/Makefile2
-rw-r--r--tools/testing/selftests/x86/sigtrap_loop.c101
22 files changed, 226 insertions, 91 deletions
diff --git a/arch/powerpc/boot/dts/microwatt.dts b/arch/powerpc/boot/dts/microwatt.dts
index c4e4d2a9b460..b7eac4e56019 100644
--- a/arch/powerpc/boot/dts/microwatt.dts
+++ b/arch/powerpc/boot/dts/microwatt.dts
@@ -4,7 +4,7 @@
/ {
#size-cells = <0x02>;
#address-cells = <0x02>;
- model-name = "microwatt";
+ model = "microwatt";
compatible = "microwatt-soc";
aliases {
diff --git a/arch/powerpc/boot/dts/mpc8315erdb.dts b/arch/powerpc/boot/dts/mpc8315erdb.dts
index e09b37d7489d..a89cb3139ca8 100644
--- a/arch/powerpc/boot/dts/mpc8315erdb.dts
+++ b/arch/powerpc/boot/dts/mpc8315erdb.dts
@@ -6,6 +6,7 @@
*/
/dts-v1/;
+#include <dt-bindings/interrupt-controller/irq.h>
/ {
compatible = "fsl,mpc8315erdb";
@@ -358,6 +359,15 @@
interrupt-parent = <&ipic>;
fsl,mpc8313-wakeup-timer = <&gtm1>;
};
+
+ gpio: gpio-controller@c00 {
+ compatible = "fsl,mpc8314-gpio";
+ reg = <0xc00 0x100>;
+ interrupts = <74 IRQ_TYPE_LEVEL_LOW>;
+ interrupt-parent = <&ipic>;
+ gpio-controller;
+ #gpio-cells = <2>;
+ };
};
pci0: pci@e0008500 {
diff --git a/arch/powerpc/include/asm/ppc_asm.h b/arch/powerpc/include/asm/ppc_asm.h
index 02897f4b0dbf..b891910fce8a 100644
--- a/arch/powerpc/include/asm/ppc_asm.h
+++ b/arch/powerpc/include/asm/ppc_asm.h
@@ -183,7 +183,7 @@
/*
* Used to name C functions called from asm
*/
-#ifdef CONFIG_PPC_KERNEL_PCREL
+#if defined(__powerpc64__) && defined(CONFIG_PPC_KERNEL_PCREL)
#define CFUNC(name) name@notoc
#else
#define CFUNC(name) name
diff --git a/arch/powerpc/include/uapi/asm/ioctls.h b/arch/powerpc/include/uapi/asm/ioctls.h
index 2c145da3b774..b5211e413829 100644
--- a/arch/powerpc/include/uapi/asm/ioctls.h
+++ b/arch/powerpc/include/uapi/asm/ioctls.h
@@ -23,10 +23,10 @@
#define TCSETSW _IOW('t', 21, struct termios)
#define TCSETSF _IOW('t', 22, struct termios)
-#define TCGETA _IOR('t', 23, struct termio)
-#define TCSETA _IOW('t', 24, struct termio)
-#define TCSETAW _IOW('t', 25, struct termio)
-#define TCSETAF _IOW('t', 28, struct termio)
+#define TCGETA 0x40147417 /* _IOR('t', 23, struct termio) */
+#define TCSETA 0x80147418 /* _IOW('t', 24, struct termio) */
+#define TCSETAW 0x80147419 /* _IOW('t', 25, struct termio) */
+#define TCSETAF 0x8014741c /* _IOW('t', 28, struct termio) */
#define TCSBRK _IO('t', 29)
#define TCXONC _IO('t', 30)
diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c
index 83fe99861eb1..ca7f7bb2b478 100644
--- a/arch/powerpc/kernel/eeh.c
+++ b/arch/powerpc/kernel/eeh.c
@@ -1509,6 +1509,8 @@ int eeh_pe_configure(struct eeh_pe *pe)
/* Invalid PE ? */
if (!pe)
return -ENODEV;
+ else
+ ret = eeh_ops->configure_bridge(pe);
return ret;
}
diff --git a/arch/powerpc/kernel/vdso/Makefile b/arch/powerpc/kernel/vdso/Makefile
index e8824f933326..8834dfe9d727 100644
--- a/arch/powerpc/kernel/vdso/Makefile
+++ b/arch/powerpc/kernel/vdso/Makefile
@@ -53,7 +53,7 @@ ldflags-$(CONFIG_LD_ORPHAN_WARN) += -Wl,--orphan-handling=$(CONFIG_LD_ORPHAN_WAR
ldflags-y += $(filter-out $(CC_AUTO_VAR_INIT_ZERO_ENABLER) $(CC_FLAGS_FTRACE) -Wa$(comma)%, $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS))
CC32FLAGS := -m32
-CC32FLAGSREMOVE := -mcmodel=medium -mabi=elfv1 -mabi=elfv2 -mcall-aixdesc
+CC32FLAGSREMOVE := -mcmodel=medium -mabi=elfv1 -mabi=elfv2 -mcall-aixdesc -mpcrel
ifdef CONFIG_CC_IS_CLANG
# This flag is supported by clang for 64-bit but not 32-bit so it will cause
# an unused command line flag warning for this file.
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 340e5468980e..71019b3b54ea 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -89,7 +89,7 @@ config X86
select ARCH_HAS_DMA_OPS if GART_IOMMU || XEN
select ARCH_HAS_EARLY_DEBUG if KGDB
select ARCH_HAS_ELF_RANDOMIZE
- select ARCH_HAS_EXECMEM_ROX if X86_64
+ select ARCH_HAS_EXECMEM_ROX if X86_64 && STRICT_MODULE_RWX
select ARCH_HAS_FAST_MULTIPLIER
select ARCH_HAS_FORTIFY_SOURCE
select ARCH_HAS_GCOV_PROFILE_ALL
diff --git a/arch/x86/include/asm/module.h b/arch/x86/include/asm/module.h
index e988bac0a4a1..3c2de4ce3b10 100644
--- a/arch/x86/include/asm/module.h
+++ b/arch/x86/include/asm/module.h
@@ -5,12 +5,20 @@
#include <asm-generic/module.h>
#include <asm/orc_types.h>
+struct its_array {
+#ifdef CONFIG_MITIGATION_ITS
+ void **pages;
+ int num;
+#endif
+};
+
struct mod_arch_specific {
#ifdef CONFIG_UNWINDER_ORC
unsigned int num_orcs;
int *orc_unwind_ip;
struct orc_entry *orc_unwind;
#endif
+ struct its_array its_pages;
};
#endif /* _ASM_X86_MODULE_H */
diff --git a/arch/x86/include/asm/sighandling.h b/arch/x86/include/asm/sighandling.h
index e770c4fc47f4..8727c7e21dd1 100644
--- a/arch/x86/include/asm/sighandling.h
+++ b/arch/x86/include/asm/sighandling.h
@@ -24,4 +24,26 @@ int ia32_setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs);
int x64_setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs);
int x32_setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs);
+/*
+ * To prevent immediate repeat of single step trap on return from SIGTRAP
+ * handler if the trap flag (TF) is set without an external debugger attached,
+ * clear the software event flag in the augmented SS, ensuring no single-step
+ * trap is pending upon ERETU completion.
+ *
+ * Note, this function should be called in sigreturn() before the original
+ * state is restored to make sure the TF is read from the entry frame.
+ */
+static __always_inline void prevent_single_step_upon_eretu(struct pt_regs *regs)
+{
+ /*
+ * If the trap flag (TF) is set, i.e., the sigreturn() SYSCALL instruction
+ * is being single-stepped, do not clear the software event flag in the
+ * augmented SS, thus a debugger won't skip over the following instruction.
+ */
+#ifdef CONFIG_X86_FRED
+ if (!(regs->flags & X86_EFLAGS_TF))
+ regs->fred_ss.swevent = 0;
+#endif
+}
+
#endif /* _ASM_X86_SIGHANDLING_H */
diff --git a/arch/x86/include/asm/tdx.h b/arch/x86/include/asm/tdx.h
index 8b19294600c4..7ddef3a69866 100644
--- a/arch/x86/include/asm/tdx.h
+++ b/arch/x86/include/asm/tdx.h
@@ -106,7 +106,7 @@ void tdx_init(void);
typedef u64 (*sc_func_t)(u64 fn, struct tdx_module_args *args);
-static inline u64 sc_retry(sc_func_t func, u64 fn,
+static __always_inline u64 sc_retry(sc_func_t func, u64 fn,
struct tdx_module_args *args)
{
int retry = RDRAND_RETRY_LOOPS;
diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index ecfe7b497cad..6455f7f751b3 100644
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -116,6 +116,24 @@ static struct module *its_mod;
#endif
static void *its_page;
static unsigned int its_offset;
+struct its_array its_pages;
+
+static void *__its_alloc(struct its_array *pages)
+{
+ void *page __free(execmem) = execmem_alloc(EXECMEM_MODULE_TEXT, PAGE_SIZE);
+ if (!page)
+ return NULL;
+
+ void *tmp = krealloc(pages->pages, (pages->num+1) * sizeof(void *),
+ GFP_KERNEL);
+ if (!tmp)
+ return NULL;
+
+ pages->pages = tmp;
+ pages->pages[pages->num++] = page;
+
+ return no_free_ptr(page);
+}
/* Initialize a thunk with the "jmp *reg; int3" instructions. */
static void *its_init_thunk(void *thunk, int reg)
@@ -151,6 +169,21 @@ static void *its_init_thunk(void *thunk, int reg)
return thunk + offset;
}
+static void its_pages_protect(struct its_array *pages)
+{
+ for (int i = 0; i < pages->num; i++) {
+ void *page = pages->pages[i];
+ execmem_restore_rox(page, PAGE_SIZE);
+ }
+}
+
+static void its_fini_core(void)
+{
+ if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX))
+ its_pages_protect(&its_pages);
+ kfree(its_pages.pages);
+}
+
#ifdef CONFIG_MODULES
void its_init_mod(struct module *mod)
{
@@ -173,10 +206,8 @@ void its_fini_mod(struct module *mod)
its_page = NULL;
mutex_unlock(&text_mutex);
- for (int i = 0; i < mod->its_num_pages; i++) {
- void *page = mod->its_page_array[i];
- execmem_restore_rox(page, PAGE_SIZE);
- }
+ if (IS_ENABLED(CONFIG_STRICT_MODULE_RWX))
+ its_pages_protect(&mod->arch.its_pages);
}
void its_free_mod(struct module *mod)
@@ -184,37 +215,33 @@ void its_free_mod(struct module *mod)
if (!cpu_feature_enabled(X86_FEATURE_INDIRECT_THUNK_ITS))
return;
- for (int i = 0; i < mod->its_num_pages; i++) {
- void *page = mod->its_page_array[i];
+ for (int i = 0; i < mod->arch.its_pages.num; i++) {
+ void *page = mod->arch.its_pages.pages[i];
execmem_free(page);
}
- kfree(mod->its_page_array);
+ kfree(mod->arch.its_pages.pages);
}
#endif /* CONFIG_MODULES */
static void *its_alloc(void)
{
- void *page __free(execmem) = execmem_alloc(EXECMEM_MODULE_TEXT, PAGE_SIZE);
+ struct its_array *pages = &its_pages;
+ void *page;
+#ifdef CONFIG_MODULE
+ if (its_mod)
+ pages = &its_mod->arch.its_pages;
+#endif
+
+ page = __its_alloc(pages);
if (!page)
return NULL;
-#ifdef CONFIG_MODULES
- if (its_mod) {
- void *tmp = krealloc(its_mod->its_page_array,
- (its_mod->its_num_pages+1) * sizeof(void *),
- GFP_KERNEL);
- if (!tmp)
- return NULL;
-
- its_mod->its_page_array = tmp;
- its_mod->its_page_array[its_mod->its_num_pages++] = page;
+ execmem_make_temp_rw(page, PAGE_SIZE);
+ if (pages == &its_pages)
+ set_memory_x((unsigned long)page, 1);
- execmem_make_temp_rw(page, PAGE_SIZE);
- }
-#endif /* CONFIG_MODULES */
-
- return no_free_ptr(page);
+ return page;
}
static void *its_allocate_thunk(int reg)
@@ -268,7 +295,9 @@ u8 *its_static_thunk(int reg)
return thunk;
}
-#endif
+#else
+static inline void its_fini_core(void) {}
+#endif /* CONFIG_MITIGATION_ITS */
/*
* Nomenclature for variable names to simplify and clarify this code and ease
@@ -2338,6 +2367,8 @@ void __init alternative_instructions(void)
apply_retpolines(__retpoline_sites, __retpoline_sites_end);
apply_returns(__return_sites, __return_sites_end);
+ its_fini_core();
+
/*
* Adjust all CALL instructions to point to func()-10, including
* those in .altinstr_replacement.
diff --git a/arch/x86/kernel/signal_32.c b/arch/x86/kernel/signal_32.c
index 98123ff10506..42bbc42bd350 100644
--- a/arch/x86/kernel/signal_32.c
+++ b/arch/x86/kernel/signal_32.c
@@ -152,6 +152,8 @@ SYSCALL32_DEFINE0(sigreturn)
struct sigframe_ia32 __user *frame = (struct sigframe_ia32 __user *)(regs->sp-8);
sigset_t set;
+ prevent_single_step_upon_eretu(regs);
+
if (!access_ok(frame, sizeof(*frame)))
goto badframe;
if (__get_user(set.sig[0], &frame->sc.oldmask)
@@ -175,6 +177,8 @@ SYSCALL32_DEFINE0(rt_sigreturn)
struct rt_sigframe_ia32 __user *frame;
sigset_t set;
+ prevent_single_step_upon_eretu(regs);
+
frame = (struct rt_sigframe_ia32 __user *)(regs->sp - 4);
if (!access_ok(frame, sizeof(*frame)))
diff --git a/arch/x86/kernel/signal_64.c b/arch/x86/kernel/signal_64.c
index ee9453891901..d483b585c6c6 100644
--- a/arch/x86/kernel/signal_64.c
+++ b/arch/x86/kernel/signal_64.c
@@ -250,6 +250,8 @@ SYSCALL_DEFINE0(rt_sigreturn)
sigset_t set;
unsigned long uc_flags;
+ prevent_single_step_upon_eretu(regs);
+
frame = (struct rt_sigframe __user *)(regs->sp - sizeof(long));
if (!access_ok(frame, sizeof(*frame)))
goto badframe;
@@ -366,6 +368,8 @@ COMPAT_SYSCALL_DEFINE0(x32_rt_sigreturn)
sigset_t set;
unsigned long uc_flags;
+ prevent_single_step_upon_eretu(regs);
+
frame = (struct rt_sigframe_x32 __user *)(regs->sp - 8);
if (!access_ok(frame, sizeof(*frame)))
diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c
index 607d6a2e66e2..8a34fff6ab2b 100644
--- a/arch/x86/mm/init_32.c
+++ b/arch/x86/mm/init_32.c
@@ -30,7 +30,6 @@
#include <linux/initrd.h>
#include <linux/cpumask.h>
#include <linux/gfp.h>
-#include <linux/execmem.h>
#include <asm/asm.h>
#include <asm/bios_ebda.h>
@@ -749,8 +748,6 @@ void mark_rodata_ro(void)
pr_info("Write protecting kernel text and read-only data: %luk\n",
size >> 10);
- execmem_cache_make_ro();
-
kernel_set_to_readonly = 1;
#ifdef CONFIG_CPA_DEBUG
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index ee66fae9ebcc..fdb6cab524f0 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -34,7 +34,6 @@
#include <linux/gfp.h>
#include <linux/kcore.h>
#include <linux/bootmem_info.h>
-#include <linux/execmem.h>
#include <asm/processor.h>
#include <asm/bios_ebda.h>
@@ -1392,8 +1391,6 @@ void mark_rodata_ro(void)
(end - start) >> 10);
set_memory_ro(start, (end - start) >> PAGE_SHIFT);
- execmem_cache_make_ro();
-
kernel_set_to_readonly = 1;
/*
diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c
index 46edc11726b7..8834c76f91c9 100644
--- a/arch/x86/mm/pat/set_memory.c
+++ b/arch/x86/mm/pat/set_memory.c
@@ -1257,6 +1257,9 @@ static int collapse_pmd_page(pmd_t *pmd, unsigned long addr,
pgprot_t pgprot;
int i = 0;
+ if (!cpu_feature_enabled(X86_FEATURE_PSE))
+ return 0;
+
addr &= PMD_MASK;
pte = pte_offset_kernel(pmd, addr);
first = *pte;
diff --git a/arch/x86/virt/vmx/tdx/tdx.c b/arch/x86/virt/vmx/tdx/tdx.c
index 2457d13c3f9e..c7a9a087ccaf 100644
--- a/arch/x86/virt/vmx/tdx/tdx.c
+++ b/arch/x86/virt/vmx/tdx/tdx.c
@@ -75,8 +75,9 @@ static inline void seamcall_err_ret(u64 fn, u64 err,
args->r9, args->r10, args->r11);
}
-static inline int sc_retry_prerr(sc_func_t func, sc_err_func_t err_func,
- u64 fn, struct tdx_module_args *args)
+static __always_inline int sc_retry_prerr(sc_func_t func,
+ sc_err_func_t err_func,
+ u64 fn, struct tdx_module_args *args)
{
u64 sret = sc_retry(func, fn, args);
diff --git a/include/linux/execmem.h b/include/linux/execmem.h
index ca42d5e46ccc..3be35680a54f 100644
--- a/include/linux/execmem.h
+++ b/include/linux/execmem.h
@@ -54,7 +54,7 @@ enum execmem_range_flags {
EXECMEM_ROX_CACHE = (1 << 1),
};
-#if defined(CONFIG_ARCH_HAS_EXECMEM_ROX) && defined(CONFIG_EXECMEM)
+#ifdef CONFIG_ARCH_HAS_EXECMEM_ROX
/**
* execmem_fill_trapping_insns - set memory to contain instructions that
* will trap
@@ -94,15 +94,9 @@ int execmem_make_temp_rw(void *ptr, size_t size);
* Return: 0 on success or negative error code on failure.
*/
int execmem_restore_rox(void *ptr, size_t size);
-
-/*
- * Called from mark_readonly(), where the system transitions to ROX.
- */
-void execmem_cache_make_ro(void);
#else
static inline int execmem_make_temp_rw(void *ptr, size_t size) { return 0; }
static inline int execmem_restore_rox(void *ptr, size_t size) { return 0; }
-static inline void execmem_cache_make_ro(void) { }
#endif
/**
diff --git a/include/linux/module.h b/include/linux/module.h
index 92e1420fccdf..5faa1fb1f4b4 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -586,11 +586,6 @@ struct module {
atomic_t refcnt;
#endif
-#ifdef CONFIG_MITIGATION_ITS
- int its_num_pages;
- void **its_page_array;
-#endif
-
#ifdef CONFIG_CONSTRUCTORS
/* Constructor functions. */
ctor_fn_t *ctors;
diff --git a/mm/execmem.c b/mm/execmem.c
index 9720ac2dfa41..2b683e7d864d 100644
--- a/mm/execmem.c
+++ b/mm/execmem.c
@@ -254,34 +254,6 @@ out_unlock:
return ptr;
}
-static bool execmem_cache_rox = false;
-
-void execmem_cache_make_ro(void)
-{
- struct maple_tree *free_areas = &execmem_cache.free_areas;
- struct maple_tree *busy_areas = &execmem_cache.busy_areas;
- MA_STATE(mas_free, free_areas, 0, ULONG_MAX);
- MA_STATE(mas_busy, busy_areas, 0, ULONG_MAX);
- struct mutex *mutex = &execmem_cache.mutex;
- void *area;
-
- execmem_cache_rox = true;
-
- mutex_lock(mutex);
-
- mas_for_each(&mas_free, area, ULONG_MAX) {
- unsigned long pages = mas_range_len(&mas_free) >> PAGE_SHIFT;
- set_memory_ro(mas_free.index, pages);
- }
-
- mas_for_each(&mas_busy, area, ULONG_MAX) {
- unsigned long pages = mas_range_len(&mas_busy) >> PAGE_SHIFT;
- set_memory_ro(mas_busy.index, pages);
- }
-
- mutex_unlock(mutex);
-}
-
static int execmem_cache_populate(struct execmem_range *range, size_t size)
{
unsigned long vm_flags = VM_ALLOW_HUGE_VMAP;
@@ -302,15 +274,9 @@ static int execmem_cache_populate(struct execmem_range *range, size_t size)
/* fill memory with instructions that will trap */
execmem_fill_trapping_insns(p, alloc_size, /* writable = */ true);
- if (execmem_cache_rox) {
- err = set_memory_rox((unsigned long)p, vm->nr_pages);
- if (err)
- goto err_free_mem;
- } else {
- err = set_memory_x((unsigned long)p, vm->nr_pages);
- if (err)
- goto err_free_mem;
- }
+ err = set_memory_rox((unsigned long)p, vm->nr_pages);
+ if (err)
+ goto err_free_mem;
err = execmem_cache_add(p, alloc_size);
if (err)
diff --git a/tools/testing/selftests/x86/Makefile b/tools/testing/selftests/x86/Makefile
index f703fcfe9f7c..83148875a12c 100644
--- a/tools/testing/selftests/x86/Makefile
+++ b/tools/testing/selftests/x86/Makefile
@@ -12,7 +12,7 @@ CAN_BUILD_WITH_NOPIE := $(shell ./check_cc.sh "$(CC)" trivial_program.c -no-pie)
TARGETS_C_BOTHBITS := single_step_syscall sysret_ss_attrs syscall_nt test_mremap_vdso \
check_initial_reg_state sigreturn iopl ioperm \
- test_vsyscall mov_ss_trap \
+ test_vsyscall mov_ss_trap sigtrap_loop \
syscall_arg_fault fsgsbase_restore sigaltstack
TARGETS_C_BOTHBITS += nx_stack
TARGETS_C_32BIT_ONLY := entry_from_vm86 test_syscall_vdso unwind_vdso \
diff --git a/tools/testing/selftests/x86/sigtrap_loop.c b/tools/testing/selftests/x86/sigtrap_loop.c
new file mode 100644
index 000000000000..9d065479e89f
--- /dev/null
+++ b/tools/testing/selftests/x86/sigtrap_loop.c
@@ -0,0 +1,101 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2025 Intel Corporation
+ */
+#define _GNU_SOURCE
+
+#include <err.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ucontext.h>
+
+#ifdef __x86_64__
+# define REG_IP REG_RIP
+#else
+# define REG_IP REG_EIP
+#endif
+
+static void sethandler(int sig, void (*handler)(int, siginfo_t *, void *), int flags)
+{
+ struct sigaction sa;
+
+ memset(&sa, 0, sizeof(sa));
+ sa.sa_sigaction = handler;
+ sa.sa_flags = SA_SIGINFO | flags;
+ sigemptyset(&sa.sa_mask);
+
+ if (sigaction(sig, &sa, 0))
+ err(1, "sigaction");
+
+ return;
+}
+
+static void sigtrap(int sig, siginfo_t *info, void *ctx_void)
+{
+ ucontext_t *ctx = (ucontext_t *)ctx_void;
+ static unsigned int loop_count_on_same_ip;
+ static unsigned long last_trap_ip;
+
+ if (last_trap_ip == ctx->uc_mcontext.gregs[REG_IP]) {
+ printf("\tTrapped at %016lx\n", last_trap_ip);
+
+ /*
+ * If the same IP is hit more than 10 times in a row, it is
+ * _considered_ an infinite loop.
+ */
+ if (++loop_count_on_same_ip > 10) {
+ printf("[FAIL]\tDetected SIGTRAP infinite loop\n");
+ exit(1);
+ }
+
+ return;
+ }
+
+ loop_count_on_same_ip = 0;
+ last_trap_ip = ctx->uc_mcontext.gregs[REG_IP];
+ printf("\tTrapped at %016lx\n", last_trap_ip);
+}
+
+int main(int argc, char *argv[])
+{
+ sethandler(SIGTRAP, sigtrap, 0);
+
+ /*
+ * Set the Trap Flag (TF) to single-step the test code, therefore to
+ * trigger a SIGTRAP signal after each instruction until the TF is
+ * cleared.
+ *
+ * Because the arithmetic flags are not significant here, the TF is
+ * set by pushing 0x302 onto the stack and then popping it into the
+ * flags register.
+ *
+ * Four instructions in the following asm code are executed with the
+ * TF set, thus the SIGTRAP handler is expected to run four times.
+ */
+ printf("[RUN]\tSIGTRAP infinite loop detection\n");
+ asm volatile(
+#ifdef __x86_64__
+ /*
+ * Avoid clobbering the redzone
+ *
+ * Equivalent to "sub $128, %rsp", however -128 can be encoded
+ * in a single byte immediate while 128 uses 4 bytes.
+ */
+ "add $-128, %rsp\n\t"
+#endif
+ "push $0x302\n\t"
+ "popf\n\t"
+ "nop\n\t"
+ "nop\n\t"
+ "push $0x202\n\t"
+ "popf\n\t"
+#ifdef __x86_64__
+ "sub $-128, %rsp\n\t"
+#endif
+ );
+
+ printf("[OK]\tNo SIGTRAP infinite loop detected\n");
+ return 0;
+}
generated by cgit (git 2.34.1) at 2025-06-17 07:34:06 +0000