Merge tag 'seccomp-v5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull seccomp updates from Kees Cook:
 "The bulk of the changes are with the seccomp selftests to accommodate
  some powerpc-specific behavioral characteristics. Additional cleanups,
  fixes, and improvements are also included:

   - heavily refactor seccomp selftests (and clone3 selftests
     dependency) to fix powerpc (Kees Cook, Thadeu Lima de Souza
     Cascardo)

   - fix style issue in selftests (Zou Wei)

   - upgrade "unknown action" from KILL_THREAD to KILL_PROCESS (Rich
     Felker)

   - replace task_pt_regs(current) with current_pt_regs() (Denis
     Efremov)

   - fix corner-case race in USER_NOTIF (Jann Horn)

   - make CONFIG_SECCOMP no longer per-arch (YiFei Zhu)"

* tag 'seccomp-v5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (23 commits)
  seccomp: Make duplicate listener detection non-racy
  seccomp: Move config option SECCOMP to arch/Kconfig
  selftests/clone3: Avoid OS-defined clone_args
  selftests/seccomp: powerpc: Set syscall return during ptrace syscall exit
  selftests/seccomp: Allow syscall nr and ret value to be set separately
  selftests/seccomp: Record syscall during ptrace entry
  selftests/seccomp: powerpc: Fix seccomp return value testing
  selftests/seccomp: Remove SYSCALL_NUM_RET_SHARE_REG in favor of SYSCALL_RET_SET
  selftests/seccomp: Avoid redundant register flushes
  selftests/seccomp: Convert REGSET calls into ARCH_GETREG/ARCH_SETREG
  selftests/seccomp: Convert HAVE_GETREG into ARCH_GETREG/ARCH_SETREG
  selftests/seccomp: Remove syscall setting #ifdefs
  selftests/seccomp: mips: Remove O32-specific macro
  selftests/seccomp: arm64: Define SYSCALL_NUM_SET macro
  selftests/seccomp: arm: Define SYSCALL_NUM_SET macro
  selftests/seccomp: mips: Define SYSCALL_NUM_SET macro
  selftests/seccomp: Provide generic syscall setting macro
  selftests/seccomp: Refactor arch register macros to avoid xtensa special case
  selftests/seccomp: Use __NR_mknodat instead of __NR_mknod
  selftests/seccomp: Use bitwise instead of arithmetic operator for flags
  ...

23 files changed, 397 insertions, 437 deletions

diff --git a/arch/Kconfig b/arch/Kconfig
index 76ec3395b843..8519d9f42e33 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -450,10 +450,23 @@ config ARCH_WANT_OLD_COMPAT_IPC
 	select ARCH_WANT_COMPAT_IPC_PARSE_VERSION
 	bool
 
+config HAVE_ARCH_SECCOMP
+	bool
+	help
+	  An arch should select this symbol to support seccomp mode 1 (the fixed
+	  syscall policy), and must provide an overrides for __NR_seccomp_sigreturn,
+	  and compat syscalls if the asm-generic/seccomp.h defaults need adjustment:
+	  - __NR_seccomp_read_32
+	  - __NR_seccomp_write_32
+	  - __NR_seccomp_exit_32
+	  - __NR_seccomp_sigreturn_32
+
 config HAVE_ARCH_SECCOMP_FILTER
 	bool
+	select HAVE_ARCH_SECCOMP
 	help
 	  An arch should select this symbol if it provides all of these things:
+	  - all the requirements for HAVE_ARCH_SECCOMP
 	  - syscall_get_arch()
 	  - syscall_get_arguments()
 	  - syscall_rollback()
@@ -464,6 +477,23 @@ config HAVE_ARCH_SECCOMP_FILTER
 	    results in the system call being skipped immediately.
 	  - seccomp syscall wired up
 
+config SECCOMP
+	prompt "Enable seccomp to safely execute untrusted bytecode"
+	def_bool y
+	depends on HAVE_ARCH_SECCOMP
+	help
+	  This kernel feature is useful for number crunching applications
+	  that may need to handle untrusted bytecode during their
+	  execution. By using pipes or other transports made available
+	  to the process as file descriptors supporting the read/write
+	  syscalls, it's possible to isolate those applications in their
+	  own address space using seccomp. Once seccomp is enabled via
+	  prctl(PR_SET_SECCOMP) or the seccomp() syscall, it cannot be
+	  disabled and the task is only allowed to execute a few safe
+	  syscalls defined by each seccomp mode.
+
+	  If unsure, say Y.
+
 config SECCOMP_FILTER
 	def_bool y
 	depends on HAVE_ARCH_SECCOMP_FILTER && SECCOMP && NET
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index e67ef15c800f..82d0b00bc7a5 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -68,6 +68,7 @@ config ARM
 	select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL && !CPU_ENDIAN_BE32 && MMU
 	select HAVE_ARCH_KGDB if !CPU_ENDIAN_BE32 && MMU
 	select HAVE_ARCH_MMAP_RND_BITS if MMU
+	select HAVE_ARCH_SECCOMP
 	select HAVE_ARCH_SECCOMP_FILTER if AEABI && !OABI_COMPAT
 	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
 	select HAVE_ARCH_TRACEHOOK
@@ -1618,20 +1619,6 @@ config UACCESS_WITH_MEMCPY
 	  However, if the CPU data cache is using a write-allocate mode,
 	  this option is unlikely to provide any performance gain.
 
-config SECCOMP
-	bool
-	prompt "Enable seccomp to safely compute untrusted bytecode"
-	help
-	  This kernel feature is useful for number crunching applications
-	  that may need to compute untrusted bytecode during their
-	  execution. By using pipes or other transports made available to
-	  the process as file descriptors supporting the read/write
-	  syscalls, it's possible to isolate those applications in
-	  their own address space using seccomp. Once seccomp is
-	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
-	  and the task is only allowed to execute a few safe syscalls
-	  defined by each seccomp mode.
-
 config PARAVIRT
 	bool "Enable paravirtualization code"
 	help
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 4b136e923ccb..9cd317f00034 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -1041,19 +1041,6 @@ config ARCH_ENABLE_SPLIT_PMD_PTLOCK
 config CC_HAVE_SHADOW_CALL_STACK
 	def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18)
 
-config SECCOMP
-	bool "Enable seccomp to safely compute untrusted bytecode"
-	help
-	  This kernel feature is useful for number crunching applications
-	  that may need to compute untrusted bytecode during their
-	  execution. By using pipes or other transports made available to
-	  the process as file descriptors supporting the read/write
-	  syscalls, it's possible to isolate those applications in
-	  their own address space using seccomp. Once seccomp is
-	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
-	  and the task is only allowed to execute a few safe syscalls
-	  defined by each seccomp mode.
-
 config PARAVIRT
 	bool "Enable paravirtualization code"
 	help
diff --git a/arch/csky/Kconfig b/arch/csky/Kconfig
index 3d5afb5f5685..7f424c85772c 100644
--- a/arch/csky/Kconfig
+++ b/arch/csky/Kconfig
@@ -309,16 +309,3 @@ endmenu
 source "arch/csky/Kconfig.platforms"
 
 source "kernel/Kconfig.hz"
-
-config SECCOMP
-	bool "Enable seccomp to safely compute untrusted bytecode"
-	help
-	  This kernel feature is useful for number crunching applications
-	  that may need to compute untrusted bytecode during their
-	  execution. By using pipes or other transports made available to
-	  the process as file descriptors supporting the read/write
-	  syscalls, it's possible to isolate those applications in
-	  their own address space using seccomp. Once seccomp is
-	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
-	  and the task is only allowed to execute a few safe syscalls
-	  defined by each seccomp mode.
diff --git a/arch/microblaze/Kconfig b/arch/microblaze/Kconfig
index d262ac0c8714..37bd6a5f38fb 100644
--- a/arch/microblaze/Kconfig
+++ b/arch/microblaze/Kconfig
@@ -26,6 +26,7 @@ config MICROBLAZE
 	select GENERIC_SCHED_CLOCK
 	select HAVE_ARCH_HASH
 	select HAVE_ARCH_KGDB
+	select HAVE_ARCH_SECCOMP
 	select HAVE_DEBUG_KMEMLEAK
 	select HAVE_DMA_CONTIGUOUS
 	select HAVE_DYNAMIC_FTRACE
@@ -120,23 +121,6 @@ config CMDLINE_FORCE
 	  Set this to have arguments from the default kernel command string
 	  override those passed by the boot loader.
 
-config SECCOMP
-	bool "Enable seccomp to safely compute untrusted bytecode"
-	depends on PROC_FS
-	default y
-	help
-	  This kernel feature is useful for number crunching applications
-	  that may need to compute untrusted bytecode during their
-	  execution. By using pipes or other transports made available to
-	  the process as file descriptors supporting the read/write
-	  syscalls, it's possible to isolate those applications in
-	  their own address space using seccomp. Once seccomp is
-	  enabled via /proc/<pid>/seccomp, it cannot be disabled
-	  and the task is only allowed to execute a few safe syscalls
-	  defined by each seccomp mode.
-
-	  If unsure, say Y. Only embedded should say N here.
-
 endmenu
 
 menu "Kernel features"
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index cff19225da3d..440614dc9de2 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -3006,23 +3006,6 @@ config PHYSICAL_START
 	  specified in the "crashkernel=YM@XM" command line boot parameter
 	  passed to the panic-ed kernel).
 
-config SECCOMP
-	bool "Enable seccomp to safely compute untrusted bytecode"
-	depends on PROC_FS
-	default y
-	help
-	  This kernel feature is useful for number crunching applications
-	  that may need to compute untrusted bytecode during their
-	  execution. By using pipes or other transports made available to
-	  the process as file descriptors supporting the read/write
-	  syscalls, it's possible to isolate those applications in
-	  their own address space using seccomp. Once seccomp is
-	  enabled via /proc/<pid>/seccomp, it cannot be disabled
-	  and the task is only allowed to execute a few safe syscalls
-	  defined by each seccomp mode.
-
-	  If unsure, say Y. Only embedded should say N here.
-
 config MIPS_O32_FP64_SUPPORT
 	bool "Support for O32 binaries using 64-bit FP" if !CPU_MIPSR6
 	depends on 32BIT || MIPS32_O32
diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig
index 3b0f53dd70bc..cd4afe1e7a6c 100644
--- a/arch/parisc/Kconfig
+++ b/arch/parisc/Kconfig
@@ -378,19 +378,3 @@ endmenu
 
 
 source "drivers/parisc/Kconfig"
-
-config SECCOMP
-	def_bool y
-	prompt "Enable seccomp to safely compute untrusted bytecode"
-	help
-	  This kernel feature is useful for number crunching applications
-	  that may need to compute untrusted bytecode during their
-	  execution. By using pipes or other transports made available to
-	  the process as file descriptors supporting the read/write
-	  syscalls, it's possible to isolate those applications in
-	  their own address space using seccomp. Once seccomp is
-	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
-	  and the task is only allowed to execute a few safe syscalls
-	  defined by each seccomp mode.
-
-	  If unsure, say Y. Only embedded should say N here.
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 592036103493..1f0bd7e223f5 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -946,23 +946,6 @@ config ARCH_WANTS_FREEZER_CONTROL
 
 source "kernel/power/Kconfig"
 
-config SECCOMP
-	bool "Enable seccomp to safely compute untrusted bytecode"
-	depends on PROC_FS
-	default y
-	help
-	  This kernel feature is useful for number crunching applications
-	  that may need to compute untrusted bytecode during their
-	  execution. By using pipes or other transports made available to
-	  the process as file descriptors supporting the read/write
-	  syscalls, it's possible to isolate those applications in
-	  their own address space using seccomp. Once seccomp is
-	  enabled via /proc/<pid>/seccomp, it cannot be disabled
-	  and the task is only allowed to execute a few safe syscalls
-	  defined by each seccomp mode.
-
-	  If unsure, say Y. Only embedded should say N here.
-
 config PPC_MEM_KEYS
 	prompt "PowerPC Memory Protection Keys"
 	def_bool y
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 7766e1289468..b7821ac36d28 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -334,19 +334,6 @@ menu "Kernel features"
 
 source "kernel/Kconfig.hz"
 
-config SECCOMP
-	bool "Enable seccomp to safely compute untrusted bytecode"
-	help
-	  This kernel feature is useful for number crunching applications
-	  that may need to compute untrusted bytecode during their
-	  execution. By using pipes or other transports made available to
-	  the process as file descriptors supporting the read/write
-	  syscalls, it's possible to isolate those applications in
-	  their own address space using seccomp. Once seccomp is
-	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
-	  and the task is only allowed to execute a few safe syscalls
-	  defined by each seccomp mode.
-
 config RISCV_SBI_V01
 	bool "SBI v0.1 support"
 	default y
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 0a3899386a51..d509bf23ef78 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -792,23 +792,6 @@ config CRASH_DUMP
 
 endmenu
 
-config SECCOMP
-	def_bool y
-	prompt "Enable seccomp to safely compute untrusted bytecode"
-	depends on PROC_FS
-	help
-	  This kernel feature is useful for number crunching applications
-	  that may need to compute untrusted bytecode during their
-	  execution. By using pipes or other transports made available to
-	  the process as file descriptors supporting the read/write
-	  syscalls, it's possible to isolate those applications in
-	  their own address space using seccomp. Once seccomp is
-	  enabled via /proc/<pid>/seccomp, it cannot be disabled
-	  and the task is only allowed to execute a few safe syscalls
-	  defined by each seccomp mode.
-
-	  If unsure, say Y.
-
 config CCW
 	def_bool y
 
diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
index d20927128fce..18278152c91c 100644
--- a/arch/sh/Kconfig
+++ b/arch/sh/Kconfig
@@ -600,22 +600,6 @@ config PHYSICAL_START
 	  where the fail safe kernel needs to run at a different address
 	  than the panic-ed kernel.
 
-config SECCOMP
-	bool "Enable seccomp to safely compute untrusted bytecode"
-	depends on PROC_FS
-	help
-	  This kernel feature is useful for number crunching applications
-	  that may need to compute untrusted bytecode during their
-	  execution. By using pipes or other transports made available to
-	  the process as file descriptors supporting the read/write
-	  syscalls, it's possible to isolate those applications in
-	  their own address space using seccomp. Once seccomp is
-	  enabled via prctl, it cannot be disabled and the task is only
-	  allowed to execute a few safe syscalls defined by each seccomp
-	  mode.
-
-	  If unsure, say N.
-
 config SMP
 	bool "Symmetric multi-processing support"
 	depends on SYS_SUPPORTS_SMP
diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index 91ed1104b7f4..096530eac8e1 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -23,6 +23,7 @@ config SPARC
 	select HAVE_OPROFILE
 	select HAVE_ARCH_KGDB if !SMP || SPARC64
 	select HAVE_ARCH_TRACEHOOK
+	select HAVE_ARCH_SECCOMP if SPARC64
 	select HAVE_EXIT_THREAD
 	select HAVE_PCI
 	select SYSCTL_EXCEPTION_TRACE
@@ -227,23 +228,6 @@ config EARLYFB
 	help
 	  Say Y here to enable a faster early framebuffer boot console.
 
-config SECCOMP
-	bool "Enable seccomp to safely compute untrusted bytecode"
-	depends on SPARC64 && PROC_FS
-	default y
-	help
-	  This kernel feature is useful for number crunching applications
-	  that may need to compute untrusted bytecode during their
-	  execution. By using pipes or other transports made available to
-	  the process as file descriptors supporting the read/write
-	  syscalls, it's possible to isolate those applications in
-	  their own address space using seccomp. Once seccomp is
-	  enabled via /proc/<pid>/seccomp, it cannot be disabled
-	  and the task is only allowed to execute a few safe syscalls
-	  defined by each seccomp mode.
-
-	  If unsure, say Y. Only embedded should say N here.
-
 config HOTPLUG_CPU
 	bool "Support for hot-pluggable CPUs"
 	depends on SPARC64 && SMP
diff --git a/arch/um/Kconfig b/arch/um/Kconfig
index eb51fec75948..d49f471b02e3 100644
--- a/arch/um/Kconfig
+++ b/arch/um/Kconfig
@@ -173,22 +173,6 @@ config PGTABLE_LEVELS
 	default 3 if 3_LEVEL_PGTABLES
 	default 2
 
-config SECCOMP
-	def_bool y
-	prompt "Enable seccomp to safely compute untrusted bytecode"
-	help
-	  This kernel feature is useful for number crunching applications
-	  that may need to compute untrusted bytecode during their
-	  execution. By using pipes or other transports made available to
-	  the process as file descriptors supporting the read/write
-	  syscalls, it's possible to isolate those applications in
-	  their own address space using seccomp. Once seccomp is
-	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
-	  and the task is only allowed to execute a few safe syscalls
-	  defined by each seccomp mode.
-
-	  If unsure, say Y.
-
 config UML_TIME_TRAVEL_SUPPORT
 	bool
 	prompt "Support time-travel mode (e.g. for test execution)"
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 835d93006bd6..255084c65138 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1970,22 +1970,6 @@ config EFI_MIXED
 
 	   If unsure, say N.
 
-config SECCOMP
-	def_bool y
-	prompt "Enable seccomp to safely compute untrusted bytecode"
-	help
-	  This kernel feature is useful for number crunching applications
-	  that may need to compute untrusted bytecode during their
-	  execution. By using pipes or other transports made available to
-	  the process as file descriptors supporting the read/write
-	  syscalls, it's possible to isolate those applications in
-	  their own address space using seccomp. Once seccomp is
-	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
-	  and the task is only allowed to execute a few safe syscalls
-	  defined by each seccomp mode.
-
-	  If unsure, say Y. Only embedded should say N here.
-
 source "kernel/Kconfig.hz"
 
 config KEXEC
diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
index e997e0119c02..d8a29dc5a284 100644
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig
@@ -217,20 +217,6 @@ config HOTPLUG_CPU
 
 	  Say N if you want to disable CPU hotplug.
 
-config SECCOMP
-	bool
-	prompt "Enable seccomp to safely compute untrusted bytecode"
-	help
-	  This kernel feature is useful for number crunching applications
-	  that may need to compute untrusted bytecode during their
-	  execution. By using pipes or other transports made available to
-	  the process as file descriptors supporting the read/write
-	  syscalls, it's possible to isolate those applications in
-	  their own address space using seccomp. Once seccomp is
-	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
-	  and the task is only allowed to execute a few safe syscalls
-	  defined by each seccomp mode.
-
 config FAST_SYSCALL_XTENSA
 	bool "Enable fast atomic syscalls"
 	default n
diff --git a/kernel/seccomp.c b/kernel/seccomp.c
index 676d4af62103..8ad7a293255a 100644
--- a/kernel/seccomp.c
+++ b/kernel/seccomp.c
@@ -196,6 +196,10 @@ struct seccomp_filter {
  */
 static void populate_seccomp_data(struct seccomp_data *sd)
 {
+	/*
+	 * Instead of using current_pt_reg(), we're already doing the work
+	 * to safely fetch "current", so just use "task" everywhere below.
+	 */
 	struct task_struct *task = current;
 	struct pt_regs *regs = task_pt_regs(task);
 	unsigned long args[6];
@@ -910,7 +914,7 @@ out:
 	if (flags & SECCOMP_USER_NOTIF_FLAG_CONTINUE)
 		return 0;
 
-	syscall_set_return_value(current, task_pt_regs(current),
+	syscall_set_return_value(current, current_pt_regs(),
 				 err, ret);
 	return -1;
 }
@@ -943,13 +947,13 @@ static int __seccomp_filter(int this_syscall, const struct seccomp_data *sd,
 		/* Set low-order bits as an errno, capped at MAX_ERRNO. */
 		if (data > MAX_ERRNO)
 			data = MAX_ERRNO;
-		syscall_set_return_value(current, task_pt_regs(current),
+		syscall_set_return_value(current, current_pt_regs(),
 					 -data, 0);
 		goto skip;
 
 	case SECCOMP_RET_TRAP:
 		/* Show the handler the original registers. */
-		syscall_rollback(current, task_pt_regs(current));
+		syscall_rollback(current, current_pt_regs());
 		/* Let the filter pass back 16 bits of data. */
 		seccomp_send_sigsys(this_syscall, data);
 		goto skip;
@@ -962,7 +966,7 @@ static int __seccomp_filter(int this_syscall, const struct seccomp_data *sd,
 		/* ENOSYS these calls if there is no tracer attached. */
 		if (!ptrace_event_enabled(current, PTRACE_EVENT_SECCOMP)) {
 			syscall_set_return_value(current,
-						 task_pt_regs(current),
+						 current_pt_regs(),
 						 -ENOSYS, 0);
 			goto skip;
 		}
@@ -982,7 +986,7 @@ static int __seccomp_filter(int this_syscall, const struct seccomp_data *sd,
 		if (fatal_signal_pending(current))
 			goto skip;
 		/* Check if the tracer forced the syscall to be skipped. */
-		this_syscall = syscall_get_nr(current, task_pt_regs(current));
+		this_syscall = syscall_get_nr(current, current_pt_regs());
 		if (this_syscall < 0)
 			goto skip;
 
@@ -1020,20 +1024,20 @@ static int __seccomp_filter(int this_syscall, const struct seccomp_data *sd,
 	default:
 		seccomp_log(this_syscall, SIGSYS, action, true);
 		/* Dump core only if this is the last remaining thread. */
-		if (action == SECCOMP_RET_KILL_PROCESS ||
+		if (action != SECCOMP_RET_KILL_THREAD ||
 		    get_nr_threads(current) == 1) {
 			kernel_siginfo_t info;
 
 			/* Show the original registers in the dump. */
-			syscall_rollback(current, task_pt_regs(current));
+			syscall_rollback(current, current_pt_regs());
 			/* Trigger a manual coredump since do_exit skips it. */
 			seccomp_init_siginfo(&info, this_syscall, data);
 			do_coredump(&info);
 		}
-		if (action == SECCOMP_RET_KILL_PROCESS)
-			do_group_exit(SIGSYS);
-		else
+		if (action == SECCOMP_RET_KILL_THREAD)
 			do_exit(SIGSYS);
+		else
+			do_group_exit(SIGSYS);
 	}
 
 	unreachable();
@@ -1060,7 +1064,7 @@ int __secure_computing(const struct seccomp_data *sd)
 		return 0;
 
 	this_syscall = sd ? sd->nr :
-		syscall_get_nr(current, task_pt_regs(current));
+		syscall_get_nr(current, current_pt_regs());
 
 	switch (mode) {
 	case SECCOMP_MODE_STRICT:
@@ -1472,13 +1476,7 @@ static const struct file_operations seccomp_notify_ops = {
 
 static struct file *init_listener(struct seccomp_filter *filter)
 {
-	struct file *ret = ERR_PTR(-EBUSY);
-	struct seccomp_filter *cur;
-
-	for (cur = current->seccomp.filter; cur; cur = cur->prev) {
-		if (cur->notif)
-			goto out;
-	}
+	struct file *ret;
 
 	ret = ERR_PTR(-ENOMEM);
 	filter->notif = kzalloc(sizeof(*(filter->notif)), GFP_KERNEL);
@@ -1504,6 +1502,31 @@ out:
 	return ret;
 }
 
+/*
+ * Does @new_child have a listener while an ancestor also has a listener?
+ * If so, we'll want to reject this filter.
+ * This only has to be tested for the current process, even in the TSYNC case,
+ * because TSYNC installs @child with the same parent on all threads.
+ * Note that @new_child is not hooked up to its parent at this point yet, so
+ * we use current->seccomp.filter.
+ */
+static bool has_duplicate_listener(struct seccomp_filter *new_child)
+{
+	struct seccomp_filter *cur;
+
+	/* must be protected against concurrent TSYNC */
+	lockdep_assert_held(&current->sighand->siglock);
+
+	if (!new_child->notif)
+		return false;
+	for (cur = current->seccomp.filter; cur; cur = cur->prev) {
+		if (cur->notif)
+			return true;
+	}
+
+	return false;
+}
+
 /**
  * seccomp_set_mode_filter: internal function for setting seccomp filter
  * @flags:  flags to change filter behavior
@@ -1575,6 +1598,11 @@ static long seccomp_set_mode_filter(unsigned int flags,
 	if (!seccomp_may_assign_mode(seccomp_mode))
 		goto out;
 
+	if (has_duplicate_listener(prepared)) {
+		ret = -EBUSY;
+		goto out;
+	}
+
 	ret = seccomp_attach_filter(flags, prepared);
 	if (ret)
 		goto out;
diff --git a/tools/testing/selftests/clone3/clone3.c b/tools/testing/selftests/clone3/clone3.c
index b7e6dec36173..42be3b925830 100644
--- a/tools/testing/selftests/clone3/clone3.c
+++ b/tools/testing/selftests/clone3/clone3.c
@@ -20,13 +20,6 @@
 #include "../kselftest.h"
 #include "clone3_selftests.h"
 
-/*
- * Different sizes of struct clone_args
- */
-#ifndef CLONE3_ARGS_SIZE_V0
-#define CLONE3_ARGS_SIZE_V0 64
-#endif
-
 enum test_mode {
 	CLONE3_ARGS_NO_TEST,
 	CLONE3_ARGS_ALL_0,
@@ -38,13 +31,13 @@ enum test_mode {
 
 static int call_clone3(uint64_t flags, size_t size, enum test_mode test_mode)
 {
-	struct clone_args args = {
+	struct __clone_args args = {
 		.flags = flags,
 		.exit_signal = SIGCHLD,
 	};
 
 	struct clone_args_extended {
-		struct clone_args args;
+		struct __clone_args args;
 		__aligned_u64 excess_space[2];
 	} args_ext;
 
@@ -52,11 +45,11 @@ static int call_clone3(uint64_t flags, size_t size, enum test_mode test_mode)
 	int status;
 
 	memset(&args_ext, 0, sizeof(args_ext));
-	if (size > sizeof(struct clone_args))
+	if (size > sizeof(struct __clone_args))
 		args_ext.excess_space[1] = 1;
 
 	if (size == 0)
-		size = sizeof(struct clone_args);
+		size = sizeof(struct __clone_args);
 
 	switch (test_mode) {
 	case CLONE3_ARGS_ALL_0:
@@ -77,9 +70,9 @@ static int call_clone3(uint64_t flags, size_t size, enum test_mode test_mode)
 		break;
 	}
 
-	memcpy(&args_ext.args, &args, sizeof(struct clone_args));
+	memcpy(&args_ext.args, &args, sizeof(struct __clone_args));
 
-	pid = sys_clone3((struct clone_args *)&args_ext, size);
+	pid = sys_clone3((struct __clone_args *)&args_ext, size);
 	if (pid < 0) {
 		ksft_print_msg("%s - Failed to create new process\n",
 				strerror(errno));
@@ -144,14 +137,14 @@ int main(int argc, char *argv[])
 	else
 		ksft_test_result_skip("Skipping clone3() with CLONE_NEWPID\n");
 
-	/* Do a clone3() with CLONE3_ARGS_SIZE_V0. */
-	test_clone3(0, CLONE3_ARGS_SIZE_V0, 0, CLONE3_ARGS_NO_TEST);
+	/* Do a clone3() with CLONE_ARGS_SIZE_VER0. */
+	test_clone3(0, CLONE_ARGS_SIZE_VER0, 0, CLONE3_ARGS_NO_TEST);
 
-	/* Do a clone3() with CLONE3_ARGS_SIZE_V0 - 8 */
-	test_clone3(0, CLONE3_ARGS_SIZE_V0 - 8, -EINVAL, CLONE3_ARGS_NO_TEST);
+	/* Do a clone3() with CLONE_ARGS_SIZE_VER0 - 8 */
+	test_clone3(0, CLONE_ARGS_SIZE_VER0 - 8, -EINVAL, CLONE3_ARGS_NO_TEST);
 
 	/* Do a clone3() with sizeof(struct clone_args) + 8 */
-	test_clone3(0, sizeof(struct clone_args) + 8, 0, CLONE3_ARGS_NO_TEST);
+	test_clone3(0, sizeof(struct __clone_args) + 8, 0, CLONE3_ARGS_NO_TEST);
 
 	/* Do a clone3() with exit_signal having highest 32 bits non-zero */
 	test_clone3(0, 0, -EINVAL, CLONE3_ARGS_INVAL_EXIT_SIGNAL_BIG);
@@ -165,31 +158,31 @@ int main(int argc, char *argv[])
 	/* Do a clone3() with NSIG < exit_signal < CSIG */
 	test_clone3(0, 0, -EINVAL, CLONE3_ARGS_INVAL_EXIT_SIGNAL_NSIG);
 
-	test_clone3(0, sizeof(struct clone_args) + 8, 0, CLONE3_ARGS_ALL_0);
+	test_clone3(0, sizeof(struct __clone_args) + 8, 0, CLONE3_ARGS_ALL_0);
 
-	test_clone3(0, sizeof(struct clone_args) + 16, -E2BIG,
+	test_clone3(0, sizeof(struct __clone_args) + 16, -E2BIG,
 			CLONE3_ARGS_ALL_0);
 
-	test_clone3(0, sizeof(struct clone_args) * 2, -E2BIG,
+	test_clone3(0, sizeof(struct __clone_args) * 2, -E2BIG,
 			CLONE3_ARGS_ALL_0);
 
 	/* Do a clone3() with > page size */
 	test_clone3(0, getpagesize() + 8, -E2BIG, CLONE3_ARGS_NO_TEST);
 
-	/* Do a clone3() with CLONE3_ARGS_SIZE_V0 in a new PID NS. */
+	/* Do a clone3() with CLONE_ARGS_SIZE_VER0 in a new PID NS. */
 	if (uid == 0)
-		test_clone3(CLONE_NEWPID, CLONE3_ARGS_SIZE_V0, 0,
+		test_clone3(CLONE_NEWPID, CLONE_ARGS_SIZE_VER0, 0,
 				CLONE3_ARGS_NO_TEST);
 	else
 		ksft_test_result_skip("Skipping clone3() with CLONE_NEWPID\n");
 
-	/* Do a clone3() with CLONE3_ARGS_SIZE_V0 - 8 in a new PID NS */
-	test_clone3(CLONE_NEWPID, CLONE3_ARGS_SIZE_V0 - 8, -EINVAL,
+	/* Do a clone3() with CLONE_ARGS_SIZE_VER0 - 8 in a new PID NS */
+	test_clone3(CLONE_NEWPID, CLONE_ARGS_SIZE_VER0 - 8, -EINVAL,
 			CLONE3_ARGS_NO_TEST);
 
 	/* Do a clone3() with sizeof(struct clone_args) + 8 in a new PID NS */
 	if (uid == 0)
-		test_clone3(CLONE_NEWPID, sizeof(struct clone_args) + 8, 0,
+		test_clone3(CLONE_NEWPID, sizeof(struct __clone_args) + 8, 0,
 				CLONE3_ARGS_NO_TEST);
 	else
 		ksft_test_result_skip("Skipping clone3() with CLONE_NEWPID\n");
diff --git a/tools/testing/selftests/clone3/clone3_cap_checkpoint_restore.c b/tools/testing/selftests/clone3/clone3_cap_checkpoint_restore.c
index 9562425aa0a9..55bd387ce7ec 100644
--- a/tools/testing/selftests/clone3/clone3_cap_checkpoint_restore.c
+++ b/tools/testing/selftests/clone3/clone3_cap_checkpoint_restore.c
@@ -44,13 +44,13 @@ static int call_clone3_set_tid(struct __test_metadata *_metadata,
 	int status;
 	pid_t pid = -1;
 
-	struct clone_args args = {
+	struct __clone_args args = {
 		.exit_signal = SIGCHLD,
 		.set_tid = ptr_to_u64(set_tid),
 		.set_tid_size = set_tid_size,
 	};
 
-	pid = sys_clone3(&args, sizeof(struct clone_args));
+	pid = sys_clone3(&args, sizeof(args));
 	if (pid < 0) {
 		TH_LOG("%s - Failed to create new process", strerror(errno));
 		return -errno;
diff --git a/tools/testing/selftests/clone3/clone3_clear_sighand.c b/tools/testing/selftests/clone3/clone3_clear_sighand.c
index db5fc9c5edcf..47a8c0fc3676 100644
--- a/tools/testing/selftests/clone3/clone3_clear_sighand.c
+++ b/tools/testing/selftests/clone3/clone3_clear_sighand.c
@@ -47,7 +47,7 @@ static void test_clone3_clear_sighand(void)
 {
 	int ret;
 	pid_t pid;
-	struct clone_args args = {};
+	struct __clone_args args = {};
 	struct sigaction act;
 
 	/*
diff --git a/tools/testing/selftests/clone3/clone3_selftests.h b/tools/testing/selftests/clone3/clone3_selftests.h
index 91c1a78ddb39..e81ffaaee02b 100644
--- a/tools/testing/selftests/clone3/clone3_selftests.h
+++ b/tools/testing/selftests/clone3/clone3_selftests.h
@@ -19,13 +19,11 @@
 #define CLONE_INTO_CGROUP 0x200000000ULL /* Clone into a specific cgroup given the right permissions. */
 #endif
 
-#ifndef CLONE_ARGS_SIZE_VER0
-#define CLONE_ARGS_SIZE_VER0 64
-#endif
-
 #ifndef __NR_clone3
 #define __NR_clone3 -1
-struct clone_args {
+#endif
+
+struct __clone_args {
 	__aligned_u64 flags;
 	__aligned_u64 pidfd;
 	__aligned_u64 child_tid;
@@ -34,15 +32,21 @@ struct clone_args {
 	__aligned_u64 stack;
 	__aligned_u64 stack_size;
 	__aligned_u64 tls;
-#define CLONE_ARGS_SIZE_VER1 80
+#ifndef CLONE_ARGS_SIZE_VER0
+#define CLONE_ARGS_SIZE_VER0 64	/* sizeof first published struct */
+#endif
 	__aligned_u64 set_tid;
 	__aligned_u64 set_tid_size;
-#define CLONE_ARGS_SIZE_VER2 88
+#ifndef CLONE_ARGS_SIZE_VER1
+#define CLONE_ARGS_SIZE_VER1 80	/* sizeof second published struct */
+#endif
 	__aligned_u64 cgroup;
+#ifndef CLONE_ARGS_SIZE_VER2
+#define CLONE_ARGS_SIZE_VER2 88	/* sizeof third published struct */
+#endif
 };
-#endif /* __NR_clone3 */
 
-static pid_t sys_clone3(struct clone_args *args, size_t size)
+static pid_t sys_clone3(struct __clone_args *args, size_t size)
 {
 	fflush(stdout);
 	fflush(stderr);
@@ -52,7 +56,7 @@ static pid_t sys_clone3(struct clone_args *args, size_t size)
 static inline void test_clone3_supported(void)
 {
 	pid_t pid;
-	struct clone_args args = {};
+	struct __clone_args args = {};
 
 	if (__NR_clone3 < 0)
 		ksft_exit_skip("clone3() syscall is not supported\n");
diff --git a/tools/testing/selftests/clone3/clone3_set_tid.c b/tools/testing/selftests/clone3/clone3_set_tid.c
index 5831c1082d6d..0229e9ebb995 100644
--- a/tools/testing/selftests/clone3/clone3_set_tid.c
+++ b/tools/testing/selftests/clone3/clone3_set_tid.c
@@ -46,14 +46,14 @@ static int call_clone3_set_tid(pid_t *set_tid,
 	int status;
 	pid_t pid = -1;
 
-	struct clone_args args = {
+	struct __clone_args args = {
 		.flags = flags,
 		.exit_signal = SIGCHLD,
 		.set_tid = ptr_to_u64(set_tid),
 		.set_tid_size = set_tid_size,
 	};
 
-	pid = sys_clone3(&args, sizeof(struct clone_args));
+	pid = sys_clone3(&args, sizeof(args));
 	if (pid < 0) {
 		ksft_print_msg("%s - Failed to create new process\n",
 			       strerror(errno));
diff --git a/tools/testing/selftests/pidfd/pidfd_setns_test.c b/tools/testing/selftests/pidfd/pidfd_setns_test.c
index 7dca1aa4672d..1f085b922c6e 100644
--- a/tools/testing/selftests/pidfd/pidfd_setns_test.c
+++ b/tools/testing/selftests/pidfd/pidfd_setns_test.c
@@ -75,7 +75,7 @@ static int sys_waitid(int which, pid_t pid, int options)
 
 pid_t create_child(int *pidfd, unsigned flags)
 {
-	struct clone_args args = {
+	struct __clone_args args = {
 		.flags		= CLONE_PIDFD | flags,
 		.exit_signal	= SIGCHLD,
 		.pidfd		= ptr_to_u64(pidfd),
diff --git a/tools/testing/selftests/seccomp/seccomp_bpf.c b/tools/testing/selftests/seccomp/seccomp_bpf.c
index 7a6d40286a42..4a180439ee9e 100644
--- a/tools/testing/selftests/seccomp/seccomp_bpf.c
+++ b/tools/testing/selftests/seccomp/seccomp_bpf.c
@@ -774,8 +774,15 @@ void *kill_thread(void *data)
 	return (void *)SIBLING_EXIT_UNKILLED;
 }
 
+enum kill_t {
+	KILL_THREAD,
+	KILL_PROCESS,
+	RET_UNKNOWN
+};
+
 /* Prepare a thread that will kill itself or both of us. */
-void kill_thread_or_group(struct __test_metadata *_metadata, bool kill_process)
+void kill_thread_or_group(struct __test_metadata *_metadata,
+			  enum kill_t kill_how)
 {
 	pthread_t thread;
 	void *status;
@@ -791,11 +798,12 @@ void kill_thread_or_group(struct __test_metadata *_metadata, bool kill_process)
 		.len = (unsigned short)ARRAY_SIZE(filter_thread),
 		.filter = filter_thread,
 	};
+	int kill = kill_how == KILL_PROCESS ? SECCOMP_RET_KILL_PROCESS : 0xAAAAAAAAA;
 	struct sock_filter filter_process[] = {
 		BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
 			offsetof(struct seccomp_data, nr)),
 		BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_prctl, 0, 1),
-		BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL_PROCESS),
+		BPF_STMT(BPF_RET|BPF_K, kill),
 		BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
 	};
 	struct sock_fprog prog_process = {
@@ -808,13 +816,15 @@ void kill_thread_or_group(struct __test_metadata *_metadata, bool kill_process)
 	}
 
 	ASSERT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 0,
-			     kill_process ? &prog_process : &prog_thread));
+			     kill_how == KILL_THREAD ? &prog_thread
+						     : &prog_process));
 
 	/*
 	 * Add the KILL_THREAD rule again to make sure that the KILL_PROCESS
 	 * flag cannot be downgraded by a new filter.
 	 */
-	ASSERT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog_thread));
+	if (kill_how == KILL_PROCESS)
+		ASSERT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog_thread));
 
 	/* Start a thread that will exit immediately. */
 	ASSERT_EQ(0, pthread_create(&thread, NULL, kill_thread, (void *)false));
@@ -842,7 +852,7 @@ TEST(KILL_thread)
 	child_pid = fork();
 	ASSERT_LE(0, child_pid);
 	if (child_pid == 0) {
-		kill_thread_or_group(_metadata, false);
+		kill_thread_or_group(_metadata, KILL_THREAD);
 		_exit(38);
 	}
 
@@ -861,7 +871,7 @@ TEST(KILL_process)
 	child_pid = fork();
 	ASSERT_LE(0, child_pid);
 	if (child_pid == 0) {
-		kill_thread_or_group(_metadata, true);
+		kill_thread_or_group(_metadata, KILL_PROCESS);
 		_exit(38);
 	}
 
@@ -872,6 +882,27 @@ TEST(KILL_process)
 	ASSERT_EQ(SIGSYS, WTERMSIG(status));
 }
 
+TEST(KILL_unknown)
+{
+	int status;
+	pid_t child_pid;
+
+	child_pid = fork();
+	ASSERT_LE(0, child_pid);
+	if (child_pid == 0) {
+		kill_thread_or_group(_metadata, RET_UNKNOWN);
+		_exit(38);
+	}
+
+	ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0));
+
+	/* If the entire process was killed, we'll see SIGSYS. */
+	EXPECT_TRUE(WIFSIGNALED(status)) {
+		TH_LOG("Unknown SECCOMP_RET is only killing the thread?");
+	}
+	ASSERT_EQ(SIGSYS, WTERMSIG(status));
+}
+
 /* TODO(wad) add 64-bit versus 32-bit arg tests. */
 TEST(arg_out_of_range)
 {
@@ -1667,70 +1698,148 @@ TEST_F(TRACE_poke, getpid_runs_normally)
 }
 
 #if defined(__x86_64__)
-# define ARCH_REGS	struct user_regs_struct
-# define SYSCALL_NUM	orig_rax
-# define SYSCALL_RET	rax
+# define ARCH_REGS		struct user_regs_struct
+# define SYSCALL_NUM(_regs)	(_regs).orig_rax
+# define SYSCALL_RET(_regs)	(_regs).rax
 #elif defined(__i386__)
-# define ARCH_REGS	struct user_regs_struct
-# define SYSCALL_NUM	orig_eax
-# define SYSCALL_RET	eax
+# define ARCH_REGS		struct user_regs_struct
+# define SYSCALL_NUM(_regs)	(_regs).orig_eax
+# define SYSCALL_RET(_regs)	(_regs).eax
 #elif defined(__arm__)
-# define ARCH_REGS	struct pt_regs
-# define SYSCALL_NUM	ARM_r7
-# define SYSCALL_RET	ARM_r0
+# define ARCH_REGS		struct pt_regs
+# define SYSCALL_NUM(_regs)	(_regs).ARM_r7
+# ifndef PTRACE_SET_SYSCALL
+#  define PTRACE_SET_SYSCALL   23
+# endif
+# define SYSCALL_NUM_SET(_regs, _nr)	\
+		EXPECT_EQ(0, ptrace(PTRACE_SET_SYSCALL, tracee, NULL, _nr))
+# define SYSCALL_RET(_regs)	(_regs).ARM_r0
 #elif defined(__aarch64__)
-# define ARCH_REGS	struct user_pt_regs
-# define SYSCALL_NUM	regs[8]
-# define SYSCALL_RET	regs[0]
+# define ARCH_REGS		struct user_pt_regs
+# define SYSCALL_NUM(_regs)	(_regs).regs[8]
+# ifndef NT_ARM_SYSTEM_CALL
+#  define NT_ARM_SYSTEM_CALL 0x404
+# endif
+# define SYSCALL_NUM_SET(_regs, _nr)				\
+	do {							\
+		struct iovec __v;				\
+		typeof(_nr) __nr = (_nr);			\
+		__v.iov_base = &__nr;				\
+		__v.iov_len = sizeof(__nr);			\
+		EXPECT_EQ(0, ptrace(PTRACE_SETREGSET, tracee,	\
+				    NT_ARM_SYSTEM_CALL, &__v));	\
+	} while (0)
+# define SYSCALL_RET(_regs)	(_regs).regs[0]
 #elif defined(__riscv) && __riscv_xlen == 64
-# define ARCH_REGS	struct user_regs_struct
-# define SYSCALL_NUM	a7
-# define SYSCALL_RET	a0
+# define ARCH_REGS		struct user_regs_struct
+# define SYSCALL_NUM(_regs)	(_regs).a7
+# define SYSCALL_RET(_regs)	(_regs).a0
 #elif defined(__csky__)
-# define ARCH_REGS	struct pt_regs
-#if defined(__CSKYABIV2__)
-# define SYSCALL_NUM	regs[3]
-#else
-# define SYSCALL_NUM	regs[9]
-#endif
-# define SYSCALL_RET	a0
+# define ARCH_REGS		struct pt_regs
+#  if defined(__CSKYABIV2__)
+#   define SYSCALL_NUM(_regs)	(_regs).regs[3]
+#  else
+#   define SYSCALL_NUM(_regs)	(_regs).regs[9]
+#  endif
+# define SYSCALL_RET(_regs)	(_regs).a0
 #elif defined(__hppa__)
-# define ARCH_REGS	struct user_regs_struct
-# define SYSCALL_NUM	gr[20]
-# define SYSCALL_RET	gr[28]
+# define ARCH_REGS		struct user_regs_struct
+# define SYSCALL_NUM(_regs)	(_regs).gr[20]
+# define SYSCALL_RET(_regs)	(_regs).gr[28]
 #elif defined(__powerpc__)
-# define ARCH_REGS	struct pt_regs
-# define SYSCALL_NUM	gpr[0]
-# define SYSCALL_RET	gpr[3]
+# define ARCH_REGS		struct pt_regs
+# define SYSCALL_NUM(_regs)	(_regs).gpr[0]
+# define SYSCALL_RET(_regs)	(_regs).gpr[3]
+# define SYSCALL_RET_SET(_regs, _val)				\
+	do {							\
+		typeof(_val) _result = (_val);			\
+		/*						\
+		 * A syscall error is signaled by CR0 SO bit	\
+		 * and the code is stored as a positive value.	\
+		 */						\
+		if (_result < 0) {				\
+			SYSCALL_RET(_regs) = -result;		\
+			(_regs).ccr |= 0x10000000;		\
+		} else {					\
+			SYSCALL_RET(_regs) = result;		\
+			(_regs).ccr &= ~0x10000000;		\
+		}						\
+	} while (0)
+# define SYSCALL_RET_SET_ON_PTRACE_EXIT
 #elif defined(__s390__)
-# define ARCH_REGS     s390_regs
-# define SYSCALL_NUM   gprs[2]
-# define SYSCALL_RET   gprs[2]
-# define SYSCALL_NUM_RET_SHARE_REG
+# define ARCH_REGS		s390_regs
+# define SYSCALL_NUM(_regs)	(_regs).gprs[2]
+# define SYSCALL_RET_SET(_regs, _val)			\
+		TH_LOG("Can't modify syscall return on this architecture")
 #elif defined(__mips__)
-# define ARCH_REGS	struct pt_regs
-# define SYSCALL_NUM	regs[2]
-# define SYSCALL_SYSCALL_NUM regs[4]
-# define SYSCALL_RET	regs[2]
-# define SYSCALL_NUM_RET_SHARE_REG
+# include <asm/unistd_nr_n32.h>
+# include <asm/unistd_nr_n64.h>
+# include <asm/unistd_nr_o32.h>
+# define ARCH_REGS		struct pt_regs
+# define SYSCALL_NUM(_regs)				\
+	({						\
+		typeof((_regs).regs[2]) _nr;		\
+		if ((_regs).regs[2] == __NR_O32_Linux)	\
+			_nr = (_regs).regs[4];		\
+		else					\
+			_nr = (_regs).regs[2];		\
+		_nr;					\
+	})
+# define SYSCALL_NUM_SET(_regs, _nr)			\
+	do {						\
+		if ((_regs).regs[2] == __NR_O32_Linux)	\
+			(_regs).regs[4] = _nr;		\
+		else					\
+			(_regs).regs[2] = _nr;		\
+	} while (0)
+# define SYSCALL_RET_SET(_regs, _val)			\
+		TH_LOG("Can't modify syscall return on this architecture")
 #elif defined(__xtensa__)
-# define ARCH_REGS	struct user_pt_regs
-# define SYSCALL_NUM	syscall
+# define ARCH_REGS		struct user_pt_regs
+# define SYSCALL_NUM(_regs)	(_regs).syscall
 /*
  * On xtensa syscall return value is in the register
  * a2 of the current window which is not fixed.
  */
-#define SYSCALL_RET(reg) a[(reg).windowbase * 4 + 2]
+#define SYSCALL_RET(_regs)	(_regs).a[(_regs).windowbase * 4 + 2]
 #elif defined(__sh__)
-# define ARCH_REGS	struct pt_regs
-# define SYSCALL_NUM	gpr[3]
-# define SYSCALL_RET	gpr[0]
+# define ARCH_REGS		struct pt_regs
+# define SYSCALL_NUM(_regs)	(_regs).gpr[3]
+# define SYSCALL_RET(_regs)	(_regs).gpr[0]
 #else
 # error "Do not know how to find your architecture's registers and syscalls"
 #endif
 
+/*
+ * Most architectures can change the syscall by just updating the
+ * associated register. This is the default if not defined above.
+ */
+#ifndef SYSCALL_NUM_SET
+# define SYSCALL_NUM_SET(_regs, _nr)		\
+	do {					\
+		SYSCALL_NUM(_regs) = (_nr);	\
+	} while (0)
+#endif
+/*
+ * Most architectures can change the syscall return value by just
+ * writing to the SYSCALL_RET register. This is the default if not
+ * defined above. If an architecture cannot set the return value
+ * (for example when the syscall and return value register is
+ * shared), report it with TH_LOG() in an arch-specific definition
+ * of SYSCALL_RET_SET() above, and leave SYSCALL_RET undefined.
+ */
+#if !defined(SYSCALL_RET) && !defined(SYSCALL_RET_SET)
+# error "One of SYSCALL_RET or SYSCALL_RET_SET is needed for this arch"
+#endif
+#ifndef SYSCALL_RET_SET
+# define SYSCALL_RET_SET(_regs, _val)		\
+	do {					\
+		SYSCALL_RET(_regs) = (_val);	\
+	} while (0)
+#endif
+
 /* When the syscall return can't be changed, stub out the tests for it. */
-#ifdef SYSCALL_NUM_RET_SHARE_REG
+#ifndef SYSCALL_RET
 # define EXPECT_SYSCALL_RETURN(val, action)	EXPECT_EQ(-1, action)
 #else
 # define EXPECT_SYSCALL_RETURN(val, action)		\
@@ -1745,116 +1854,92 @@ TEST_F(TRACE_poke, getpid_runs_normally)
 	} while (0)
 #endif
 
-/* Use PTRACE_GETREGS and PTRACE_SETREGS when available. This is useful for
+/*
+ * Some architectures (e.g. powerpc) can only set syscall
+ * return values on syscall exit during ptrace.
+ */
+const bool ptrace_entry_set_syscall_nr = true;
+const bool ptrace_entry_set_syscall_ret =
+#ifndef SYSCALL_RET_SET_ON_PTRACE_EXIT
+	true;
+#else
+	false;
+#endif
+
+/*
+ * Use PTRACE_GETREGS and PTRACE_SETREGS when available. This is useful for
  * architectures without HAVE_ARCH_TRACEHOOK (e.g. User-mode Linux).
  */
 #if defined(__x86_64__) || defined(__i386__) || defined(__mips__)
-#define HAVE_GETREGS
+# define ARCH_GETREGS(_regs)	ptrace(PTRACE_GETREGS, tracee, 0, &(_regs))
+# define ARCH_SETREGS(_regs)	ptrace(PTRACE_SETREGS, tracee, 0, &(_regs))
+#else
+# define ARCH_GETREGS(_regs)	({					\
+		struct iovec __v;					\
+		__v.iov_base = &(_regs);				\
+		__v.iov_len = sizeof(_regs);				\
+		ptrace(PTRACE_GETREGSET, tracee, NT_PRSTATUS, &__v);	\
+	})
+# define ARCH_SETREGS(_regs)	({					\
+		struct iovec __v;					\
+		__v.iov_base = &(_regs);				\
+		__v.iov_len = sizeof(_regs);				\
+		ptrace(PTRACE_SETREGSET, tracee, NT_PRSTATUS, &__v);	\
+	})
 #endif
 
 /* Architecture-specific syscall fetching routine. */
 int get_syscall(struct __test_metadata *_metadata, pid_t tracee)
 {
 	ARCH_REGS regs;
-#ifdef HAVE_GETREGS
-	EXPECT_EQ(0, ptrace(PTRACE_GETREGS, tracee, 0, &regs)) {
-		TH_LOG("PTRACE_GETREGS failed");
-		return -1;
-	}
-#else
-	struct iovec iov;
 
-	iov.iov_base = &regs;
-	iov.iov_len = sizeof(regs);
-	EXPECT_EQ(0, ptrace(PTRACE_GETREGSET, tracee, NT_PRSTATUS, &iov)) {
-		TH_LOG("PTRACE_GETREGSET failed");
+	EXPECT_EQ(0, ARCH_GETREGS(regs)) {
 		return -1;
 	}
-#endif
 
-#if defined(__mips__)
-	if (regs.SYSCALL_NUM == __NR_O32_Linux)
-		return regs.SYSCALL_SYSCALL_NUM;
-#endif
-	return regs.SYSCALL_NUM;
+	return SYSCALL_NUM(regs);
 }
 
 /* Architecture-specific syscall changing routine. */
-void change_syscall(struct __test_metadata *_metadata,
-		    pid_t tracee, int syscall, int result)
+void __change_syscall(struct __test_metadata *_metadata,
+		    pid_t tracee, long *syscall, long *ret)
 {
-	int ret;
-	ARCH_REGS regs;
-#ifdef HAVE_GETREGS
-	ret = ptrace(PTRACE_GETREGS, tracee, 0, &regs);
-#else
-	struct iovec iov;
-	iov.iov_base = &regs;
-	iov.iov_len = sizeof(regs);
-	ret = ptrace(PTRACE_GETREGSET, tracee, NT_PRSTATUS, &iov);
-#endif
-	EXPECT_EQ(0, ret) {}
+	ARCH_REGS orig, regs;
 
-#if defined(__x86_64__) || defined(__i386__) || defined(__powerpc__) || \
-	defined(__s390__) || defined(__hppa__) || defined(__riscv) || \
-	defined(__xtensa__) || defined(__csky__) || defined(__sh__)
-	{
-		regs.SYSCALL_NUM = syscall;
-	}
-#elif defined(__mips__)
-	{
-		if (regs.SYSCALL_NUM == __NR_O32_Linux)
-			regs.SYSCALL_SYSCALL_NUM = syscall;
-		else
-			regs.SYSCALL_NUM = syscall;
-	}
+	/* Do not get/set registers if we have nothing to do. */
+	if (!syscall && !ret)
+		return;
 
-#elif defined(__arm__)
-# ifndef PTRACE_SET_SYSCALL
-#  define PTRACE_SET_SYSCALL   23
-# endif
-	{
-		ret = ptrace(PTRACE_SET_SYSCALL, tracee, NULL, syscall);
-		EXPECT_EQ(0, ret);
+	EXPECT_EQ(0, ARCH_GETREGS(regs)) {
+		return;
 	}
+	orig = regs;
 
-#elif defined(__aarch64__)
-# ifndef NT_ARM_SYSTEM_CALL
-#  define NT_ARM_SYSTEM_CALL 0x404
-# endif
-	{
-		iov.iov_base = &syscall;
-		iov.iov_len = sizeof(syscall);
-		ret = ptrace(PTRACE_SETREGSET, tracee, NT_ARM_SYSTEM_CALL,
-			     &iov);
-		EXPECT_EQ(0, ret);
-	}
+	if (syscall)
+		SYSCALL_NUM_SET(regs, *syscall);
 
-#else
-	ASSERT_EQ(1, 0) {
-		TH_LOG("How is the syscall changed on this architecture?");
-	}
-#endif
+	if (ret)
+		SYSCALL_RET_SET(regs, *ret);
 
-	/* If syscall is skipped, change return value. */
-	if (syscall == -1)
-#ifdef SYSCALL_NUM_RET_SHARE_REG
-		TH_LOG("Can't modify syscall return on this architecture");
+	/* Flush any register changes made. */
+	if (memcmp(&orig, &regs, sizeof(orig)) != 0)
+		EXPECT_EQ(0, ARCH_SETREGS(regs));
+}
 
-#elif defined(__xtensa__)
-		regs.SYSCALL_RET(regs) = result;
-#else
-		regs.SYSCALL_RET = result;
-#endif
+/* Change only syscall number. */
+void change_syscall_nr(struct __test_metadata *_metadata,
+		       pid_t tracee, long syscall)
+{
+	__change_syscall(_metadata, tracee, &syscall, NULL);
+}
 
-#ifdef HAVE_GETREGS
-	ret = ptrace(PTRACE_SETREGS, tracee, 0, &regs);
-#else
-	iov.iov_base = &regs;
-	iov.iov_len = sizeof(regs);
-	ret = ptrace(PTRACE_SETREGSET, tracee, NT_PRSTATUS, &iov);
-#endif
-	EXPECT_EQ(0, ret);
+/* Change syscall return value (and set syscall number to -1). */
+void change_syscall_ret(struct __test_metadata *_metadata,
+			pid_t tracee, long ret)
+{
+	long syscall = -1;
+
+	__change_syscall(_metadata, tracee, &syscall, &ret);
 }
 
 void tracer_seccomp(struct __test_metadata *_metadata, pid_t tracee,
@@ -1872,17 +1957,17 @@ void tracer_seccomp(struct __test_metadata *_metadata, pid_t tracee,
 	case 0x1002:
 		/* change getpid to getppid. */
 		EXPECT_EQ(__NR_getpid, get_syscall(_metadata, tracee));
-		change_syscall(_metadata, tracee, __NR_getppid, 0);
+		change_syscall_nr(_metadata, tracee, __NR_getppid);
 		break;
 	case 0x1003:
 		/* skip gettid with valid return code. */
 		EXPECT_EQ(__NR_gettid, get_syscall(_metadata, tracee));
-		change_syscall(_metadata, tracee, -1, 45000);
+		change_syscall_ret(_metadata, tracee, 45000);
 		break;
 	case 0x1004:
 		/* skip openat with error. */
 		EXPECT_EQ(__NR_openat, get_syscall(_metadata, tracee));
-		change_syscall(_metadata, tracee, -1, -ESRCH);
+		change_syscall_ret(_metadata, tracee, -ESRCH);
 		break;
 	case 0x1005:
 		/* do nothing (allow getppid) */
@@ -1897,12 +1982,21 @@ void tracer_seccomp(struct __test_metadata *_metadata, pid_t tracee,
 
 }
 
+FIXTURE(TRACE_syscall) {
+	struct sock_fprog prog;
+	pid_t tracer, mytid, mypid, parent;
+	long syscall_nr;
+};
+
 void tracer_ptrace(struct __test_metadata *_metadata, pid_t tracee,
 		   int status, void *args)
 {
-	int ret, nr;
+	int ret;
 	unsigned long msg;
 	static bool entry;
+	long syscall_nr_val, syscall_ret_val;
+	long *syscall_nr = NULL, *syscall_ret = NULL;
+	FIXTURE_DATA(TRACE_syscall) *self = args;
 
 	/*
 	 * The traditional way to tell PTRACE_SYSCALL entry/exit
@@ -1916,24 +2010,48 @@ void tracer_ptrace(struct __test_metadata *_metadata, pid_t tracee,
 	EXPECT_EQ(entry ? PTRACE_EVENTMSG_SYSCALL_ENTRY
 			: PTRACE_EVENTMSG_SYSCALL_EXIT, msg);
 
-	if (!entry)
-		return;
+	/*
+	 * Some architectures only support setting return values during
+	 * syscall exit under ptrace, and on exit the syscall number may
+	 * no longer be available. Therefore, save the initial sycall
+	 * number here, so it can be examined during both entry and exit
+	 * phases.
+	 */
+	if (entry)
+		self->syscall_nr = get_syscall(_metadata, tracee);
 
-	nr = get_syscall(_metadata, tracee);
+	/*
+	 * Depending on the architecture's syscall setting abilities, we
+	 * pick which things to set during this phase (entry or exit).
+	 */
+	if (entry == ptrace_entry_set_syscall_nr)
+		syscall_nr = &syscall_nr_val;
+	if (entry == ptrace_entry_set_syscall_ret)
+		syscall_ret = &syscall_ret_val;
+
+	/* Now handle the actual rewriting cases. */
+	switch (self->syscall_nr) {
+	case __NR_getpid:
+		syscall_nr_val = __NR_getppid;
+		/* Never change syscall return for this case. */
+		syscall_ret = NULL;
+		break;
+	case __NR_gettid:
+		syscall_nr_val = -1;
+		syscall_ret_val = 45000;
+		break;
+	case __NR_openat:
+		syscall_nr_val = -1;
+		syscall_ret_val = -ESRCH;
+		break;
+	default:
+		/* Unhandled, do nothing. */
+		return;
+	}
 
-	if (nr == __NR_getpid)
-		change_syscall(_metadata, tracee, __NR_getppid, 0);
-	if (nr == __NR_gettid)
-		change_syscall(_metadata, tracee, -1, 45000);
-	if (nr == __NR_openat)
-		change_syscall(_metadata, tracee, -1, -ESRCH);
+	__change_syscall(_metadata, tracee, syscall_nr, syscall_ret);
 }
 
-FIXTURE(TRACE_syscall) {
-	struct sock_fprog prog;
-	pid_t tracer, mytid, mypid, parent;
-};
-
 FIXTURE_VARIANT(TRACE_syscall) {
 	/*
 	 * All of the SECCOMP_RET_TRACE behaviors can be tested with either
@@ -1992,7 +2110,7 @@ FIXTURE_SETUP(TRACE_syscall)
 	self->tracer = setup_trace_fixture(_metadata,
 					   variant->use_ptrace ? tracer_ptrace
 							       : tracer_seccomp,
-					   NULL, variant->use_ptrace);
+					   self, variant->use_ptrace);
 
 	ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
 	ASSERT_EQ(0, ret);
@@ -3142,11 +3260,11 @@ skip:
 static int user_notif_syscall(int nr, unsigned int flags)
 {
 	struct sock_filter filter[] = {
-		BPF_STMT(BPF_LD+BPF_W+BPF_ABS,
+		BPF_STMT(BPF_LD|BPF_W|BPF_ABS,
 			offsetof(struct seccomp_data, nr)),
-		BPF_JUMP(BPF_JMP+BPF_JEQ+BPF_K, nr, 0, 1),
-		BPF_STMT(BPF_RET+BPF_K, SECCOMP_RET_USER_NOTIF),
-		BPF_STMT(BPF_RET+BPF_K, SECCOMP_RET_ALLOW),
+		BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, nr, 0, 1),
+		BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_USER_NOTIF),
+		BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW),
 	};
 
 	struct sock_fprog prog = {
@@ -3699,7 +3817,7 @@ TEST(user_notification_filter_empty)
 	long ret;
 	int status;
 	struct pollfd pollfd;
-	struct clone_args args = {
+	struct __clone_args args = {
 		.flags = CLONE_FILES,
 		.exit_signal = SIGCHLD,
 	};
@@ -3715,7 +3833,7 @@ TEST(user_notification_filter_empty)
 	if (pid == 0) {
 		int listener;
 
-		listener = user_notif_syscall(__NR_mknod, SECCOMP_FILTER_FLAG_NEW_LISTENER);
+		listener = user_notif_syscall(__NR_mknodat, SECCOMP_FILTER_FLAG_NEW_LISTENER);
 		if (listener < 0)
 			_exit(EXIT_FAILURE);
 
@@ -3753,7 +3871,7 @@ TEST(user_notification_filter_empty_threaded)
 	long ret;
 	int status;
 	struct pollfd pollfd;
-	struct clone_args args = {
+	struct __clone_args args = {
 		.flags = CLONE_FILES,
 		.exit_signal = SIGCHLD,
 	};