Implement decoding of pidfd_send_signal syscall

... introduced by Linux kernel commit v5.1-rc1~6^2~1.

* signal.c (SYS_FUNC(pidfd_send_signal)): New function.
* linux/32/syscallent.h [424]: Wire up pidfd_send_signal.
* linux/64/syscallent.h: Likewise.
* linux/arm/syscallent.h: Likewise.
* linux/hppa/syscallent.h: Likewise.
* linux/i386/syscallent.h: Likewise.
* linux/m68k/syscallent.h: Likewise.
* linux/microblaze/syscallent.h: Likewise.
* linux/powerpc/syscallent.h: Likewise.
* linux/powerpc64/syscallent.h: Likewise.
* linux/s390/syscallent.h: Likewise.
* linux/s390x/syscallent.h: Likewise.
* linux/sh/syscallent.h: Likewise.
* linux/sh64/syscallent.h: Likewise.
* linux/sparc/syscallent.h: Likewise.
* linux/sparc64/syscallent.h: Likewise.
* linux/x32/syscallent.h: Likewise.
* linux/x86_64/syscallent.h: Likewise.
* linux/xtensa/syscallent.h: Likewise.
* linux/alpha/syscallent.h [534]: Likewise.
* linux/ia64/syscallent.h [1024 + 424]: Likewise.
* linux/mips/syscallent-n32.h [6424]: Likewise.
* linux/mips/syscallent-n64.h [5424]: Likewise.
* linux/mips/syscallent-o32.h [4424]: Likewise.
* NEWS: Mention this change.
* tests/pidfd_send_signal.c: New file.
* tests/gen_tests.in (pidfd_send_signal): New entry.
* tests/pure_executables.list: Add pidfd_send_signal.
* tests/.gitignore: Likewise.

29 files changed, 114 insertions, 3 deletions

diff --git a/NEWS b/NEWS
index 11fa59536..d4d3e9443 100644
--- a/NEWS
+++ b/NEWS
@@ -7,13 +7,13 @@ Noteworthy changes in release ?.? (????-??-??)
 * Improvements
   * Added C-SKY architecture support.
   * Implemented decoding of SO_TIMESTAMP*_NEW control messages.
-  * Wired up clock_gettime64, clock_settime64, clock_adjtime64,
+  * Implemented decoding of clock_gettime64, clock_settime64, clock_adjtime64,
     clock_getres_time64, clock_nanosleep_time64, timer_gettime64,
     timer_settime64, timerfd_gettime64, timerfd_settime64, utimensat_time64,
     pselect6_time64, ppoll_time64, io_pgetevents_time64, recvmmsg_time64,
     mq_timedsend_time64, mq_timedreceive_time64, semtimedop_time64,
-    rt_sigtimedwait_time64, futex_time64, and sched_rr_get_interval_time64
-    syscalls.
+    rt_sigtimedwait_time64, futex_time64, sched_rr_get_interval_time64,
+    and pidfd_send_signal syscalls.
   * Wired up getegid, geteuid, getppid, io_pgetevents, statfs64, and fstatfs64
     syscalls on alpha.
   * Wired up kexec_file_load and migrate_pages syscalls on arm.
diff --git a/linux/32/syscallent.h b/linux/32/syscallent.h
index 3fba90512..0d78f42e9 100644
--- a/linux/32/syscallent.h
+++ b/linux/32/syscallent.h
@@ -312,6 +312,7 @@
 [421] = { 4,	TS,		SEN(rt_sigtimedwait_time64),	"rt_sigtimedwait_time64"},
 [422] = { 6,	0,		SEN(futex_time64),		"futex_time64"		},
 [423] = { 2,	0,		SEN(sched_rr_get_interval_time64),	"sched_rr_get_interval_time64"	},
+[424] = { 4,	TD|TS,		SEN(pidfd_send_signal),		"pidfd_send_signal"	},
 
 #undef sys_ARCH_mmap
 #undef ARCH_WANT_SYNC_FILE_RANGE2
diff --git a/linux/64/syscallent.h b/linux/64/syscallent.h
index 4335145dc..7188f73bd 100644
--- a/linux/64/syscallent.h
+++ b/linux/64/syscallent.h
@@ -286,3 +286,4 @@
 [293] = { 4,	0,		SEN(rseq),			"rseq"			},
 [294] = { 5,	TD,		SEN(kexec_file_load),		"kexec_file_load"	},
 /* [295 ... 423] - reserved to sync up with other architectures */
+[424] = { 4,	TD|TS,		SEN(pidfd_send_signal),		"pidfd_send_signal"	},
diff --git a/linux/alpha/syscallent.h b/linux/alpha/syscallent.h
index a48e5a75c..c78a120a0 100644
--- a/linux/alpha/syscallent.h
+++ b/linux/alpha/syscallent.h
@@ -476,3 +476,5 @@
 [530] = { 0,	PU|NF,		SEN(getegid),			"getegid"		},
 [531] = { 0,	PU|NF,		SEN(geteuid),			"geteuid"		},
 [532] = { 0,	PU|NF,		SEN(getppid),			"getppid"		},
+/* all other architectures have common numbers for new syscalls, alpha is the exception */
+[534] = { 4,	TD|TS,		SEN(pidfd_send_signal),		"pidfd_send_signal"	},
diff --git a/linux/arm/syscallent.h b/linux/arm/syscallent.h
index f17b85b20..73d29eff2 100644
--- a/linux/arm/syscallent.h
+++ b/linux/arm/syscallent.h
@@ -430,6 +430,7 @@
 [421] = { 4,	TS,		SEN(rt_sigtimedwait_time64),	"rt_sigtimedwait_time64"},
 [422] = { 6,	0,		SEN(futex_time64),		"futex_time64"		},
 [423] = { 2,	0,		SEN(sched_rr_get_interval_time64),	"sched_rr_get_interval_time64"	},
+[424] = { 4,	TD|TS,		SEN(pidfd_send_signal),		"pidfd_send_signal"	},
 
 #ifdef __ARM_EABI__
 # define ARM_FIRST_SHUFFLED_SYSCALL 500
diff --git a/linux/hppa/syscallent.h b/linux/hppa/syscallent.h
index ebeaa1839..56f5682be 100644
--- a/linux/hppa/syscallent.h
+++ b/linux/hppa/syscallent.h
@@ -379,3 +379,4 @@
 [421] = { 4,	TS,		SEN(rt_sigtimedwait_time64),	"rt_sigtimedwait_time64"},
 [422] = { 6,	0,		SEN(futex_time64),		"futex_time64"		},
 [423] = { 2,	0,		SEN(sched_rr_get_interval_time64),	"sched_rr_get_interval_time64"	},
+[424] = { 4,	TD|TS,		SEN(pidfd_send_signal),		"pidfd_send_signal"	},
diff --git a/linux/i386/syscallent.h b/linux/i386/syscallent.h
index 123c74b40..fee1cddf8 100644
--- a/linux/i386/syscallent.h
+++ b/linux/i386/syscallent.h
@@ -424,6 +424,7 @@
 [421] = { 4,	TS,		SEN(rt_sigtimedwait_time64),	"rt_sigtimedwait_time64"},
 [422] = { 6,	0,		SEN(futex_time64),		"futex_time64"		},
 [423] = { 2,	0,		SEN(sched_rr_get_interval_time64),	"sched_rr_get_interval_time64"	},
+[424] = { 4,	TD|TS,		SEN(pidfd_send_signal),		"pidfd_send_signal"	},
 
 #define SYS_socket_subcall	500
 #include "subcall32.h"
diff --git a/linux/ia64/syscallent.h b/linux/ia64/syscallent.h
index bdbf44726..1e3934be5 100644
--- a/linux/ia64/syscallent.h
+++ b/linux/ia64/syscallent.h
@@ -342,3 +342,4 @@
 [1024 + 332] = { 1,	0,		SEN(pkey_free),			"pkey_free"		},
 [1024 + 333] = { 4,	0,		SEN(rseq),			"rseq"			},
 /* [1024 + 334 ... 1024 + 423] - reserved to sync up with other architectures */
+[1024 + 424] = { 4,	TD|TS,		SEN(pidfd_send_signal),		"pidfd_send_signal"	},
diff --git a/linux/m68k/syscallent.h b/linux/m68k/syscallent.h
index 2e9dc8351..c35b0765e 100644
--- a/linux/m68k/syscallent.h
+++ b/linux/m68k/syscallent.h
@@ -422,6 +422,7 @@
 [421] = { 4,	TS,		SEN(rt_sigtimedwait_time64),	"rt_sigtimedwait_time64"},
 [422] = { 6,	0,		SEN(futex_time64),		"futex_time64"		},
 [423] = { 2,	0,		SEN(sched_rr_get_interval_time64),	"sched_rr_get_interval_time64"	},
+[424] = { 4,	TD|TS,		SEN(pidfd_send_signal),		"pidfd_send_signal"	},
 
 #define SYS_socket_subcall	500
 #include "subcall32.h"
diff --git a/linux/microblaze/syscallent.h b/linux/microblaze/syscallent.h
index ad23bee82..aeda7b84e 100644
--- a/linux/microblaze/syscallent.h
+++ b/linux/microblaze/syscallent.h
@@ -428,3 +428,4 @@
 [421] = { 4,	TS,		SEN(rt_sigtimedwait_time64),	"rt_sigtimedwait_time64"},
 [422] = { 6,	0,		SEN(futex_time64),		"futex_time64"		},
 [423] = { 2,	0,		SEN(sched_rr_get_interval_time64),	"sched_rr_get_interval_time64"	},
+[424] = { 4,	TD|TS,		SEN(pidfd_send_signal),		"pidfd_send_signal"	},
diff --git a/linux/mips/syscallent-n32.h b/linux/mips/syscallent-n32.h
index 7f7aa07b3..e9c5e5d23 100644
--- a/linux/mips/syscallent-n32.h
+++ b/linux/mips/syscallent-n32.h
@@ -361,6 +361,7 @@
 [6421] = { 4,	TS,		SEN(rt_sigtimedwait_time64),	"rt_sigtimedwait_time64"},
 [6422] = { 6,	0,		SEN(futex_time64),		"futex_time64"		},
 [6423] = { 2,	0,		SEN(sched_rr_get_interval_time64),	"sched_rr_get_interval_time64"	},
+[6424] = { 4,	TD|TS,		SEN(pidfd_send_signal),		"pidfd_send_signal"	},
 
 # define SYS_socket_subcall      6500
 # include "subcall32.h"
diff --git a/linux/mips/syscallent-n64.h b/linux/mips/syscallent-n64.h
index baaab654b..f2bb30c52 100644
--- a/linux/mips/syscallent-n64.h
+++ b/linux/mips/syscallent-n64.h
@@ -337,6 +337,7 @@
 [5327] = { 4,	0,		SEN(rseq),			"rseq"			},
 [5328] = { 6,	0,		SEN(io_pgetevents_time64),	"io_pgetevents"		},
 /* [5329 ... 5423] - reserved to sync up with other architectures */
+[5424] = { 4,	TD|TS,		SEN(pidfd_send_signal),		"pidfd_send_signal"	},
 
 # define SYS_socket_subcall      5500
 # include "subcall64.h"
diff --git a/linux/mips/syscallent-o32.h b/linux/mips/syscallent-o32.h
index df0c98a58..9cd3b1d0c 100644
--- a/linux/mips/syscallent-o32.h
+++ b/linux/mips/syscallent-o32.h
@@ -408,6 +408,7 @@
 [4421] = { 4,	TS,		SEN(rt_sigtimedwait_time64),	"rt_sigtimedwait_time64"},
 [4422] = { 6,	0,		SEN(futex_time64),		"futex_time64"		},
 [4423] = { 2,	0,		SEN(sched_rr_get_interval_time64),	"sched_rr_get_interval_time64"	},
+[4424] = { 4,	TD|TS,		SEN(pidfd_send_signal),		"pidfd_send_signal"	},
 
 # define SYS_socket_subcall      4500
 # include "subcall32.h"
diff --git a/linux/powerpc/syscallent.h b/linux/powerpc/syscallent.h
index b5eeaece2..ecda494c2 100644
--- a/linux/powerpc/syscallent.h
+++ b/linux/powerpc/syscallent.h
@@ -416,6 +416,7 @@
 [421] = { 4,	TS,		SEN(rt_sigtimedwait_time64),	"rt_sigtimedwait_time64"},
 [422] = { 6,	0,		SEN(futex_time64),		"futex_time64"		},
 [423] = { 2,	0,		SEN(sched_rr_get_interval_time64),	"sched_rr_get_interval_time64"	},
+[424] = { 4,	TD|TS,		SEN(pidfd_send_signal),		"pidfd_send_signal"	},
 
 #define SYS_socket_subcall	500
 #include "subcall32.h"
diff --git a/linux/powerpc64/syscallent.h b/linux/powerpc64/syscallent.h
index e282198b1..3352b346e 100644
--- a/linux/powerpc64/syscallent.h
+++ b/linux/powerpc64/syscallent.h
@@ -393,6 +393,7 @@
 [401] = { 5,	TI,		SEN(msgrcv),			"msgrcv"		},
 [402] = { 3,	TI,		SEN(msgctl),			"msgctl"		},
 /* [403 ... 423] - reserved to sync up with other architectures */
+[424] = { 4,	TD|TS,		SEN(pidfd_send_signal),		"pidfd_send_signal"	},
 
 #define SYS_socket_subcall	500
 #include "subcall64.h"
diff --git a/linux/s390/syscallent.h b/linux/s390/syscallent.h
index eff90fc06..8eaeae737 100644
--- a/linux/s390/syscallent.h
+++ b/linux/s390/syscallent.h
@@ -427,6 +427,7 @@
 [421] = { 4,	TS,		SEN(rt_sigtimedwait_time64),	"rt_sigtimedwait_time64"},
 [422] = { 6,	0,		SEN(futex_time64),		"futex_time64"		},
 [423] = { 2,	0,		SEN(sched_rr_get_interval_time64),	"sched_rr_get_interval_time64"	},
+[424] = { 4,	TD|TS,		SEN(pidfd_send_signal),		"pidfd_send_signal"	},
 
 #define SYS_socket_subcall	500
 #include "subcall32.h"
diff --git a/linux/s390x/syscallent.h b/linux/s390x/syscallent.h
index 8561fdd16..3cf61144c 100644
--- a/linux/s390x/syscallent.h
+++ b/linux/s390x/syscallent.h
@@ -393,6 +393,7 @@
 [401] = { 5,	TI,		SEN(msgrcv),			"msgrcv"		},
 [402] = { 3,	TI,		SEN(msgctl),			"msgctl"		},
 /* [403 ... 423] - reserved to sync up with other architectures */
+[424] = { 4,	TD|TS,		SEN(pidfd_send_signal),		"pidfd_send_signal"	},
 
 #define SYS_socket_subcall	500
 #include "subcall64.h"
diff --git a/linux/sh/syscallent.h b/linux/sh/syscallent.h
index d97f0aaae..b14d7ed1a 100644
--- a/linux/sh/syscallent.h
+++ b/linux/sh/syscallent.h
@@ -425,6 +425,7 @@
 [421] = { 4,	TS,		SEN(rt_sigtimedwait_time64),	"rt_sigtimedwait_time64"},
 [422] = { 6,	0,		SEN(futex_time64),		"futex_time64"		},
 [423] = { 2,	0,		SEN(sched_rr_get_interval_time64),	"sched_rr_get_interval_time64"	},
+[424] = { 4,	TD|TS,		SEN(pidfd_send_signal),		"pidfd_send_signal"	},
 
 #define SYS_socket_subcall	500
 #include "subcall32.h"
diff --git a/linux/sh64/syscallent.h b/linux/sh64/syscallent.h
index c5a8fdea0..8a068ce5c 100644
--- a/linux/sh64/syscallent.h
+++ b/linux/sh64/syscallent.h
@@ -399,6 +399,7 @@
 [392] = { 6,	TD,		SEN(preadv2),			"preadv2"		},
 [393] = { 6,	TD,		SEN(pwritev2),			"pwritev2"		},
 /* [403 ... 423] - reserved to sync up with other architectures */
+[424] = { 4,	TD|TS,		SEN(pidfd_send_signal),		"pidfd_send_signal"	},
 
 #define SYS_socket_subcall	500
 #include "subcall64.h"
diff --git a/linux/sparc/syscallent.h b/linux/sparc/syscallent.h
index 18aa94f99..19900af32 100644
--- a/linux/sparc/syscallent.h
+++ b/linux/sparc/syscallent.h
@@ -402,6 +402,7 @@
 [421] = { 4,	TS,		SEN(rt_sigtimedwait_time64),	"rt_sigtimedwait_time64"},
 [422] = { 6,	0,		SEN(futex_time64),		"futex_time64"		},
 [423] = { 2,	0,		SEN(sched_rr_get_interval_time64),	"sched_rr_get_interval_time64"	},
+[424] = { 4,	TD|TS,		SEN(pidfd_send_signal),		"pidfd_send_signal"	},
 
 #define SYS_socket_subcall	500
 #include "subcall32.h"
diff --git a/linux/sparc64/syscallent.h b/linux/sparc64/syscallent.h
index 77123091f..1ed0dc234 100644
--- a/linux/sparc64/syscallent.h
+++ b/linux/sparc64/syscallent.h
@@ -382,6 +382,7 @@
 [401] = { 5,	TI,		SEN(msgrcv),			"msgrcv"		},
 [402] = { 3,	TI,		SEN(msgctl),			"msgctl"		},
 /* [403 ... 423] - reserved to sync up with other architectures */
+[424] = { 4,	TD|TS,		SEN(pidfd_send_signal),		"pidfd_send_signal"	},
 
 #define SYS_socket_subcall	500
 #include "subcall64.h"
diff --git a/linux/x32/syscallent.h b/linux/x32/syscallent.h
index 2446f0b30..d0f8e8db0 100644
--- a/linux/x32/syscallent.h
+++ b/linux/x32/syscallent.h
@@ -341,6 +341,7 @@
 [333] = { 6,	0,		SEN(io_pgetevents_time64),	"io_pgetevents"		},
 [334] = { 4,	0,		SEN(rseq),			"rseq"			},
 /* [335 ... 423] - reserved to sync up with other architectures */
+[424] = { 4,	TD|TS,		SEN(pidfd_send_signal),		"pidfd_send_signal"	},
 /*
  * x32-specific system call numbers start at 512 to avoid cache impact
  * for native 64-bit operation.
diff --git a/linux/x86_64/syscallent.h b/linux/x86_64/syscallent.h
index 3e0ce6198..2ac8dc6c1 100644
--- a/linux/x86_64/syscallent.h
+++ b/linux/x86_64/syscallent.h
@@ -341,3 +341,4 @@
 [333] = { 6,	0,		SEN(io_pgetevents_time64),	"io_pgetevents"		},
 [334] = { 4,	0,		SEN(rseq),			"rseq"			},
 /* [335 ... 423] - reserved to sync up with other architectures */
+[424] = { 4,	TD|TS,		SEN(pidfd_send_signal),		"pidfd_send_signal"	},
diff --git a/linux/xtensa/syscallent.h b/linux/xtensa/syscallent.h
index d01c7957d..6d0925710 100644
--- a/linux/xtensa/syscallent.h
+++ b/linux/xtensa/syscallent.h
@@ -369,3 +369,4 @@
 [421] = { 4,	TS,		SEN(rt_sigtimedwait_time64),	"rt_sigtimedwait_time64"},
 [422] = { 6,	0,		SEN(futex_time64),		"futex_time64"		},
 [423] = { 2,	0,		SEN(sched_rr_get_interval_time64),	"sched_rr_get_interval_time64"	},
+[424] = { 4,	TD|TS,		SEN(pidfd_send_signal),		"pidfd_send_signal"	},
diff --git a/signal.c b/signal.c
index a8c78a9f3..fcaf9d4ff 100644
--- a/signal.c
+++ b/signal.c
@@ -648,6 +648,19 @@ SYS_FUNC(rt_tgsigqueueinfo)
 	return RVAL_DECODED;
 }
 
+SYS_FUNC(pidfd_send_signal)
+{
+	/* int pidfd */
+	printfd(tcp, tcp->u_arg[0]);
+	/* int sig, siginfo_t *info */
+	tprints(", ");
+	print_sigqueueinfo(tcp, tcp->u_arg[1], tcp->u_arg[2]);
+	/* unsigned int flags */
+	tprintf(", %#x", (unsigned int) tcp->u_arg[3]);
+
+	return RVAL_DECODED;
+}
+
 static int
 do_rt_sigtimedwait(struct tcb *const tcp, const print_obj_by_addr_fn print_ts,
 		   const sprint_obj_by_addr_fn sprint_ts)
diff --git a/tests/.gitignore b/tests/.gitignore
index 0d881d935..40380ac6e 100644
--- a/tests/.gitignore
+++ b/tests/.gitignore
@@ -374,6 +374,7 @@ personality
 personality-Xabbrev
 personality-Xraw
 personality-Xverbose
+pidfd_send_signal
 pipe
 pipe2
 pkey_alloc
diff --git a/tests/gen_tests.in b/tests/gen_tests.in
index 8bdf6ba82..b81e67d02 100644
--- a/tests/gen_tests.in
+++ b/tests/gen_tests.in
@@ -319,6 +319,7 @@ perf_event_open_unabbrev	-a1 -v -e trace=perf_event_open
 personality-Xabbrev	+personality.test -Xabbrev
 personality-Xraw	+personality.test -a15 -Xraw
 personality-Xverbose	+personality.test -Xverbose
+pidfd_send_signal
 pipe2	-a15
 pkey_alloc	-a17
 pkey_free	-a13
diff --git a/tests/pidfd_send_signal.c b/tests/pidfd_send_signal.c
new file mode 100644
index 000000000..014e43de0
--- /dev/null
+++ b/tests/pidfd_send_signal.c
@@ -0,0 +1,71 @@
+/*
+ * Check decoding of pidfd_send_signal syscall.
+ *
+ * Copyright (c) 2015-2019 The strace developers.
+ * All rights reserved.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "tests.h"
+#include <unistd.h>
+#include <asm/unistd.h>
+#include "scno.h"
+
+#ifdef __NR_pidfd_send_signal
+
+# include <fcntl.h>
+# include <stdio.h>
+# include <signal.h>
+
+static const char *errstr;
+
+static long
+sys_pidfd_send_signal(int pidfd, int sig, const void *info, int flags)
+{
+	kernel_ulong_t fill = (kernel_ulong_t) 0xdefaced00000000ULL;
+	kernel_ulong_t arg1 = fill | (unsigned int) pidfd;
+	kernel_ulong_t arg2 = fill | (unsigned int) sig;
+	kernel_ulong_t arg3 = (unsigned long) info;
+	kernel_ulong_t arg4 = fill | (unsigned int) flags;
+
+	long rc = syscall(__NR_pidfd_send_signal, arg1, arg2, arg3, arg4);
+	errstr = sprintrc(rc);
+	return rc;
+}
+
+int
+main(void)
+{
+	static const char null_path[] = "/dev/null";
+
+	int fd = open(null_path, O_RDONLY);
+	if (fd < 0)
+		perror_msg_and_fail("open: %s", null_path);
+
+	TAIL_ALLOC_OBJECT_CONST_PTR(siginfo_t, si);
+	const void *esi = (const void *) si + 1;
+
+	sys_pidfd_send_signal(fd, SIGUSR1, esi, 0);
+	printf("pidfd_send_signal(%d, SIGUSR1, %p, 0) = %s\n",
+	       fd, esi, errstr);
+
+	si->si_signo = SIGUSR1;
+	si->si_code = SI_QUEUE;
+
+	sys_pidfd_send_signal(fd, SIGUSR2, si, -1);
+	printf("pidfd_send_signal(%d, SIGUSR2, {si_signo=SIGUSR1"
+	       ", si_code=SI_QUEUE, si_errno=%d, si_pid=%u, si_uid=%u"
+	       ", si_value={int=%d, ptr=%p}}, %#x) = %s\n",
+	       fd, si->si_errno, si->si_pid, si->si_uid, si->si_int, si->si_ptr,
+	       -1U, errstr);
+
+	puts("+++ exited with 0 +++");
+	return 0;
+}
+
+#else
+
+SKIP_MAIN_UNDEFINED("__NR_pidfd_send_signal")
+
+#endif
diff --git a/tests/pure_executables.list b/tests/pure_executables.list
index 502ce5b37..258b8c65f 100755
--- a/tests/pure_executables.list
+++ b/tests/pure_executables.list
@@ -318,6 +318,7 @@ personality
 personality-Xabbrev
 personality-Xraw
 personality-Xverbose
+pidfd_send_signal
 pipe
 pipe2
 pkey_alloc