linux: update sys/ptrace.h comments

* sysdeps/unix/sysv/linux/sys/ptrace.h (__ptrace_request): Add comments
about PTRACE_PEEKSIGINFO, PTRACE_GETSIGMASK, PTRACE_SETSIGMASK, and
PTRACE_SECCOMP_GET_FILTER.  Update comments about PTRACE_SINGLESTEP
and PTRACE_SYSCALL.
* sysdeps/unix/sysv/linux/aarch64/sys/ptrace.h: Likewise.
* sysdeps/unix/sysv/linux/ia64/sys/ptrace.h: Likewise.
* sysdeps/unix/sysv/linux/powerpc/sys/ptrace.h: Likewise.
* sysdeps/unix/sysv/linux/s390/sys/ptrace.h: Likewise.
* sysdeps/unix/sysv/linux/sparc/sys/ptrace.h: Likewise.
* sysdeps/unix/sysv/linux/tile/sys/ptrace.h: Likewise.

7 files changed, 49 insertions, 25 deletions

diff --git a/sysdeps/unix/sysv/linux/aarch64/sys/ptrace.h b/sysdeps/unix/sysv/linux/aarch64/sys/ptrace.h
index f95547087f..111d54e63d 100644
--- a/sysdeps/unix/sysv/linux/aarch64/sys/ptrace.h
+++ b/sysdeps/unix/sysv/linux/aarch64/sys/ptrace.h
@@ -66,7 +66,7 @@ enum __ptrace_request
   PTRACE_KILL = 8,
 #define PT_KILL PTRACE_KILL
 
-  /* Single step the process. */
+  /* Single step the process.  */
   PTRACE_SINGLESTEP = 9,
 #define PT_STEP PTRACE_SINGLESTEP
 
@@ -80,7 +80,7 @@ enum __ptrace_request
 
   PTRACE_GET_THREAD_AREA = 22,
 
-  /* Continue and stop at the next (return from) syscall.  */
+  /* Continue and stop at the next entry to or return from syscall.  */
   PTRACE_SYSCALL = 24,
 #define PT_SYSCALL PTRACE_SYSCALL
 
@@ -127,15 +127,19 @@ enum __ptrace_request
   PTRACE_LISTEN = 0x4208,
 #define PTRACE_LISTEN PTRACE_LISTEN
 
+  /* Retrieve siginfo_t structures without removing signals from a queue.  */
   PTRACE_PEEKSIGINFO = 0x4209,
 #define PTRACE_PEEKSIGINFO PTRACE_PEEKSIGINFO
 
+  /* Get the mask of blocked signals.  */
   PTRACE_GETSIGMASK = 0x420a,
 #define PTRACE_GETSIGMASK PTRACE_GETSIGMASK
 
+  /* Change the mask of blocked signals.  */
   PTRACE_SETSIGMASK = 0x420b,
 #define PTRACE_SETSIGMASK PTRACE_SETSIGMASK
 
+  /* Get seccomp BPF filters.  */
   PTRACE_SECCOMP_GET_FILTER = 0x420c
 #define PTRACE_SECCOMP_GET_FILTER PTRACE_SECCOMP_GET_FILTER
 };
diff --git a/sysdeps/unix/sysv/linux/ia64/sys/ptrace.h b/sysdeps/unix/sysv/linux/ia64/sys/ptrace.h
index d08a738c48..0ca8237796 100644
--- a/sysdeps/unix/sysv/linux/ia64/sys/ptrace.h
+++ b/sysdeps/unix/sysv/linux/ia64/sys/ptrace.h
@@ -67,8 +67,7 @@ enum __ptrace_request
   PTRACE_KILL = 8,
 #define PT_KILL PTRACE_KILL
 
-  /* Single step the process.
-     This is not supported on all machines.  */
+  /* Single step the process.  */
   PTRACE_SINGLESTEP = 9,
 #define PT_STEP PTRACE_SINGLESTEP
 
@@ -92,7 +91,7 @@ enum __ptrace_request
   PTRACE_SETREGS = 19,
 #define PT_SETREGS PTRACE_SETREGS
 
-  /* Continue and stop at the next (return from) syscall.  */
+  /* Continue and stop at the next entry to or return from syscall.  */
   PTRACE_SYSCALL = 24,
 #define PT_SYSCALL PTRACE_SYSCALL
 
@@ -133,15 +132,19 @@ enum __ptrace_request
   PTRACE_LISTEN = 0x4208,
 #define PTRACE_LISTEN PTRACE_LISTEN
 
+  /* Retrieve siginfo_t structures without removing signals from a queue.  */
   PTRACE_PEEKSIGINFO = 0x4209,
 #define PTRACE_PEEKSIGINFO PTRACE_PEEKSIGINFO
 
+  /* Get the mask of blocked signals.  */
   PTRACE_GETSIGMASK = 0x420a,
 #define PTRACE_GETSIGMASK PTRACE_GETSIGMASK
 
+  /* Change the mask of blocked signals.  */
   PTRACE_SETSIGMASK = 0x420b,
 #define PTRACE_SETSIGMASK PTRACE_SETSIGMASK
 
+  /* Get seccomp BPF filters.  */
   PTRACE_SECCOMP_GET_FILTER = 0x420c
 #define PTRACE_SECCOMP_GET_FILTER PTRACE_SECCOMP_GET_FILTER
 };
diff --git a/sysdeps/unix/sysv/linux/powerpc/sys/ptrace.h b/sysdeps/unix/sysv/linux/powerpc/sys/ptrace.h
index 799b81cf38..40e9836ba9 100644
--- a/sysdeps/unix/sysv/linux/powerpc/sys/ptrace.h
+++ b/sysdeps/unix/sysv/linux/powerpc/sys/ptrace.h
@@ -65,8 +65,7 @@ enum __ptrace_request
   PTRACE_KILL = 8,
 #define PT_KILL PTRACE_KILL
 
-  /* Single step the process.
-     This is not supported on all machines.  */
+  /* Single step the process.  */
   PTRACE_SINGLESTEP = 9,
 #define PT_STEP PTRACE_SINGLESTEP
 
@@ -78,7 +77,7 @@ enum __ptrace_request
   PTRACE_DETACH = 17,
 #define PT_DETACH PTRACE_DETACH
 
-  /* Continue and stop at the next (return from) syscall.  */
+  /* Continue and stop at the next entry to or return from syscall.  */
   PTRACE_SYSCALL = 24,
 #define PT_SYSCALL PTRACE_SYSCALL
 
@@ -119,15 +118,19 @@ enum __ptrace_request
   PTRACE_LISTEN = 0x4208,
 #define PTRACE_LISTEN PTRACE_LISTEN
 
+  /* Retrieve siginfo_t structures without removing signals from a queue.  */
   PTRACE_PEEKSIGINFO = 0x4209,
 #define PTRACE_PEEKSIGINFO PTRACE_PEEKSIGINFO
 
+  /* Get the mask of blocked signals.  */
   PTRACE_GETSIGMASK = 0x420a,
 #define PTRACE_GETSIGMASK PTRACE_GETSIGMASK
 
+  /* Change the mask of blocked signals.  */
   PTRACE_SETSIGMASK = 0x420b,
 #define PTRACE_SETSIGMASK PTRACE_SETSIGMASK
 
+  /* Get seccomp BPF filters.  */
   PTRACE_SECCOMP_GET_FILTER = 0x420c
 #define PTRACE_SECCOMP_GET_FILTER PTRACE_SECCOMP_GET_FILTER
 };
diff --git a/sysdeps/unix/sysv/linux/s390/sys/ptrace.h b/sysdeps/unix/sysv/linux/s390/sys/ptrace.h
index 57c9793bc6..8d19b725cd 100644
--- a/sysdeps/unix/sysv/linux/s390/sys/ptrace.h
+++ b/sysdeps/unix/sysv/linux/s390/sys/ptrace.h
@@ -120,8 +120,7 @@ enum __ptrace_request
   PTRACE_KILL = 8,
 #define PT_KILL PTRACE_KILL
 
-  /* Single step the process.
-     This is not supported on all machines.  */
+  /* Single step the process.  */
   PTRACE_SINGLESTEP = 9,
 #define PT_STEP PTRACE_SINGLESTEP
 
@@ -137,7 +136,7 @@ enum __ptrace_request
   PTRACE_DETACH = 17,
 #define PT_DETACH PTRACE_DETACH
 
-  /* Continue and stop at the next (return from) syscall.  */
+  /* Continue and stop at the next entry to or return from syscall.  */
   PTRACE_SYSCALL = 24,
 #define PT_SYSCALL PTRACE_SYSCALL
 
@@ -178,15 +177,19 @@ enum __ptrace_request
   PTRACE_LISTEN = 0x4208,
 #define PTRACE_LISTEN PTRACE_LISTEN
 
+  /* Retrieve siginfo_t structures without removing signals from a queue.  */
   PTRACE_PEEKSIGINFO = 0x4209,
 #define PTRACE_PEEKSIGINFO PTRACE_PEEKSIGINFO
 
+  /* Get the mask of blocked signals.  */
   PTRACE_GETSIGMASK = 0x420a,
 #define PTRACE_GETSIGMASK PTRACE_GETSIGMASK
 
+  /* Change the mask of blocked signals.  */
   PTRACE_SETSIGMASK = 0x420b,
 #define PTRACE_SETSIGMASK PTRACE_SETSIGMASK
 
+  /* Get seccomp BPF filters.  */
   PTRACE_SECCOMP_GET_FILTER = 0x420c,
 #define PTRACE_SECCOMP_GET_FILTER PTRACE_SECCOMP_GET_FILTER
 
diff --git a/sysdeps/unix/sysv/linux/sparc/sys/ptrace.h b/sysdeps/unix/sysv/linux/sparc/sys/ptrace.h
index 8e0a4886f1..b1eaefe634 100644
--- a/sysdeps/unix/sysv/linux/sparc/sys/ptrace.h
+++ b/sysdeps/unix/sysv/linux/sparc/sys/ptrace.h
@@ -78,8 +78,7 @@ enum __ptrace_request
   PTRACE_KILL = 8,
 #define PT_KILL PTRACE_KILL
 
-  /* Single step the process.
-     This is not supported on all machines.  */
+  /* Single step the process.  */
   PTRACE_SINGLESTEP = 9,
 #define PT_STEP PTRACE_SINGLESTEP
 
@@ -146,7 +145,7 @@ enum __ptrace_request
 
 #endif
 
-  /* Continue and stop at the next (return from) syscall.  */
+  /* Continue and stop at the next entry to or return from syscall.  */
   PTRACE_SYSCALL = 24,
 #define PTRACE_SYSCALL PTRACE_SYSCALL
 
@@ -201,15 +200,19 @@ enum __ptrace_request
   PTRACE_LISTEN = 0x4208,
 #define PTRACE_LISTEN PTRACE_LISTEN
 
+  /* Retrieve siginfo_t structures without removing signals from a queue.  */
   PTRACE_PEEKSIGINFO = 0x4209,
 #define PTRACE_PEEKSIGINFO PTRACE_PEEKSIGINFO
 
+  /* Get the mask of blocked signals.  */
   PTRACE_GETSIGMASK = 0x420a,
 #define PTRACE_GETSIGMASK PTRACE_GETSIGMASK
 
+  /* Change the mask of blocked signals.  */
   PTRACE_SETSIGMASK = 0x420b,
 #define PTRACE_SETSIGMASK PTRACE_SETSIGMASK
 
+  /* Get seccomp BPF filters.  */
   PTRACE_SECCOMP_GET_FILTER = 0x420c
 #define PTRACE_SECCOMP_GET_FILTER PTRACE_SECCOMP_GET_FILTER
 };
diff --git a/sysdeps/unix/sysv/linux/sys/ptrace.h b/sysdeps/unix/sysv/linux/sys/ptrace.h
index 096e2635fd..6bdc91d436 100644
--- a/sysdeps/unix/sysv/linux/sys/ptrace.h
+++ b/sysdeps/unix/sysv/linux/sys/ptrace.h
@@ -1,5 +1,6 @@
 /* `ptrace' debugger support interface.  Linux version.
    Copyright (C) 1996-2017 Free Software Foundation, Inc.
+
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or
@@ -65,29 +66,28 @@ enum __ptrace_request
   PTRACE_KILL = 8,
 #define PT_KILL PTRACE_KILL
 
-  /* Single step the process.
-     This is not supported on all machines.  */
+  /* Single step the process.  */
   PTRACE_SINGLESTEP = 9,
 #define PT_STEP PTRACE_SINGLESTEP
 
   /* Get all general purpose registers used by a processes.
      This is not supported on all machines.  */
-   PTRACE_GETREGS = 12,
+  PTRACE_GETREGS = 12,
 #define PT_GETREGS PTRACE_GETREGS
 
   /* Set all general purpose registers used by a processes.
      This is not supported on all machines.  */
-   PTRACE_SETREGS = 13,
+  PTRACE_SETREGS = 13,
 #define PT_SETREGS PTRACE_SETREGS
 
   /* Get all floating point registers used by a processes.
      This is not supported on all machines.  */
-   PTRACE_GETFPREGS = 14,
+  PTRACE_GETFPREGS = 14,
 #define PT_GETFPREGS PTRACE_GETFPREGS
 
   /* Set all floating point registers used by a processes.
      This is not supported on all machines.  */
-   PTRACE_SETFPREGS = 15,
+  PTRACE_SETFPREGS = 15,
 #define PT_SETFPREGS PTRACE_SETFPREGS
 
   /* Attach to a process that is already running. */
@@ -100,15 +100,15 @@ enum __ptrace_request
 
   /* Get all extended floating point registers used by a processes.
      This is not supported on all machines.  */
-   PTRACE_GETFPXREGS = 18,
+  PTRACE_GETFPXREGS = 18,
 #define PT_GETFPXREGS PTRACE_GETFPXREGS
 
   /* Set all extended floating point registers used by a processes.
      This is not supported on all machines.  */
-   PTRACE_SETFPXREGS = 19,
+  PTRACE_SETFPXREGS = 19,
 #define PT_SETFPXREGS PTRACE_SETFPXREGS
 
-  /* Continue and stop at the next (return from) syscall.  */
+  /* Continue and stop at the next entry to or return from syscall.  */
   PTRACE_SYSCALL = 24,
 #define PT_SYSCALL PTRACE_SYSCALL
 
@@ -149,15 +149,19 @@ enum __ptrace_request
   PTRACE_LISTEN = 0x4208,
 #define PTRACE_LISTEN PTRACE_LISTEN
 
+  /* Retrieve siginfo_t structures without removing signals from a queue.  */
   PTRACE_PEEKSIGINFO = 0x4209,
 #define PTRACE_PEEKSIGINFO PTRACE_PEEKSIGINFO
 
+  /* Get the mask of blocked signals.  */
   PTRACE_GETSIGMASK = 0x420a,
 #define PTRACE_GETSIGMASK PTRACE_GETSIGMASK
 
+  /* Change the mask of blocked signals.  */
   PTRACE_SETSIGMASK = 0x420b,
 #define PTRACE_SETSIGMASK PTRACE_SETSIGMASK
 
+  /* Get seccomp BPF filters.  */
   PTRACE_SECCOMP_GET_FILTER = 0x420c
 #define PTRACE_SECCOMP_GET_FILTER PTRACE_SECCOMP_GET_FILTER
 };
diff --git a/sysdeps/unix/sysv/linux/tile/sys/ptrace.h b/sysdeps/unix/sysv/linux/tile/sys/ptrace.h
index 455d291444..92e335fa9e 100644
--- a/sysdeps/unix/sysv/linux/tile/sys/ptrace.h
+++ b/sysdeps/unix/sysv/linux/tile/sys/ptrace.h
@@ -66,7 +66,7 @@ enum __ptrace_request
   PTRACE_KILL = 8,
 #define PT_KILL PTRACE_KILL
 
-  /* Single step the process. */
+  /* Single step the process.  */
   PTRACE_SINGLESTEP = 9,
 #define PT_STEP PTRACE_SINGLESTEP
 
@@ -86,7 +86,7 @@ enum __ptrace_request
   PTRACE_DETACH = 17,
 #define PT_DETACH PTRACE_DETACH
 
-  /* Continue and stop at the next (return from) syscall.  */
+  /* Continue and stop at the next entry to or return from syscall.  */
   PTRACE_SYSCALL = 24,
 #define PT_SYSCALL PTRACE_SYSCALL
 
@@ -123,15 +123,19 @@ enum __ptrace_request
   PTRACE_LISTEN = 0x4208,
 #define PTRACE_LISTEN PTRACE_LISTEN
 
+  /* Retrieve siginfo_t structures without removing signals from a queue.  */
   PTRACE_PEEKSIGINFO = 0x4209,
 #define PTRACE_PEEKSIGINFO PTRACE_PEEKSIGINFO
 
+  /* Get the mask of blocked signals.  */
   PTRACE_GETSIGMASK = 0x420a,
 #define PTRACE_GETSIGMASK PTRACE_GETSIGMASK
 
+  /* Change the mask of blocked signals.  */
   PTRACE_SETSIGMASK = 0x420b,
 #define PTRACE_SETSIGMASK PTRACE_SETSIGMASK
 
+  /* Get seccomp BPF filters.  */
   PTRACE_SECCOMP_GET_FILTER = 0x420c
 #define PTRACE_SECCOMP_GET_FILTER PTRACE_SECCOMP_GET_FILTER
 };