This complementary patch defines SIGINFO as a synonym for SIGPWR
on every architecture supported by the kernel.
SIGPWR looks like a nice candidate for this role, because it is
defined on every supported arch; it is currently only used to inform
PID 1 of power failures, and daemons that care about low-level
events do not tend to have a controlling terminal.
However, on sparcs SIGPWR is a synonym for SIGLOST, a signal unique
to that architecture, with a narrow set of intended uses that do not
combine well with interactively requesting status.
SIGLOST is not used by any kernel code at the moment.
SIGINFO is not defined as a real-time signal for the following reasons:
* SIGRTMIN and SIGRTMAX can not be changed without breaking userspace
* the lack of queuing is irrelevant for the main use-case, since the
consumption rate of information by a terminal user and the
practical tty keypress processing rates are much slower than SIGINFO
processing by the line discipline.
Signed-off-by: Arseny Maslennikov <ar@xxxxxxxxx>
---
arch/arm/include/uapi/asm/signal.h | 1 +
arch/h8300/include/uapi/asm/signal.h | 1 +
arch/ia64/include/uapi/asm/signal.h | 1 +
arch/m68k/include/uapi/asm/signal.h | 1 +
arch/mips/include/uapi/asm/signal.h | 1 +
arch/parisc/include/uapi/asm/signal.h | 1 +
arch/powerpc/include/uapi/asm/signal.h | 1 +
arch/s390/include/uapi/asm/signal.h | 1 +
arch/sparc/include/uapi/asm/signal.h | 2 ++
arch/x86/include/uapi/asm/signal.h | 1 +
arch/xtensa/include/uapi/asm/signal.h | 1 +
include/uapi/asm-generic/signal.h | 1 +
12 files changed, 13 insertions(+)
diff --git a/arch/arm/include/uapi/asm/signal.h b/arch/arm/include/uapi/asm/signal.h
index 9b4185ba4..b80b53a17 100644
--- a/arch/arm/include/uapi/asm/signal.h
+++ b/arch/arm/include/uapi/asm/signal.h
@@ -50,6 +50,7 @@ typedef unsigned long sigset_t;
#define SIGLOST 29
*/
#define SIGPWR 30
+#define SIGINFO SIGPWR
#define SIGSYS 31
#define SIGUNUSED 31
diff --git a/arch/h8300/include/uapi/asm/signal.h b/arch/h8300/include/uapi/asm/signal.h
index e15521037..7a2b783af 100644
--- a/arch/h8300/include/uapi/asm/signal.h
+++ b/arch/h8300/include/uapi/asm/signal.h
@@ -50,6 +50,7 @@ typedef unsigned long sigset_t;
#define SIGLOST 29
*/
#define SIGPWR 30
+#define SIGINFO SIGPWR
#define SIGSYS 31
#define SIGUNUSED 31
diff --git a/arch/ia64/include/uapi/asm/signal.h b/arch/ia64/include/uapi/asm/signal.h
index aa98ff1b9..b4c98cb17 100644
--- a/arch/ia64/include/uapi/asm/signal.h
+++ b/arch/ia64/include/uapi/asm/signal.h
@@ -45,6 +45,7 @@
#define SIGLOST 29
*/
#define SIGPWR 30
+#define SIGINFO SIGPWR
#define SIGSYS 31
/* signal 31 is no longer "unused", but the SIGUNUSED macro remains for backwards compatibility */
#define SIGUNUSED 31
diff --git a/arch/m68k/include/uapi/asm/signal.h b/arch/m68k/include/uapi/asm/signal.h
index 915cc755a..a0b4e4108 100644
--- a/arch/m68k/include/uapi/asm/signal.h
+++ b/arch/m68k/include/uapi/asm/signal.h
@@ -50,6 +50,7 @@ typedef unsigned long sigset_t;
#define SIGLOST 29
*/
#define SIGPWR 30
+#define SIGINFO SIGPWR
#define SIGSYS 31
#define SIGUNUSED 31
diff --git a/arch/mips/include/uapi/asm/signal.h b/arch/mips/include/uapi/asm/signal.h
index 53104b10a..975a6f0d3 100644
--- a/arch/mips/include/uapi/asm/signal.h
+++ b/arch/mips/include/uapi/asm/signal.h
@@ -43,6 +43,7 @@ typedef unsigned long old_sigset_t; /* at least 32 bits */
#define SIGCHLD 18 /* Child status has changed (POSIX). */
#define SIGCLD SIGCHLD /* Same as SIGCHLD (System V). */
#define SIGPWR 19 /* Power failure restart (System V). */
+#define SIGINFO SIGPWR /* Keyboard status request (4.2 BSD). */
#define SIGWINCH 20 /* Window size change (4.3 BSD, Sun). */
#define SIGURG 21 /* Urgent condition on socket (4.2 BSD). */
#define SIGIO 22 /* I/O now possible (4.2 BSD). */
diff --git a/arch/parisc/include/uapi/asm/signal.h b/arch/parisc/include/uapi/asm/signal.h
index d38563a39..fe2e00d59 100644
--- a/arch/parisc/include/uapi/asm/signal.h
+++ b/arch/parisc/include/uapi/asm/signal.h
@@ -22,6 +22,7 @@
#define SIGUSR2 17
#define SIGCHLD 18
#define SIGPWR 19
+#define SIGINFO SIGPWR
#define SIGVTALRM 20
#define SIGPROF 21
#define SIGIO 22
diff --git a/arch/powerpc/include/uapi/asm/signal.h b/arch/powerpc/include/uapi/asm/signal.h
index 85b0a7aa4..e7f388590 100644
--- a/arch/powerpc/include/uapi/asm/signal.h
+++ b/arch/powerpc/include/uapi/asm/signal.h
@@ -53,6 +53,7 @@ typedef struct {
#define SIGLOST 29
*/
#define SIGPWR 30
+#define SIGINFO SIGPWR
#define SIGSYS 31
#define SIGUNUSED 31
diff --git a/arch/s390/include/uapi/asm/signal.h b/arch/s390/include/uapi/asm/signal.h
index 9a14a611e..12ee62987 100644
--- a/arch/s390/include/uapi/asm/signal.h
+++ b/arch/s390/include/uapi/asm/signal.h
@@ -58,6 +58,7 @@ typedef unsigned long sigset_t;
#define SIGLOST 29
*/
#define SIGPWR 30
+#define SIGINFO SIGPWR
#define SIGSYS 31
#define SIGUNUSED 31
diff --git a/arch/sparc/include/uapi/asm/signal.h b/arch/sparc/include/uapi/asm/signal.h
index ff9505923..b65516319 100644
--- a/arch/sparc/include/uapi/asm/signal.h
+++ b/arch/sparc/include/uapi/asm/signal.h
@@ -71,6 +71,8 @@
#define SIGWINCH 28
#define SIGLOST 29
#define SIGPWR SIGLOST
+/* XXX: is it OK for SIGINFO to collide with LOST? */
+#define SIGINFO SIGPWR
#define SIGUSR1 30
#define SIGUSR2 31
diff --git a/arch/x86/include/uapi/asm/signal.h b/arch/x86/include/uapi/asm/signal.h
index e5745d593..1539bb288 100644
--- a/arch/x86/include/uapi/asm/signal.h
+++ b/arch/x86/include/uapi/asm/signal.h
@@ -55,6 +55,7 @@ typedef unsigned long sigset_t;
#define SIGLOST 29
*/
#define SIGPWR 30
+#define SIGINFO SIGPWR
#define SIGSYS 31
#define SIGUNUSED 31
diff --git a/arch/xtensa/include/uapi/asm/signal.h b/arch/xtensa/include/uapi/asm/signal.h
index 005dec5bf..d64423430 100644
--- a/arch/xtensa/include/uapi/asm/signal.h
+++ b/arch/xtensa/include/uapi/asm/signal.h
@@ -65,6 +65,7 @@ typedef struct {
#define SIGPOLL SIGIO
/* #define SIGLOST 29 */
#define SIGPWR 30
+#define SIGINFO SIGPWR
#define SIGSYS 31
#define SIGUNUSED 31
diff --git a/include/uapi/asm-generic/signal.h b/include/uapi/asm-generic/signal.h
index 5c716a952..9f9a1db0d 100644
--- a/include/uapi/asm-generic/signal.h
+++ b/include/uapi/asm-generic/signal.h
@@ -43,6 +43,7 @@
#define SIGLOST 29
*/
#define SIGPWR 30
+#define SIGINFO SIGPWR
#define SIGSYS 31
#define SIGUNUSED 31
--
2.26.2
