“b89d607b590397c04b63d94a9e2fca9649917955”上不存在“README.md”
  • H
    parisc: Reduce SIGRTMIN from 37 to 32 to behave like other Linux architectures · 1f25df2e
    Helge Deller 提交于
    This patch reduces the value of SIGRTMIN on PARISC from 37 to 32, thus
    increasing the number of available RT signals and bring it in sync with other
    Linux architectures.
    
    Historically we wanted to natively support HP-UX 32bit binaries with the
    PA-RISC Linux port.  Because of that we carried the various available signals
    from HP-UX (e.g. SIGEMT and SIGLOST) and folded them in between the native
    Linux signals.  Although this was the right decision at that time, this
    required us to increase SIGRTMIN to at least 37 which left us with 27 (64-37)
    RT signals.
    
    Those 27 RT signals haven't been a problem in the past, but with the upcoming
    importance of systemd we now got the problem that systemd alloctes (hardcoded)
    signals up to SIGRTMIN+29 which is beyond our NSIG of 64. Because of that we
    have not been able to use systemd on the PARISC Linux port yet.
    
    Of course we could ask the systemd developers to not use those hardcoded
    values, but this change is very unlikely, esp. with PA-RISC being a niche
    architecture.
    
    The other possibility would be to increase NSIG to e.g. 128, but this would
    mean to duplicate most of the existing Linux signal handling code into the
    parisc specific Linux kernel tree which would most likely introduce lots of new
    bugs beside the code duplication.
    
    The third option is to drop some HP-UX signals and shuffle some other signals
    around to bring SIGRTMIN to 32.  This is of course an ABI change, but testing
    has shown that existing Linux installations are not visibly affected by this
    change - most likely because we move those signals around which are rarely used
    and move them to slots which haven't been used in Linux yet. In an existing
    installation I was able to exchange either the Linux kernel or glibc (or both)
    without affecting the boot process and installed applications.
    
    Dropping the HP-UX signals isn't an issue either, since support for HP-UX was
    basically dropped a few months back with Kernel 3.14 in commit
    f5a408d5 already, when we changed EWOULDBLOCK
    to be equal to EAGAIN.
    
    So, even if this is an ABI change, it's better to change it now and thus bring
    PARISC Linux in sync with other architectures to avoid other issues in the
    future.
    Signed-off-by: NHelge Deller <deller@gmx.de>
    Cc: Carlos O'Donell <carlos@systemhalted.org>
    Cc: John David Anglin <dave.anglin@bell.net>
    Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
    Cc: Aaro Koskinen <aaro.koskinen@iki.fi>
    Cc: PARISC Linux Kernel Mailinglist <linux-parisc@vger.kernel.org>
    Tested-by: NAaro Koskinen <aaro.koskinen@iki.fi>
    1f25df2e
signal.h 2.8 KB
#ifndef _UAPI_ASM_PARISC_SIGNAL_H
#define _UAPI_ASM_PARISC_SIGNAL_H

#define SIGHUP		 1
#define SIGINT		 2
#define SIGQUIT		 3
#define SIGILL		 4
#define SIGTRAP		 5
#define SIGABRT		 6
#define SIGIOT		 6
#define SIGSTKFLT	 7
#define SIGFPE		 8
#define SIGKILL		 9
#define SIGBUS		10
#define SIGSEGV		11
#define SIGXCPU		12
#define SIGPIPE		13
#define SIGALRM		14
#define SIGTERM		15
#define SIGUSR1		16
#define SIGUSR2		17
#define SIGCHLD		18
#define SIGPWR		19
#define SIGVTALRM	20
#define SIGPROF		21
#define SIGIO		22
#define SIGPOLL		SIGIO
#define SIGWINCH	23
#define SIGSTOP		24
#define SIGTSTP		25
#define SIGCONT		26
#define SIGTTIN		27
#define SIGTTOU		28
#define SIGURG		29
#define SIGXFSZ		30
#define SIGUNUSED	31
#define SIGSYS		31 /* Linux doesn't use this */

/* These should not be considered constants from userland.  */
#define SIGRTMIN	32
#define SIGRTMAX	_NSIG /* it's 44 under HP/UX */

/*
 * SA_FLAGS values:
 *
 * SA_ONSTACK indicates that a registered stack_t will be used.
 * SA_RESTART flag to get restarting signals (which were the default long ago)
 * SA_NOCLDSTOP flag to turn off SIGCHLD when children stop.
 * SA_RESETHAND clears the handler when the signal is delivered.
 * SA_NOCLDWAIT flag on SIGCHLD to inhibit zombies.
 * SA_NODEFER prevents the current signal from being masked in the handler.
 *
 * SA_ONESHOT and SA_NOMASK are the historical Linux names for the Single
 * Unix names RESETHAND and NODEFER respectively.
 */
#define SA_ONSTACK	0x00000001
#define SA_RESETHAND	0x00000004
#define SA_NOCLDSTOP	0x00000008
#define SA_SIGINFO	0x00000010
#define SA_NODEFER	0x00000020
#define SA_RESTART	0x00000040
#define SA_NOCLDWAIT	0x00000080
#define _SA_SIGGFAULT	0x00000100 /* HPUX */

#define SA_NOMASK	SA_NODEFER
#define SA_ONESHOT	SA_RESETHAND

#define MINSIGSTKSZ	2048
#define SIGSTKSZ	8192


#define SIG_BLOCK          0	/* for blocking signals */
#define SIG_UNBLOCK        1	/* for unblocking signals */
#define SIG_SETMASK        2	/* for setting the signal mask */

#define SIG_DFL	((__sighandler_t)0)	/* default signal handling */
#define SIG_IGN	((__sighandler_t)1)	/* ignore signal */
#define SIG_ERR	((__sighandler_t)-1)	/* error return from signal */

# ifndef __ASSEMBLY__

#  include <linux/types.h>

/* Avoid too many header ordering problems.  */
struct siginfo;

/* Type of a signal handler.  */
#ifdef CONFIG_64BIT
/* function pointers on 64-bit parisc are pointers to little structs and the
 * compiler doesn't support code which changes or tests the address of
 * the function in the little struct.  This is really ugly -PB
 */
typedef char __user *__sighandler_t;
#else
typedef void __signalfn_t(int);
typedef __signalfn_t __user *__sighandler_t;
#endif

typedef struct sigaltstack {
	void __user *ss_sp;
	int ss_flags;
	size_t ss_size;
} stack_t;

#endif /* !__ASSEMBLY */
#endif /* _UAPI_ASM_PARISC_SIGNAL_H */
反馈
建议
客服 返回
顶部