Date: Sun, 9 Feb 2020 12:29:51 +0000 (UTC) From: Konstantin Belousov <kib@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r357700 - in head/sys: kern sys Message-ID: <202002091229.019CTpR0018639@repo.freebsd.org>
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Author: kib Date: Sun Feb 9 12:29:51 2020 New Revision: 357700 URL: https://svnweb.freebsd.org/changeset/base/357700 Log: Add sysctl kern.proc.sigfastblk for reporting sigfastblock word address. Tested by: pho Disscussed with: cem, emaste, jilles Sponsored by: The FreeBSD Foundation Differential revision: https://reviews.freebsd.org/D12773 Modified: head/sys/kern/kern_proc.c head/sys/sys/sysctl.h Modified: head/sys/kern/kern_proc.c ============================================================================== --- head/sys/kern/kern_proc.c Sun Feb 9 12:29:13 2020 (r357699) +++ head/sys/kern/kern_proc.c Sun Feb 9 12:29:51 2020 (r357700) @@ -2962,6 +2962,77 @@ sysctl_kern_proc_sigtramp(SYSCTL_HANDLER_ARGS) return (error); } +static int +sysctl_kern_proc_sigfastblk(SYSCTL_HANDLER_ARGS) +{ + int *name = (int *)arg1; + u_int namelen = arg2; + pid_t pid; + struct proc *p; + struct thread *td1; + uintptr_t addr; +#ifdef COMPAT_FREEBSD32 + uint32_t addr32; +#endif + int error; + + if (namelen != 1 || req->newptr != NULL) + return (EINVAL); + + pid = (pid_t)name[0]; + error = pget(pid, PGET_HOLD | PGET_NOTWEXIT | PGET_CANDEBUG, &p); + if (error != 0) + return (error); + + PROC_LOCK(p); +#ifdef COMPAT_FREEBSD32 + if (SV_CURPROC_FLAG(SV_ILP32)) { + if (!SV_PROC_FLAG(p, SV_ILP32)) { + error = EINVAL; + goto errlocked; + } + } +#endif + if (pid <= PID_MAX) { + td1 = FIRST_THREAD_IN_PROC(p); + } else { + FOREACH_THREAD_IN_PROC(p, td1) { + if (td1->td_tid == pid) + break; + } + } + if (td1 == NULL) { + error = ESRCH; + goto errlocked; + } + /* + * The access to the private thread flags. It is fine as far + * as no out-of-thin-air values are read from td_pflags, and + * usermode read of the td_sigblock_ptr is racy inherently, + * since target process might have already changed it + * meantime. + */ + if ((td1->td_pflags & TDP_SIGFASTBLOCK) != 0) + addr = (uintptr_t)td1->td_sigblock_ptr; + else + error = ENOTTY; + +errlocked: + _PRELE(p); + PROC_UNLOCK(p); + if (error != 0) + return (error); + +#ifdef COMPAT_FREEBSD32 + if (SV_CURPROC_FLAG(SV_ILP32)) { + addr32 = addr; + error = SYSCTL_OUT(req, &addr32, sizeof(addr32)); + } else +#endif + error = SYSCTL_OUT(req, &addr, sizeof(addr)); + return (error); +} + SYSCTL_NODE(_kern, KERN_PROC, proc, CTLFLAG_RD, 0, "Process table"); SYSCTL_PROC(_kern_proc, KERN_PROC_ALL, all, CTLFLAG_RD|CTLTYPE_STRUCT| @@ -3074,6 +3145,10 @@ static SYSCTL_NODE(_kern_proc, KERN_PROC_OSREL, osrel, static SYSCTL_NODE(_kern_proc, KERN_PROC_SIGTRAMP, sigtramp, CTLFLAG_RD | CTLFLAG_MPSAFE, sysctl_kern_proc_sigtramp, "Process signal trampoline location"); + +static SYSCTL_NODE(_kern_proc, KERN_PROC_SIGFASTBLK, sigfastblk, CTLFLAG_RD | + CTLFLAG_ANYBODY | CTLFLAG_MPSAFE, sysctl_kern_proc_sigfastblk, + "Thread sigfastblock address"); int allproc_gen; Modified: head/sys/sys/sysctl.h ============================================================================== --- head/sys/sys/sysctl.h Sun Feb 9 12:29:13 2020 (r357699) +++ head/sys/sys/sysctl.h Sun Feb 9 12:29:51 2020 (r357700) @@ -1017,6 +1017,7 @@ TAILQ_HEAD(sysctl_ctx_list, sysctl_ctx_entry); #define KERN_PROC_SIGTRAMP 41 /* signal trampoline location */ #define KERN_PROC_CWD 42 /* process current working directory */ #define KERN_PROC_NFDS 43 /* number of open file descriptors */ +#define KERN_PROC_SIGFASTBLK 44 /* address of fastsigblk magic word */ /* * KERN_IPC identifiers
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