Date: Tue, 5 Sep 2017 13:52:15 +0000 (UTC) From: Mark Johnston <markj@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-11@freebsd.org Subject: svn commit: r323180 - in stable/11: . cddl/contrib/opensolaris/cmd/lockstat share/man/man4 sys/dev/ksyms sys/sys Message-ID: <201709051352.v85DqFI2081588@repo.freebsd.org>
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Author: markj Date: Tue Sep 5 13:52:15 2017 New Revision: 323180 URL: https://svnweb.freebsd.org/changeset/base/323180 Log: MFC r321963: Rework and simplify the ksyms implementation. Deleted: stable/11/sys/sys/ksyms.h Modified: stable/11/ObsoleteFiles.inc stable/11/cddl/contrib/opensolaris/cmd/lockstat/sym.c stable/11/share/man/man4/ksyms.4 stable/11/sys/dev/ksyms/ksyms.c Directory Properties: stable/11/ (props changed) Modified: stable/11/ObsoleteFiles.inc ============================================================================== --- stable/11/ObsoleteFiles.inc Tue Sep 5 13:40:10 2017 (r323179) +++ stable/11/ObsoleteFiles.inc Tue Sep 5 13:52:15 2017 (r323180) @@ -38,6 +38,8 @@ # xargs -n1 | sort | uniq -d; # done +# 20170802: ksyms(4) ioctl interface was removed +OLD_FILES+=usr/include/sys/ksyms.h # 20170620: remove stale manpage OLD_FILES+=usr/share/man/man2/cap_rights_get.2.gz # 20170610: chown-f_test replaced by chown_test Modified: stable/11/cddl/contrib/opensolaris/cmd/lockstat/sym.c ============================================================================== --- stable/11/cddl/contrib/opensolaris/cmd/lockstat/sym.c Tue Sep 5 13:40:10 2017 (r323179) +++ stable/11/cddl/contrib/opensolaris/cmd/lockstat/sym.c Tue Sep 5 13:52:15 2017 (r323180) @@ -48,7 +48,6 @@ #include <kstat.h> #else #include <sys/elf.h> -#include <sys/ksyms.h> #include <sys/param.h> #include <sys/module.h> #include <sys/linker.h> Modified: stable/11/share/man/man4/ksyms.4 ============================================================================== --- stable/11/share/man/man4/ksyms.4 Tue Sep 5 13:40:10 2017 (r323179) +++ stable/11/share/man/man4/ksyms.4 Tue Sep 5 13:52:15 2017 (r323180) @@ -27,7 +27,7 @@ .\" .\" $FreeBSD$ .\" -.Dd April 5, 2009 +.Dd August 2, 2017 .Dt KSYMS 4 .Os .Sh NAME @@ -69,24 +69,6 @@ driver does not block the loading or unloading of modu while the .Pa /dev/ksyms file is open but may contain stale data. -.Sh IOCTLS -The -.Xr ioctl 2 -command codes below are defined in -.Aq Pa sys/ksyms.h . -.Pp -The (third) argument to the -.Xr ioctl 2 -should be a pointer to the type indicated. -.Bl -tag -width indent -offset indent -.It Dv KIOCGSIZE (size_t) -Returns the total size of the current symbol table. -This can be used when allocating a buffer to make a copy of -the kernel symbol table. -.It Dv KIOCGADDR (void *) -Returns the address of the kernel symbol table mapped in -the process memory. -.El .Sh FILES .Bl -tag -width /dev/ksymsX .It Pa /dev/ksyms @@ -112,7 +94,6 @@ This may occur if the kernel was in the process of loa unloading a module. .El .Sh SEE ALSO -.Xr ioctl 2 , .Xr nlist 3 , .Xr elf 5 , .Xr kldload 8 @@ -152,12 +133,3 @@ file once at a time. The process must close the .Pa /dev/ksyms before it is allowed to open it again. -.Pp -The -.Nm -driver uses the calling process' memory address space to store the snapshot. -.Xr ioctl 2 -can be used to get the memory address where the symbol table is stored to -save kernel memory. -.Xr mmap 2 -may also be used but it will map it to another address. Modified: stable/11/sys/dev/ksyms/ksyms.c ============================================================================== --- stable/11/sys/dev/ksyms/ksyms.c Tue Sep 5 13:40:10 2017 (r323179) +++ stable/11/sys/dev/ksyms/ksyms.c Tue Sep 5 13:52:15 2017 (r323180) @@ -32,16 +32,15 @@ #include <sys/conf.h> #include <sys/elf.h> -#include <sys/ksyms.h> #include <sys/linker.h> #include <sys/malloc.h> #include <sys/mman.h> #include <sys/module.h> -#include <sys/mutex.h> #include <sys/proc.h> #include <sys/queue.h> #include <sys/resourcevar.h> #include <sys/stat.h> +#include <sys/sx.h> #include <sys/uio.h> #include <machine/elf.h> @@ -49,7 +48,7 @@ #include <vm/pmap.h> #include <vm/vm.h> #include <vm/vm_extern.h> -#include <vm/vm_map.h> +#include <vm/vm_object.h> #include "linker_if.h" @@ -68,18 +67,14 @@ static d_open_t ksyms_open; static d_read_t ksyms_read; -static d_close_t ksyms_close; -static d_ioctl_t ksyms_ioctl; -static d_mmap_t ksyms_mmap; +static d_mmap_single_t ksyms_mmap_single; static struct cdevsw ksyms_cdevsw = { .d_version = D_VERSION, .d_flags = D_TRACKCLOSE, .d_open = ksyms_open, - .d_close = ksyms_close, .d_read = ksyms_read, - .d_ioctl = ksyms_ioctl, - .d_mmap = ksyms_mmap, + .d_mmap_single = ksyms_mmap_single, .d_name = KSYMS_DNAME }; @@ -87,11 +82,12 @@ struct ksyms_softc { LIST_ENTRY(ksyms_softc) sc_list; vm_offset_t sc_uaddr; size_t sc_usize; - pmap_t sc_pmap; + vm_object_t sc_obj; + vm_size_t sc_objsz; struct proc *sc_proc; }; -static struct mtx ksyms_mtx; +static struct sx ksyms_mtx; static struct cdev *ksyms_dev; static LIST_HEAD(, ksyms_softc) ksyms_list = LIST_HEAD_INITIALIZER(ksyms_list); @@ -112,6 +108,7 @@ struct tsizes { }; struct toffsets { + struct ksyms_softc *to_sc; vm_offset_t to_symoff; vm_offset_t to_stroff; unsigned to_stridx; @@ -155,11 +152,25 @@ ksyms_size_calc(struct tsizes *ts) (void)linker_file_foreach(ksyms_size_permod, ts); } -#define KSYMS_EMIT(src, des, sz) do { \ - copyout(src, (void *)des, sz); \ - des += sz; \ -} while (0) +static int +ksyms_emit(struct ksyms_softc *sc, void *buf, off_t off, size_t sz) +{ + struct iovec iov; + struct uio uio; + iov.iov_base = buf; + iov.iov_len = sz; + uio.uio_iov = &iov; + uio.uio_iovcnt = 1; + uio.uio_offset = off; + uio.uio_resid = (ssize_t)sz; + uio.uio_segflg = UIO_SYSSPACE; + uio.uio_rw = UIO_WRITE; + uio.uio_td = curthread; + + return (uiomove_object(sc->sc_obj, sc->sc_objsz, &uio)); +} + #define SYMBLKSZ (256 * sizeof(Elf_Sym)) /* @@ -170,24 +181,24 @@ static int ksyms_add(linker_file_t lf, void *arg) { char *buf; + struct ksyms_softc *sc; struct toffsets *to; const Elf_Sym *symtab; Elf_Sym *symp; caddr_t strtab; - long symsz; - size_t strsz, numsyms; + size_t len, numsyms, strsz, symsz; linker_symval_t symval; - int i, nsyms, len; + int error, i, nsyms; + buf = malloc(SYMBLKSZ, M_KSYMS, M_WAITOK); to = arg; + sc = to->to_sc; MOD_SLOCK; numsyms = LINKER_SYMTAB_GET(lf, &symtab); strsz = LINKER_STRTAB_GET(lf, &strtab); symsz = numsyms * sizeof(Elf_Sym); - buf = malloc(SYMBLKSZ, M_KSYMS, M_WAITOK); - while (symsz > 0) { len = min(SYMBLKSZ, symsz); bcopy(symtab, buf, len); @@ -213,7 +224,13 @@ ksyms_add(linker_file_t lf, void *arg) return (ENXIO); } to->to_resid -= len; - KSYMS_EMIT(buf, to->to_symoff, len); + error = ksyms_emit(sc, buf, to->to_symoff, len); + to->to_symoff += len; + if (error != 0) { + MOD_SUNLOCK; + free(buf, M_KSYMS); + return (error); + } symtab += nsyms; symsz -= len; @@ -224,10 +241,11 @@ ksyms_add(linker_file_t lf, void *arg) if (strsz > to->to_resid) return (ENXIO); to->to_resid -= strsz; - KSYMS_EMIT(strtab, to->to_stroff, strsz); + error = ksyms_emit(sc, strtab, to->to_stroff, strsz); + to->to_stroff += strsz; to->to_stridx += strsz; - return (0); + return (error); } /* @@ -236,11 +254,11 @@ ksyms_add(linker_file_t lf, void *arg) * 0 on success, otherwise error. */ static int -ksyms_snapshot(struct tsizes *ts, vm_offset_t uaddr, size_t resid) +ksyms_snapshot(struct ksyms_softc *sc, struct tsizes *ts) { - struct ksyms_hdr *hdr; struct toffsets to; - int error = 0; + struct ksyms_hdr *hdr; + int error; hdr = malloc(sizeof(*hdr), M_KSYMS, M_WAITOK | M_ZERO); @@ -334,39 +352,41 @@ ksyms_snapshot(struct tsizes *ts, vm_offset_t uaddr, s /* Copy shstrtab into the header. */ bcopy(ksyms_shstrtab, hdr->kh_shstrtab, sizeof(ksyms_shstrtab)); - to.to_symoff = uaddr + hdr->kh_shdr[SHDR_SYMTAB].sh_offset; - to.to_stroff = uaddr + hdr->kh_shdr[SHDR_STRTAB].sh_offset; + to.to_sc = sc; + to.to_symoff = hdr->kh_shdr[SHDR_SYMTAB].sh_offset; + to.to_stroff = hdr->kh_shdr[SHDR_STRTAB].sh_offset; to.to_stridx = 0; - if (sizeof(struct ksyms_hdr) > resid) { - free(hdr, M_KSYMS); - return (ENXIO); - } - to.to_resid = resid - sizeof(struct ksyms_hdr); + to.to_resid = sc->sc_objsz - sizeof(struct ksyms_hdr); /* emit header */ - copyout(hdr, (void *)uaddr, sizeof(struct ksyms_hdr)); - + error = ksyms_emit(sc, hdr, 0, sizeof(*hdr)); free(hdr, M_KSYMS); + if (error != 0) + return (error); /* Add symbol and string tables for each kernel module. */ error = linker_file_foreach(ksyms_add, &to); - + if (error != 0) + return (error); if (to.to_resid != 0) return (ENXIO); - - return (error); + return (0); } static void ksyms_cdevpriv_dtr(void *data) { struct ksyms_softc *sc; + vm_object_t obj; sc = (struct ksyms_softc *)data; - mtx_lock(&ksyms_mtx); + sx_xlock(&ksyms_mtx); LIST_REMOVE(sc, sc_list); - mtx_unlock(&ksyms_mtx); + sx_xunlock(&ksyms_mtx); + obj = sc->sc_obj; + if (obj != NULL) + vm_object_deallocate(obj); free(sc, M_KSYMS); } @@ -375,34 +395,31 @@ ksyms_open(struct cdev *dev, int flags, int fmt __unus { struct tsizes ts; struct ksyms_softc *sc; - size_t total_elf_sz; + vm_size_t elfsz; int error, try; /* * Limit one open() per process. The process must close() * before open()'ing again. */ - mtx_lock(&ksyms_mtx); + sx_xlock(&ksyms_mtx); LIST_FOREACH(sc, &ksyms_list, sc_list) { if (sc->sc_proc == td->td_proc) { - mtx_unlock(&ksyms_mtx); + sx_xunlock(&ksyms_mtx); return (EBUSY); } } - sc = malloc(sizeof(*sc), M_KSYMS, M_NOWAIT | M_ZERO); - if (sc == NULL) { - mtx_unlock(&ksyms_mtx); - return (ENOMEM); - } + sc = malloc(sizeof(*sc), M_KSYMS, M_WAITOK | M_ZERO); sc->sc_proc = td->td_proc; - sc->sc_pmap = &td->td_proc->p_vmspace->vm_pmap; LIST_INSERT_HEAD(&ksyms_list, sc, sc_list); - mtx_unlock(&ksyms_mtx); + sx_xunlock(&ksyms_mtx); error = devfs_set_cdevpriv(sc, ksyms_cdevpriv_dtr); - if (error != 0) - goto failed; + if (error != 0) { + ksyms_cdevpriv_dtr(sc); + return (error); + } /* * MOD_SLOCK doesn't work here (because of a lock reversal with @@ -412,32 +429,20 @@ ksyms_open(struct cdev *dev, int flags, int fmt __unus * time. */ for (try = 0; try < 3; try++) { - /* - * Map a buffer in the calling process memory space and - * create a snapshot of the kernel symbol table in it. - */ - - /* Compute the size of buffer needed. */ ksyms_size_calc(&ts); - total_elf_sz = sizeof(struct ksyms_hdr) + ts.ts_symsz + - ts.ts_strsz; + elfsz = sizeof(struct ksyms_hdr) + ts.ts_symsz + ts.ts_strsz; - error = copyout_map(td, &sc->sc_uaddr, (vm_size_t)total_elf_sz); - if (error != 0) - break; - sc->sc_usize = total_elf_sz; + sc->sc_obj = vm_object_allocate(OBJT_DEFAULT, + OFF_TO_IDX(round_page(elfsz))); + sc->sc_objsz = elfsz; - error = ksyms_snapshot(&ts, sc->sc_uaddr, total_elf_sz); + error = ksyms_snapshot(sc, &ts); if (error == 0) - /* successful snapshot */ - return (0); + break; - /* Snapshot failed, unmap the memory and try again. */ - (void)copyout_unmap(td, sc->sc_uaddr, sc->sc_usize); + vm_object_deallocate(sc->sc_obj); + sc->sc_obj = NULL; } - -failed: - ksyms_cdevpriv_dtr(sc); return (error); } @@ -445,125 +450,38 @@ static int ksyms_read(struct cdev *dev, struct uio *uio, int flags __unused) { struct ksyms_softc *sc; - char *buf; - off_t off; - size_t len, sz; - vm_size_t ubase; int error; error = devfs_get_cdevpriv((void **)&sc); if (error != 0) return (error); - - off = uio->uio_offset; - len = uio->uio_resid; - - if (off < 0 || off > sc->sc_usize) - return (EFAULT); - - if (len > sc->sc_usize - off) - len = sc->sc_usize - off; - if (len == 0) - return (0); - - /* - * Since the snapshot buffer is in the user space we have to copy it - * in to the kernel and then back out. The extra copy saves valuable - * kernel memory. - */ - buf = malloc(PAGE_SIZE, M_KSYMS, M_WAITOK); - ubase = sc->sc_uaddr + off; - - while (len) { - sz = min(PAGE_SIZE, len); - if (copyin((void *)ubase, buf, sz) != 0) - error = EFAULT; - else - error = uiomove(buf, sz, uio); - if (error != 0) - break; - - len -= sz; - ubase += sz; - } - free(buf, M_KSYMS); - - return (error); + return (uiomove_object(sc->sc_obj, sc->sc_objsz, uio)); } static int -ksyms_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int32_t flag __unused, - struct thread *td __unused) +ksyms_mmap_single(struct cdev *dev, vm_ooffset_t *offset, vm_size_t size, + vm_object_t *objp, int nprot) { struct ksyms_softc *sc; + vm_object_t obj; int error; error = devfs_get_cdevpriv((void **)&sc); if (error != 0) return (error); - switch (cmd) { - case KIOCGSIZE: - /* - * Return the size (in bytes) of the symbol table - * snapshot. - */ - *(size_t *)data = sc->sc_usize; - break; - case KIOCGADDR: - /* - * Return the address of the symbol table snapshot. - * XXX - compat32 version of this? - */ - *(void **)data = (void *)sc->sc_uaddr; - break; - default: - error = ENOTTY; - break; - } + if (*offset < 0 || *offset >= round_page(sc->sc_objsz) || + size > round_page(sc->sc_objsz) - *offset || + (nprot & ~PROT_READ) != 0) + return (EINVAL); - return (error); -} - -static int -ksyms_mmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr, - int prot __unused, vm_memattr_t *memattr __unused) -{ - struct ksyms_softc *sc; - int error; - - error = devfs_get_cdevpriv((void **)&sc); - if (error != 0) - return (error); - - /* - * XXX mmap() will actually map the symbol table into the process - * address space again. - */ - if (offset > round_page(sc->sc_usize) || - (*paddr = pmap_extract(sc->sc_pmap, - (vm_offset_t)sc->sc_uaddr + offset)) == 0) - return (-1); - + obj = sc->sc_obj; + vm_object_reference(obj); + *objp = obj; return (0); } static int -ksyms_close(struct cdev *dev, int flags __unused, int fmt __unused, - struct thread *td) -{ - struct ksyms_softc *sc; - int error; - - error = devfs_get_cdevpriv((void **)&sc); - if (error != 0) - return (error); - - /* Unmap the buffer from the process address space. */ - return (copyout_unmap(td, sc->sc_uaddr, sc->sc_usize)); -} - -static int ksyms_modevent(module_t mod __unused, int type, void *data __unused) { int error; @@ -571,7 +489,7 @@ ksyms_modevent(module_t mod __unused, int type, void * error = 0; switch (type) { case MOD_LOAD: - mtx_init(&ksyms_mtx, "KSyms mtx", NULL, MTX_DEF); + sx_init(&ksyms_mtx, "KSyms mtx"); ksyms_dev = make_dev(&ksyms_cdevsw, 0, UID_ROOT, GID_WHEEL, 0400, KSYMS_DNAME); break; @@ -579,7 +497,7 @@ ksyms_modevent(module_t mod __unused, int type, void * if (!LIST_EMPTY(&ksyms_list)) return (EBUSY); destroy_dev(ksyms_dev); - mtx_destroy(&ksyms_mtx); + sx_destroy(&ksyms_mtx); break; case MOD_SHUTDOWN: break;
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