Author: markj Date: Mon Dec 7 21:33:15 2015 New Revision: 291961 URL: https://svnweb.freebsd.org/changeset/base/291961
Log: Add helper functions proc_readmem() and proc_writemem(). These helper functions can be used to read in or write a buffer from or to an arbitrary process' address space. Without them, this can only be done using proc_rwmem(), which requires the caller to fill out a uio. This is onerous and results in code duplication; the new functions provide a simpler interface which is sufficient for most existing callers of proc_rwmem(). This change also adds a manual page for proc_rwmem() and the new functions. Reviewed by: jhb, kib Differential Revision: https://reviews.freebsd.org/D4245 Modified: head/share/man/man9/Makefile head/sys/arm/arm/machdep.c head/sys/cddl/contrib/opensolaris/uts/intel/dtrace/fasttrap_isa.c head/sys/cddl/contrib/opensolaris/uts/powerpc/dtrace/fasttrap_isa.c head/sys/kern/kern_proc.c head/sys/kern/sys_process.c head/sys/mips/mips/pm_machdep.c head/sys/sys/ptrace.h Modified: head/share/man/man9/Makefile ============================================================================== --- head/share/man/man9/Makefile Mon Dec 7 21:04:27 2015 (r291960) +++ head/share/man/man9/Makefile Mon Dec 7 21:33:15 2015 (r291961) @@ -239,6 +239,7 @@ MAN= accept_filter.9 \ printf.9 \ prison_check.9 \ priv.9 \ + proc_rwmem.9 \ pseudofs.9 \ psignal.9 \ random.9 \ @@ -1340,6 +1341,8 @@ MLINKS+=printf.9 log.9 \ printf.9 uprintf.9 MLINKS+=priv.9 priv_check.9 \ priv.9 priv_check_cred.9 +MLINKS+=proc_rwmem.9 proc_readmem.9 \ + proc_rwmem.9 proc_writemem.9 MLINKS+=psignal.9 gsignal.9 \ psignal.9 pgsignal.9 \ psignal.9 tdsignal.9 Modified: head/sys/arm/arm/machdep.c ============================================================================== --- head/sys/arm/arm/machdep.c Mon Dec 7 21:04:27 2015 (r291960) +++ head/sys/arm/arm/machdep.c Mon Dec 7 21:33:15 2015 (r291961) @@ -598,41 +598,21 @@ set_dbregs(struct thread *td, struct dbr static int -ptrace_read_int(struct thread *td, vm_offset_t addr, u_int32_t *v) +ptrace_read_int(struct thread *td, vm_offset_t addr, uint32_t *v) { - struct iovec iov; - struct uio uio; - PROC_LOCK_ASSERT(td->td_proc, MA_NOTOWNED); - iov.iov_base = (caddr_t) v; - iov.iov_len = sizeof(u_int32_t); - uio.uio_iov = &iov; - uio.uio_iovcnt = 1; - uio.uio_offset = (off_t)addr; - uio.uio_resid = sizeof(u_int32_t); - uio.uio_segflg = UIO_SYSSPACE; - uio.uio_rw = UIO_READ; - uio.uio_td = td; - return proc_rwmem(td->td_proc, &uio); + if (proc_readmem(td, td->td_proc, addr, v, sizeof(*v)) != sizeof(*v)) + return (ENOMEM); + return (0); } static int -ptrace_write_int(struct thread *td, vm_offset_t addr, u_int32_t v) +ptrace_write_int(struct thread *td, vm_offset_t addr, uint32_t v) { - struct iovec iov; - struct uio uio; - PROC_LOCK_ASSERT(td->td_proc, MA_NOTOWNED); - iov.iov_base = (caddr_t) &v; - iov.iov_len = sizeof(u_int32_t); - uio.uio_iov = &iov; - uio.uio_iovcnt = 1; - uio.uio_offset = (off_t)addr; - uio.uio_resid = sizeof(u_int32_t); - uio.uio_segflg = UIO_SYSSPACE; - uio.uio_rw = UIO_WRITE; - uio.uio_td = td; - return proc_rwmem(td->td_proc, &uio); + if (proc_writemem(td, td->td_proc, addr, &v, sizeof(v)) != sizeof(v)) + return (ENOMEM); + return (0); } static u_int Modified: head/sys/cddl/contrib/opensolaris/uts/intel/dtrace/fasttrap_isa.c ============================================================================== --- head/sys/cddl/contrib/opensolaris/uts/intel/dtrace/fasttrap_isa.c Mon Dec 7 21:04:27 2015 (r291960) +++ head/sys/cddl/contrib/opensolaris/uts/intel/dtrace/fasttrap_isa.c Mon Dec 7 21:33:15 2015 (r291961) @@ -60,43 +60,31 @@ #include <sys/ptrace.h> static int -proc_ops(int op, proc_t *p, void *kaddr, off_t uaddr, size_t len) +uread(proc_t *p, void *kaddr, size_t len, uintptr_t uaddr) { - struct iovec iov; - struct uio uio; + ssize_t n; - iov.iov_base = kaddr; - iov.iov_len = len; - uio.uio_offset = uaddr; - uio.uio_iov = &iov; - uio.uio_resid = len; - uio.uio_iovcnt = 1; - uio.uio_segflg = UIO_SYSSPACE; - uio.uio_td = curthread; - uio.uio_rw = op; PHOLD(p); - if (proc_rwmem(p, &uio) != 0) { - PRELE(p); - return (-1); - } + n = proc_readmem(curthread, p, uaddr, kaddr, len); PRELE(p); - + if (n != len) + return (ENOMEM); return (0); } static int -uread(proc_t *p, void *kaddr, size_t len, uintptr_t uaddr) -{ - - return (proc_ops(UIO_READ, p, kaddr, uaddr, len)); -} - -static int uwrite(proc_t *p, void *kaddr, size_t len, uintptr_t uaddr) { + ssize_t n; - return (proc_ops(UIO_WRITE, p, kaddr, uaddr, len)); + PHOLD(p); + n = proc_writemem(curthread, p, uaddr, kaddr, len); + PRELE(p); + if (n != len) + return (ENOMEM); + return (0); } + #endif /* illumos */ #ifdef __i386__ #define r_rax r_eax Modified: head/sys/cddl/contrib/opensolaris/uts/powerpc/dtrace/fasttrap_isa.c ============================================================================== --- head/sys/cddl/contrib/opensolaris/uts/powerpc/dtrace/fasttrap_isa.c Mon Dec 7 21:04:27 2015 (r291960) +++ head/sys/cddl/contrib/opensolaris/uts/powerpc/dtrace/fasttrap_isa.c Mon Dec 7 21:33:15 2015 (r291961) @@ -43,44 +43,30 @@ #define OP_RA(x) (((x) & 0x001F0000) >> 16) #define OP_RB(x) (((x) & 0x0000F100) >> 11) - static int -proc_ops(int op, proc_t *p, void *kaddr, off_t uaddr, size_t len) +uread(proc_t *p, void *kaddr, size_t len, uintptr_t uaddr) { - struct iovec iov; - struct uio uio; + ssize_t n; - iov.iov_base = kaddr; - iov.iov_len = len; - uio.uio_offset = uaddr; - uio.uio_iov = &iov; - uio.uio_resid = len; - uio.uio_iovcnt = 1; - uio.uio_segflg = UIO_SYSSPACE; - uio.uio_td = curthread; - uio.uio_rw = op; PHOLD(p); - if (proc_rwmem(p, &uio) != 0) { - PRELE(p); - return (-1); - } + n = proc_readmem(curthread, p, uaddr, kaddr, len); PRELE(p); - + if (n <= 0 || n < len) + return (ENOMEM); return (0); } static int -uread(proc_t *p, void *kaddr, size_t len, uintptr_t uaddr) -{ - - return (proc_ops(UIO_READ, p, kaddr, uaddr, len)); -} - -static int uwrite(proc_t *p, void *kaddr, size_t len, uintptr_t uaddr) { + ssize_t n; - return (proc_ops(UIO_WRITE, p, kaddr, uaddr, len)); + PHOLD(p); + n = proc_writemem(curthread, p, uaddr, kaddr, len); + PRELE(p); + if (n <= 0 || n < len) + return (ENOMEM); + return (0); } int Modified: head/sys/kern/kern_proc.c ============================================================================== --- head/sys/kern/kern_proc.c Mon Dec 7 21:04:27 2015 (r291960) +++ head/sys/kern/kern_proc.c Mon Dec 7 21:33:15 2015 (r291961) @@ -1526,50 +1526,20 @@ pargs_drop(struct pargs *pa) } static int -proc_read_mem(struct thread *td, struct proc *p, vm_offset_t offset, void* buf, - size_t len) -{ - struct iovec iov; - struct uio uio; - - iov.iov_base = (caddr_t)buf; - iov.iov_len = len; - uio.uio_iov = &iov; - uio.uio_iovcnt = 1; - uio.uio_offset = offset; - uio.uio_resid = (ssize_t)len; - uio.uio_segflg = UIO_SYSSPACE; - uio.uio_rw = UIO_READ; - uio.uio_td = td; - - return (proc_rwmem(p, &uio)); -} - -static int proc_read_string(struct thread *td, struct proc *p, const char *sptr, char *buf, size_t len) { - size_t i; - int error; + ssize_t n; - error = proc_read_mem(td, p, (vm_offset_t)sptr, buf, len); /* - * Reading the chunk may validly return EFAULT if the string is shorter - * than the chunk and is aligned at the end of the page, assuming the - * next page is not mapped. So if EFAULT is returned do a fallback to - * one byte read loop. + * This may return a short read if the string is shorter than the chunk + * and is aligned at the end of the page, and the following page is not + * mapped. */ - if (error == EFAULT) { - for (i = 0; i < len; i++, buf++, sptr++) { - error = proc_read_mem(td, p, (vm_offset_t)sptr, buf, 1); - if (error != 0) - return (error); - if (*buf == '\0') - break; - } - error = 0; - } - return (error); + n = proc_readmem(td, p, (vm_offset_t)sptr, buf, len); + if (n <= 0) + return (ENOMEM); + return (0); } #define PROC_AUXV_MAX 256 /* Safety limit on auxv size. */ @@ -1593,10 +1563,10 @@ get_proc_vector32(struct thread *td, str size_t vsize, size; int i, error; - error = proc_read_mem(td, p, (vm_offset_t)(p->p_sysent->sv_psstrings), - &pss, sizeof(pss)); - if (error != 0) - return (error); + error = 0; + if (proc_readmem(td, p, (vm_offset_t)p->p_sysent->sv_psstrings, &pss, + sizeof(pss)) != sizeof(pss)) + return (ENOMEM); switch (type) { case PROC_ARG: vptr = (vm_offset_t)PTRIN(pss.ps_argvstr); @@ -1618,9 +1588,9 @@ get_proc_vector32(struct thread *td, str if (vptr % 4 != 0) return (ENOEXEC); for (ptr = vptr, i = 0; i < PROC_AUXV_MAX; i++) { - error = proc_read_mem(td, p, ptr, &aux, sizeof(aux)); - if (error != 0) - return (error); + if (proc_readmem(td, p, ptr, &aux, sizeof(aux)) != + sizeof(aux)) + return (ENOMEM); if (aux.a_type == AT_NULL) break; ptr += sizeof(aux); @@ -1635,9 +1605,10 @@ get_proc_vector32(struct thread *td, str return (EINVAL); } proc_vector32 = malloc(size, M_TEMP, M_WAITOK); - error = proc_read_mem(td, p, vptr, proc_vector32, size); - if (error != 0) + if (proc_readmem(td, p, vptr, proc_vector32, size) != size) { + error = ENOMEM; goto done; + } if (type == PROC_AUX) { *proc_vectorp = (char **)proc_vector32; *vsizep = vsize; @@ -1663,16 +1634,15 @@ get_proc_vector(struct thread *td, struc vm_offset_t vptr, ptr; char **proc_vector; size_t vsize, size; - int error, i; + int i; #ifdef COMPAT_FREEBSD32 if (SV_PROC_FLAG(p, SV_ILP32) != 0) return (get_proc_vector32(td, p, proc_vectorp, vsizep, type)); #endif - error = proc_read_mem(td, p, (vm_offset_t)(p->p_sysent->sv_psstrings), - &pss, sizeof(pss)); - if (error != 0) - return (error); + if (proc_readmem(td, p, (vm_offset_t)p->p_sysent->sv_psstrings, &pss, + sizeof(pss)) != sizeof(pss)) + return (ENOMEM); switch (type) { case PROC_ARG: vptr = (vm_offset_t)pss.ps_argvstr; @@ -1709,9 +1679,9 @@ get_proc_vector(struct thread *td, struc * to the allocated proc_vector. */ for (ptr = vptr, i = 0; i < PROC_AUXV_MAX; i++) { - error = proc_read_mem(td, p, ptr, &aux, sizeof(aux)); - if (error != 0) - return (error); + if (proc_readmem(td, p, ptr, &aux, sizeof(aux)) != + sizeof(aux)) + return (ENOMEM); if (aux.a_type == AT_NULL) break; ptr += sizeof(aux); @@ -1732,12 +1702,9 @@ get_proc_vector(struct thread *td, struc return (EINVAL); /* In case we are built without INVARIANTS. */ } proc_vector = malloc(size, M_TEMP, M_WAITOK); - if (proc_vector == NULL) - return (ENOMEM); - error = proc_read_mem(td, p, vptr, proc_vector, size); - if (error != 0) { + if (proc_readmem(td, p, vptr, proc_vector, size) != size) { free(proc_vector, M_TEMP); - return (error); + return (ENOMEM); } *proc_vectorp = proc_vector; *vsizep = vsize; Modified: head/sys/kern/sys_process.c ============================================================================== --- head/sys/kern/sys_process.c Mon Dec 7 21:04:27 2015 (r291960) +++ head/sys/kern/sys_process.c Mon Dec 7 21:33:15 2015 (r291961) @@ -252,6 +252,7 @@ proc_rwmem(struct proc *p, struct uio *u * from exiting out from under us until this operation completes. */ PROC_ASSERT_HELD(p); + PROC_LOCK_ASSERT(p, MA_NOTOWNED); /* * The map we want... @@ -327,6 +328,49 @@ proc_rwmem(struct proc *p, struct uio *u return (error); } +static ssize_t +proc_iop(struct thread *td, struct proc *p, vm_offset_t va, void *buf, + size_t len, enum uio_rw rw) +{ + struct iovec iov; + struct uio uio; + ssize_t slen; + int error; + + MPASS(len < SSIZE_MAX); + slen = (ssize_t)len; + + iov.iov_base = (caddr_t)buf; + iov.iov_len = len; + uio.uio_iov = &iov; + uio.uio_iovcnt = 1; + uio.uio_offset = va; + uio.uio_resid = slen; + uio.uio_segflg = UIO_SYSSPACE; + uio.uio_rw = rw; + uio.uio_td = td; + error = proc_rwmem(p, &uio); + if (uio.uio_resid == slen) + return (-1); + return (slen - uio.uio_resid); +} + +ssize_t +proc_readmem(struct thread *td, struct proc *p, vm_offset_t va, void *buf, + size_t len) +{ + + return (proc_iop(td, p, va, buf, len, UIO_READ)); +} + +ssize_t +proc_writemem(struct thread *td, struct proc *p, vm_offset_t va, void *buf, + size_t len) +{ + + return (proc_iop(td, p, va, buf, len, UIO_WRITE)); +} + static int ptrace_vm_entry(struct thread *td, struct proc *p, struct ptrace_vm_entry *pve) { @@ -644,7 +688,7 @@ kern_ptrace(struct thread *td, int req, struct thread *td2 = NULL, *td3; struct ptrace_io_desc *piod = NULL; struct ptrace_lwpinfo *pl; - int error, write, tmp, num; + int error, num, tmp; int proctree_locked = 0; lwpid_t tid = 0, *buf; #ifdef COMPAT_FREEBSD32 @@ -674,7 +718,6 @@ kern_ptrace(struct thread *td, int req, break; } - write = 0; if (req == PT_TRACE_ME) { p = td->td_proc; PROC_LOCK(p); @@ -1033,46 +1076,28 @@ kern_ptrace(struct thread *td, int req, case PT_WRITE_I: case PT_WRITE_D: td2->td_dbgflags |= TDB_USERWR; - write = 1; - /* FALLTHROUGH */ + PROC_UNLOCK(p); + error = 0; + if (proc_writemem(td, p, (off_t)(uintptr_t)addr, &data, + sizeof(int)) != sizeof(int)) + error = ENOMEM; + else + CTR3(KTR_PTRACE, "PT_WRITE: pid %d: %p <= %#x", + p->p_pid, addr, data); + PROC_LOCK(p); + break; + case PT_READ_I: case PT_READ_D: PROC_UNLOCK(p); - tmp = 0; - /* write = 0 set above */ - iov.iov_base = write ? (caddr_t)&data : (caddr_t)&tmp; - iov.iov_len = sizeof(int); - uio.uio_iov = &iov; - uio.uio_iovcnt = 1; - uio.uio_offset = (off_t)(uintptr_t)addr; - uio.uio_resid = sizeof(int); - uio.uio_segflg = UIO_SYSSPACE; /* i.e.: the uap */ - uio.uio_rw = write ? UIO_WRITE : UIO_READ; - uio.uio_td = td; - error = proc_rwmem(p, &uio); - if (uio.uio_resid != 0) { - /* - * XXX proc_rwmem() doesn't currently return ENOSPC, - * so I think write() can bogusly return 0. - * XXX what happens for short writes? We don't want - * to write partial data. - * XXX proc_rwmem() returns EPERM for other invalid - * addresses. Convert this to EINVAL. Does this - * clobber returns of EPERM for other reasons? - */ - if (error == 0 || error == ENOSPC || error == EPERM) - error = EINVAL; /* EOF */ - } - if (!write) - td->td_retval[0] = tmp; - if (error == 0) { - if (write) - CTR3(KTR_PTRACE, "PT_WRITE: pid %d: %p <= %#x", - p->p_pid, addr, data); - else - CTR3(KTR_PTRACE, "PT_READ: pid %d: %p >= %#x", - p->p_pid, addr, tmp); - } + error = tmp = 0; + if (proc_readmem(td, p, (off_t)(uintptr_t)addr, &tmp, + sizeof(int)) != sizeof(int)) + error = ENOMEM; + else + CTR3(KTR_PTRACE, "PT_READ: pid %d: %p >= %#x", + p->p_pid, addr, tmp); + td->td_retval[0] = tmp; PROC_LOCK(p); break; Modified: head/sys/mips/mips/pm_machdep.c ============================================================================== --- head/sys/mips/mips/pm_machdep.c Mon Dec 7 21:04:27 2015 (r291960) +++ head/sys/mips/mips/pm_machdep.c Mon Dec 7 21:33:15 2015 (r291961) @@ -214,39 +214,19 @@ ptrace_set_pc(struct thread *td, unsigne static int ptrace_read_int(struct thread *td, off_t addr, int *v) { - struct iovec iov; - struct uio uio; - PROC_LOCK_ASSERT(td->td_proc, MA_NOTOWNED); - iov.iov_base = (caddr_t) v; - iov.iov_len = sizeof(int); - uio.uio_iov = &iov; - uio.uio_iovcnt = 1; - uio.uio_offset = (off_t)addr; - uio.uio_resid = sizeof(int); - uio.uio_segflg = UIO_SYSSPACE; - uio.uio_rw = UIO_READ; - uio.uio_td = td; - return proc_rwmem(td->td_proc, &uio); + if (proc_readmem(td, td->td_proc, addr, v, sizeof(*v)) != sizeof(*v)) + return (ENOMEM); + return (0); } static int ptrace_write_int(struct thread *td, off_t addr, int v) { - struct iovec iov; - struct uio uio; - PROC_LOCK_ASSERT(td->td_proc, MA_NOTOWNED); - iov.iov_base = (caddr_t) &v; - iov.iov_len = sizeof(int); - uio.uio_iov = &iov; - uio.uio_iovcnt = 1; - uio.uio_offset = (off_t)addr; - uio.uio_resid = sizeof(int); - uio.uio_segflg = UIO_SYSSPACE; - uio.uio_rw = UIO_WRITE; - uio.uio_td = td; - return proc_rwmem(td->td_proc, &uio); + if (proc_writemem(td, td->td_proc, addr, &v, sizeof(v)) != sizeof(v)) + return (ENOMEM); + return (0); } int Modified: head/sys/sys/ptrace.h ============================================================================== --- head/sys/sys/ptrace.h Mon Dec 7 21:04:27 2015 (r291960) +++ head/sys/sys/ptrace.h Mon Dec 7 21:33:15 2015 (r291961) @@ -166,6 +166,10 @@ int proc_read_dbregs(struct thread *_td, int proc_write_dbregs(struct thread *_td, struct dbreg *_dbreg); int proc_sstep(struct thread *_td); int proc_rwmem(struct proc *_p, struct uio *_uio); +ssize_t proc_readmem(struct thread *_td, struct proc *_p, vm_offset_t _va, + void *_buf, size_t _len); +ssize_t proc_writemem(struct thread *_td, struct proc *_p, vm_offset_t _va, + void *_buf, size_t _len); #ifdef COMPAT_FREEBSD32 struct reg32; struct fpreg32; _______________________________________________ [email protected] mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "[email protected]"
