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

1 files changed, 8 insertions, 28 deletions

diff --git a/sys/mips/mips/pm_machdep.c b/sys/mips/mips/pm_machdep.c
index d5f6df0..9bccaec 100644
--- a/sys/mips/mips/pm_machdep.c
+++ b/sys/mips/mips/pm_machdep.c
@@ -214,39 +214,19 @@ ptrace_set_pc(struct thread *td, unsigned long addr)
 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