From: Dmitry V. Levin <ldv@altlinux.org>
Date: Tue, 15 Sep 2015 02:17:32 +0000 (+0000)
Subject: Add a new helper function umove_ulong_array_or_printaddr
X-Git-Tag: v4.11~202
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=b172a94d0263f163d33e0f2a0395267719916576;p=strace

Add a new helper function umove_ulong_array_or_printaddr

* defs.h (umove_ulong_array_or_printaddr): New prototype.
* util.c (umove_ulong_array_or_printaddr): New function.
* desc.c (sys_pselect6): Use it instead of open-coding
a proxy struct parser for different personalities.
* io.c (tprint_iov_upto): Use it instead of open-coding
a struct iovec parser for different personalities.
* kexec.c (print_kexec_segments): Use it instead of open-coding
a struct kexec_segment parser for different personalities.
(print_seg): Pass arguments using an array.
---

diff --git a/defs.h b/defs.h
index 8833dfc8..cad250a4 100644
--- a/defs.h
+++ b/defs.h
@@ -542,6 +542,7 @@ extern int umoven_or_printaddr(struct tcb *, long, unsigned int, void *);
 #define umove_or_printaddr(pid, addr, objp)	\
 	umoven_or_printaddr((pid), (addr), sizeof(*(objp)), (void *) (objp))
 extern int umove_ulong_or_printaddr(struct tcb *, long, unsigned long *);
+extern int umove_ulong_array_or_printaddr(struct tcb *, long, unsigned long *, size_t);
 extern int umovestr(struct tcb *, long, unsigned int, char *);
 extern int upeek(int pid, long, long *);
 
diff --git a/desc.c b/desc.c
index 91b2be93..ea9f3bd5 100644
--- a/desc.c
+++ b/desc.c
@@ -441,30 +441,15 @@ SYS_FUNC(pselect6)
 {
 	int rc = decode_select(tcp, tcp->u_arg, BITNESS_CURRENT);
 	if (entering(tcp)) {
-		long r;
-		struct {
-			unsigned long ptr;
-			unsigned long len;
-		} data;
+		unsigned long data[2];
 
 		tprints(", ");
-#if SUPPORTED_PERSONALITIES > 1 && SIZEOF_LONG > 4
-		if (current_wordsize == 4) {
-			struct {
-				uint32_t ptr;
-				uint32_t len;
-			} data32;
-			r = umove_or_printaddr(tcp, tcp->u_arg[5], &data32);
-			data.ptr = data32.ptr;
-			data.len = data32.len;
-		} else
-#endif
-			r = umove_or_printaddr(tcp, tcp->u_arg[5], &data);
-		if (r == 0) {
+		if (!umove_ulong_array_or_printaddr(tcp, tcp->u_arg[5], data,
+						    ARRAY_SIZE(data))) {
 			tprints("{");
-			/* NB: kernel requires data.len == NSIG / 8 */
-			print_sigset_addr_len(tcp, data.ptr, data.len);
-			tprintf(", %lu}", data.len);
+			/* NB: kernel requires data[1] == NSIG / 8 */
+			print_sigset_addr_len(tcp, data[0], data[1]);
+			tprintf(", %lu}", data[1]);
 		}
 	}
 	return rc;
diff --git a/io.c b/io.c
index dcc38599..0cdc469f 100644
--- a/io.c
+++ b/io.c
@@ -64,24 +64,9 @@ SYS_FUNC(write)
 void
 tprint_iov_upto(struct tcb *tcp, unsigned long len, unsigned long addr, int decode_iov, unsigned long data_size)
 {
-#if SUPPORTED_PERSONALITIES > 1
-	union {
-		struct { u_int32_t base; u_int32_t len; } iov32;
-		struct { u_int64_t base; u_int64_t len; } iov64;
-	} iov;
-#define sizeof_iov \
-	(current_wordsize == 4 ? sizeof(iov.iov32) : sizeof(iov.iov64))
-#define iov_iov_base \
-	(current_wordsize == 4 ? (uint64_t) iov.iov32.base : iov.iov64.base)
-#define iov_iov_len \
-	(current_wordsize == 4 ? (uint64_t) iov.iov32.len : iov.iov64.len)
-#else
-	struct iovec iov;
-#define sizeof_iov sizeof(iov)
-#define iov_iov_base iov.iov_base
-#define iov_iov_len iov.iov_len
-#endif
+	unsigned long iov[2];
 	unsigned long size, cur, end, abbrev_end;
+	const unsigned long sizeof_iov = current_wordsize * 2;
 
 	if (!len) {
 		tprints("[]");
@@ -109,23 +94,21 @@ tprint_iov_upto(struct tcb *tcp, unsigned long len, unsigned long addr, int deco
 			tprints("...");
 			break;
 		}
-		if (umoven_or_printaddr(tcp, cur, sizeof_iov, &iov))
+		if (umove_ulong_array_or_printaddr(tcp, cur, iov,
+						   ARRAY_SIZE(iov)))
 			break;
 		tprints("{");
 		if (decode_iov) {
-			unsigned long len = iov_iov_len;
+			unsigned long len = iov[1];
 			if (len > data_size)
 				len = data_size;
 			data_size -= len;
-			printstr(tcp, (long) iov_iov_base, len);
+			printstr(tcp, iov[0], len);
 		} else
-			printaddr((long) iov_iov_base);
-		tprintf(", %lu}", (unsigned long)iov_iov_len);
+			printaddr(iov[0]);
+		tprintf(", %lu}", iov[1]);
 	}
 	tprints("]");
-#undef sizeof_iov
-#undef iov_iov_base
-#undef iov_iov_len
 }
 
 void
diff --git a/kexec.c b/kexec.c
index e7ce07a0..2cfe1381 100644
--- a/kexec.c
+++ b/kexec.c
@@ -11,48 +11,21 @@
 #endif
 
 static void
-print_seg(const long seg_buf, const unsigned long seg_bufsz,
-	  const long seg_mem, const unsigned long seg_memsz)
+print_seg(const unsigned long *seg)
 {
 	tprints("{");
-	printaddr(seg_buf);
-	tprintf(", %lu, ", seg_bufsz);
-	printaddr(seg_mem);
-	tprintf(", %lu}", seg_memsz);
+	printaddr(seg[0]);
+	tprintf(", %lu, ", seg[1]);
+	printaddr(seg[2]);
+	tprintf(", %lu}", seg[3]);
 }
 
 static void
 print_kexec_segments(struct tcb *tcp, const unsigned long addr,
 		     const unsigned long len)
 {
-#if SUPPORTED_PERSONALITIES > 1
-	union {
-		struct { u_int32_t buf, bufsz, mem, memsz; } seg32;
-		struct { u_int64_t buf, bufsz, mem, memsz; } seg64;
-	} seg;
-# define sizeof_seg \
-	(current_wordsize == 4 ? sizeof(seg.seg32) : sizeof(seg.seg64))
-# define seg_buf \
-	(current_wordsize == 4 ? (uint64_t) seg.seg32.buf : seg.seg64.buf)
-# define seg_bufsz \
-	(current_wordsize == 4 ? (uint64_t) seg.seg32.bufsz : seg.seg64.bufsz)
-# define seg_mem \
-	(current_wordsize == 4 ? (uint64_t) seg.seg32.mem : seg.seg64.mem)
-# define seg_memsz \
-	(current_wordsize == 4 ? (uint64_t) seg.seg32.memsz : seg.seg64.memsz)
-#else
-	struct {
-		void *buf;
-		size_t bufsz;
-		void *mem;
-		size_t memsz;
-	} seg;
-# define sizeof_seg sizeof(seg)
-# define seg_buf seg.buf
-# define seg_bufsz seg.bufsz
-# define seg_mem seg.mem
-# define seg_memsz seg.memsz
-#endif
+	unsigned long seg[4];
+	const size_t sizeof_seg = ARRAY_SIZE(seg) * current_wordsize;
 	unsigned int i;
 
 	if (!len) {
@@ -65,20 +38,19 @@ print_kexec_segments(struct tcb *tcp, const unsigned long addr,
 		return;
 	}
 
-	if (umoven_or_printaddr(tcp, addr, sizeof_seg, &seg))
+	if (umove_ulong_array_or_printaddr(tcp, addr, seg, ARRAY_SIZE(seg)))
 		return;
 
 	tprints("[");
-	print_seg((unsigned long) seg_buf, seg_bufsz,
-		  (unsigned long) seg_mem, seg_memsz);
+	print_seg(seg);
 
 	for (i = 1; i < len; ++i) {
 		tprints(", ");
-		if (umoven_or_printaddr(tcp, addr + i * sizeof_seg,
-					sizeof_seg, &seg))
+		if (umove_ulong_array_or_printaddr(tcp,
+						   addr + i * sizeof_seg,
+						   seg, ARRAY_SIZE(seg)))
 			break;
-		print_seg((unsigned long) seg_buf, seg_bufsz,
-			  (unsigned long) seg_mem, seg_memsz);
+		print_seg(seg);
 	}
 
 	tprints("]");
diff --git a/util.c b/util.c
index afd298ec..c3e3fdaf 100644
--- a/util.c
+++ b/util.c
@@ -1145,6 +1145,24 @@ umove_ulong_or_printaddr(struct tcb *tcp, const long addr, unsigned long *ptr)
 	return umove_or_printaddr(tcp, addr, ptr);
 }
 
+int
+umove_ulong_array_or_printaddr(struct tcb *tcp, const long addr,
+			       unsigned long *ptr, size_t n)
+{
+	if (current_wordsize < sizeof(*ptr)) {
+		uint32_t ptr32[n];
+		int r = umove_or_printaddr(tcp, addr, &ptr32);
+		if (!r) {
+			size_t i;
+
+			for (i = 0; i < n; ++i)
+				ptr[i] = (unsigned long) ptr32[i];
+		}
+		return r;
+	}
+	return umoven_or_printaddr(tcp, addr, n * sizeof(*ptr), ptr);
+}
+
 /*
  * Like `umove' but make the additional effort of looking
  * for a terminating zero byte.