Create null mmaps if section paddr + psize exceeds filesize

radareorg · Nov 17, 2023 · 58cf322 · 58cf322
1 parent 8bf7fdf
commit 58cf322
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Showing 3 changed files with 14 additions and 12 deletions.
diff --git a/libr/core/cbin.c b/libr/core/cbin.c
@@ -2764,11 +2764,10 @@ static RIODesc *findReusableFile(RIO *io, const char *uri, int perm) {
 	return arg.desc;
 }
 
-static bool io_create_mem_map(RIO *io, RBinSection *sec, ut64 at) {
+static bool io_create_mem_map(RIO *io, RBinSection *sec, ut64 at, ut64 gap) {
 	r_return_val_if_fail (io && sec, false);
 
 	bool reused = false;
-	ut64 gap = sec->vsize - sec->size;
 	char *uri = r_str_newf ("null://%"PFMT64u, gap);
 	RIODesc *desc = findReusableFile (io, uri, sec->perm);
 	if (desc) {
@@ -2800,25 +2799,26 @@ static bool io_create_mem_map(RIO *io, RBinSection *sec, ut64 at) {
 	return true;
 }
 
+
+
+
 static void add_section(RCore *core, RBinSection *sec, ut64 addr, int fd) {
 	if (!r_io_desc_get (core->io, fd) || UT64_ADD_OVFCHK (sec->size, sec->paddr) ||
 			UT64_ADD_OVFCHK (sec->size, addr) || !sec->vsize) {
 		return;
 	}
 
 	ut64 size = sec->vsize;
+	const ut64 fdsize = r_io_fd_size (core->io, fd);
+	const ut64 psize = (sec->paddr < fdsize)? R_MIN (sec->size, fdsize - sec->paddr): 0LL;
 	// if there is some part of the section that needs to be zeroed by the loader
 	// we add a null map that takes care of it
-	if (sec->vsize > sec->size) {
-		if (!io_create_mem_map (core->io, sec, addr + sec->size)) {
-			return;
-		}
-		size = sec->size;
-		if (!size) {
+	if (sec->vsize > psize) {
+		size = psize;
+		if (!io_create_mem_map (core->io, sec, addr + psize, sec->vsize - psize) || !size) {
 			return;
 		}
 	}
-
 	// then we map the part of the section that comes from the physical file
 	char *map_name = r_str_newf ("fmap.%s", sec->name);
 	if (!map_name) {

diff --git a/test/db/cmd/cmd_open b/test/db/cmd/cmd_open
@@ -69,7 +69,7 @@ oon
 o
 EOF
 EXPECT=<<EOF
- 4 * r-- 0x00009730 bins/mach0/mac-ls2
+ 5 * r-- 0x00009730 bins/mach0/mac-ls2
 EOF
 RUN
 
@@ -127,7 +127,7 @@ o bins/mach0/mac-ls
 s
 obo 3
 s
-obo 4
+obo 5
 s
 EOF
 EXPECT=<<EOF
@@ -653,6 +653,7 @@ stripped false
 subsys   darwin
 va       true
 -- o
+ 4 - r-- 0x00003f14 null://16148
 -- ob
 - 0 3 arm-32 ba:0x00000000 sz:65536 ./bins/mach0/test-arm32
 * 1 3 arm-32 ba:0x00004000 sz:65536 ./bins/mach0/test-arm32

diff --git a/test/db/formats/elf/tiny b/test/db/formats/elf/tiny
@@ -15,6 +15,7 @@ NAME=ELF: corkami tiny.elf - sections
 FILE=bins/elf/analysis/tiny.elf
 CMDS=om
 EXPECT=<<EOF
-* 1 fd: 3 +0x00000000 0x00010000 - 0x0002001f r-- fmap.LOAD0
+* 2 fd: 3 +0x00000000 0x00010000 - 0x0001002c r-- fmap.LOAD0
+- 1 fd: 4 +0x00000000 0x0001002d - 0x0002001f r-- mmap.LOAD0
 EOF
 RUN