xiaoxiang781216 commented on code in PR #21215:
URL: https://github.com/apache/nuttx/pull/21215#discussion_r4425414513
##########
libs/libc/elf/elf_load.c:
##########
@@ -56,9 +56,11 @@
#define ELF_ALIGNUP(a) (((unsigned long)(a) + ELF_ALIGN_MASK) &
~ELF_ALIGN_MASK)
#define ELF_ALIGNDOWN(a) ((unsigned long)(a) & ~ELF_ALIGN_MASK)
-/* _ALIGN_UP: 'a' is assumed to be a power of two */
+/* _ALIGN_UP: 'a' is assumed to be a power of two. 0 and 1 mean no
+ * alignment (sh_addralign in the ELF specification).
+ */
-#define _ALIGN_UP(v, a) (((v) + ((a) - 1)) & ~((a) - 1))
+#define _ALIGN_UP(v, a) ((a) > 1 ? (((v) + ((a) - 1)) & ~((a) - 1)) : (v))
Review Comment:
why not use ALIGN_UP from nuttx/nuttx.h
##########
libs/libc/elf/elf_load.c:
##########
@@ -56,9 +56,11 @@
#define ELF_ALIGNUP(a) (((unsigned long)(a) + ELF_ALIGN_MASK) &
~ELF_ALIGN_MASK)
#define ELF_ALIGNDOWN(a) ((unsigned long)(a) & ~ELF_ALIGN_MASK)
Review Comment:
map to ALIGN_UP/ALIGN_DOWN
##########
libs/libc/elf/elf_load.c:
##########
@@ -145,15 +145,54 @@ static int libelf_section_alloc(FAR struct mod_loadinfo_s
*loadinfo,
}
#endif
+/****************************************************************************
+ * Name: libelf_addsize
+ *
+ * Description:
+ * Add a section of the given alignment and size to a running size.
+ * The ELF specification allows only 0 and powers of two as alignment.
+ * Fail with -ENOEXEC for any other alignment, and when a size is more
+ * than half of the address space: no image can be that large, and the
+ * later round-ups (to the alignment, to pages) then cannot wrap.
+ *
+ ****************************************************************************/
+
+static int libelf_addsize(FAR size_t *total, uintmax_t align,
+ uintmax_t size)
+{
+ size_t start;
+ size_t end;
+
+ if ((align & (align - 1)) != 0 || align > SIZE_MAX / 2 ||
+ size > SIZE_MAX / 2)
+ {
+ return -ENOEXEC;
+ }
+
+ start = _ALIGN_UP(*total, (size_t)align);
Review Comment:
remove the cast
##########
libs/libc/elf/elf_load.c:
##########
@@ -145,15 +145,54 @@ static int libelf_section_alloc(FAR struct mod_loadinfo_s
*loadinfo,
}
#endif
+/****************************************************************************
+ * Name: libelf_addsize
+ *
+ * Description:
+ * Add a section of the given alignment and size to a running size.
+ * The ELF specification allows only 0 and powers of two as alignment.
+ * Fail with -ENOEXEC for any other alignment, and when a size is more
+ * than half of the address space: no image can be that large, and the
+ * later round-ups (to the alignment, to pages) then cannot wrap.
+ *
+ ****************************************************************************/
+
+static int libelf_addsize(FAR size_t *total, uintmax_t align,
+ uintmax_t size)
+{
+ size_t start;
+ size_t end;
+
+ if ((align & (align - 1)) != 0 || align > SIZE_MAX / 2 ||
+ size > SIZE_MAX / 2)
+ {
+ return -ENOEXEC;
+ }
+
+ start = _ALIGN_UP(*total, (size_t)align);
+ end = start + ELF_ALIGNUP(size);
+ if (start < *total || end < start || end > SIZE_MAX / 2)
+ {
+ return -ENOEXEC;
+ }
+
+ *total = end;
+ return OK;
+}
+
/****************************************************************************
* Name: libelf_elfsize
*
* Description:
* Calculate total memory allocation for the ELF file.
*
+ * Returned Value:
+ * 0 (OK) is returned on success; -ENOEXEC when a section has an invalid
+ * alignment or the sizes are more than half of the address space.
+ *
****************************************************************************/
-static void libelf_elfsize(FAR struct mod_loadinfo_s *loadinfo, bool alloc)
+static int libelf_elfsize(FAR struct mod_loadinfo_s *loadinfo, bool alloc)
Review Comment:
int to bool?
##########
libs/libc/elf/elf_load.c:
##########
@@ -145,15 +145,54 @@ static int libelf_section_alloc(FAR struct mod_loadinfo_s
*loadinfo,
}
#endif
+/****************************************************************************
+ * Name: libelf_addsize
+ *
+ * Description:
+ * Add a section of the given alignment and size to a running size.
+ * The ELF specification allows only 0 and powers of two as alignment.
+ * Fail with -ENOEXEC for any other alignment, and when a size is more
+ * than half of the address space: no image can be that large, and the
+ * later round-ups (to the alignment, to pages) then cannot wrap.
+ *
+ ****************************************************************************/
+
+static int libelf_addsize(FAR size_t *total, uintmax_t align,
Review Comment:
let's swap the order of align and size
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