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-rw-r--r--src/readelf.c124
1 files changed, 103 insertions, 21 deletions
diff --git a/src/readelf.c b/src/readelf.c
index 1d507cf9..85fa92bc 100644
--- a/src/readelf.c
+++ b/src/readelf.c
@@ -114,7 +114,7 @@ static const struct argp_option options[] =
{ "wide", 'W', NULL, 0,
N_("Ignored for compatibility (lines always wide)"), 0 },
{ "decompress", 'z', NULL, 0,
- N_("Show compression information for compressed sections (when used with -S)."), 0 },
+ N_("Show compression information for compressed sections (when used with -S); decompress section before dumping data (when used with -p or -x)"), 0 },
{ NULL, 0, NULL, 0, NULL, 0 }
};
@@ -806,6 +806,20 @@ process_file (int fd, const char *fname, bool only_one)
close (fd);
}
+/* Check whether there are any compressed sections in the ELF file. */
+static bool
+elf_contains_chdrs (Elf *elf)
+{
+ Elf_Scn *scn = NULL;
+ while ((scn = elf_nextscn (elf, scn)) != NULL)
+ {
+ GElf_Shdr shdr_mem;
+ GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem);
+ if (shdr != NULL && (shdr->sh_flags & SHF_COMPRESSED) != 0)
+ return true;
+ }
+ return false;
+}
/* Process one ELF file. */
static void
@@ -844,17 +858,21 @@ process_elf_file (Dwfl_Module *dwflmod, int fd)
gettext ("cannot determine number of program headers: %s"),
elf_errmsg (-1));
- /* For an ET_REL file, libdwfl has adjusted the in-core shdrs
- and may have applied relocation to some sections.
- So we need to get a fresh Elf handle on the file to display those. */
- bool print_unrelocated = (print_section_header
- || print_relocations
- || dump_data_sections != NULL
- || print_notes);
+ /* For an ET_REL file, libdwfl has adjusted the in-core shdrs and
+ may have applied relocation to some sections. If there are any
+ compressed sections, any pass (or libdw/libdwfl) might have
+ uncompressed them. So we need to get a fresh Elf handle on the
+ file to display those. */
+ bool print_unchanged = ((print_section_header
+ || print_relocations
+ || dump_data_sections != NULL
+ || print_notes)
+ && (ehdr->e_type == ET_REL
+ || elf_contains_chdrs (ebl->elf)));
Elf *pure_elf = NULL;
Ebl *pure_ebl = ebl;
- if (ehdr->e_type == ET_REL && print_unrelocated)
+ if (print_unchanged)
{
/* Read the file afresh. */
off_t aroff = elf_getaroff (elf);
@@ -1503,7 +1521,17 @@ print_scngrp (Ebl *ebl)
GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem);
if (shdr != NULL && shdr->sh_type == SHT_GROUP)
- handle_scngrp (ebl, scn, shdr);
+ {
+ if ((shdr->sh_flags & SHF_COMPRESSED) != 0)
+ {
+ if (elf_compress (scn, 0, 0) < 0)
+ printf ("WARNING: %s [%zd]\n",
+ gettext ("Couldn't uncompress section"),
+ elf_ndxscn (scn));
+ shdr = gelf_getshdr (scn, &shdr_mem);
+ }
+ handle_scngrp (ebl, scn, shdr);
+ }
}
}
@@ -2202,7 +2230,17 @@ print_symtab (Ebl *ebl, int type)
GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem);
if (shdr != NULL && shdr->sh_type == (GElf_Word) type)
- handle_symtab (ebl, scn, shdr);
+ {
+ if ((shdr->sh_flags & SHF_COMPRESSED) != 0)
+ {
+ if (elf_compress (scn, 0, 0) < 0)
+ printf ("WARNING: %s [%zd]\n",
+ gettext ("Couldn't uncompress section"),
+ elf_ndxscn (scn));
+ shdr = gelf_getshdr (scn, &shdr_mem);
+ }
+ handle_symtab (ebl, scn, shdr);
+ }
}
}
@@ -3271,6 +3309,16 @@ handle_hash (Ebl *ebl)
if (likely (shdr != NULL))
{
+ if ((shdr->sh_type == SHT_HASH || shdr->sh_type == SHT_GNU_HASH)
+ && (shdr->sh_flags & SHF_COMPRESSED) != 0)
+ {
+ if (elf_compress (scn, 0, 0) < 0)
+ printf ("WARNING: %s [%zd]\n",
+ gettext ("Couldn't uncompress section"),
+ elf_ndxscn (scn));
+ shdr = gelf_getshdr (scn, &shdr_mem);
+ }
+
if (shdr->sh_type == SHT_HASH)
{
if (ebl_sysvhash_entrysize (ebl) == sizeof (Elf64_Xword))
@@ -8320,11 +8368,9 @@ print_debug (Dwfl_Module *dwflmod, Ebl *ebl, GElf_Ehdr *ehdr)
int n;
for (n = 0; n < ndebug_sections; ++n)
if (strcmp (name, debug_sections[n].name) == 0
-#if USE_ZLIB
|| (name[0] == '.' && name[1] == 'z'
&& debug_sections[n].name[1] == 'd'
&& strcmp (&name[2], &debug_sections[n].name[1]) == 0)
-#endif
)
{
if ((print_debug_sections | implicit_debug_sections)
@@ -9456,16 +9502,34 @@ dump_data_section (Elf_Scn *scn, const GElf_Shdr *shdr, const char *name)
elf_ndxscn (scn), name);
else
{
+ if (print_decompress)
+ {
+ /* We try to decompress the section, but keep the old shdr around
+ so we can show both the original shdr size and the uncompressed
+ data size. */
+ if ((shdr->sh_flags & SHF_COMPRESSED) != 0)
+ elf_compress (scn, 0, 0);
+ else if (strncmp (name, ".zdebug", strlen (".zdebug")) == 0)
+ elf_compress_gnu (scn, 0, 0);
+ }
+
Elf_Data *data = elf_rawdata (scn, NULL);
if (data == NULL)
error (0, 0, gettext ("cannot get data for section [%zu] '%s': %s"),
elf_ndxscn (scn), name, elf_errmsg (-1));
else
{
- printf (gettext ("\nHex dump of section [%zu] '%s', %" PRIu64
- " bytes at offset %#0" PRIx64 ":\n"),
- elf_ndxscn (scn), name,
- shdr->sh_size, shdr->sh_offset);
+ if (data->d_size == shdr->sh_size)
+ printf (gettext ("\nHex dump of section [%zu] '%s', %" PRIu64
+ " bytes at offset %#0" PRIx64 ":\n"),
+ elf_ndxscn (scn), name,
+ shdr->sh_size, shdr->sh_offset);
+ else
+ printf (gettext ("\nHex dump of section [%zu] '%s', %" PRIu64
+ " bytes (%zd uncompressed) at offset %#0"
+ PRIx64 ":\n"),
+ elf_ndxscn (scn), name,
+ shdr->sh_size, data->d_size, shdr->sh_offset);
hex_dump (data->d_buf, data->d_size);
}
}
@@ -9479,16 +9543,34 @@ print_string_section (Elf_Scn *scn, const GElf_Shdr *shdr, const char *name)
elf_ndxscn (scn), name);
else
{
+ if (print_decompress)
+ {
+ /* We try to decompress the section, but keep the old shdr around
+ so we can show both the original shdr size and the uncompressed
+ data size. */
+ if ((shdr->sh_flags & SHF_COMPRESSED) != 0)
+ elf_compress (scn, 0, 0);
+ else if (strncmp (name, ".zdebug", strlen (".zdebug")) == 0)
+ elf_compress_gnu (scn, 0, 0);
+ }
+
Elf_Data *data = elf_rawdata (scn, NULL);
if (data == NULL)
error (0, 0, gettext ("cannot get data for section [%zu] '%s': %s"),
elf_ndxscn (scn), name, elf_errmsg (-1));
else
{
- printf (gettext ("\nString section [%zu] '%s' contains %" PRIu64
- " bytes at offset %#0" PRIx64 ":\n"),
- elf_ndxscn (scn), name,
- shdr->sh_size, shdr->sh_offset);
+ if (data->d_size == shdr->sh_size)
+ printf (gettext ("\nString section [%zu] '%s' contains %" PRIu64
+ " bytes at offset %#0" PRIx64 ":\n"),
+ elf_ndxscn (scn), name,
+ shdr->sh_size, shdr->sh_offset);
+ else
+ printf (gettext ("\nString section [%zu] '%s' contains %" PRIu64
+ " bytes (%zd uncompressed) at offset %#0"
+ PRIx64 ":\n"),
+ elf_ndxscn (scn), name,
+ shdr->sh_size, data->d_size, shdr->sh_offset);
const char *start = data->d_buf;
const char *const limit = start + data->d_size;
generated by cgit v1.2.3 (git 2.25.1) at 2025-12-16 13:39:01 +0000