From: Mark Wielaard <mark@klomp.org>
To: elfutils-devel@sourceware.org
Cc: Mark Wielaard <mark@klomp.org>
Subject: [COMMITTED] readelf: Check phdr != NULL or shdr != NULL in handle_dynamic.
Date: Thu, 3 Nov 2022 14:17:42 +0100 [thread overview]
Message-ID: <20221103131742.18109-1-mark@klomp.org> (raw)
The compiler doesn't know that when use_dynamic_segment is true,
then phdr should/will be non-NULL and otherwise shdr is non-NULL.
Add explicit checks to help the compiler out and in case an error
is made calling the handle_dynamic function.
Signed-off-by: Mark Wielaard <mark@klomp.org>
---
src/ChangeLog | 5 +++++
src/readelf.c | 10 +++++-----
2 files changed, 10 insertions(+), 5 deletions(-)
diff --git a/src/ChangeLog b/src/ChangeLog
index d3399a5c..0c5ab37e 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,8 @@
+2022-11-03 Mark Wielaard <mark@klomp.org>
+
+ * readelf.c (handle_dynamic): Check phdr != NULL when
+ use_dynamic_segment, otherwise check shdr != NULL.
+
2022-10-28 Arsen Arsenović <arsen@aarsen.me>
* readelf.c (options): Add Binutils-style --syms alias.
diff --git a/src/readelf.c b/src/readelf.c
index 0e0b05c4..e721a209 100644
--- a/src/readelf.c
+++ b/src/readelf.c
@@ -1828,7 +1828,7 @@ handle_dynamic (Ebl *ebl, Elf_Scn *scn, GElf_Shdr *shdr, GElf_Phdr *phdr)
size_t dyn_ents;
/* Get the data of the section. */
- if (use_dynamic_segment)
+ if (use_dynamic_segment && phdr != NULL)
data = elf_getdata_rawchunk(ebl->elf, phdr->p_offset,
phdr->p_filesz, ELF_T_DYN);
else
@@ -1840,7 +1840,7 @@ handle_dynamic (Ebl *ebl, Elf_Scn *scn, GElf_Shdr *shdr, GElf_Phdr *phdr)
/* Get the dynamic section entry number */
dyn_ents = get_dyn_ents (data);
- if (!use_dynamic_segment)
+ if (!use_dynamic_segment && shdr != NULL)
{
/* Get the section header string table index. */
if (unlikely (elf_getshdrstrndx (ebl->elf, &shstrndx) < 0))
@@ -1862,7 +1862,7 @@ handle_dynamic (Ebl *ebl, Elf_Scn *scn, GElf_Shdr *shdr, GElf_Phdr *phdr)
(int) shdr->sh_link,
elf_strptr (ebl->elf, shstrndx, glink->sh_name));
}
- else
+ else if (phdr != NULL)
{
printf (ngettext ("\
\nDynamic segment contains %lu entry:\n Addr: %#0*" PRIx64 " Offset: %#08" PRIx64 "\n",
@@ -1879,7 +1879,7 @@ handle_dynamic (Ebl *ebl, Elf_Scn *scn, GElf_Shdr *shdr, GElf_Phdr *phdr)
/* if --use-dynamic option is enabled,
use the string table to get the related library info. */
Elf_Data *strtab_data = NULL;
- if (use_dynamic_segment)
+ if (use_dynamic_segment && phdr != NULL)
{
strtab_data = get_dynscn_strtab(ebl->elf, phdr);
if (strtab_data == NULL)
@@ -1903,7 +1903,7 @@ handle_dynamic (Ebl *ebl, Elf_Scn *scn, GElf_Shdr *shdr, GElf_Phdr *phdr)
|| dyn->d_tag == DT_RPATH
|| dyn->d_tag == DT_RUNPATH)
{
- if (! use_dynamic_segment)
+ if (! use_dynamic_segment && shdr != NULL)
name = elf_strptr (ebl->elf, shdr->sh_link, dyn->d_un.d_val);
else if (dyn->d_un.d_val < strtab_data->d_size
&& memrchr (strtab_data->d_buf + dyn->d_un.d_val, '\0',
--
2.18.4
reply other threads:[~2022-11-03 13:17 UTC|newest]
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