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[COMMITTED] nm: Simplify naming of invalid sections, check shdr isn't NULL.
- From: Mark Wielaard <mark at klomp dot org>
- To: elfutils-devel at sourceware dot org
- Cc: Mark Wielaard <mark at klomp dot org>
- Date: Sun, 28 Apr 2019 17:56:53 +0200
- Subject: [COMMITTED] nm: Simplify naming of invalid sections, check shdr isn't NULL.
When shdr is NULL or the sh_name index is invalid, don't try to use
it. Just call the section "[invalid section name]". Don't try to be
too smart by creating a dynamic invalid name using alloca to simplify
memory usage in this exceptional case.
Signed-off-by: Mark Wielaard <mark@klomp.org>
---
src/ChangeLog | 5 +++++
src/nm.c | 14 ++++++--------
2 files changed, 11 insertions(+), 8 deletions(-)
diff --git a/src/ChangeLog b/src/ChangeLog
index 3786f3432..3020bd768 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,8 @@
+2019-04-28 Mark Wielaard <mark@klomp.org>
+
+ * nm.c (show_symbols_sysv): Check gelf_getshdr doesn't return
+ NULL. Simplify naming of invalid sections, don't use alloca.
+
2019-04-28 Mark Wielaard <mark@klomp.org>
* elfcmp.c (main): Check shdr1 and shdr2 are not NULL.
diff --git a/src/nm.c b/src/nm.c
index ffe8ca691..da1350b4c 100644
--- a/src/nm.c
+++ b/src/nm.c
@@ -751,19 +751,17 @@ show_symbols_sysv (Ebl *ebl, GElf_Word strndx, const char *fullname,
while ((scn = elf_nextscn (ebl->elf, scn)) != NULL)
{
GElf_Shdr shdr_mem;
+ GElf_Shdr *shdr;
assert (elf_ndxscn (scn) == cnt);
cnt++;
- char *name = elf_strptr (ebl->elf, shstrndx,
- gelf_getshdr (scn, &shdr_mem)->sh_name);
+ char *name = NULL;
+ shdr = gelf_getshdr (scn, &shdr_mem);
+ if (shdr != NULL)
+ name = elf_strptr (ebl->elf, shstrndx, shdr->sh_name);
if (unlikely (name == NULL))
- {
- const size_t bufsz = sizeof "[invalid sh_name 0x12345678]";
- name = alloca (bufsz);
- snprintf (name, bufsz, "[invalid sh_name %#" PRIx32 "]",
- gelf_getshdr (scn, &shdr_mem)->sh_name);
- }
+ name = "[invalid section name]";
scnnames[elf_ndxscn (scn)] = name;
}
--
2.20.1