[PATCH] Fix unsigned overflow in minsyms reader.

[John Baldwin]

Use a ssize_t helper variable for the number of bytes to shrink the
msymbols obstack rather than relying on unsigned overflow to shrink
the size of the obstack.

gdb/ChangeLog:

* minsyms.c (minimal_symbol_reader::install): Fix unsigned
overflow.
---
gdb/ChangeLog | 5 +++++
gdb/minsyms.c | 5 +++--
2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 68ecef7728..4120c62f33 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,8 @@
[phone] John Baldwin <***@FreeBSD.org>
+
+ * minsyms.c (minimal_symbol_reader::install): Fix unsigned
+ overflow.
+
2018-11-06 John Baldwin <***@FreeBSD.org>

* riscv-fbsd-nat.c (getregs_supplies): Return true for
diff --git a/gdb/minsyms.c b/gdb/minsyms.c
index 4409e6f8b3..0f854422e0 100644
--- a/gdb/minsyms.c
+++ b/gdb/minsyms.c
@@ -1375,8 +1375,9 @@ minimal_symbol_reader::install ()

mcount = compact_minimal_symbols (msymbols, mcount, m_objfile);

- obstack_blank_fast (&m_objfile->per_bfd->storage_obstack,
- (mcount + 1 - alloc_count) * sizeof (struct minimal_symbol));
+ ssize_t shrink_bytes
+ = (mcount + 1 - alloc_count) * sizeof (struct minimal_symbol);
+ obstack_blank_fast (&m_objfile->per_bfd->storage_obstack, shrink_bytes);
msymbols = (struct minimal_symbol *)
obstack_finish (&m_objfile->per_bfd->storage_obstack);

[Kevin Buettner]

On Tue, 6 Nov 2018 11:04:23 -0800

Post by John Baldwin
Use a ssize_t helper variable for the number of bytes to shrink the
msymbols obstack rather than relying on unsigned overflow to shrink
the size of the obstack.
* minsyms.c (minimal_symbol_reader::install): Fix unsigned
overflow.

Okay.

Kevin