From: Dodji Seketeli <dodji@redhat.com>
To: libabigail@sourceware.org
Cc: maennich@google.com, gprocida@google.com
Subject: [PATCH 1/2] symtab-reader: Remove an over-agressive assertion
Date: Mon, 07 Feb 2022 12:09:45 +0100 [thread overview]
Message-ID: <87r18flypy.fsf@seketeli.org> (raw)
In-Reply-To: <87v8xrlyyd.fsf@redhat.com> (Dodji Seketeli via Libabigail's message of "Mon, 07 Feb 2022 12:04:42 +0100")
In symtab::load, the symtab reader walks the symbol table and records
each relation "symbol <-> address".
So, the relation "foo <-> address-of-foo" is going to be recorded.
The relation "foo.cfi <-> address-of-foo.cfi" is going to be recorded
as well.
But then, because the symbol foo.cfi has a special meaning, in the
realm of "control flow integrity", the relation "foo.cfi <->
address-of-foo.cfi" (as well as all the *.cfi <-> address-of*.cfi
relations) is going to be recorded (again but) in a particular way by
calling symtab::add_alternative_address_lookups.
The problem is that in, symtab::add_alternative_address_lookups there
is an assert that (wrongly) assumes that the relation foo.cfi <->
address-of-foo.cfi is being seen for the first time. This is wrong
because the loop in symtab::load that records all the "symbol <->
address" relations has seen and recorded this foo.cfi <->
address-of-foo.cfi relation once already.
This patch removes that assert so that the kernel referred to in the bug
report of PR26646, as mentioned in
https://sourceware.org/bugzilla/show_bug.cgi?id=26646#c5, can be
processed by abidw without crashing.
* src/abg-symtab-reader.cc
(symtab::add_alternative_address_lookups): Remove over-aggressive
assert.
Signed-off-by: Dodji Seketeli <dodji@redhat.com>
---
src/abg-symtab-reader.cc | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/src/abg-symtab-reader.cc b/src/abg-symtab-reader.cc
index 78dec36d..b42ce87d 100644
--- a/src/abg-symtab-reader.cc
+++ b/src/abg-symtab-reader.cc
@@ -651,9 +651,7 @@ symtab::add_alternative_address_lookups(Elf* elf_handle)
symbol_sptr);
}
- const auto result =
- addr_symbol_map_.emplace(symbol_value, symbol_sptr);
- ABG_ASSERT(result.second);
+ addr_symbol_map_.emplace(symbol_value, symbol_sptr);
}
}
}
--
2.35.0.rc2
--
Dodji
next prev parent reply other threads:[~2022-02-07 11:09 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-07 11:04 Patch review request for Bug 2664 - unexpected declaration-only types Dodji Seketeli
2022-02-07 11:09 ` Dodji Seketeli [this message]
2022-02-07 15:33 ` [PATCH 1/2] symtab-reader: Remove an over-agressive assertion Giuliano Procida
2022-02-07 16:49 ` Dodji Seketeli
2022-02-07 11:11 ` [PATCH 2/2] Bug 26646 - unexpected declaration-only types Dodji Seketeli
[not found] ` <CAGvU0H=UV0FxvzqhQWRjU6F7_yRMxhEK5P_t3NKMAD02e55rpw@mail.gmail.com>
2022-02-08 10:27 ` Dodji Seketeli
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