[Libguestfs] [PATCH v2] Fix trace segfault for non-daemon functions (RHBZ#682756).
Richard W.M. Jones
rjones at redhat.com
Mon Mar 7 16:46:08 UTC 2011
Previous patch broke RConstOptString. Try this updated version.
Rich.
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>From 7c721e4fd674c409b3eee60fe237d480afa1c5e2 Mon Sep 17 00:00:00 2001
From: Richard W.M. Jones <rjones at redhat.com>
Date: Mon, 7 Mar 2011 15:55:56 +0000
Subject: [PATCH] Fix trace segfault for non-daemon functions (RHBZ#682756).
Previously we expanded the code for 'trace_return' unconditionally for
all non-daemon functions. However this code was not prepared to
handle all error conditions, and in fact would segfault if it tried to
print RStringList or RHashtable where r == NULL.
We need to make the code conditional on the return value, calling
either 'trace_return' or 'trace_return_error' as appropriate.
Note the difficult case for RConstOptString which returns NULL in
non-error cases.
---
generator/generator_c.ml | 47 +++++++++++++++++++++++++++++----------------
1 files changed, 30 insertions(+), 17 deletions(-)
diff --git a/generator/generator_c.ml b/generator/generator_c.ml
index c4915ea..99cf327 100644
--- a/generator/generator_c.ml
+++ b/generator/generator_c.ml
@@ -887,22 +887,24 @@ check_state (guestfs_h *g, const char *caller)
shortname style;
pr "{\n";
pr " int trace_flag = g->trace;\n";
- (match ret with
- | RErr | RInt _ | RBool _ ->
- pr " int r;\n"
- | RInt64 _ ->
- pr " int64_t r;\n"
- | RConstString _ | RConstOptString _ ->
- pr " const char *r;\n"
- | RString _ | RBufferOut _ ->
- pr " char *r;\n"
- | RStringList _ | RHashtable _ ->
- pr " char **r;\n"
- | RStruct (_, typ) ->
- pr " struct guestfs_%s *r;\n" typ
- | RStructList (_, typ) ->
- pr " struct guestfs_%s_list *r;\n" typ
- );
+ let errcode =
+ match ret with
+ | RErr | RInt _ | RBool _ ->
+ pr " int r;\n"; Some "-1"
+ | RInt64 _ ->
+ pr " int64_t r;\n"; Some "-1"
+ | RConstString _ ->
+ pr " const char *r;\n"; Some "NULL"
+ | RConstOptString _ ->
+ pr " const char *r;\n"; None
+ | RString _ | RBufferOut _ ->
+ pr " char *r;\n"; Some "NULL"
+ | RStringList _ | RHashtable _ ->
+ pr " char **r;\n"; Some "NULL"
+ | RStruct (_, typ) ->
+ pr " struct guestfs_%s *r;\n" typ; Some "NULL"
+ | RStructList (_, typ) ->
+ pr " struct guestfs_%s_list *r;\n" typ; Some "NULL" in
pr "\n";
check_null_strings shortname style;
reject_unknown_optargs shortname style;
@@ -910,7 +912,18 @@ check_state (guestfs_h *g, const char *caller)
pr " r = guestfs__%s " shortname;
generate_c_call_args ~handle:"g" style;
pr ";\n";
- trace_return shortname style "r";
+ pr "\n";
+ (match errcode with
+ | Some errcode ->
+ pr " if (r != %s) {\n" errcode;
+ trace_return ~indent:4 shortname style "r";
+ pr " } else {\n";
+ trace_return_error ~indent:4 shortname style;
+ pr " }\n";
+ | None ->
+ trace_return shortname style "r";
+ );
+ pr "\n";
pr " return r;\n";
pr "}\n";
pr "\n"
--
1.7.4
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