klibc - Jan 2019 - [klibc:update-dash] eval: Restore input files in evalcommand

Commit-ID:  2b231302b19d9213263d001b0c467e28ecc033f3
Gitweb:    
http://git.kernel.org/?p=libs/klibc/klibc.git;a=commit;h=2b231302b19d9213263d001b0c467e28ecc033f3
Author:     Herbert Xu <herbert at gondor.apana.org.au>
AuthorDate: Tue, 27 Mar 2018 00:39:35 +0800
Committer:  Ben Hutchings <ben at decadent.org.uk>
CommitDate: Fri, 25 Jan 2019 02:57:21 +0000

[klibc] eval: Restore input files in evalcommand

When evalcommand invokes a command that modifies parsefile and
then bails out without popping the file, we need to ensure the
input file is restored so that the shell can continue to execute.

Reported-by: Martijn Dekker <martijn at inlv.org>
Signed-off-by: Herbert Xu <herbert at gondor.apana.org.au>
Signed-off-by: Ben Hutchings <ben at decadent.org.uk>

---
 usr/dash/eval.c  |  3 +++
 usr/dash/input.c | 10 ++++++++--
 usr/dash/input.h |  1 +
 3 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/usr/dash/eval.c b/usr/dash/eval.c
index 811c28a4..5fd1c7c1 100644
--- a/usr/dash/eval.c
+++ b/usr/dash/eval.c
@@ -694,6 +694,7 @@ evalcommand(union node *cmd, int flags)
 #endif
 {
 	struct localvar_list *localvar_stop;
+	struct parsefile *file_stop;
 	struct redirtab *redir_stop;
 	struct stackmark smark;
 	union node *argp;
@@ -722,6 +723,7 @@ evalcommand(union node *cmd, int flags)
 	TRACE(("evalcommand(0x%lx, %d) called\n", (long)cmd, flags));
 	setstackmark(&smark);
 	localvar_stop = pushlocalvars();
+	file_stop = parsefile;
 	back_exitstatus = 0;
 
 	cmdentry.cmdtype = CMDBUILTIN;
@@ -896,6 +898,7 @@ out:
 	if (cmd->ncmd.redirect)
 		popredir(execcmd);
 	unwindredir(redir_stop);
+	unwindfiles(file_stop);
 	unwindlocalvars(localvar_stop);
 	if (lastarg)
 		/* dsl: I think this is intended to be used to support
diff --git a/usr/dash/input.c b/usr/dash/input.c
index e53423c5..ae0c4c80 100644
--- a/usr/dash/input.c
+++ b/usr/dash/input.c
@@ -479,6 +479,13 @@ popfile(void)
 }
 
 
+void unwindfiles(struct parsefile *stop)
+{
+	while (parsefile != stop)
+		popfile();
+}
+
+
 /*
  * Return to top level.
  */
@@ -486,8 +493,7 @@ popfile(void)
 void
 popallfiles(void)
 {
-	while (parsefile != &basepf)
-		popfile();
+	unwindfiles(&basepf);
 }
 
 
diff --git a/usr/dash/input.h b/usr/dash/input.h
index ec97c1d6..a9c05174 100644
--- a/usr/dash/input.h
+++ b/usr/dash/input.h
@@ -97,5 +97,6 @@ void popstring(void);
 int setinputfile(const char *, int);
 void setinputstring(char *);
 void popfile(void);
+void unwindfiles(struct parsefile *);
 void popallfiles(void);
 void closescript(void);