From 924db2678641f028a5701af31783def219d8df0d Mon Sep 17 00:00:00 2001
From: Fotios Valasiadis <fvalasiad@csd.auth.gr>
Date: Wed, 8 Feb 2023 12:11:53 +0200
Subject: [PATCH] add checks for errors

---
 src/hash.c   |  4 +++-
 src/record.c |  4 +++-
 src/tracer.c | 29 ++++++++++++++++++++++++++++-
 3 files changed, 34 insertions(+), 3 deletions(-)

diff --git a/src/hash.c b/src/hash.c
index a8b1204..a182911 100644
--- a/src/hash.c
+++ b/src/hash.c
@@ -91,7 +91,9 @@ hash_file_contents(char *name, size_t sz)
     SHA1_Update(&ctx, buf, sz);
     SHA1_Final(hash, &ctx);
 
-    close(fd);
+    if (close(fd) < 0) {
+	error(EXIT_FAILURE, errno, "on hash_file_contents close");
+    }
 
     if (munmap(buf, sz) < 0) {
 	error(EXIT_FAILURE, errno, "unmapping `%s'", name);
diff --git a/src/record.c b/src/record.c
index 1d0f985..20b6af1 100644
--- a/src/record.c
+++ b/src/record.c
@@ -68,7 +68,9 @@ get_cmdline(pid_t pid)
     char data[CMD_LINE_SIZE + 1];
     ssize_t n = read(fd, data, CMD_LINE_SIZE);
 
-    close(fd);
+    if (close(fd) < 0) {
+	error(EXIT_FAILURE, errno, "on get_cmdline close");
+    }
 
     if (n < 0) {
 	error(EXIT_FAILURE, errno, "on get_cmdline read");
diff --git a/src/tracer.c b/src/tracer.c
index 7b18267..82bdad5 100644
--- a/src/tracer.c
+++ b/src/tracer.c
@@ -56,11 +56,20 @@ init(void)
 {
     pinfo_size = DEFAULT_PINFO_SIZE;
     pinfo = calloc(pinfo_size, sizeof (PROCESS_INFO));
+    if (pinfo == NULL) {
+	error(EXIT_FAILURE, errno, "on init pinfo calloc");
+    }
     pids = malloc(pinfo_size * sizeof (int));
+    if (pids == NULL) {
+	error(EXIT_FAILURE, errno, "on init pids malloc");
+    }
     numpinfo = -1;
 
     finfo_size = DEFAULT_FINFO_SIZE;
     finfo = calloc(finfo_size, sizeof (FILE_INFO));
+    if (finfo == NULL) {
+	error(EXIT_FAILURE, errno, "on init finfo calloc");
+    }
     numfinfo = -1;
 }
 
@@ -104,7 +113,13 @@ pinfo_new(PROCESS_INFO *self, char ignore_one_sigstop)
     self->finfo_size = DEFAULT_FINFO_SIZE;
     self->numfinfo = -1;
     self->finfo = malloc(self->finfo_size * sizeof (FILE_INFO));
+    if (self->finfo == NULL) {
+	error(EXIT_FAILURE, errno, "on pinfo_new self->finfo malloc");
+    }
     self->fds = malloc(self->finfo_size * sizeof (int));
+    if (self->fds == NULL) {
+	error(EXIT_FAILURE, errno, "on pinfo_new self->fds malloc");
+    }
     self->ignore_one_sigstop = ignore_one_sigstop;
 }
 
@@ -203,9 +218,13 @@ get_str_from_process(pid_t pid, void *addr)
     size_t i = 0;
 
     do {
+	errno = 0;
 	data.lval =
 		ptrace(PTRACE_PEEKDATA, pid, (char *) addr + i * sizeof (long),
 		       NULL);
+	if (errno != 0) {
+	    error(EXIT_FAILURE, errno, "on get_str_from_process ptrace");
+	}
 	for (unsigned j = 0; j < sizeof (long); j++) {
 	    *dest++ = data.cval[j];
 	    if (data.cval[j] == 0)
@@ -339,6 +358,10 @@ static void
 handle_rename_entry(pid_t pid, PROCESS_INFO *pi, int olddirfd, char *oldpath)
 {
     char *abspath = absolutepath(pid, olddirfd, oldpath);
+
+    if (abspath == NULL) {
+	error(EXIT_FAILURE, errno, "on handle_rename_entry absolutepath");
+    }
     char *hash = get_file_hash(abspath);
 
     FILE_INFO *f = find_finfo(abspath, hash);
@@ -356,7 +379,7 @@ handle_rename_entry(pid_t pid, PROCESS_INFO *pi, int olddirfd, char *oldpath)
 
     pi->entry_info = (void *) (f - finfo);
     if (pi->entry_info == NULL)
-	error(EXIT_FAILURE, errno, "on handle_rename_entry absolutepath");
+	error(EXIT_FAILURE, errno, "on handle_rename_entry entry_info");
 }
 
 static void
@@ -366,6 +389,10 @@ handle_rename_exit(pid_t pid, PROCESS_INFO *pi, int newdirfd, char *newpath)
 
     char *abspath = absolutepath(pid, newdirfd, newpath);
 
+    if (abspath == NULL) {
+	error(EXIT_FAILURE, errno, "on handle_rename_exit absolutepath");
+    }
+
     FILE_INFO *to = next_finfo();
 
     finfo_new(to, newpath, abspath, from->hash);