From 73d531205083eaf19934b516b37b1cf4940895c7 Mon Sep 17 00:00:00 2001 From: Bernd Edlinger Date: Mon, 17 Feb 2020 17:40:07 +0100 Subject: [PATCH] Fix -save-temp leaking files in /tmp And avoid signal handler calling signal unsafe functions, and/or calling unlink with uninitialized memory pointer. 2020-02-19 Bernd Edlinger * collect2.c (c_file, o_file): Make const again. (ldout,lderrout, dump_ld_file): Remove. (tool_cleanup): Avoid calling not signal-safe functions. (maybe_run_lto_and_relink): Avoid possible signal handler access to unintialzed memory (lto_o_files). (main): Avoid leaking temp files in $TMPDIR. Initialize c_file/o_file with concat, which avoids exposing uninitialized memory to signal handler, which calls unlink(!). Avoid calling maybe_unlink when the main function returns, since the atexit handler is already doing this. * collect2.h (dump_ld_file, ldout, lderrout): Remove. --- gcc/ChangeLog | 14 ++++++ gcc/collect2.c | 130 ++++++------------------------------------------- gcc/collect2.h | 4 -- 3 files changed, 30 insertions(+), 118 deletions(-) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 7ebeaed89e0..6cd941a5ff8 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,17 @@ +2020-02-19 Bernd Edlinger + + * collect2.c (c_file, o_file): Make const again. + (ldout,lderrout, dump_ld_file): Remove. + (tool_cleanup): Avoid calling not signal-safe functions. + (maybe_run_lto_and_relink): Avoid possible signal handler + access to unintialzed memory (lto_o_files). + (main): Avoid leaking temp files in $TMPDIR. + Initialize c_file/o_file with concat, which avoids exposing + uninitialized memory to signal handler, which calls unlink(!). + Avoid calling maybe_unlink when the main function returns, + since the atexit handler is already doing this. + * collect2.h (dump_ld_file, ldout, lderrout): Remove. + 2020-02-19 Martin Jambor PR tree-optimization/93776 diff --git a/gcc/collect2.c b/gcc/collect2.c index 502d629141c..f7d9f103ddc 100644 --- a/gcc/collect2.c +++ b/gcc/collect2.c @@ -205,14 +205,12 @@ bool helpflag; /* true if --help */ static int shared_obj; /* true if -shared */ static int static_obj; /* true if -static */ -static char *c_file; /* .c for constructor/destructor list. */ -static char *o_file; /* .o for constructor/destructor list. */ +static const char *c_file; /* .c for constructor/destructor list. */ +static const char *o_file; /* .o for constructor/destructor list. */ #ifdef COLLECT_EXPORT_LIST static const char *export_file; /* .x for AIX export list. */ #endif static char **lto_o_files; /* Output files for LTO. */ -const char *ldout; /* File for ld stdout. */ -const char *lderrout; /* File for ld stderr. */ static const char *output_file; /* Output file for ld. */ static const char *nm_file_name; /* pathname of nm */ #ifdef LDD_SUFFIX @@ -384,6 +382,10 @@ static void scan_prog_file (const char *, scanpass, scanfilter); void tool_cleanup (bool from_signal) { + /* maybe_unlink may call notice, which is not signal safe. */ + if (from_signal) + verbose = false; + if (c_file != 0 && c_file[0]) maybe_unlink (c_file); @@ -397,20 +399,6 @@ tool_cleanup (bool from_signal) if (lto_o_files) maybe_unlink_list (lto_o_files); - - if (ldout != 0 && ldout[0]) - { - if (!from_signal) - dump_ld_file (ldout, stdout); - maybe_unlink (ldout); - } - - if (lderrout != 0 && lderrout[0]) - { - if (!from_signal) - dump_ld_file (lderrout, stderr); - maybe_unlink (lderrout); - } } static void @@ -476,77 +464,6 @@ extract_string (const char **pp) return XOBFINISH (&temporary_obstack, char *); } -void -dump_ld_file (const char *name, FILE *to) -{ - FILE *stream = fopen (name, "r"); - - if (stream == 0) - return; - while (1) - { - int c; - while (c = getc (stream), - c != EOF && (ISIDNUM (c) || c == '$' || c == '.')) - obstack_1grow (&temporary_obstack, c); - if (obstack_object_size (&temporary_obstack) > 0) - { - const char *word, *p; - char *result; - obstack_1grow (&temporary_obstack, '\0'); - word = XOBFINISH (&temporary_obstack, const char *); - - if (*word == '.') - ++word, putc ('.', to); - p = word; - if (!strncmp (p, USER_LABEL_PREFIX, strlen (USER_LABEL_PREFIX))) - p += strlen (USER_LABEL_PREFIX); - -#ifdef HAVE_LD_DEMANGLE - result = 0; -#else - if (no_demangle) - result = 0; - else - result = cplus_demangle (p, DMGL_PARAMS | DMGL_ANSI | DMGL_VERBOSE); -#endif - - if (result) - { - int diff; - fputs (result, to); - - diff = strlen (word) - strlen (result); - while (diff > 0 && c == ' ') - --diff, putc (' ', to); - if (diff < 0 && c == ' ') - { - while (diff < 0 && c == ' ') - ++diff, c = getc (stream); - if (!ISSPACE (c)) - { - /* Make sure we output at least one space, or - the demangled symbol name will run into - whatever text follows. */ - putc (' ', to); - } - } - - free (result); - } - else - fputs (word, to); - - fflush (to); - obstack_free (&temporary_obstack, temporary_firstobj); - } - if (c == EOF) - break; - putc (c, to); - } - fclose (stream); -} - /* Return the kind of symbol denoted by name S. */ static symkind @@ -744,7 +661,10 @@ maybe_run_lto_and_relink (char **lto_ld_argv, char **object_lst, ++num_files; } - lto_o_files = XNEWVEC (char *, num_files + 1); + /* signal handler may access uninitialized memory + and delete whatever it points to, if lto_o_files + is not allocatted with calloc. */ + lto_o_files = XCNEWVEC (char *, num_files + 1); lto_o_files[num_files] = NULL; start = XOBFINISH (&temporary_obstack, char *); for (i = 0; i < num_files; ++i) @@ -1262,27 +1182,19 @@ main (int argc, char **argv) /* Make temp file names. */ if (save_temps) { - c_file = (char *) xmalloc (strlen (output_file) - + sizeof (".cdtor.c") + 1); - strcpy (c_file, output_file); - strcat (c_file, ".cdtor.c"); - o_file = (char *) xmalloc (strlen (output_file) - + sizeof (".cdtor.o") + 1); - strcpy (o_file, output_file); - strcat (o_file, ".cdtor.o"); + c_file = concat (output_file, ".cdtor.c", NULL); + o_file = concat (output_file, ".cdtor.o", NULL); +#ifdef COLLECT_EXPORT_LIST + export_file = concat (output_file, ".x", NULL); +#endif } else { c_file = make_temp_file (".cdtor.c"); o_file = make_temp_file (".cdtor.o"); - } #ifdef COLLECT_EXPORT_LIST - export_file = make_temp_file (".x"); + export_file = make_temp_file (".x"); #endif - if (!debug) - { - ldout = make_temp_file (".ld"); - lderrout = make_temp_file (".le"); } /* Build the command line to compile the ctor/dtor list. */ *c_ptr++ = c_file_name; @@ -1811,9 +1723,6 @@ main (int argc, char **argv) maybe_unlink (export_file); #endif post_ld_pass (/*temp_file*/false); - - maybe_unlink (c_file); - maybe_unlink (o_file); return 0; } @@ -1912,13 +1821,6 @@ main (int argc, char **argv) scan_prog_file (output_file, PASS_SECOND, SCAN_ALL); #endif - maybe_unlink (c_file); - maybe_unlink (o_file); - -#ifdef COLLECT_EXPORT_LIST - maybe_unlink (export_file); -#endif - return 0; } diff --git a/gcc/collect2.h b/gcc/collect2.h index ab5fcdf0ed8..aa8a03e7d87 100644 --- a/gcc/collect2.h +++ b/gcc/collect2.h @@ -25,12 +25,8 @@ extern struct pex_obj *collect_execute (const char *, char **, const char *, extern int collect_wait (const char *, struct pex_obj *); -extern void dump_ld_file (const char *, FILE *); - extern int file_exists (const char *); -extern const char *ldout; -extern const char *lderrout; extern const char *c_file_name; extern struct obstack temporary_obstack; extern char *temporary_firstobj; -- 2.30.2