.gitignore | 4 +++ doc/guide.rst | 6 ++-- doc/posix.rst | 16 +++++----- libfiu/Makefile | 2 +- libfiu/fiu.c | 4 +-- libfiu/libfiu.3 | 9 ++++++ preload/posix/Makefile | 38 ++++++++++++++++++++++----- preload/posix/build-env.h.in | 12 ++++++++ preload/posix/codegen.c | 3 +- preload/posix/codegen.h | 16 ++++++++--- preload/posix/modules/libc.mm.custom.c | 8 +++++- preload/posix/modules/posix.custom.c | 11 ++++++- preload/posix/modules/posix.io.mod | 45 +++++++++++++++++-------------- preload/posix/modules/posix.mm.mod | 8 +++++ preload/posix/modules/posix.proc.mod | 3 ++ preload/run/Makefile | 17 ++++++++--- 16 files changed, 146 insertions(+), 56 deletions(-) diff --git a/.gitignore b/.gitignore index 7740f5e..24e7bb9 100644 --- a/.gitignore +++ b/.gitignore @@ -10,6 +10,9 @@ libfiu/build-flags preload/posix/*.o preload/posix/*.so preload/posix/build-flags +preload/posix/build-libcsoname +preload/posix/build-needlibdl +preload/posix/build-env.h preload/posix/function_list preload/posix/modules/*.o preload/posix/modules/*.mod.c @@ -18,4 +21,5 @@ preload/run/*.o preload/run/*.so preload/run/fiu-run preload/run/build-flags +preload/run/build-needlibdl diff --git a/doc/guide.rst b/doc/guide.rst index e4ef6fc..c401b46 100644 --- a/doc/guide.rst +++ b/doc/guide.rst @@ -31,8 +31,8 @@ Code overview Let's take a look to a small (fictitious) code sample to see what's the general idea behind libfiu. -Let's say you have this code that check if there's enough free space to fit a -given file:: +Let's say you have this code that checks if there's enough free space to store +a given file:: size_t free_space() { [code to find out how much free space there is] @@ -130,7 +130,7 @@ It is recommended that you use meaningful names for your points of failure, to be able to easily identify their purpose. You can also name them hierarchically (for example, using names like *"io/write"*, *"io/read"*, and so on), to be able to enable entire groups of points of failure (like -*"io/\*"*,). To this end, any separator will do, the *'/'* is not special at +*"io/\*"*). To this end, any separator will do, the *'/'* is not special at all. diff --git a/doc/posix.rst b/doc/posix.rst index eecadbf..d10ff91 100644 --- a/doc/posix.rst +++ b/doc/posix.rst @@ -40,15 +40,15 @@ Run it several times and you can see that sometimes it works, but sometimes it doesn't, reporting an error reading, which means a *read()* failed as expected. -When fortune is run, every time fortune calls *read()* it has a 1% chance to -fail, which selects an errno at random from the list of the ones that read() -is allowed to return. If you want to select an specific errno, you can do it -by passing its numerical value using the *-i* parameter. +When fortune is run, every *read()* has a 1% chance to fail, selecting an +*errno* at random from the list of the ones that read() is allowed to return. +If you want to select an specific *errno*, you can do it by passing its +numerical value using the *-i* parameter. The name of the failure points are fixed, and there is at least one for each -function that libfiu supports injecting failures to. Not all POSIX is -included, but most of the important pieces are, and it is easily extended. See -below for details. +function that libfiu supports injecting failures to. Not all POSIX functions +are included, but most of the important pieces are, and it can be easily +extended. See below for details. To see the list of supported functions and names, see the (automatically generated) *preload/posix/function_list* file that comes in the libfiu @@ -64,7 +64,7 @@ instead of from the beginning, as *fiu-run* does. To that end, you can combine *fiu-run* with the second tool, called *fiu-ctrl*. -Let's suppose you want to see what the "top" program does when it can't open +Let's suppose we want to see what the "top" program does when it can't open files. First, we run it with *fiu-run*:: $ fiu-run -x top diff --git a/libfiu/Makefile b/libfiu/Makefile index 98a0c61..ed98034 100644 --- a/libfiu/Makefile +++ b/libfiu/Makefile @@ -30,7 +30,7 @@ else NICE_CC = $(CC) endif -LIB_VER=0.13 +LIB_VER=0.14 LIB_SO_VER=0 diff --git a/libfiu/fiu.c b/libfiu/fiu.c index 2a01c91..8a849dd 100644 --- a/libfiu/fiu.c +++ b/libfiu/fiu.c @@ -365,11 +365,9 @@ static int insert_new_fail(const char *name, int failnum, void *failinfo, external_cb_t *external_cb) { struct pf_info *pf; - int rv; + int rv = -1; size_t prev_len; - rv = -1; - rec_count++; /* See if it's already there and update the data if so, or if we have diff --git a/libfiu/libfiu.3 b/libfiu/libfiu.3 index ab46ae1..b7e3616 100644 --- a/libfiu/libfiu.3 +++ b/libfiu/libfiu.3 @@ -168,6 +168,15 @@ functions. Enables remote control over named pipes with the given basename. See the remote control documentation that comes with the library for more detail. +.SS THREAD SAFETY + +The library is thread-safe. The list of enabled failure points is shared among +all threads. + +Care should be taken in the user-provided functions given to +.BR fiu_enable_external() , +as they can be run in parallel. + .SH SEE ALSO .BR fiu-run (1), .BR fiu-ctrl (1). diff --git a/preload/posix/Makefile b/preload/posix/Makefile index 40ca573..b2afa58 100644 --- a/preload/posix/Makefile +++ b/preload/posix/Makefile @@ -1,7 +1,7 @@ CFLAGS += -std=c99 -Wall -O3 ALL_CFLAGS = -D_XOPEN_SOURCE=600 -fPIC -DFIU_ENABLE=1 \ - -I. -I../../libfiu/ -L../../libfiu/ $(CFLAGS) + -I. -I../../libfiu/ $(CFLAGS) ifdef DEBUG ALL_CFLAGS += -g @@ -60,14 +60,37 @@ $(OBJS): build-flags .c.o: $(NICE_CC) $(ALL_CFLAGS) -c $< -o $@ -# some platforms do not have libdl, we only use it if available -NEED_LIBDL := $(shell ld -o dlcheck.so -shared -ldl 2>/dev/null && echo -ldl; \ - rm -f dlcheck.so) -fiu_posix_preload.so: build-flags $(OBJS) - $(NICE_CC) $(ALL_CFLAGS) -shared -fPIC $(OBJS) -lfiu $(NEED_LIBDL) \ +# some platforms do not have libdl, we only use it if available +build-needlibdl: + @$(LD) -ldl -o dlcheck.so 2>/dev/null \ + && echo -ldl > $@ || echo > $@ + @rm -f dlcheck.so + +# libc's soname depends on the platform (most use libc.so.6, but for example +# ia64 and alpha use libc.so.6.1), so find which one to use at build-time. +# Please note that the argument to ldd *must* start with "./", otherwise some +# "ldd"s won't work (for example, the one in FreeBSD 8.1). +build-libcsoname: + @$(CC) -x c /dev/null -lc -shared -o build-libccheck.so + @ldd ./build-libccheck.so | grep libc.so | awk '{ print $$1 }' > $@ + @rm build-libccheck.so + @test "`cat $@`" != "" || \ + (echo "Error finding soname, please report"; rm $@; exit 1) + +build-env.h: build-env.h.in build-libcsoname + @echo " GEN $@" + $(Q) sed "s+@@LIBC_SONAME@@+`cat build-libcsoname`+g" build-env.h.in \ + > build-env.h + + +fiu_posix_preload.so: build-flags build-env.h build-needlibdl $(OBJS) + $(NICE_CC) $(ALL_CFLAGS) -shared -fPIC $(OBJS) \ + -L../../libfiu/ \ + -lfiu `cat build-needlibdl` \ -o fiu_posix_preload.so + # this should only be needed when building the function list and not the # preload library %.mod.fl: %.mod @@ -86,7 +109,8 @@ uninstall: $(RM) $(PREFIX)/lib/fiu_posix_preload.so clean: - rm -f $(OBJS) $(GEN_OBJS:.o=.c) $(GEN_FL) build-flags + rm -f $(OBJS) $(GEN_OBJS:.o=.c) $(GEN_FL) + rm -f build-flags build-env.h build-libcsoname build-needlibdl rm -f function_list fiu_posix_preload.so rm -f *.bb *.bbg *.da *.gcov *.gcda *.gcno gmon.out diff --git a/preload/posix/build-env.h.in b/preload/posix/build-env.h.in new file mode 100644 index 0000000..63c06f6 --- /dev/null +++ b/preload/posix/build-env.h.in @@ -0,0 +1,12 @@ + +#ifndef _BUILD_ENV_H +#define _BUILD_ENV_H + +/* + * Constants taken from the build environment + */ + +/* libc's soname, used for dlopen()ing the C library */ +#define LIBC_SONAME "@@LIBC_SONAME@@" + +#endif diff --git a/preload/posix/codegen.c b/preload/posix/codegen.c index 71644c5..177fdcd 100644 --- a/preload/posix/codegen.c +++ b/preload/posix/codegen.c @@ -4,6 +4,7 @@ #include #include #include "codegen.h" +#include "build-env.h" /* Dynamically load libc */ void *_fiu_libc; @@ -30,7 +31,7 @@ void constructor_attr(200) _fiu_init(void) if (initialized) goto exit; - _fiu_libc = dlopen("libc.so.6", RTLD_NOW); + _fiu_libc = dlopen(LIBC_SONAME, RTLD_NOW); if (_fiu_libc == NULL) { fprintf(stderr, "Error loading libc: %s\n", dlerror()); exit(1); diff --git a/preload/posix/codegen.h b/preload/posix/codegen.h index 6a3444e..0999159 100644 --- a/preload/posix/codegen.h +++ b/preload/posix/codegen.h @@ -13,11 +13,17 @@ void _fiu_init(void); /* Recursion counter, per-thread */ extern int __thread _fiu_called; -/* GCC >= 4.3 supports constructor priorities only on some platforms. Since we - * don't rely on them, but use them for clarity purposes, use a macro so - * libfiu builds on systems where they're not supported. */ -#if (defined __linux__) && (defined __GNUC__) \ - && __GNUC__ >= 4 && __GNUC_MINOR__ >= 3 +/* Some compilers support constructor priorities. Since we don't rely on them, + * but use them for clarity purposes, use a macro so libfiu builds on systems + * where they're not supported. + * Compilers that are known to support constructor priorities: + * - GCC >= 4.3 on Linux + * - clang as of 2010-03-14 + */ +#if \ + ( (defined __GNUC__) \ + && __GNUC__ >= 4 && __GNUC_MINOR__ >= 3 ) \ + || (defined __clang__) #define constructor_attr(prio) __attribute__((constructor(prio))) #else #define NO_CONSTRUCTOR_PRIORITIES 1 diff --git a/preload/posix/modules/libc.mm.custom.c b/preload/posix/modules/libc.mm.custom.c index 9878ea3..4ed23e7 100644 --- a/preload/posix/modules/libc.mm.custom.c +++ b/preload/posix/modules/libc.mm.custom.c @@ -8,7 +8,13 @@ * We use __malloc_hook, the glibc-specific interface, so this is glibc-only. */ -#include +/* We need to include features.h, which in turns defines __GLIBC__. However, + * features.h is glibc-specific and does not exist on other platforms, so we + * can't include it directly or the file won't build. + * Instead, we have to resort to this ugly trick of including limits.h, which + * is standard and we know glibc's implementation includes features.h. + */ +#include #ifndef __GLIBC__ #warning "Not using glibc, so no malloc() wrappers will be available" diff --git a/preload/posix/modules/posix.custom.c b/preload/posix/modules/posix.custom.c index 5caff6f..1c709cd 100644 --- a/preload/posix/modules/posix.custom.c +++ b/preload/posix/modules/posix.custom.c @@ -37,12 +37,19 @@ int open(const char *pathname, int flags, ...) /* Differences from the generated code begin here */ - int mode; + mode_t mode; va_list l; if (flags & O_CREAT) { va_start(l, flags); - mode = va_arg(l, mode_t); + + /* va_arg() can only take fully promoted types, and mode_t + * sometimes is smaller than an int, so we should always pass + * int to it, and not mode_t. Not doing so would may result in + * a compile-time warning and run-time error. We asume that it + * is never bigger than an int, which holds in practise. */ + mode = va_arg(l, int); + va_end(l); } else { /* set it to 0, it's ignored anyway */ diff --git a/preload/posix/modules/posix.io.mod b/preload/posix/modules/posix.io.mod index dd9bb2d..4d31077 100644 --- a/preload/posix/modules/posix.io.mod +++ b/preload/posix/modules/posix.io.mod @@ -111,26 +111,31 @@ int rename(const char *oldpath, const char *newpath); ENOENT ENOMEM ENOSPC ENOTDIR ENOTEMPTY EPERM EROFS EXDEV -fiu name base: posix/io/stat/ - -include: -include: -include: - -int stat(const char *path, struct stat *buf); - on error: -1 - valid errnos: EACCES EBADF EFAULT ELOOP ENAMETOOLONG ENOENT ENOMEM \ - ENOTDIR EOVERFLOW - -int fstat(int fd, struct stat *buf); - on error: -1 - valid errnos: EACCES EBADF EFAULT ELOOP ENAMETOOLONG ENOENT ENOMEM \ - ENOTDIR EOVERFLOW - -int lstat(const char *path, struct stat *buf); - on error: -1 - valid errnos: EACCES EBADF EFAULT ELOOP ENAMETOOLONG ENOENT ENOMEM \ - ENOTDIR EOVERFLOW +# NOTE: These are disabled because the stat family function is usually defined +# within one of the standard headers, which (besides being ugly) makes +# overriding them this way much harder. The definitions below are commented +# out for reference and testing purposes. +# +#fiu name base: posix/io/stat/ +# +#include: +#include: +#include: +# +#int stat(const char *path, struct stat *buf); +# on error: -1 +# valid errnos: EACCES EBADF EFAULT ELOOP ENAMETOOLONG ENOENT ENOMEM \ +# ENOTDIR EOVERFLOW +# +#int fstat(int fd, struct stat *buf); +# on error: -1 +# valid errnos: EACCES EBADF EFAULT ELOOP ENAMETOOLONG ENOENT ENOMEM \ +# ENOTDIR EOVERFLOW +# +#int lstat(const char *path, struct stat *buf); +# on error: -1 +# valid errnos: EACCES EBADF EFAULT ELOOP ENAMETOOLONG ENOENT ENOMEM \ +# ENOTDIR EOVERFLOW fiu name base: posix/io/net/ diff --git a/preload/posix/modules/posix.mm.mod b/preload/posix/modules/posix.mm.mod index 443f816..6d96a93 100644 --- a/preload/posix/modules/posix.mm.mod +++ b/preload/posix/modules/posix.mm.mod @@ -24,9 +24,17 @@ int msync(void *addr, size_t length, int flags); on error: -1 valid errnos: EBUSY EINVAL ENOMEM +# glibc's mprotect() does not use const in the first argument, as the standard +# says it should +v: #ifdef __GLIBC__ int mprotect(void *addr, size_t len, int prot); on error: -1 valid errnos: EACCES EINVAL ENOMEM +v: #else +int mprotect(const void *addr, size_t len, int prot); + on error: -1 + valid errnos: EACCES EINVAL ENOMEM +v: #endif int madvise(void *addr, size_t length, int advice); on error: -1 diff --git a/preload/posix/modules/posix.proc.mod b/preload/posix/modules/posix.proc.mod index 1054513..2db8802 100644 --- a/preload/posix/modules/posix.proc.mod +++ b/preload/posix/modules/posix.proc.mod @@ -19,9 +19,12 @@ pid_t waitpid(pid_t pid, int *status, int options); on error: -1 valid errnos: ECHILD EINTR EINVAL +# FreeBSD does not have waitid() +v: #ifndef __FreeBSD__ int waitid(idtype_t idtype, id_t id, siginfo_t *infop, int options); on error: -1 valid errnos: ECHILD EINTR EINVAL +v: #endif int kill(pid_t pid, int sig); on error: -1 diff --git a/preload/run/Makefile b/preload/run/Makefile index bd4fca3..c0d864c 100644 --- a/preload/run/Makefile +++ b/preload/run/Makefile @@ -1,7 +1,7 @@ CFLAGS += -std=c99 -Wall -O3 ALL_CFLAGS = -D_XOPEN_SOURCE=600 -fPIC -DFIU_ENABLE=1 \ - -I. -I../../libfiu/ -L../../libfiu/ $(CFLAGS) + -I. -I../../libfiu/ $(CFLAGS) ifdef DEBUG ALL_CFLAGS += -g @@ -49,14 +49,21 @@ $(OBJS): build-flags .c.o: $(NICE_CC) $(ALL_CFLAGS) -c $< -o $@ + # some platforms do not have libdl, we only use it if available -NEED_LIBDL := $(shell ld -o dlcheck.so -shared -ldl 2>/dev/null && echo -ldl; \ - rm -f dlcheck.so) +build-needlibdl: + @$(LD) -ldl -o dlcheck.so 2>/dev/null \ + && echo -ldl > $@ || echo > $@ + @rm -f dlcheck.so + -fiu_run_preload.so: build-flags $(OBJS) - $(NICE_CC) $(ALL_CFLAGS) -shared -fPIC $(OBJS) -lfiu $(NEED_LIBDL) \ +fiu_run_preload.so: build-flags build-needlibdl $(OBJS) + $(NICE_CC) $(ALL_CFLAGS) -shared -fPIC $(OBJS) \ + -L../../libfiu/ \ + -lfiu `cat build-needlibdl` \ -o fiu_run_preload.so + fiu-run: build-flags fiu-run.in cat fiu-run.in | sed "s+@@PLIBPATH@@+$(PLIBPATH)+g" > fiu-run chmod +x fiu-run