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Commit Graph

24 Commits

Author SHA1 Message Date
gr
ef42295fe8 tccrun.c: standalone backtraces with -bt[N] or -b
This makes it possible to get backtraces with executables
(including DLLs/SOs) like we had it already with -g -run.

Option -b includes -bt, and -bt includes -g.

- new file lib/bt-exe.c: used to link rt_printline and the
  exception handler from tccrun.c into executables/DLLs.

- new file lib/bt-log.c: provides a function that may be
  called from user code to print out a backtrace with a
  message (currently for i386/x86_64 only):

     int (*tcc_backtrace)(const char *fmt, ...);

  As an extra hack, if 'fmt' is prefixed like "^file.c^..."
  then the backtrace will skip calls from within 'file.c'.

- new file lib/bt-dll.c:  used on win32 to link the backtrace
  and bcheck functions with the main module at runtime

- bcheck.c: now uses the tcc_backtrace function from above

- tccgen.c: minor cleanups

- tccelf.c: stab sections get SHF_ALLOC for easy access.
  Also in relocate_section(): 64bit relocations for stabs
  in DLLs cannot work.  To find DLL addresses, the DLL base
  is added manually in tccrun.c via rc.prog_base instead.

- tccpe.c: there are some changes to allow merging sections,
  used to merge .finit_array into .data in the first place.

- tccpp.c: tcc -run now #defines __TCC_RUN__
  also: refactor a line in tal_realloc that was incompatible
  with bcheck

- tcctest.c: fixed a problem with r12 which tcc cannot preserve
  as well as gcc does.

- tests2/112_backtrace.c: test the feature and the bcheck test18
  that previously was in boundtest.c
2020-01-17 22:58:39 +01:00
herman ten brugge
3877618785 Update bound checking code.
Add __attribute__((constructor)) to __bounds_init.
- remove tcc_add_bcheck from i386-link.c and x86_64-link.c
- add simplified tcc_add_bcheck to tccelf.c
- Update tccrun.c to call constructor/destructor.
Set dynsym sh_info to number of local symbols in tccelf.c
Reduce stack size when bounds checking is enabled.
Added variable TCC_LIBBCHECK for windows support.
Add signal stack to detect stack overflow.
Add all & parameters in lbound_section and remove them if not used.
Close fd in tcc_relocate in tccrun.c
Fix section type constructor/destructor in tccelf.c
Add check code in tests/boundtest.c for mem/str functions.
Remove -ba from documentation.
Add bounds check signal info in documentation.

bcheck.c:
- Fix initial_pool alignment.
. Fix printf statements.
. Add prototypes for all external interface functions.
- Add TCC_BOUNDS_WARN_POINTER_ADD environment variable.
. Add ctype and errno data.
- Fix alloca when multithreading is used.
- Add lock for __bound_checking and __bound_never_fatal.
- Catch pthread_create and use locks when called.
- Detect in loaded in shared lib and use locks when found
- Use spin locks instead of semaphore locks.
- Make spin locked code as small as possible.
- Fix mem/str functions checking.
- Fix overlap checking mem/str functions.
2020-01-15 08:53:19 +01:00
grischka
56db092ab7 bcheck cleanup
- revert Makefiles to state before last bcheck additions
  Instead, just load bcheck.o explicitly if that is
  what is wanted.

- move tcc_add_bcheck() to the <target>-link.c files and
  remove revently added arguments.  This function is to
  support tccelf.c with linking, not for tccgen.c to
  support compilation.

- remove -ba option:  It said:
  "-ba  Enable better address checking with bounds checker"
  Okay, if it is better then to have it is not an option.

- remove va_copy. It is C99 and we try to stay C89 in tinycc
  when possible.  For example, MS compilers do not have va_copy.

- win64: revert any 'fixes' to alloca
  It was correct as it was before, except for bound_checking
  where it was not implemented.  This should now work too.

- remove parasitic filename:linenum features
  Such feature is already present with rt_printline in
  tccrun.c.  If it doesn't work it can be fixed.

- revert changes to gen_bounded_ptr_add()
  gen_bounded_ptr_add() was working as it should before
  (mostly).  For the sake of simplicity I switched it to
  CDECL.  Anyway, FASTCALL means SLOWCALL with tinycc.

In exchange you get one addition which is required for
bounds_cnecking function arguments.  The important thing
is to check them *BEFORE* they are loaded into registers.
New function gbound_args() does that.

In any case, code instrumentation with the bounds-check
functions as such now seems to work flawlessly again,
which means when they are inserted as NOPs, any code that
tcc can compile, seems to behave just the same as without
them.

What these functions then do when fully enabled, is a
differnt story.  I did not touch this.
2019-12-14 13:26:18 +01:00
herman ten brugge
4a2e33d160 Update bounds checking.
The bounds checking code has now enabled gen_bounded_ptr_add tests.
This makes the code slower but finds more errors.
I had to correct some things in tcc to make it work.
- Fixed off by one in lib/bcheck.c
- Corrected tccelf.c sym_versions.
- Disabled USE_TAL when using bounds checking.
- Fixed cstr_printf va_start.
- Fixed tests/tests2/46_grep.c off by one error.
- Updated gen_bounded_ptr_add in x86_64-gen.c
- Fixed x86_64-link.c pointer diff.
For gen_vla_alloc now always use alloca call when bounds checking.
Added line/filename in %rax before bound calls to find location of error.
2019-12-12 12:56:06 +01:00
grischka
72729d8e36 allow libtcc states to be used concurrently
This allows creation of TCCStates and operation with API
calls independently from each other, even from threads.

Frontend (option parsing/libtcc.c) and backend (linker/tccelf.c)
now depend only on the TCCState (s1) argument.

Compilation per se (tccpp.c, tccgen.c) is still using
globals for convenience.  There is only one entry point
to this section which is tcc_compile() which is protected
by a semaphore.

There are some hacks involved to avoid too many changes,
as well as some changes in order to avoid too many hacks ;)

The test libtcc_test_mt.c shows the feature.  Except this
new file the patch adds 87 lines overall.
2019-12-11 02:36:19 +01:00
grischka
df349ddc43 versym cleanup
get rid of some globals, in the first place.  Also, for the
PE target, ifdef out ELF executable creation.
2019-12-10 20:41:35 +01:00
Michael Matz
1353ccd9e2 riscv: Handle some usual relocs
this is enough to let me link a tcctest.c compiled by GCC
using some current debian sid riscv64 system.  It needs
linking against libgcc.a for various floating point TFmode
routines.  The result runs.
2019-08-14 18:19:00 +02:00
Michael Matz
adbe794a46 Properly access sym_attrs
in corner cases the direct access to the sym_attrs[] array in the
backends is out of bounds and replacec garbage symindices into
the relocs.
2019-01-13 02:55:44 +01:00
grischka
d348a9a51d final update for 0.9.27
tccgen.c:
- fix ldouble asm hack
- fix a VLA problem on Win64 (also x86_64-gen.c)
- patch_type(): make sure that no symbol ever changes
  from global to static

tcc.c:
- tcc -vv: print libtcc1.a path also on win32

tccpe.c, tcctools.c:
- use unix LF mode to for .def output files (that is for
  creating reproducible output trees)

Makefile:
- suppress some warnings when makeinfo is missing
- call 'which install' only on win32

tests/Makefile:
- change PATH only on WINNT systems (i.e. not if cross-compiling
  on linux for win32)
- asm-c-connect.test: slim output and do diff

tccrun.c tccpe.c *-link.c:
- integrate former 'pe_relocate_rva()' into normal relocation
  This also fixes linkage of the unwind data on WIN64 for -run
  (reported by Janus Lynggaard Thorborg)

tccasm.c, tests/tcctest.c:
- fix dot (sym_index of -1 crashed in put_elf_reloc)
- massage .set a bit (see test)

other:
- #define SECTION_ABS removed
- ST_DATA Section *strtab_section: removed
- put_extern_sym2(): take int section number

Conflicts:
	tccelf.c
	tccpe.c

Conflicts:
	tccelf.c
2017-12-12 17:57:20 +01:00
Aron BARATH
307b7b183d the R_X86_64_GOTOFF64 relocation was missing 2017-05-16 07:03:26 +02:00
Aron BARATH
3a9d6b3655 added 64-bit relocation types that required to linking against 64-bit (large model) libraries 2017-05-12 09:31:09 +02:00
Larry Doolittle
19d8b8a173 Spelling fixes in C comments only 2017-05-07 21:38:09 -07:00
Michael Matz
680e84fe42 elf: Support STB_LOCAL dynamic symbols
local symbols can be resolved statically, they don't have to be
done dynamically, so this is a slight speedup at load time for
produced executables and shared libs.  The musl libc also rejects
any STB_LOCAL symbols for dynamic symbol resolution, so there it
also fixes use of shared libs created by tcc.
2017-05-07 04:41:40 +02:00
Andrei Warkentin
63b2f907bd tcc: fixup clang warnings
The O(xxx) stuff in i386-asm.c had me scratching my head. Extracting
the macro and trying it out in a separate program doesn't give
me any warnings, so I'm confused about what could be going on there.
Any cast will make things happy. I used a uint64_t to catch actual
cases of overflow, which will still cause a -Wconstant-conversion
warning.

Signed-off-by: Andrei Warkentin <andrey.warkentin@gmail.com>
2017-04-25 13:55:18 +03:00
Michael Matz
77d7ea04ac Fix gawk miscompile
See testcase.  Function pointer use was hosed when the destination
function wasn't also called normally by the program.
2016-12-18 05:20:14 +01:00
Michael Matz
975c74c1f5 x86-64: Prefer 32S relocations
This target has _32 and _32S relocs (the latter being for signed
32 bit entities).  All instruction displacements have to use
the 32S variants.  Normal references like
  .long s
normally would use the _32 variant.  For normal executables this
doesn't matter.  For shared libraries neither (which use PC-relative
relocs).  But it matters for things like the kernel that are linked
to high addresses (signed ones).  There the GNU linker would error
out on overflow for the _32 variant.

To keep life simple we simply switch from _32 to _32S altogether.
Strictly speaking it's still wrong, but in practice using _32 is
more often wrong than using _32S ;)
2016-12-15 17:47:12 +01:00
grischka
ca92bfc3c6 tccelf: some linker cleanup
- generate and use SYM@PLT for plt addresses
- get rid of patch_dynsym_undef hack (no idea what it did on FreeBSD)
- use sym_attrs instead of symtab_to_dynsym
- special case for function pointers into .so on i386
- libtcc_test: test tcc_add_symbol with data object
- move target specicic code to *-link.c files
- add R_XXX_RELATIVE (needed for PE)
2016-12-15 17:01:22 +01:00
Thomas Preud'homme
fe6453f8f0 Use functions to get relocation info
MSVC does not support array designator so cannot compile source using
relocs_info. This commit replace the relocs_info array into a set of
functions, each returning the value given by a given field of the struct
reloc_info.
2016-12-10 18:14:10 +00:00
Thomas Preud'homme
d31226c873 Remove now useless pltoff_addend reloc info
Last use for pltoff_addend field of relocs_info array was removed in
commit 25927df3b7. It is now useless so
this commit removes it and all initialization related to it.
2016-12-10 18:13:23 +00:00
Thomas Preud'homme
0bf262864c Fix PLT creation for i386
i386 target does not have PC relative loads. Its ABI therefore require
ebx register to points to the GOT when executing a PLT entry. This means
that PLT entry cannot be used transparently, the compiler needs to
expect execution of a PLT entry to be able to use one, that is a PLT
entry should only be created if the relocation explicitely asks for it
(eg. R_386_PLT32).

This patch creates a new target macro PCRELATIVE_DLLPLT to indicate
whether a target can do a PC relative load in PLT entry when building a
dynamic library. Executable do not normally pose a problem because they
are loaded at a fixed address and thus the absolute address of GOT can
be used.

Note that in such a case, if the compiler does not use a PLT aware
relocation for external access then the code relocation will fall on the
dynamic loader since there is no PLT entry to relocate too.
2016-12-10 09:44:09 +00:00
Thomas Preud'homme
59391d5520 Fix relocs_info declaration in tcc.h
C standard specifies that array should be declared with a non null size
or with * for standard array. Declaration of relocs_info in tcc.h was
not respecting this rule. This commit add a R_NUM macro that maps to the
R_<ARCH>_NUM macros and declare relocs_info using it. This commit also
moves all linker-related macros from <arch>-gen.c files to <arch>-link.c
ones.
2016-12-05 20:51:10 +00:00
Thomas Preud'homme
25927df3b7 Consolidate all relocations in relocate_section
Static relocation of functions in dynamic libraries must use the PLT
entry as the target. Before this commit, it used to be done in 2 parts
for ARM, with the offset of the PLT entry from the beginning of the PLT
being put in the relocated place in build_got_entries () and then the
address of the PLT being added in relocate_section.

This led to code dealing with reading the offset of a bl instruction in
build_got_entries. Furthermore, the addition of the address of the start
of the PLT was done based on the relocation type which does not convey
whether a PLT entry should be used to reach the symbol.

This commit moves the decision to use the PLT as the target in
relocate_section, therefore having the instruction aware code contained
to the target-specific bit of that function (in <target>-link.c).

Note that relocate_syms is *not* the right place to do this because two
different relocations for the same symbol can make different decision.
This is the case in tcc -run mode where the static and dynamic
relocation are done by tcc.

Storing the PLT entry address in the symbol's st_value field and relying
on the specific relocation type being used for dynamic relocation would
work but the PLT entry address would then appear in the static symbol
table (symtab). This would also make the static symbol table entry
differ from the dynamic symbol table entry.
2016-12-03 17:26:51 +00:00
Thomas Preud'homme
1c811a4d1d Make build_got_entries more target independent
Factor most of common logic between targets in build_got_entries by
defining target specific info into structures in the backends.
2016-12-03 17:26:51 +00:00
Thomas Preud'homme
cb273fdad8 Do section relocation in architecture backend 2016-12-03 17:26:51 +00:00