|
dd5bd030
|
2021-04-07T05:42:10
|
|
Fix building for arm windows with mingw toolchains (#631)
* arm: Check _WIN32 instead of _M_ARM or _MSC_VER for detecting windows
This matches what was done for ARM64 in
c06468fa6674d3783a0edb1d0fae9afc8bc28513.
* arm: Only use armasm source when building with MSVC
When building for windows/arm with clang, the normal gas style .S
source works fine (if fixed up to support thumb and other windows
specifics).
This matches what was done for ARM64 in
c06468fa6674d3783a0edb1d0fae9afc8bc28513.
* arm: Fix sysv.S to work in thumb mode
Align cases in jump tables (adding nop padding to make sure each
case starts where expected).
Rewrite instructions that add directly to the pc register.
For ffi_closure_ret, factor out a call_epilogue subroutine that
restores both sp and pc from the stack; the thumb version of ldm
can't load into the sp register. To avoid excessive ifdeffing, keep
using call_epilogue in arm mode, but keep the shorter "ldm sp, {sp, pc}"
epilogue in that case.
* arm: Add win32 version of trampoline to sysv.S
This matches the version of it in sysv_msvc_arm32.S. The calling
C code expects a specific form of the trampoline on windows; make
sure these work the same on windows regardless of the form of
assembly used.
* arm: Avoid optimizing out clearing the thumb bit of ffi_arm_trampoline
We clear the thumb bit of ffi_arm_trampoline with a bitmask before
memcpying its instructions into closure->tramp.
If the bit isn't cleared, the memcpy of the trampoline function
copies the wrong instructions.
If the ffi_arm_trampoline symbol is declared as an array of int,
the compiler can assume that it is aligned to a 4 byte boundary
and the bitmask operation is a no-op, and optimize it out.
See https://godbolt.org/z/dE3jE1WTz; both Clang and GCC optimize
out the bitmask as it is, while MSVC doesn't. By declaring the
trampoline as an array of unsigned char, the bitmask works as
intended.
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|
d271dbe0
|
2021-03-20T06:06:28
|
|
Add some missing #if conditionals from Apple's code drop (#620)
* arm/aarch64: Add FFI_CLOSURES conditionals where appropriate
Signed-off-by: Jeremy Huddleston Sequoia <jeremyhu@apple.com>
* aarch64: Don't emit the do_closure label when building without FFI_GO_CLOSURES
Signed-off-by: Jeremy Huddleston Sequoia <jeremyhu@apple.com>
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9ba55921
|
2021-03-05T10:07:30
|
|
Static tramp v5 (#624)
* Static Trampolines
Closure Trampoline Security Issue
=================================
Currently, the trampoline code used in libffi is not statically defined in
a source file (except for MACH). The trampoline is either pre-defined
machine code in a data buffer. Or, it is generated at runtime. In order to
execute a trampoline, it needs to be placed in a page with executable
permissions.
Executable data pages are attack surfaces for attackers who may try to
inject their own code into the page and contrive to have it executed. The
security settings in a system may prevent various tricks used in user land
to write code into a page and to have it executed somehow. On such systems,
libffi trampolines would not be able to run.
Static Trampoline
=================
To solve this problem, the trampoline code needs to be defined statically
in a source file, compiled and placed in the text segment so it can be
mapped and executed naturally without any tricks. However, the trampoline
needs to be able to access the closure pointer at runtime.
PC-relative data referencing
============================
The solution implemented in this patch set uses PC-relative data references.
The trampoline is mapped in a code page. Adjacent to the code page, a data
page is mapped that contains the parameters of the trampoline:
- the closure pointer
- pointer to the ABI handler to jump to
The trampoline code uses an offset relative to its current PC to access its
data.
Some architectures support PC-relative data references in the ISA itself.
E.g., X64 supports RIP-relative references. For others, the PC has to
somehow be loaded into a general purpose register to do PC-relative data
referencing. To do this, we need to define a get_pc() kind of function and
call it to load the PC in a desired register.
There are two cases:
1. The call instruction pushes the return address on the stack.
In this case, get_pc() will extract the return address from the stack
and load it in the desired register and return.
2. The call instruction stores the return address in a designated register.
In this case, get_pc() will copy the return address to the desired
register and return.
Either way, the PC next to the call instruction is obtained.
Scratch register
================
In order to do its job, the trampoline code would need to use a scratch
register. Depending on the ABI, there may not be a register available for
scratch. This problem needs to be solved so that all ABIs will work.
The trampoline will save two values on the stack:
- the closure pointer
- the original value of the scratch register
This is what the stack will look like:
sp before trampoline ------> --------------------
| closure pointer |
--------------------
| scratch register |
sp after trampoline -------> --------------------
The ABI handler can do the following as needed by the ABI:
- the closure pointer can be loaded in a desired register
- the scratch register can be restored to its original value
- the stack pointer can be restored to its original value
(the value when the trampoline was invoked)
To do this, I have defined prolog code for each ABI handler. The legacy
trampoline jumps to the ABI handler directly. But the static trampoline
defined in this patch jumps tp the prolog code which performs the above
actions before jumping to the ABI handler.
Trampoline Table
================
In order to reduce the trampoline memory footprint, the trampoline code
would be defined as a code array in the text segment. This array would be
mapped into the address space of the caller. The mapping would, therefore,
contain a trampoline table.
Adjacent to the trampoline table mapping, there will be a data mapping that
contains a parameter table, one parameter block for each trampoline. The
parameter block will contain:
- a pointer to the closure
- a pointer to the ABI handler
The static trampoline code would finally look like this:
- Make space on the stack for the closure and the scratch register
by moving the stack pointer down
- Store the original value of the scratch register on the stack
- Using PC-relative reference, get the closure pointer
- Store the closure pointer on the stack
- Using PC-relative reference, get the ABI handler pointer
- Jump to the ABI handler
Mapping size
============
The size of the code mapping that contains the trampoline table needs to be
determined on a per architecture basis. If a particular architecture
supports multiple base page sizes, then the largest supported base page size
needs to be chosen. E.g., we choose 16K for ARM64.
Trampoline allocation and free
==============================
Static trampolines are allocated in ffi_closure_alloc() and freed in
ffi_closure_free().
Normally, applications use these functions. But there are some cases out
there where the user of libffi allocates and manages its own closure
memory. In such cases, static trampolines cannot be used. These will
fall back to using legacy trampolines. The user has to make sure that
the memory is executable.
ffi_closure structure
=====================
I did not want to make any changes to the size of the closure structure for
this feature to guarantee compatibility. But the opaque static trampoline
handle needs to be stored in the closure. I have defined it as follows:
- char tramp[FFI_TRAMPOLINE_SIZE];
+ union {
+ char tramp[FFI_TRAMPOLINE_SIZE];
+ void *ftramp;
+ };
If static trampolines are used, then tramp[] is not needed to store a
dynamic trampoline. That space can be reused to store the handle. Hence,
the union.
Architecture Support
====================
Support has been added for x64, i386, aarch64 and arm. Support for other
architectures can be added very easily in the future.
OS Support
==========
Support has been added for Linux. Support for other OSes can be added very
easily.
Signed-off-by: Madhavan T. Venkataraman <madvenka@linux.microsoft.com>
* x86: Support for Static Trampolines
- Define the arch-specific initialization function ffi_tramp_arch ()
that returns trampoline size information to common code.
- Define the trampoline code mapping and data mapping sizes.
- Define the trampoline code table statically. Define two tables,
actually, one with CET and one without.
- Introduce a tiny prolog for each ABI handling function. The ABI
handlers addressed are:
- ffi_closure_unix64
- ffi_closure_unix64_sse
- ffi_closure_win64
The prolog functions are called:
- ffi_closure_unix64_alt
- ffi_closure_unix64_sse_alt
- ffi_closure_win64_alt
The legacy trampoline jumps to the ABI handler. The static
trampoline jumps to the prolog function. The prolog function uses
the information provided by the static trampoline, sets things up
for the ABI handler and then jumps to the ABI handler.
- Call ffi_tramp_set_parms () in ffi_prep_closure_loc () to
initialize static trampoline parameters.
Signed-off-by: Madhavan T. Venkataraman <madvenka@linux.microsoft.com>
* i386: Support for Static Trampolines
- Define the arch-specific initialization function ffi_tramp_arch ()
that returns trampoline size information to common code.
- Define the trampoline code table statically. Define two tables,
actually, one with CET and one without.
- Define the trampoline code table statically.
- Introduce a tiny prolog for each ABI handling function. The ABI
handlers addressed are:
- ffi_closure_i386
- ffi_closure_STDCALL
- ffi_closure_REGISTER
The prolog functions are called:
- ffi_closure_i386_alt
- ffi_closure_STDCALL_alt
- ffi_closure_REGISTER_alt
The legacy trampoline jumps to the ABI handler. The static
trampoline jumps to the prolog function. The prolog function uses
the information provided by the static trampoline, sets things up
for the ABI handler and then jumps to the ABI handler.
- Call ffi_tramp_set_parms () in ffi_prep_closure_loc () to
initialize static trampoline parameters.
Signed-off-by: Madhavan T. Venkataraman <madvenka@linux.microsoft.com>
* arm64: Support for Static Trampolines
- Define the arch-specific initialization function ffi_tramp_arch ()
that returns trampoline size information to common code.
- Define the trampoline code mapping and data mapping sizes.
- Define the trampoline code table statically.
- Introduce a tiny prolog for each ABI handling function. The ABI
handlers addressed are:
- ffi_closure_SYSV
- ffi_closure_SYSV_V
The prolog functions are called:
- ffi_closure_SYSV_alt
- ffi_closure_SYSV_V_alt
The legacy trampoline jumps to the ABI handler. The static
trampoline jumps to the prolog function. The prolog function uses
the information provided by the static trampoline, sets things up
for the ABI handler and then jumps to the ABI handler.
- Call ffi_tramp_set_parms () in ffi_prep_closure_loc () to
initialize static trampoline parameters.
Signed-off-by: Madhavan T. Venkataraman <madvenka@linux.microsoft.com>
* arm: Support for Static Trampolines
- Define the arch-specific initialization function ffi_tramp_arch ()
that returns trampoline size information to common code.
- Define the trampoline code mapping and data mapping sizes.
- Define the trampoline code table statically.
- Introduce a tiny prolog for each ABI handling function. The ABI
handlers addressed are:
- ffi_closure_SYSV
- ffi_closure_VFP
The prolog functions are called:
- ffi_closure_SYSV_alt
- ffi_closure_VFP_alt
The legacy trampoline jumps to the ABI handler. The static
trampoline jumps to the prolog function. The prolog function uses
the information provided by the static trampoline, sets things up
for the ABI handler and then jumps to the ABI handler.
- Call ffi_tramp_set_parms () in ffi_prep_closure_loc () to
initialize static trampoline parameters.
Signed-off-by: Madhavan T. Venkataraman <madvenka@linux.microsoft.com>
|
|
|
053b04c5
|
2020-04-26T05:02:14
|
|
arm: Fix the clang specific version of the assembly (#556)
Also fix the same error in the comment for the non-clang case.
That typo there seems to have existed since the code was written
in that form, in e7f15f60e86 - and when the clang specific codepath
was added in e3d2812ce43, the typo in the comment made it into the
actual code.
|
|
|
05a17964
|
2019-02-19T04:11:28
|
|
Cleanup symbol exports on darwin and add architecture preprocessor checks to assist in building fat binaries (eg: i386+x86_64 on macOS or arm+aarch64 on iOS) (#450)
* x86: Ensure _efi64 suffixed symbols are not exported
* x86: Ensure we do not export ffi_prep_cif_machdep
Signed-off-by: Jeremy Huddleston Sequoia <jeremyhu@apple.com>
* x86: Ensure we don't export ffi_call_win64, ffi_closure_win64, or ffi_go_closure_win64
Signed-off-by: Jeremy Huddleston Sequoia <jeremyhu@apple.com>
* closures: Silence a semantic warning
libffi/src/closures.c:175:23: This function declaration is not a prototype
Signed-off-by: Jeremy Huddleston Sequoia <jeremyhu@apple.com>
* aarch64: Ensure we don't export ffi_prep_cif_machdep
Signed-off-by: Jeremy Huddleston Sequoia <jeremyhu@apple.com>
* arm: Ensure we don't export ffi_prep_cif_machdep
Signed-off-by: Jeremy Huddleston Sequoia <jeremyhu@apple.com>
* aarch64, arm, x86: Add architecture preprocessor checks to support easier fat builds (eg: iOS)
Signed-off-by: Jeremy Huddleston Sequoia <jeremyhu@apple.com>
* x86: Silence some static analysis warnings
libffi/src/x86/ffi64.c:286:21: The left operand of '!=' is a garbage value due to array index out of bounds
libffi/src/x86/ffi64.c:297:22: The left operand of '!=' is a garbage value due to array index out of bounds
Signed-off-by: Jeremy Huddleston Sequoia <jeremyhu@apple.com>
* aarch: Use FFI_HIDDEN rather than .hidden
Signed-off-by: Jeremy Huddleston Sequoia <jeremyhu@apple.com>
* ffi.h: Don't advertise ffi_java_rvalue_to_raw, ffi_prep_java_raw_closure, and ffi_prep_java_raw_closure_loc when FFI_NATIVE_RAW_API is 0
Signed-off-by: Jeremy Huddleston Sequoia <jeremyhu@apple.com>
|
|
ba73a671
|
2018-07-20T09:37:43
|
|
Update FFI_HIDDEN() to use .private_extern on Apple platforms and use the macro where appropriate
Fix issue #439
Signed-off-by: Jeremy Huddleston Sequoia <jeremyhu@macports.org>
|
|
|
1d704051
|
2018-06-17T17:01:50
|
|
i386: Fix missing break; in case statement leading to incorrectly returned FFI_BAD_ABI (#437)
* i386: Add missing break triggering dead store static analyzer checks.
Register calling sequence is being reported as bad ABI instead of working as intended.
Found-by: Clang Static Analysis
Signed-off-by: Jeremy Huddleston Sequoia <jeremyhu@macports.org>
* Mark ffi arm sysv entry points as private_extern.
Signed-off-by: Jeremy Huddleston Sequoia <jeremyhu@macports.org>
* x86_64: Add implementation of compact unwind for ffi_call_unix64.
Signed-off-by: Jeremy Huddleston Sequoia <jeremyhu@apple.com>
|
|
00406945
|
2016-07-12T16:08:42
|
|
Update Xcodeproj
Include all currently relevent files.
Call autogen is build script.
Fix compiler settings.
Fix mach include.
|
|
bc4fc07a
|
2015-12-21T00:37:06
|
|
Fixed #181 -- Corrected problems with ARMv7 build under iOS.
Based on a patch from @fealebenpae, with input from @SolaWing and @rth7680,
and testing from @superdump.
|
|
|
e3d2812c
|
2015-04-25T19:03:03
|
|
Modified arm/sysv.S to remove directives not allowed by clang.
|
|
ab83cbb9
|
2014-10-29T14:38:42
|
|
arm: Add support for Go closures
|
|
|
a4b785ea
|
2014-10-17T02:07:32
|
|
arm: Rewrite ffi_closure
Move the push of the argument registers into ffi_closure_SYSV,
reducing the size of the trampoline.
|
|
|
e7f15f60
|
2014-10-17T01:27:16
|
|
arm: Rewrite ffi_call
Use the trick to allocate the stack frame for ffi_call_SYSV
within ffi_call itself.
|
|
001aaf4b
|
2014-02-28T00:20:17
|
|
When no VFP arguments are present the IP register is used
uninitialized. Initialize it to the value of FP.
This fixes a number of testsuite failures when configured for
armv7l-unknown-linux-gnueabihf
|
|
6eff9ff9
|
2013-12-30T17:48:10
|
|
Darwin/iOS: Improve unified syntax use for LLVM
|
|
|
3dc3f32c
|
2013-12-05T16:23:25
|
|
Undo iOS ARM64 changes.
|
|
953b6f14
|
2012-04-24T11:16:20
|
|
Darwin/iOS: More unified syntax support w/ Clang.
Signed-off-by: Zachary Waldowski <zwaldowski@gmail.com>
|
|
|
c713a553
|
2012-04-24T10:25:29
|
|
Darwin/iOS: Simplify RETLDM arguments for LLVM 3.1
Signed-off-by: Zachary Waldowski <zwaldowski@gmail.com>
|
|
b4112098
|
2013-03-27T16:38:35
|
|
create separated versions of ffi_prep_incoming_args_* for SYSV and VFP ABIs.
The different versions will be called depending on the value of cif->abi
|
|
|
0f2ff2d4
|
2013-03-26T19:22:02
|
|
separate ARM ffi_prepare_args in a version implementing the simple SYSV calling convention and one for the hard-float calling convention
|
|
|
39dccddb
|
2012-04-05T12:32:41
|
|
Fix building with Clang for Darwin (OS X 10.6+ and iOS
4.0+)
|
|
|
e1539266
|
2012-03-30T00:40:18
|
|
ARM VFP fix for old toolchains
|
|
|
3d56106b
|
2011-11-12T07:20:24
|
|
Rebase
|
|
|
09f8f310
|
2011-02-28T15:36:07
|
|
More AIX fixes. rc9.
|
|
8195e0e1
|
2011-02-12T11:27:00
|
|
Fix symbol prefixes on Darwin.
|
|
|
28a00f61
|
2011-02-12T11:01:48
|
|
Apple assembler support; fixed most gas/ELF-isms.
|
|
|
7f2ea33a
|
2011-02-12T10:39:18
|
|
Replace RETLDM macro.
The macro is incompatible with Apple's assembler; switch to
a simple inline version.
|
|
|
0cad4386
|
2011-02-09T06:11:46
|
|
Add ChangeLog entry. Fix copyright headers.
|
|
|
1106229a
|
2011-02-08T19:20:09
|
|
Add iOS support
|
|
|
0e584399
|
2011-02-08T07:52:40
|
|
Refresh from GCC
|
|
|
2db72615
|
2010-11-21T10:50:56
|
|
Rebase
|
|
|
f38364b3
|
2010-09-19T10:42:36
|
|
Fix symbol prefix for ffi_closure_SYSV_inner on Darwin.
|
|
|
70150bdf
|
2010-09-18T16:38:03
|
|
Add missing UNWIND entry; disables .pad on non-EABI targets.
|
|
|
6b452baf
|
2010-09-18T16:21:32
|
|
Apple assembler support; fixed most gas/ELF-isms.
|
|
|
8ddac835
|
2010-09-18T15:38:06
|
|
Fix placement of the __APPLE__ macro.
|
|
|
69043d02
|
2010-09-18T15:32:08
|
|
Work-around libffi's FP ABI detection.
On iOS, we must use the AAPCS floating point return value calling
conventions. libffi's ARM implementation will only use these conventions
if __SOFTFP__ is defined, which is not the case when GCC's
-mfloat-abi defaults to 'softfp' instead of 'soft'. To work around this
we manually define __SOFTFP__ for Apple platforms in the ARM-specific
sysv.S.
See also:
http://developer.apple.com/library/ios/#documentation/Xcode/Conceptual/iPhoneOSABIReference/Introduction/Introduction.html
http://infocenter.arm.com/help/topic/com.arm.doc.ihi0042d/IHI0042D_aapcs.pdf
|
|
9dc9a293
|
2010-04-13T10:33:52
|
|
Rebase to latest GCC sources
|
|
|
c6dddbd0
|
2009-10-04T08:11:33
|
|
Initial commit
|