Removing the dependency on the libucontext library makes it easier to…

… build for macOS on arm processors (#892)
VKCOM · Sep 21, 2023 · daa5577 · daa5577
1 parent 99d4257
commit daa5577
Show file tree

Hide file tree

Showing 9 changed files with 248 additions and 48 deletions.
diff --git a/common/common.cmake b/common/common.cmake
@@ -35,11 +35,17 @@ prepend(COMMON_TL_METHODS_SOURCES ${COMMON_DIR}/tl/methods/
         rwm.cpp
         string.cpp)
 
+if (APPLE AND CMAKE_SYSTEM_PROCESSOR STREQUAL "arm64")
+    prepend(COMMON_UCONTEXT_SOURCES ${COMMON_DIR}/ucontext/
+            ucontext.cpp)
+endif()
+
 set(COMMON_ALL_SOURCES
     ${COMMON_MAIN_SOURCES}
     ${COMMON_KFS_SOURCES}
     ${COMMON_TL_METHODS_SOURCES}
-    ${COMMON_TL_SOURCES})
+    ${COMMON_TL_SOURCES}
+    ${COMMON_UCONTEXT_SOURCES})
 
 if(COMPILER_CLANG)
     set_source_files_properties(${COMMON_DIR}/string-processing.cpp PROPERTIES COMPILE_FLAGS -Wno-invalid-source-encoding)

diff --git a/common/server/crash-dump.cpp b/common/server/crash-dump.cpp
@@ -11,7 +11,7 @@
 #include <unistd.h>
 
 #include "common/kprintf.h"
-#include "server/ucontext-portable.h"
+#include "common/ucontext/ucontext-portable.h"
 
 struct crash_dump_buffer {
   char scratchpad[1024];

diff --git a/server/ucontext-portable.h → common/ucontext/ucontext-portable.h b/server/ucontext-portable.h → common/ucontext/ucontext-portable.h
@@ -16,14 +16,9 @@
 
 #else
 // for M1, we can't use native makecontext() and others: they compile, but hang up when called
-// instead, we require the ucontext library: https://github.com/kaniini/libucontext
-// see the docs: https://vkcom.github.io/kphp/kphp-internals/developing-and-extending-kphp/compiling-kphp-from-sources.html
-// here we expect, that libucontext include/ folder is copied into a default include path (to homebrew)
-extern "C" {
-#include <libucontext/libucontext.h>
-}
+#include "common/ucontext/ucontext.h"
 
-#define ucontext_t_portable libucontext_ucontext_t
+#define ucontext_t_portable libucontext_ucontext
 #define setcontext_portable libucontext_setcontext
 #define getcontext_portable libucontext_getcontext
 #define makecontext_portable libucontext_makecontext

diff --git a/common/ucontext/ucontext.cpp b/common/ucontext/ucontext.cpp
@@ -0,0 +1,199 @@
+// Compiler for PHP (aka KPHP)
+// libucontext (c) https://github.com/kaniini/libucontext/tree/master (copied as third-party and slightly modified)
+// Copyright (c) 2023 LLC «V Kontakte»
+// Distributed under the GPL v3 License, see LICENSE.notice.txt
+
+#include "common/ucontext/ucontext.h"
+
+#include <cstdarg>
+#include <cstdint>
+#include <cstdio>
+#include <cstdlib>
+
+enum { SP_OFFSET = 432, PC_OFFSET = 440, PSTATE_OFFSET = 448, FPSIMD_CONTEXT_OFFSET = 464 };
+
+#define R0_OFFSET REG_OFFSET(0)
+
+#define REG_OFFSET(__reg) (MCONTEXT_GREGS + ((__reg)*REG_SZ))
+
+#define REG_SZ (8)
+#define MCONTEXT_GREGS (184)
+
+_Static_assert(offsetof(libucontext_ucontext, uc_mcontext.regs[0]) == R0_OFFSET, "R0_OFFSET is invalid");
+_Static_assert(offsetof(libucontext_ucontext, uc_mcontext.sp) == SP_OFFSET, "SP_OFFSET is invalid");
+_Static_assert(offsetof(libucontext_ucontext, uc_mcontext.pc) == PC_OFFSET, "PC_OFFSET is invalid");
+_Static_assert(offsetof(libucontext_ucontext, uc_mcontext.pstate) == PSTATE_OFFSET, "PSTATE_OFFSET is invalid");
+
+__attribute__((visibility("hidden"))) void libucontext_trampoline() {
+  libucontext_ucontext *uc_link = nullptr;
+
+  asm("mov	%0, x19" : "=r"((uc_link)));
+
+  if (uc_link == nullptr) {
+    exit(0);
+  }
+
+  libucontext_setcontext(uc_link);
+}
+
+void libucontext_makecontext(libucontext_ucontext *ucp, void (*func)(), int argc, ...) {
+  unsigned long *sp;
+  unsigned long *regp;
+  va_list va;
+  int i;
+
+  sp = reinterpret_cast<unsigned long *>(reinterpret_cast<uintptr_t>(ucp->uc_stack.ss_sp) + ucp->uc_stack.ss_size);
+  sp -= argc < 8 ? 0 : argc - 8;
+  sp = reinterpret_cast<unsigned long *>(((reinterpret_cast<uintptr_t>(sp) & -16L)));
+
+  ucp->uc_mcontext.sp = reinterpret_cast<uintptr_t>(sp);
+  ucp->uc_mcontext.pc = reinterpret_cast<uintptr_t>(func);
+  ucp->uc_mcontext.regs[19] = reinterpret_cast<uintptr_t>(ucp->uc_link);
+  ucp->uc_mcontext.regs[30] = reinterpret_cast<uintptr_t>(&libucontext_trampoline);
+
+  va_start(va, argc);
+
+  regp = &(ucp->uc_mcontext.regs[0]);
+
+  for (i = 0; (i < argc && i < 8); i++) {
+    *regp++ = va_arg(va, unsigned long);
+  }
+
+  for (; i < argc; i++) {
+    *sp++ = va_arg(va, unsigned long);
+  }
+
+  va_end(va);
+}
+
+asm(R"(
+.global _libucontext_getcontext;
+.align  2;
+_libucontext_getcontext:
+	str	xzr, [x0, #((184) + ((0) * (8)))]       // #REG_OFFSET(0)
+
+	/* save GPRs */
+	stp	x0, x1,   [x0, #((184) + ((0) * (8)))]  // REG_OFFSET(0)
+	stp	x2, x3,   [x0, #((184) + ((2) * (8)))]  // REG_OFFSET(2)
+	stp	x4, x5,   [x0, #((184) + ((4) * (8)))]  // REG_OFFSET(4)
+	stp	x6, x7,   [x0, #((184) + ((6) * (8)))]  // REG_OFFSET(6)
+	stp	x8, x9,   [x0, #((184) + ((8) * (8)))]  // REG_OFFSET(8)
+	stp	x10, x11, [x0, #((184) + ((10) * (8)))] // REG_OFFSET(10)
+	stp	x12, x13, [x0, #((184) + ((12) * (8)))] // REG_OFFSET(12)
+	stp	x14, x15, [x0, #((184) + ((14) * (8)))] // REG_OFFSET(14)
+	stp	x16, x17, [x0, #((184) + ((16) * (8)))] // REG_OFFSET(16)
+	stp	x18, x19, [x0, #((184) + ((18) * (8)))] // REG_OFFSET(18)
+	stp	x20, x21, [x0, #((184) + ((20) * (8)))] // REG_OFFSET(20)
+	stp	x22, x23, [x0, #((184) + ((22) * (8)))] // REG_OFFSET(22)
+	stp	x24, x25, [x0, #((184) + ((24) * (8)))] // REG_OFFSET(24)
+	stp	x26, x27, [x0, #((184) + ((26) * (8)))] // REG_OFFSET(26)
+	stp	x28, x29, [x0, #((184) + ((28) * (8)))] // REG_OFFSET(28)
+	str	x30,      [x0, #((184) + ((30) * (8)))] // REG_OFFSET(30)
+
+	/* save current program counter in link register */
+	str	x30, [x0, #440]                         // PC_OFFSET
+
+	/* save current stack pointer */
+	mov	x2, sp
+	str	x2, [x0, #432]                          // SP_OFFSET
+
+	/* save pstate */
+	str	xzr, [x0, #448]                         // PSTATE_OFFSET
+
+	add x2, x0, #464                            // FPSIMD_CONTEXT_OFFSET
+	stp q8, q9,   [x2, #144]
+	stp q10, q11, [x2, #176]
+	stp q12, q13, [x2, #208]
+	stp q14, q15, [x2, #240]
+
+	mov	x0, #0
+	ret
+)");
+
+asm(R"(
+.global _libucontext_setcontext;
+.align  2;
+_libucontext_setcontext:
+  /* restore GPRs */
+  ldp	x18, x19, [x0, #((184) + ((18) * (8)))] // REG_OFFSET(18)
+  ldp	x20, x21, [x0, #((184) + ((20) * (8)))] // REG_OFFSET(20)
+  ldp	x22, x23, [x0, #((184) + ((22) * (8)))] // REG_OFFSET(22)
+  ldp	x24, x25, [x0, #((184) + ((24) * (8)))] // REG_OFFSET(24)
+  ldp	x26, x27, [x0, #((184) + ((26) * (8)))] // REG_OFFSET(26)
+  ldp	x28, x29, [x0, #((184) + ((28) * (8)))] // REG_OFFSET(28)
+  ldr	x30,      [x0, #((184) + ((30) * (8)))] // REG_OFFSET(30)
+
+  /* save current stack pointer */
+  ldr	x2, [x0, #432]  // SP_OFFSET
+  mov	sp, x2
+
+  add x2, x0, #464                            // FPSIMD_CONTEXT_OFFSET
+  ldp q8, q9,   [x2, #144]
+  ldp q10, q11, [x2, #176]
+  ldp q12, q13, [x2, #208]
+  ldp q14, q15, [x2, #240]
+
+  /* save current program counter in link register */
+  ldr	x16, [x0, #440]                         // PC_OFFSET
+
+  /* restore args */
+  ldp	x2, x3, [x0, #((184) + ((2) * (8)))]    // REG_OFFSET(2)
+  ldp	x4, x5, [x0, #((184) + ((4) * (8)))]    // REG_OFFSET(4)
+  ldp	x6, x7, [x0, #((184) + ((6) * (8)))]    // REG_OFFSET(6)
+  ldp	x0, x1, [x0, #((184) + ((0) * (8)))]    // REG_OFFSET(8)
+
+  /* jump to new PC */
+  br	x16
+)");
+
+asm(R"(
+.global _libucontext_swapcontext;
+.align  2;
+_libucontext_swapcontext:
+	str	xzr, [x0, #((184) + ((0) * (8)))]       // REG_OFFSET(0)
+
+	/* save GPRs */
+	stp	x2, x3,   [x0, #((184) + ((2) * (8)))]  // REG_OFFSET(2)
+	stp	x4, x5,   [x0, #((184) + ((4) * (8)))]  // REG_OFFSET(4)
+	stp	x6, x7,   [x0, #((184) + ((6) * (8)))]  // REG_OFFSET(6)
+	stp	x8, x9,   [x0, #((184) + ((8) * (8)))]  // REG_OFFSET(8)
+	stp	x10, x11, [x0, #((184) + ((10) * (8)))] // REG_OFFSET(10)
+	stp	x12, x13, [x0, #((184) + ((12) * (8)))] // REG_OFFSET(12)
+	stp	x14, x15, [x0, #((184) + ((14) * (8)))] // REG_OFFSET(14)
+	stp	x16, x17, [x0, #((184) + ((16) * (8)))] // REG_OFFSET(16)
+	stp	x18, x19, [x0, #((184) + ((18) * (8)))] // REG_OFFSET(18)
+	stp	x20, x21, [x0, #((184) + ((20) * (8)))] // REG_OFFSET(20)
+	stp	x22, x23, [x0, #((184) + ((22) * (8)))] // REG_OFFSET(22)
+	stp	x24, x25, [x0, #((184) + ((24) * (8)))] // REG_OFFSET(24)
+	stp	x26, x27, [x0, #((184) + ((26) * (8)))] // REG_OFFSET(26)
+	stp	x28, x29, [x0, #((184) + ((28) * (8)))] // REG_OFFSET(28)
+	str	x30,      [x0, #((184) + ((30) * (8)))] // REG_OFFSET(30)
+
+	/* save current program counter in link register */
+	str	x30, [x0, #440]                         // PC_OFFSET
+
+	/* save current stack pointer */
+	mov	x2, sp
+	str	x2, [x0, #432]                          // SP_OFFSET
+
+	/* save pstate */
+	str	xzr, [x0, #448]                         // PSTATE_OFFSET
+
+	add x2, x0, #464                            // FPSIMD_CONTEXT_OFFSET
+	stp q8, q9,   [x2, #144]
+	stp q10, q11, [x2, #176]
+	stp q12, q13, [x2, #208]
+	stp q14, q15, [x2, #240]
+
+	/* context to swap to is in x1 so... we move to x0 and call setcontext */
+	/* store our link register in x28 */
+	mov	x28, x30
+
+	/* move x1 to x0 and call setcontext */
+	mov	x0, x1
+	bl _libucontext_setcontext
+
+	/* hmm, we came back here try to return */
+	mov	x30, x28
+	ret
+)");
diff --git a/common/ucontext/ucontext.h b/common/ucontext/ucontext.h
@@ -0,0 +1,37 @@
+// Compiler for PHP (aka KPHP)
+// Copyright (c) 2018-2022 Ariadne Conill <[email protected]>
+// https://github.com/kaniini/libucontext/tree/master (copied as third-party and slightly modified)
+// Copyright (c) 2023 LLC «V Kontakte»
+// Distributed under the GPL v3 License, see LICENSE.notice.txt
+
+#pragma once
+
+#include <cstddef>
+
+struct libucontext_mcontext {
+  unsigned long fault_address;
+  unsigned long regs[31];
+  unsigned long sp, pc, pstate;
+  long double __reserved[256];
+};
+
+struct libucontext_stack {
+  void *ss_sp;
+  int ss_flags;
+  size_t ss_size;
+};
+
+struct libucontext_ucontext {
+  unsigned long uc_flags;
+  struct libucontext_ucontext *uc_link;
+  libucontext_stack uc_stack;
+  unsigned char __pad[136];
+  libucontext_mcontext uc_mcontext;
+};
+
+extern "C" {
+void libucontext_makecontext(libucontext_ucontext *, void (*)(), int, ...);
+int libucontext_getcontext(libucontext_ucontext *);
+int libucontext_setcontext(const libucontext_ucontext *);
+int libucontext_swapcontext(libucontext_ucontext *, const libucontext_ucontext *);
+}
diff --git a/compiler/compiler-settings.cpp b/compiler/compiler-settings.cpp
@@ -332,12 +332,6 @@ void CompilerSettings::init() {
   ld_flags.value_ += " -L /usr/local/lib";
 #endif
 
-#if defined(__APPLE__) && defined(__arm64__)
-  // for development under M1, manual installation of libucontext is needed
-  // see the docs: https://vkcom.github.io/kphp/kphp-internals/developing-and-extending-kphp/compiling-kphp-from-sources.html
-  ld_flags.value_ += " /opt/homebrew/lib/libucontext.a";
-#endif
-
   std::vector<vk::string_view> external_libs{"pthread", "m", "dl"};
 
 #ifdef PDO_DRIVER_MYSQL

diff --git a/docs/kphp-internals/developing-and-extending-kphp/compiling-kphp-from-sources.md b/docs/kphp-internals/developing-and-extending-kphp/compiling-kphp-from-sources.md
@@ -107,34 +107,6 @@ cmake ..
 sudo make install
 ```
 
-##### MacOS with Apple M1 chipset
-
-```note
-Probably, there is an easier way to do this, but I couldn't find it, at least for late 2021.
-```
-
-Follow the steps above. Later on, you'll have to patch the [libucontext](https://github.com/kaniini/libucontext) library locally.
-```bash
-git clone https://github.com/kaniini/libucontext
-cd libucontext
-nano Makefile
-```
-Find assignment to `LIBUCONTEXT_LINKER_FLAGS` and replace it with:
-```text
-LIBUCONTEXT_LINKER_FLAGS = -dynamiclib -install_name ${LIBUCONTEXT_SONAME} -current_version ${LIBUCONTEXT_SOVERSION} -compatibility_version ${LIBUCONTEXT_SOVERSION}
-```
-Now we are ready to make libucontext:
-```
-make FREESTANDING=yes ARCH=aarch64
-```
-Finally, copy resulting files to the default brew search folder `/opt/homebrew`:
-```
-cp libucontext.a /opt/homebrew/lib
-cp libucontext.dylib /opt/homebrew/lib
-cp -r include/* /opt/homebrew/include/
-```
-
-
 ##### Other Linux
 Make sure you are using the same package list. You may use system default libcurl package, it would work, but without DNS resolving. `uber-h3` must be installed from sources.
 

diff --git a/server/php-runner.h b/server/php-runner.h
@@ -7,15 +7,15 @@
 #include <csetjmp>
 
 #include "common/dl-utils-lite.h"
+#include "common/kprintf.h"
 #include "common/mixin/not_copyable.h"
 #include "common/sanitizer.h"
-#include "common/kprintf.h"
+#include "common/ucontext/ucontext-portable.h"
 
 #include "server/php-engine-vars.h"
 #include "server/php-init-scripts.h"
 #include "server/php-queries-types.h"
 #include "server/php-query-data.h"
-#include "server/ucontext-portable.h"
 
 DECLARE_VERBOSITY(php_runner);
 

diff --git a/tests/tests.cmake b/tests/tests.cmake
@@ -3,9 +3,6 @@ if(KPHP_TESTS)
         set(TEST_NAME unittests-${TEST_NAME})
         add_executable(${TEST_NAME} ${ARGN})
         target_link_libraries(${TEST_NAME} PRIVATE GTest::GTest GTest::Main gmock ${SRC_LIBS} vk::popular_common)
-        if(NOT CMAKE_SYSTEM_PROCESSOR STREQUAL "x86_64" AND APPLE)
-            target_link_libraries(${TEST_NAME} PRIVATE /opt/homebrew/lib/libucontext.a)
-        endif()
         target_link_options(${TEST_NAME} PRIVATE ${NO_PIE})
 
         # because of https://github.com/VKCOM/kphp/actions/runs/5463884925/jobs/9945150190