build: remove glibc backcompat

CMakeLists.txt

@@ -881,12 +881,6 @@ else()
     set(LD_SECURITY_FLAGS "${LD_SECURITY_FLAGS} -Wl,-z,noexecheap")
   endif()
 
-  if(BACKCOMPAT)
-      add_linker_flag_if_supported(-Wl,--wrap=__divmoddi4 LD_BACKCOMPAT_FLAGS)
-      add_linker_flag_if_supported(-Wl,--wrap=glob LD_BACKCOMPAT_FLAGS)
-      message(STATUS "Using Lib C back compat flags: ${LD_BACKCOMPAT_FLAGS}")
-  endif()
-
   # some windows linker bits
   if (WIN32)
     add_linker_flag_if_supported(-Wl,--dynamicbase LD_SECURITY_FLAGS)
@@ -907,7 +901,7 @@ else()
 
   set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -D_GNU_SOURCE ${MINGW_FLAG} ${STATIC_ASSERT_FLAG} ${WARNINGS} ${C_WARNINGS} ${PIC_FLAG} ${C_SECURITY_FLAGS}")
   set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -D_GNU_SOURCE ${MINGW_FLAG} ${STATIC_ASSERT_CPP_FLAG} ${WARNINGS} ${CXX_WARNINGS} ${PIC_FLAG} ${CXX_SECURITY_FLAGS}")
-  set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} ${LD_SECURITY_FLAGS} ${LD_BACKCOMPAT_FLAGS}")
+  set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} ${LD_SECURITY_FLAGS}")
 
   # With GCC 6.1.1 the compiled binary malfunctions due to aliasing. Until that
   # is fixed in the code (Issue #847), force compiler to be conservative.

README.md

@@ -508,7 +508,7 @@ The required packages are the names for each toolchain on apt. Depending on your
 
 Using `depends` might also be easier to compile Monero on Windows than using MSYS. Activate Windows Subsystem for Linux (WSL) with a distro (for example Ubuntu), install the apt build-essentials and follow the `depends` steps as depicted above.
 
-The produced binaries still link libc dynamically. If the binary is compiled on a current distribution, it might not run on an older distribution with an older installation of libc. Passing `-DBACKCOMPAT=ON` to cmake will make sure that the binary will run on systems having at least libc version 2.17.
+The produced binaries still link libc dynamically. If the binary is compiled on a current distribution, it might not run on an older distribution with an older installation of libc.
 
 ### Trezor hardware wallet support
 

contrib/depends/packages/sodium.mk

@@ -3,7 +3,7 @@ $(package)_version=1.0.18
 $(package)_download_path=https://download.libsodium.org/libsodium/releases/
 $(package)_file_name=libsodium-$($(package)_version).tar.gz
 $(package)_sha256_hash=6f504490b342a4f8a4c4a02fc9b866cbef8622d5df4e5452b46be121e46636c1
-$(package)_patches=disable-glibc-getrandom-getentropy.patch fix-whitespace.patch
+$(package)_patches=fix-whitespace.patch
 
 define $(package)_set_vars
 $(package)_config_opts=--enable-static --disable-shared
@@ -11,7 +11,6 @@ $(package)_config_opts+=--prefix=$(host_prefix)
 endef
 
 define $(package)_preprocess_cmds
-  patch -p1 < $($(package)_patch_dir)/disable-glibc-getrandom-getentropy.patch &&\
   autoconf &&\
   patch -p1 < $($(package)_patch_dir)/fix-whitespace.patch
 endef

contrib/depends/packages/unbound.mk

@@ -4,7 +4,6 @@ $(package)_download_path=https://www.nlnetlabs.nl/downloads/$(package)/
 $(package)_file_name=$(package)-$($(package)_version).tar.gz
 $(package)_sha256_hash=bc1d576f3dd846a0739adc41ffaa702404c6767d2b6082deb9f2f97cbb24a3a9
 $(package)_dependencies=openssl expat
-$(package)_patches=disable-glibc-reallocarray.patch
 
 
 define $(package)_set_vars
@@ -19,7 +18,6 @@ define $(package)_set_vars
 endef
 
 define $(package)_preprocess_cmds
-  patch -p1 < $($(package)_patch_dir)/disable-glibc-reallocarray.patch &&\
   autoconf
 endef
 

contrib/depends/patches/sodium/disable-glibc-getrandom-getentropy.patch

@@ -1,25 +0,0 @@
-diff --git a/configure.ac b/configure.ac
-index 9e2de27c..0fa85c2d 100644
---- a/configure.ac
-+++ b/configure.ac
-@@ -807,6 +807,10 @@ AS_IF([test "x$EMSCRIPTEN" = "x"],[
- # include <sys/random.h>
- #endif
- ]], [[
-+#ifdef __linux__
-+# error getrandom() is currently disabled on Linux to support glibc < 2.25
-+#endif
-+
- unsigned char buf;
- (void) getrandom((void *) &buf, 1U, 0U);
-   ]])],
-@@ -825,6 +829,9 @@ unsigned char buf;
- # include <sys/random.h>
- #endif
- ]], [[
-+#ifdef __linux__
-+# error getentropy() is currently disabled on Linux to support glibc < 2.25
-+#endif
- #ifdef __APPLE__
- # error getentropy() is currently disabled on Apple operating systems
- #endif

contrib/depends/patches/unbound/disable-glibc-reallocarray.patch

@@ -1,14 +0,0 @@
-diff --git a/configure.ac b/configure.ac
-index 5c7da197..e2b25288 100644
---- a/configure.ac
-+++ b/configure.ac
-@@ -1702,6 +1702,9 @@ AC_LINK_IFELSE([AC_LANG_SOURCE(AC_INCLUDES_DEFAULT
- #ifndef _OPENBSD_SOURCE
- #define _OPENBSD_SOURCE 1
- #endif
-+#ifdef __linux__
-+# error reallocarray() is currently disabled on Linux to support glibc < 2.26
-+#endif
- #include <stdlib.h>
- int main(void) {
- 	void* p = reallocarray(NULL, 10, 100);

src/common/CMakeLists.txt

@@ -52,10 +52,6 @@ if (STACK_TRACE)
   list(APPEND common_sources stack_trace.cpp)
 endif()
 
-if (BACKCOMPAT)
-  list(APPEND common_sources compat/glibc_compat.cpp)
-endif()
-
 set(common_headers)
 
 monero_find_all_headers(common_private_headers "${CMAKE_CURRENT_SOURCE_DIR}")

src/common/compat/glibc_compat.cpp

@@ -1,98 +0,0 @@
-#include <cstddef>
-#include <cstdint>
-#include <strings.h>
-#include <string.h>
-#include <glob.h>
-#include <unistd.h>
-#include <fnmatch.h>
-
-#if defined(HAVE_SYS_SELECT_H)
-#include <sys/select.h>
-#endif
-
-// Prior to GLIBC_2.14, memcpy was aliased to memmove.
-extern "C" void* memmove(void* a, const void* b, size_t c);
-//extern "C" void* memset(void* a, int b, long unsigned int c);
-extern "C" void* memcpy(void* a, const void* b, size_t c)
-{
-    return memmove(a, b, c);
-}
-
-extern "C" void __chk_fail(void) __attribute__((__noreturn__));
-
-#if defined(__i386__) || defined(__arm__)
-
-extern "C" int64_t __udivmoddi4(uint64_t u, uint64_t v, uint64_t* rp);
-
-extern "C" int64_t __wrap___divmoddi4(int64_t u, int64_t v, int64_t* rp)
-{
-    int32_t c1 = 0, c2 = 0;
-    int64_t uu = u, vv = v;
-    int64_t w;
-    int64_t r;
-
-    if (uu < 0) {
-        c1 = ~c1, c2 = ~c2, uu = -uu;
-    }
-    if (vv < 0) {
-        c1 = ~c1, vv = -vv;
-    }
-
-    w = __udivmoddi4(uu, vv, (uint64_t*)&r);
-    if (c1)
-        w = -w;
-    if (c2)
-        r = -r;
-
-    *rp = r;
-    return w;
-}
-#endif
-
-/* glibc-internal users use __explicit_bzero_chk, and explicit_bzero
-   redirects to that.  */
-#undef explicit_bzero
-/* Set LEN bytes of S to 0.  The compiler will not delete a call to
-   this function, even if S is dead after the call.  */
-void
-explicit_bzero (void *s, size_t len)
-{
-  memset (s, '\0', len);
-  /* Compiler barrier.  */
-  asm volatile ("" ::: "memory");
-}
-
-// Redefine explicit_bzero_chk
-void
-__explicit_bzero_chk (void *dst, size_t len, size_t dstlen)
-{
-  /* Inline __memset_chk to avoid a PLT reference to __memset_chk.  */
-  if (__glibc_unlikely (dstlen < len))
-    __chk_fail ();
-  memset (dst, '\0', len);
-  /* Compiler barrier.  */
-  asm volatile ("" ::: "memory");
-}
-/* libc-internal references use the hidden
-   __explicit_bzero_chk_internal symbol.  This is necessary if
-   __explicit_bzero_chk is implemented as an IFUNC because some
-   targets do not support hidden references to IFUNC symbols.  */
-#define strong_alias (__explicit_bzero_chk, __explicit_bzero_chk_internal)
-
-#undef glob
-extern "C" int glob_old(const char * pattern, int flags, int (*errfunc) (const char *epath, int eerrno), glob_t *pglob);
-#ifdef __i386__
-__asm__(".symver glob_old,glob@GLIBC_2.0");
-#elif defined(__amd64__)
-__asm__(".symver glob_old,glob@GLIBC_2.2.5");
-#elif defined(__arm__)
-__asm(".symver glob_old,glob@GLIBC_2.4");
-#elif defined(__aarch64__)
-__asm__(".symver glob_old,glob@GLIBC_2.17");
-#endif
-
-extern "C" int __wrap_glob(const char * pattern, int flags, int (*errfunc) (const char *epath, int eerrno), glob_t *pglob)
-{
-    return glob_old(pattern, flags, errfunc, pglob);
-}
-