First cut of decent aarch64 support.

README.md

@@ -37,7 +37,7 @@ $ ./polyfill-glibc --target-glibc=2.17 /path/to/my-program
 
 If running it _isn't_ this simple, then open a GitHub issue describing why not, and we'll try to improve things.
 
-Note that at present, the `--target-glibc` operation of polyfill-glibc is only implemented for x86_64. If other architectures are of interest to you, open a GitHub issue so that we can gauge demand.
+Note that at present, the `--target-glibc` operation of polyfill-glibc is only implemented for x86_64 and aarch64. If other architectures are of interest to you, open a GitHub issue so that we can gauge demand.
 
 If distributing shared libraries, polyfill-glibc can also be used to inspect dependencies (with the `--print-imports` and `--print-exports` operations), and to modify how shared libraries are loaded (with the `--set-rpath`, `--set-runpath`, and `--set-soname` operations). Consult [the documentation](docs/Command_line_options.md) for a full list of command line options.
 

build.ninja

@@ -16,8 +16,19 @@ rule run_polyfill_glibc_txt
 rule run_polyfill_glibc
   command = ./polyfill-glibc --output $out $in $link_opt
 
-build polyfill-glibc: link build/main.o build/renamer.o build/polyfiller.o build/x86_64/polyfiller.o build/erw.o build/v2f.o build/tokenise.o build/sht.o build/uuht.o build/arena.o build/reloc_kind.o build/common.o
+build polyfill-glibc: link build/main.o build/renamer.o build/polyfiller.o build/aarch64/polyfiller.o build/x86_64/polyfiller.o build/print_eh_frame.o build/erw.o build/v2f.o build/tokenise.o build/sht.o build/uuht.o build/arena.o build/reloc_kind.o build/common.o
 default polyfill-glibc
+build build/aarch64/polyfills.so: create_polyfill_so polyfill-glibc
+  arch = aarch64
+  target_glibc = 2.17
+build build/aarch64/polyfiller.o: cc src/aarch64/polyfiller.c | build/aarch64/assembled_gen.h
+build build/aarch64/assembled_gen.h: run build/aarch64/assembler src/aarch64/_init.s src/aarch64/atexit.s src/aarch64/c11_thread.s src/aarch64/fatal.s src/aarch64/glibc_2_18.s src/aarch64/glibc_2_25.s src/aarch64/glibc_2_26.s src/aarch64/glibc_2_30.s src/aarch64/glibc_2_31.s src/aarch64/glibc_2_34.s src/aarch64/glibc_2_36.s src/aarch64/stdbit.s src/aarch64/syscalls.s src/aarch64/syscalls_ac.s
+build build/aarch64/assembler: link build/aarch64/assembler.o build/tokenise.o build/sht.o build/uuht.o build/common.o
+build build/aarch64/assembler.o: cc src/aarch64/assembler.c | build/aarch64/assembler_gen.h
+build build/aarch64/assembler_gen.h: run build/aarch64/build_assembler src/aarch64/insn_encoding.txt
+build build/aarch64/build_assembler: link build/aarch64/build_assembler.o build/tokenise.o build/sht.o build/uuht.o
+build build/aarch64/build_assembler.o: cc src/aarch64/build_assembler.c
+build build/aarch64/renames.h: run build/parse_renames src/aarch64/renames.txt
 build build/x86_64/polyfills.so: create_polyfill_so polyfill-glibc
   arch = x86_64
   target_glibc = 2.3.2
@@ -39,9 +50,10 @@ build build/x86_64/set_relative_interp: link build/x86_64/set_relative_interp.o
 build build/x86_64/set_relative_interp.o: cc src/x86_64/set_relative_interp.c | build/x86_64/relative_interp_payload.h
 build build/polyfiller.o: cc src/polyfiller.c
 build build/main.o: cc src/main.c
-build build/renamer.o: cc src/renamer.c | build/x86_64/renames.h
+build build/renamer.o: cc src/renamer.c | build/aarch64/renames.h build/x86_64/renames.h
 build build/parse_renames: link build/parse_renames.o build/tokenise.o build/sht.o build/common.o
 build build/parse_renames.o: cc src/parse_renames.c
+build build/print_eh_frame.o: cc src/print_eh_frame.c
 build build/erw.o: cc src/erw.c
 build build/v2f.o: cc src/v2f.c
 build build/tokenise.o: cc src/tokenise.c
@@ -51,6 +63,35 @@ build build/arena.o: cc src/arena.c
 build build/reloc_kind.o: cc src/reloc_kind.c
 build build/common.o: cc src/common.c
 
+build build/aarch64/test/arc4random.txt: run build/aarch64/test/arc4random build/aarch64/polyfills.so
+build build/aarch64/test/arc4random: link build/aarch64/test/arc4random.o build/test/syscall_filter.o
+  link_opt = -ldl
+build build/aarch64/test/arc4random.o: cc test/aarch64/arc4random.c
+
+build build/aarch64/test/memfd_pread_pwrite.txt: run build/aarch64/test/memfd_pread_pwrite build/aarch64/polyfills.so
+build build/aarch64/test/memfd_pread_pwrite: link build/aarch64/test/memfd_pread_pwrite.o build/test/syscall_filter.o
+  link_opt = -ldl
+build build/aarch64/test/memfd_pread_pwrite.o: cc test/aarch64/memfd_pread_pwrite.c
+
+build build/aarch64/test/nan.txt: run build/aarch64/test/nan build/aarch64/polyfills.so
+build build/aarch64/test/nan: link build/aarch64/test/nan.o
+  link_opt = -ldl
+build build/aarch64/test/nan.o: cc test/aarch64/nan.c
+
+build build/aarch64/test/stdbit.txt: run build/aarch64/test/stdbit build/aarch64/polyfills.so
+build build/aarch64/test/stdbit: link build/aarch64/test/stdbit.o
+  link_opt = -ldl
+build build/aarch64/test/stdbit.o: cc test/aarch64/stdbit.c
+
+build build/aarch64/test/totalorder.txt: run build/aarch64/test/totalorder build/aarch64/polyfills.so
+build build/aarch64/test/totalorder: link build/aarch64/test/totalorder.o
+  link_opt = -ldl
+build build/aarch64/test/totalorder.o: cc test/aarch64/totalorder.c
+
+build build/aarch64/test/twalk_r.txt: run build/x86_64/test/twalk_r build/aarch64/polyfills.so
+
+build test/aarch64: phony build/aarch64/test/arc4random.txt build/aarch64/test/memfd_pread_pwrite.txt build/aarch64/test/nan.txt build/aarch64/test/stdbit.txt build/aarch64/test/totalorder.txt build/aarch64/test/twalk_r.txt
+
 build build/x86_64/test/arc4random.txt: run build/x86_64/test/arc4random build/x86_64/polyfills.so
 build build/x86_64/test/arc4random: link build/x86_64/test/arc4random.o build/test/syscall_filter.o
   link_opt = -ldl
@@ -61,6 +102,11 @@ build build/x86_64/test/glibc_2_38: link build/x86_64/test/glibc_2_38.o
   link_opt = -ldl
 build build/x86_64/test/glibc_2_38.o: cc test/x86_64/glibc_2_38.c
 
+build build/x86_64/test/memfd_pread_pwrite.txt: run build/x86_64/test/memfd_pread_pwrite build/x86_64/polyfills.so
+build build/x86_64/test/memfd_pread_pwrite: link build/x86_64/test/memfd_pread_pwrite.o build/test/syscall_filter.o
+  link_opt = -ldl
+build build/x86_64/test/memfd_pread_pwrite.o: cc test/x86_64/memfd_pread_pwrite.c
+
 build build/x86_64/test/nan.txt: run build/x86_64/test/nan build/x86_64/polyfills.so
 build build/x86_64/test/nan: link build/x86_64/test/nan.o
   link_opt = -ldl
@@ -86,7 +132,7 @@ build build/x86_64/test/twalk_r: link build/x86_64/test/twalk_r.o
   link_opt = -ldl
 build build/x86_64/test/twalk_r.o: cc test/x86_64/twalk_r.c
 
-build test/x86_64: phony build/x86_64/test/arc4random.txt build/x86_64/test/glibc_2_38.txt build/x86_64/test/qsort_r.txt build/x86_64/test/stdbit.txt build/x86_64/test/totalorder.txt build/x86_64/test/twalk_r.txt
+build test/x86_64: phony build/x86_64/test/arc4random.txt build/x86_64/test/glibc_2_38.txt build/x86_64/test/qsort_r.txt build/x86_64/test/memfd_pread_pwrite.txt build/x86_64/test/nan.txt build/x86_64/test/stdbit.txt build/x86_64/test/totalorder.txt build/x86_64/test/twalk_r.txt
 
 build build/test/getauxval.txt: run build/test/getauxval_pf build/test/getauxval_imp.txt build/test/getauxval_imp_pf.txt
 build build/test/getauxval_imp_pf.txt: run_polyfill_glibc_txt build/test/getauxval_pf | polyfill-glibc

docs/Command_line_options.md

@@ -20,7 +20,7 @@ Flags that change the effect of other actions: `--output`, `--dry`, `--page-size
 
 Takes as an argument a glibc version, for example `--target-glibc=2.17`. The action identifies all dependencies that the file has on glibc functions and variables newer than the specified version, and employs [various strategies](How_does_polyfill_glibc_work.md) to remove those dependencies.
 
-Note that `--target-glibc` is currently only implemented for x86_64 files. If other architectures are of interest to you, open a GitHub issue so that we can gauge interest.
+Note that `--target-glibc` is currently only implemented for x86_64 files and aarch64 files. If other architectures are of interest to you, open a GitHub issue so that we can gauge interest.
 
 If there are any strong dependencies that `--target-glibc` cannot remove, then it'll fail and report the problematic dependencies, for example:
 
@@ -174,7 +174,7 @@ The `--polyfill-cfi` flag controls whether CFI is provided for statically linked
 
 In some cases, `--target-glibc` and `--rename-dynamic-symbols` can cause additional executable code to be statically linked into the file. For some people, this can be undesirable, and so `--create-polyfill-so` and `--use-polyfill-so` are provided instead, with the effect of putting the additional executable code in a separate shared object and then dynamically linking against that shared object.
 
-If the `--create-polyfill-so` flag is specified, then the behaviour of `--rename-dynamic-symbols` is modified: whenever `polyfill::NAME` is given as the new symbol name (regardless of whether the old symbol name is present), then `NAME@POLYFILL` is added as an _export_ to the file, with the statically linked code as the implementation of that export. The behaviour of `--target-glibc` is similarly modified: any statically linked code that _could_ be used to remove a problematic dependency (regardless of whether the problem is present) is added an _export_ to the file. The `--create-polyfill-so` flag is usually used in combination with the special input filename `empty:x86_64`, which denotes an empty ELF file. Accordingly, an invocation like the following can be used to create a shared object called `polyfills.so` with all the code required to polyfill back to glibc 2.3.2:
+If the `--create-polyfill-so` flag is specified, then the behaviour of `--rename-dynamic-symbols` is modified: whenever `polyfill::NAME` is given as the new symbol name (regardless of whether the old symbol name is present), then `NAME@POLYFILL` is added as an _export_ to the file, with the statically linked code as the implementation of that export. The behaviour of `--target-glibc` is similarly modified: any statically linked code that _could_ be used to remove a problematic dependency (regardless of whether the problem is present) is added an _export_ to the file. The `--create-polyfill-so` flag is usually used in combination with the special input filename `empty:x86_64` or `empty:aarch64`, which denotes an empty ELF file. Accordingly, an invocation like the following can be used to create a shared object called `polyfills.so` with all the code required to polyfill back to glibc 2.3.2:
 ```
 polyfill-glibc empty:x86_64 --add-hash --add-gnu-hash --create-polyfill-so --target-glibc=2.3.2 --output polyfills.so
 ```

docs/Limitations.md

@@ -1,6 +1,6 @@
 ## Limitations of polyfill-glibc
 
-Currently, the `--target-glibc` operation of polyfill-glibc is only implemented for x86_64. If other architectures are of interest to you, open a GitHub issue so that we can gauge interest. Note that lower level operations, for example `--set-rpath`, are implemented for all architectures.
+Currently, the `--target-glibc` operation of polyfill-glibc is only implemented for x86_64 and aarch64. If other architectures are of interest to you, open a GitHub issue so that we can gauge interest. Note that lower level operations, for example `--set-rpath`, are implemented for all architectures.
 
 Polyfills have not yet been written for every glibc function. If you're hitting such a case, open a GitHub issue so that we can gauge interest.