| Message ID | 20230912212842.658374-3-fufuyqqqqqq@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | Native Library Calls | expand |
On 9/12/23 23:28, Yeqi Fu wrote: > This commit implements a shared library, where native functions are > rewritten as special instructions. At runtime, user programs load > the shared library, and special instructions are executed when > native functions are called. Hello Yeqi, I like the idea of speeding up linux-user with your approach. Do you have a git tree which I can pull for testing (or please mention the base commit your patches are based on)? How does the emulation behaves if a guest has bugs and accesses wrong memory locations, e.g.: memcpy(NULL, "Hello", 6) Will it segfault the same way as if it would have run natively? At least I think the signal IP addresses will be different. Regarding you implemenation: > diff --git a/common-user/native/libnative.S b/common-user/native/libnative.S > new file mode 100644 > index 0000000000..bc51dabedf > --- /dev/null > +++ b/common-user/native/libnative.S > @@ -0,0 +1,51 @@ > +.macro special_instr sym > +#if defined(__i386__) you use here #ifdefs, > + ud0 \sym-1f, %eax; 1: > +#elif defined(__x86_64__) > + ud0 \sym(%rip), %eax > +#elif defined(__arm__) || defined(__aarch64__) > + hlt 0xffff > +1: .word \sym - 1b > +#elif defined(__mips__) > + syscall 0xffff > +1: .word \sym - 1b > +#else > +# error > +#endif > +.endm > + > +.macro ret_instr > +#if defined(__i386__) || defined(__x86_64__) || defined(__aarch64__) and here again, > + ret > +#elif defined(__arm__) > + bx lr > +#elif defined(__mips__) > + jr $ra > +#else > +# error > +#endif > +.endm > + > +/* Symbols of native functions */ > + > +.macro define_function name > + .text > +\name: > + special_instr 9f and here the pointer to the string. > + ret_instr > + .globl \name > + .type \name, %function > + .size \name, . - \name > + > + .section .rodata > +9: .asciz "\name" > +.endm IMHO, I think it would be easier if you just do: +/* wrapper for native functions */ + +.macro define_function name + .text + .align 8 /* function is 8-byte aligned */ +\name: +/* every arch has up to 8 bytes for trigger and return instruction */ +#if defined(__i386__) + ud0 0, %eax + ret +#elif defined(__x86_64__) + ud0 0, %eax + ret +#elif defined(__mips__) + syscall 0xffff + jr $ra +#<...more ifdef for arches...> +#endif + +/* the native function name is stored 8 bytes behind \name symbol: */ + .align 8 + .asciz "\name" + + .globl \name + .type \name, %function + .size \name, . - \name +.endm with that you - save some bytes, code & pointers - don't need to load the pointer to the native function string (as it's always stored as ascii 8 bytes behind the function itself) - don't need to adjust the IP - simplifies the asm code and reduced the ifdefs - ... Helge > + > +define_function memcmp > +define_function memcpy > +define_function memset > +define_function strcat > +define_function strcmp > +define_function strcpy > +define_function strncmp > +define_function strncpy
diff --git a/Makefile b/Makefile index 5d48dfac18..6f6147b40f 100644 --- a/Makefile +++ b/Makefile @@ -182,6 +182,8 @@ SUBDIR_MAKEFLAGS=$(if $(V),,--no-print-directory --quiet) include $(SRC_PATH)/tests/Makefile.include +include $(SRC_PATH)/common-user/native/Makefile.include + all: recurse-all ROMS_RULES=$(foreach t, all clean distclean, $(addsuffix /$(t), $(ROMS))) diff --git a/common-user/native/Makefile.include b/common-user/native/Makefile.include new file mode 100644 index 0000000000..65b10fddac --- /dev/null +++ b/common-user/native/Makefile.include @@ -0,0 +1,8 @@ +.PHONY: build-native +build-native: $(NATIVE_TARGETS:%=build-native-library-%) +$(NATIVE_TARGETS:%=build-native-library-%): build-native-library-%: + $(call quiet-command, \ + $(MAKE) -C common-user/native/$* $(SUBDIR_MAKEFLAGS), \ + "BUILD","$* native library") + +all: build-native diff --git a/common-user/native/Makefile.target b/common-user/native/Makefile.target new file mode 100644 index 0000000000..65d90102e2 --- /dev/null +++ b/common-user/native/Makefile.target @@ -0,0 +1,22 @@ +# -*- Mode: makefile -*- +# +# Library for native calls +# + +all: +-include ../../../config-host.mak +-include config-target.mak + +CFLAGS+=-shared -D $(TARGET_NAME) +LDFLAGS+= + +SRC = $(SRC_PATH)/common-user/native/libnative.S +LIBNATIVE = libnative.so + +all: $(LIBNATIVE) + +$(LIBNATIVE): $(SRC) + $(CC) $(CFLAGS) $(EXTRA_CFLAGS) $(EXTRA_NATIVE_CALL_FLAGS) $< -o $@ $(LDFLAGS) + +clean: + rm -f $(LIBNATIVE) diff --git a/common-user/native/libnative.S b/common-user/native/libnative.S new file mode 100644 index 0000000000..bc51dabedf --- /dev/null +++ b/common-user/native/libnative.S @@ -0,0 +1,51 @@ +.macro special_instr sym +#if defined(__i386__) + ud0 \sym-1f, %eax; 1: +#elif defined(__x86_64__) + ud0 \sym(%rip), %eax +#elif defined(__arm__) || defined(__aarch64__) + hlt 0xffff +1: .word \sym - 1b +#elif defined(__mips__) + syscall 0xffff +1: .word \sym - 1b +#else +# error +#endif +.endm + +.macro ret_instr +#if defined(__i386__) || defined(__x86_64__) || defined(__aarch64__) + ret +#elif defined(__arm__) + bx lr +#elif defined(__mips__) + jr $ra +#else +# error +#endif +.endm + +/* Symbols of native functions */ + +.macro define_function name + .text +\name: + special_instr 9f + ret_instr + .globl \name + .type \name, %function + .size \name, . - \name + + .section .rodata +9: .asciz "\name" +.endm + +define_function memcmp +define_function memcpy +define_function memset +define_function strcat +define_function strcmp +define_function strcpy +define_function strncmp +define_function strncpy diff --git a/configure b/configure index 7a1e463d9c..de533b27a2 100755 --- a/configure +++ b/configure @@ -1826,6 +1826,45 @@ if test "$tcg" = "enabled"; then fi ) +# common-user/native configuration +(mkdir -p common-user/native + +native_targets= +for target in $target_list; do + case $target in + *-softmmu) + continue + ;; + esac + + # native call is only supported on these architectures + arch=${target%%-*} + config_target_mak=common-user/native/${target}/config-target.mak + case $arch in + i386|x86_64|arm|aarch64|mips|mips64) + if test -f cross-build/${target}/config-target.mak; then + mkdir -p "common-user/native/${target}" + ln -srf cross-build/${target}/config-target.mak "$config_target_mak" + if test $arch = arm; then + echo "EXTRA_NATIVE_CALL_FLAGS=-marm" >> "$config_target_mak" + fi + if test $arch = $cpu || \ + { test $arch = i386 && test $cpu = x86_64; } || \ + { test $arch = arm && test $cpu = aarch64; } || \ + { test $arch = mips && test $cpu = mips64; }; then + echo "LD_PREFIX=/" >> "$config_target_mak" + fi + echo "LIBNATIVE=$PWD/common-user/native/${target}/libnative.so" >> "$config_target_mak" + ln -sf ${source_path}/common-user/native/Makefile.target common-user/native/${target}/Makefile + native_targets="$native_targets ${target}" + fi + ;; + esac +done + +echo "NATIVE_TARGETS=$native_targets" >> config-host.mak +) + if test "$skip_meson" = no; then cross="config-meson.cross.new" meson_quote() {
This commit implements a shared library, where native functions are rewritten as special instructions. At runtime, user programs load the shared library, and special instructions are executed when native functions are called. Signed-off-by: Yeqi Fu <fufuyqqqqqq@gmail.com> --- Makefile | 2 ++ common-user/native/Makefile.include | 8 +++++ common-user/native/Makefile.target | 22 +++++++++++++ common-user/native/libnative.S | 51 +++++++++++++++++++++++++++++ configure | 39 ++++++++++++++++++++++ 5 files changed, 122 insertions(+) create mode 100644 common-user/native/Makefile.include create mode 100644 common-user/native/Makefile.target create mode 100644 common-user/native/libnative.S