| Message ID | 20230808141739.3110740-3-fufuyqqqqqq@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | Native Library Calls | expand |
Yeqi Fu <fufuyqqqqqq@gmail.com> writes: > 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 | 9 ++++ > common-user/native/Makefile.target | 22 ++++++++++ > common-user/native/libnative.c | 67 +++++++++++++++++++++++++++++ > configure | 39 +++++++++++++++++ > include/native/libnative.h | 8 ++++ > 6 files changed, 147 insertions(+) > create mode 100644 common-user/native/Makefile.include > create mode 100644 common-user/native/Makefile.target > create mode 100644 common-user/native/libnative.c > create mode 100644 include/native/libnative.h > > 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..40d20bcd4c > --- /dev/null > +++ b/common-user/native/Makefile.include > @@ -0,0 +1,9 @@ > +.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") > +# endif > + > +all: build-native > diff --git a/common-user/native/Makefile.target b/common-user/native/Makefile.target > new file mode 100644 > index 0000000000..0c1241b368 > --- /dev/null > +++ b/common-user/native/Makefile.target > @@ -0,0 +1,22 @@ > +# -*- Mode: makefile -*- > +# > +# Library for native calls > +# > + > +all: > +-include ../../config-host.mak This is sensitive to the out of tree build structure the user chooses. For example: β pwd /home/alex/lsrc/qemu.git/builds/user/common-user/native/aarch64-linux-user π16:20:08 alex@zen:common-user/native/aarch64-linux-user on ξ review/native-lib-calls-v4 [$!?] β make libnative.so make: *** No rule to make target '/common-user/native/libnative.c', needed by 'libnative.so'. Stop. π16:20:13 alex@zen:common-user/native/aarch64-linux-user on ξ review/native-lib-calls-v4 [$!?] [π΄ USAGE] β I think this can be solved the same way as we do for tests/tcg by symlinking the config-host.mak into place and referring to it directly or adjusting the include to ../../../config-host.mak because the top of the build tree has a symlinked copy as well. > +-include config-target.mak > + > +CFLAGS+=-O1 -fPIC -shared -fno-stack-protector -I$(SRC_PATH)/include -D$(TARGET_NAME) > +LDFLAGS+= > + > +SRC = $(SRC_PATH)/common-user/native/libnative.c > +LIBNATIVE = libnative.so > + > +all: $(LIBNATIVE) > + > +$(LIBNATIVE): $(SRC) > + $(CC) $(CFLAGS) $(EXTRA_CFLAGS) $(EXTRA_NATIVE_CALL_FLAGS) $< -o $@ $(LDFLAGS) > + > +clean: > + rm -f $(LIBNATIVE) > diff --git a/common-user/native/libnative.c b/common-user/native/libnative.c > new file mode 100644 > index 0000000000..662ae6fbfe > --- /dev/null > +++ b/common-user/native/libnative.c > @@ -0,0 +1,67 @@ > +#include <stdint.h> > +#include <stdio.h> > +#include <stdlib.h> > + > +#include "native/libnative.h" > + > +#define WRAP_NATIVE() \ > + do { \ > + __asm__ volatile(__CALL_EXPR : : : "memory"); \ > + } while (0) > + > +#if defined(i386) || defined(x86_64) > +/* > + * An unused instruction is utilized to mark a native call. > + */ > +#define __CALL_EXPR ".byte 0x0f, 0xff;" > +#endif > + > +#if defined(arm) || defined(aarch64) > +/* > + * HLT is an invalid instruction for userspace and usefully has 16 > + * bits of spare immeadiate data which we can stuff data in. > + */ > +#define __CALL_EXPR "hlt 0xffff;" > +#endif > + > +#if defined(mips) || defined(mips64) > +/* > + * The syscall instruction contains 20 unused bits, which are typically > + * set to 0. These bits can be used to store non-zero data, > + * distinguishing them from a regular syscall instruction. > + */ > +#define __CALL_EXPR "syscall 0xffff;" > +#endif > + > +void *memcpy(void *dest, const void *src, size_t n) > +{ > + WRAP_NATIVE(); > +} > +int memcmp(const void *s1, const void *s2, size_t n) > +{ > + WRAP_NATIVE(); > +} > +void *memset(void *s, int c, size_t n) > +{ > + WRAP_NATIVE(); > +} > +char *strncpy(char *dest, const char *src, size_t n) > +{ > + WRAP_NATIVE(); > +} > +int strncmp(const char *s1, const char *s2, size_t n) > +{ > + WRAP_NATIVE(); > +} > +char *strcpy(char *dest, const char *src) > +{ > + WRAP_NATIVE(); > +} > +char *strcat(char *dest, const char *src) > +{ > + WRAP_NATIVE(); > +} > +int strcmp(const char *s1, const char *s2) > +{ > + WRAP_NATIVE(); > +} > diff --git a/configure b/configure > index a076583141..e02fc2c5c0 100755 > --- a/configure > +++ b/configure > @@ -1822,6 +1822,45 @@ if test "$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 "$skip_meson" = no; then > cross="config-meson.cross.new" > meson_quote() { > diff --git a/include/native/libnative.h b/include/native/libnative.h > new file mode 100644 > index 0000000000..ec990d8e5f > --- /dev/null > +++ b/include/native/libnative.h > @@ -0,0 +1,8 @@ > +void *memset(void *s, int c, size_t n); > +void *memcpy(void *dest, const void *src, size_t n); > +char *strncpy(char *dest, const char *src, size_t n); > +int memcmp(const void *s1, const void *s2, size_t n); > +int strncmp(const char *s1, const char *s2, size_t n); > +char *strcpy(char *dest, const char *src); > +char *strcat(char *dest, const char *src); > +int strcmp(const char *s1, const char *s2);
On 8/8/23 07:17, Yeqi Fu wrote: > +#if defined(i386) || defined(x86_64) > +/* > + * An unused instruction is utilized to mark a native call. > + */ > +#define __CALL_EXPR ".byte 0x0f, 0xff;" > +#endif This is 2 of the 3 (or more) bytes of the UD0 instruction. At minimum you should include a third byte for the modrm. For example, 0F FF C0 ud0 %eax, %eax If you want to encode more data, or simply magic numbers, you can use 0F FF 80 78 56 34 12 ud0 0x12345678(%eax), %eax or with modrm + sib bytes, 0F FF 84 00 78 56 34 12 ud0 0x12345678(%eax, %eax, 0), %eax So you have up to 32 (displacement) + 3 * 3 (registers) + 2 (shift) = 43 bits that you can vary while staying within the encoding of UD0. You can even have the assembler help encode a displacement to associated data: .text 0: ud0 label-0b(%eax), %eax .rodata label: .byte some stuff r~
diff --git a/Makefile b/Makefile index 5d48dfac18..6f6147b40f 100644 --- a/Makefile +++ b/Makefile @@ -182,6 +182,8 @@ SUBDIR_MAKEFLAGS=$(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..40d20bcd4c --- /dev/null +++ b/common-user/native/Makefile.include @@ -0,0 +1,9 @@ +.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") +# endif + +all: build-native diff --git a/common-user/native/Makefile.target b/common-user/native/Makefile.target new file mode 100644 index 0000000000..0c1241b368 --- /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+=-O1 -fPIC -shared -fno-stack-protector -I$(SRC_PATH)/include -D$(TARGET_NAME) +LDFLAGS+= + +SRC = $(SRC_PATH)/common-user/native/libnative.c +LIBNATIVE = libnative.so + +all: $(LIBNATIVE) + +$(LIBNATIVE): $(SRC) + $(CC) $(CFLAGS) $(EXTRA_CFLAGS) $(EXTRA_NATIVE_CALL_FLAGS) $< -o $@ $(LDFLAGS) + +clean: + rm -f $(LIBNATIVE) diff --git a/common-user/native/libnative.c b/common-user/native/libnative.c new file mode 100644 index 0000000000..662ae6fbfe --- /dev/null +++ b/common-user/native/libnative.c @@ -0,0 +1,67 @@ +#include <stdint.h> +#include <stdio.h> +#include <stdlib.h> + +#include "native/libnative.h" + +#define WRAP_NATIVE() \ + do { \ + __asm__ volatile(__CALL_EXPR : : : "memory"); \ + } while (0) + +#if defined(i386) || defined(x86_64) +/* + * An unused instruction is utilized to mark a native call. + */ +#define __CALL_EXPR ".byte 0x0f, 0xff;" +#endif + +#if defined(arm) || defined(aarch64) +/* + * HLT is an invalid instruction for userspace and usefully has 16 + * bits of spare immeadiate data which we can stuff data in. + */ +#define __CALL_EXPR "hlt 0xffff;" +#endif + +#if defined(mips) || defined(mips64) +/* + * The syscall instruction contains 20 unused bits, which are typically + * set to 0. These bits can be used to store non-zero data, + * distinguishing them from a regular syscall instruction. + */ +#define __CALL_EXPR "syscall 0xffff;" +#endif + +void *memcpy(void *dest, const void *src, size_t n) +{ + WRAP_NATIVE(); +} +int memcmp(const void *s1, const void *s2, size_t n) +{ + WRAP_NATIVE(); +} +void *memset(void *s, int c, size_t n) +{ + WRAP_NATIVE(); +} +char *strncpy(char *dest, const char *src, size_t n) +{ + WRAP_NATIVE(); +} +int strncmp(const char *s1, const char *s2, size_t n) +{ + WRAP_NATIVE(); +} +char *strcpy(char *dest, const char *src) +{ + WRAP_NATIVE(); +} +char *strcat(char *dest, const char *src) +{ + WRAP_NATIVE(); +} +int strcmp(const char *s1, const char *s2) +{ + WRAP_NATIVE(); +} diff --git a/configure b/configure index a076583141..e02fc2c5c0 100755 --- a/configure +++ b/configure @@ -1822,6 +1822,45 @@ if test "$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() { diff --git a/include/native/libnative.h b/include/native/libnative.h new file mode 100644 index 0000000000..ec990d8e5f --- /dev/null +++ b/include/native/libnative.h @@ -0,0 +1,8 @@ +void *memset(void *s, int c, size_t n); +void *memcpy(void *dest, const void *src, size_t n); +char *strncpy(char *dest, const char *src, size_t n); +int memcmp(const void *s1, const void *s2, size_t n); +int strncmp(const char *s1, const char *s2, size_t n); +char *strcpy(char *dest, const char *src); +char *strcat(char *dest, const char *src); +int strcmp(const char *s1, const char *s2);
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 | 9 ++++ common-user/native/Makefile.target | 22 ++++++++++ common-user/native/libnative.c | 67 +++++++++++++++++++++++++++++ configure | 39 +++++++++++++++++ include/native/libnative.h | 8 ++++ 6 files changed, 147 insertions(+) create mode 100644 common-user/native/Makefile.include create mode 100644 common-user/native/Makefile.target create mode 100644 common-user/native/libnative.c create mode 100644 include/native/libnative.h