diff options
89 files changed, 1949 insertions, 239 deletions
diff --git a/Documentation/ABI/stable/vdso b/Documentation/ABI/stable/vdso index 951838d42781..85dbb6a160df 100644 --- a/Documentation/ABI/stable/vdso +++ b/Documentation/ABI/stable/vdso @@ -9,9 +9,11 @@ maps an ELF DSO into that program's address space. This DSO is called the vDSO and it often contains useful and highly-optimized alternatives to real syscalls. -These functions are called just like ordinary C function according to -your platform's ABI. Call them from a sensible context. (For example, -if you set CS on x86 to something strange, the vDSO functions are +These functions are called according to your platform's ABI. On many +platforms they are called just like ordinary C function. On other platforms +(ex: powerpc) they are called with the same convention as system calls which +is different from ordinary C functions. Call them from a sensible context. +(For example, if you set CS on x86 to something strange, the vDSO functions are within their rights to crash.) In addition, if you pass a bad pointer to a vDSO function, you might get SIGSEGV instead of -EFAULT. diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index ed15b876fa74..8f2df6ed745d 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -263,6 +263,7 @@ config ARM64 select TRACE_IRQFLAGS_NMI_SUPPORT select HAVE_SOFTIRQ_ON_OWN_STACK select USER_STACKTRACE_SUPPORT + select VDSO_GETRANDOM help ARM 64-bit (AArch64) Linux support. diff --git a/arch/arm64/include/asm/alternative-macros.h b/arch/arm64/include/asm/alternative-macros.h index d328f549b1a6..c8c77f9e36d6 100644 --- a/arch/arm64/include/asm/alternative-macros.h +++ b/arch/arm64/include/asm/alternative-macros.h @@ -230,7 +230,11 @@ alternative_has_cap_likely(const unsigned long cpucap) return false; asm goto( +#ifdef BUILD_VDSO + ALTERNATIVE("b %l[l_no]", "nop", %[cpucap]) +#else ALTERNATIVE_CB("b %l[l_no]", %[cpucap], alt_cb_patch_nops) +#endif : : [cpucap] "i" (cpucap) : diff --git a/arch/arm64/include/asm/mman.h b/arch/arm64/include/asm/mman.h index 52791715f6e6..9e39217b4afb 100644 --- a/arch/arm64/include/asm/mman.h +++ b/arch/arm64/include/asm/mman.h @@ -2,9 +2,11 @@ #ifndef __ASM_MMAN_H__ #define __ASM_MMAN_H__ +#include <uapi/asm/mman.h> + +#ifndef BUILD_VDSO #include <linux/compiler.h> #include <linux/types.h> -#include <uapi/asm/mman.h> static inline unsigned long arch_calc_vm_prot_bits(unsigned long prot, unsigned long pkey) @@ -68,4 +70,6 @@ static inline bool arch_validate_flags(unsigned long vm_flags) } #define arch_validate_flags(vm_flags) arch_validate_flags(vm_flags) +#endif /* !BUILD_VDSO */ + #endif /* ! __ASM_MMAN_H__ */ diff --git a/arch/arm64/include/asm/vdso/getrandom.h b/arch/arm64/include/asm/vdso/getrandom.h new file mode 100644 index 000000000000..342f807e2044 --- /dev/null +++ b/arch/arm64/include/asm/vdso/getrandom.h @@ -0,0 +1,50 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef __ASM_VDSO_GETRANDOM_H +#define __ASM_VDSO_GETRANDOM_H + +#ifndef __ASSEMBLY__ + +#include <asm/unistd.h> +#include <asm/vdso/vsyscall.h> +#include <vdso/datapage.h> + +/** + * getrandom_syscall - Invoke the getrandom() syscall. + * @buffer: Destination buffer to fill with random bytes. + * @len: Size of @buffer in bytes. + * @flags: Zero or more GRND_* flags. + * Returns: The number of random bytes written to @buffer, or a negative value indicating an error. + */ +static __always_inline ssize_t getrandom_syscall(void *_buffer, size_t _len, unsigned int _flags) +{ + register void *buffer asm ("x0") = _buffer; + register size_t len asm ("x1") = _len; + register unsigned int flags asm ("x2") = _flags; + register long ret asm ("x0"); + register long nr asm ("x8") = __NR_getrandom; + + asm volatile( + " svc #0\n" + : "=r" (ret) + : "r" (buffer), "r" (len), "r" (flags), "r" (nr) + : "memory"); + + return ret; +} + +static __always_inline const struct vdso_rng_data *__arch_get_vdso_rng_data(void) +{ + /* + * The RNG data is in the real VVAR data page, but if a task belongs to a time namespace + * then VVAR_DATA_PAGE_OFFSET points to the namespace-specific VVAR page and VVAR_TIMENS_ + * PAGE_OFFSET points to the real VVAR page. + */ + if (IS_ENABLED(CONFIG_TIME_NS) && _vdso_data->clock_mode == VDSO_CLOCKMODE_TIMENS) + return (void *)&_vdso_rng_data + VVAR_TIMENS_PAGE_OFFSET * (1UL << CONFIG_PAGE_SHIFT); + return &_vdso_rng_data; +} + +#endif /* !__ASSEMBLY__ */ + +#endif /* __ASM_VDSO_GETRANDOM_H */ diff --git a/arch/arm64/include/asm/vdso/vsyscall.h b/arch/arm64/include/asm/vdso/vsyscall.h index f94b1457c117..5b6d0dd3cef5 100644 --- a/arch/arm64/include/asm/vdso/vsyscall.h +++ b/arch/arm64/include/asm/vdso/vsyscall.h @@ -2,11 +2,19 @@ #ifndef __ASM_VDSO_VSYSCALL_H #define __ASM_VDSO_VSYSCALL_H +#define __VDSO_RND_DATA_OFFSET 480 + #ifndef __ASSEMBLY__ #include <linux/timekeeper_internal.h> #include <vdso/datapage.h> +enum vvar_pages { + VVAR_DATA_PAGE_OFFSET, + VVAR_TIMENS_PAGE_OFFSET, + VVAR_NR_PAGES, +}; + #define VDSO_PRECISION_MASK ~(0xFF00ULL<<48) extern struct vdso_data *vdso_data; @@ -22,6 +30,13 @@ struct vdso_data *__arm64_get_k_vdso_data(void) #define __arch_get_k_vdso_data __arm64_get_k_vdso_data static __always_inline +struct vdso_rng_data *__arm64_get_k_vdso_rnd_data(void) +{ + return (void *)vdso_data + __VDSO_RND_DATA_OFFSET; +} +#define __arch_get_k_vdso_rng_data __arm64_get_k_vdso_rnd_data + +static __always_inline void __arm64_update_vsyscall(struct vdso_data *vdata, struct timekeeper *tk) { vdata[CS_HRES_COARSE].mask = VDSO_PRECISION_MASK; diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c index 89b6e7840002..706c9c3a7a50 100644 --- a/arch/arm64/kernel/vdso.c +++ b/arch/arm64/kernel/vdso.c @@ -34,12 +34,6 @@ enum vdso_abi { VDSO_ABI_AA32, }; -enum vvar_pages { - VVAR_DATA_PAGE_OFFSET, - VVAR_TIMENS_PAGE_OFFSET, - VVAR_NR_PAGES, -}; - struct vdso_abi_info { const char *name; const char *vdso_code_start; diff --git a/arch/arm64/kernel/vdso/Makefile b/arch/arm64/kernel/vdso/Makefile index d11da6461278..35685c036044 100644 --- a/arch/arm64/kernel/vdso/Makefile +++ b/arch/arm64/kernel/vdso/Makefile @@ -9,7 +9,7 @@ # Include the generic Makefile to check the built vdso. include $(srctree)/lib/vdso/Makefile -obj-vdso := vgettimeofday.o note.o sigreturn.o +obj-vdso := vgettimeofday.o note.o sigreturn.o vgetrandom.o vgetrandom-chacha.o # Build rules targets := $(obj-vdso) vdso.so vdso.so.dbg @@ -34,19 +34,28 @@ ccflags-y := -fno-common -fno-builtin -fno-stack-protector -ffixed-x18 ccflags-y += -DDISABLE_BRANCH_PROFILING -DBUILD_VDSO # -Wmissing-prototypes and -Wmissing-declarations are removed from -# the CFLAGS of vgettimeofday.c to make possible to build the -# kernel with CONFIG_WERROR enabled. -CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) -Os $(CC_FLAGS_SCS) \ - $(RANDSTRUCT_CFLAGS) $(GCC_PLUGINS_CFLAGS) \ - $(CC_FLAGS_LTO) $(CC_FLAGS_CFI) \ - -Wmissing-prototypes -Wmissing-declarations +# the CFLAGS to make possible to build the kernel with CONFIG_WERROR enabled. +CC_FLAGS_REMOVE_VDSO := $(CC_FLAGS_FTRACE) -Os $(CC_FLAGS_SCS) \ + $(RANDSTRUCT_CFLAGS) $(GCC_PLUGINS_CFLAGS) \ + $(CC_FLAGS_LTO) $(CC_FLAGS_CFI) \ + -Wmissing-prototypes -Wmissing-declarations -CFLAGS_vgettimeofday.o = -O2 -mcmodel=tiny -fasynchronous-unwind-tables +CC_FLAGS_ADD_VDSO := -O2 -mcmodel=tiny -fasynchronous-unwind-tables + +CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_REMOVE_VDSO) +CFLAGS_REMOVE_vgetrandom.o = $(CC_FLAGS_REMOVE_VDSO) + +CFLAGS_vgettimeofday.o = $(CC_FLAGS_ADD_VDSO) +CFLAGS_vgetrandom.o = $(CC_FLAGS_ADD_VDSO) ifneq ($(c-gettimeofday-y),) CFLAGS_vgettimeofday.o += -include $(c-gettimeofday-y) endif +ifneq ($(c-getrandom-y),) + CFLAGS_vgetrandom.o += -include $(c-getrandom-y) +endif + targets += vdso.lds CPPFLAGS_vdso.lds += -P -C -U$(ARCH) diff --git a/arch/arm64/kernel/vdso/vdso.lds.S b/arch/arm64/kernel/vdso/vdso.lds.S index 45354f2ddf70..f204a9ddc833 100644 --- a/arch/arm64/kernel/vdso/vdso.lds.S +++ b/arch/arm64/kernel/vdso/vdso.lds.S @@ -11,7 +11,9 @@ #include <linux/const.h> #include <asm/page.h> #include <asm/vdso.h> +#include <asm/vdso/vsyscall.h> #include <asm-generic/vmlinux.lds.h> +#include <vdso/datapage.h> OUTPUT_FORMAT("elf64-littleaarch64", "elf64-bigaarch64", "elf64-littleaarch64") OUTPUT_ARCH(aarch64) @@ -19,6 +21,7 @@ OUTPUT_ARCH(aarch64) SECTIONS { PROVIDE(_vdso_data = . - __VVAR_PAGES * PAGE_SIZE); + PROVIDE(_vdso_rng_data = _vdso_data + __VDSO_RND_DATA_OFFSET); #ifdef CONFIG_TIME_NS PROVIDE(_timens_data = _vdso_data + PAGE_SIZE); #endif @@ -102,6 +105,7 @@ VERSION __kernel_gettimeofday; __kernel_clock_gettime; __kernel_clock_getres; + __kernel_getrandom; local: *; }; } diff --git a/arch/arm64/kernel/vdso/vgetrandom-chacha.S b/arch/arm64/kernel/vdso/vgetrandom-chacha.S new file mode 100644 index 000000000000..67890b445309 --- /dev/null +++ b/arch/arm64/kernel/vdso/vgetrandom-chacha.S @@ -0,0 +1,172 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <linux/linkage.h> +#include <asm/cache.h> +#include <asm/assembler.h> + + .text + +#define state0 v0 +#define state1 v1 +#define state2 v2 +#define state3 v3 +#define copy0 v4 +#define copy0_q q4 +#define copy1 v5 +#define copy2 v6 +#define copy3 v7 +#define copy3_d d7 +#define one_d d16 +#define one_q q16 +#define one_v v16 +#define tmp v17 +#define rot8 v18 + +/* + * ARM64 ChaCha20 implementation meant for vDSO. Produces a given positive + * number of blocks of output with nonce 0, taking an input key and 8-bytes + * counter. Importantly does not spill to the stack. + * + * This implementation avoids d8-d15 because they are callee-save in user + * space. + * + * void __arch_chacha20_blocks_nostack(uint8_t *dst_bytes, + * const uint8_t *key, + * uint32_t *counter, + * size_t nblocks) + * + * x0: output bytes + * x1: 32-byte key input + * x2: 8-byte counter input/output + * x3: number of 64-byte block to write to output + */ +SYM_FUNC_START(__arch_chacha20_blocks_nostack) + + /* copy0 = "expand 32-byte k" */ + mov_q x8, 0x3320646e61707865 + mov_q x9, 0x6b20657479622d32 + mov copy0.d[0], x8 + mov copy0.d[1], x9 + + /* copy1,copy2 = key */ + ld1 { copy1.4s, copy2.4s }, [x1] + /* copy3 = counter || zero nonce */ + ld1 { copy3.2s }, [x2] + + movi one_v.2s, #1 + uzp1 one_v.4s, one_v.4s, one_v.4s + +.Lblock: + /* copy state to auxiliary vectors for the final add after the permute. */ + mov state0.16b, copy0.16b + mov state1.16b, copy1.16b + mov state2.16b, copy2.16b + mov state3.16b, copy3.16b + + mov w4, 20 +.Lpermute: + /* + * Permute one 64-byte block where the state matrix is stored in the four NEON + * registers state0-state3. It performs matrix operations on four words in parallel, + * but requires shuffling to rearrange the words after each round. + */ + +.Ldoubleround: + /* state0 += state1, state3 = rotl32(state3 ^ state0, 16) */ + add state0.4s, state0.4s, state1.4s + eor state3.16b, state3.16b, state0.16b + rev32 state3.8h, state3.8h + + /* state2 += state3, state1 = rotl32(state1 ^ state2, 12) */ + add state2.4s, state2.4s, state3.4s + eor tmp.16b, state1.16b, state2.16b + shl state1.4s, tmp.4s, #12 + sri state1.4s, tmp.4s, #20 + + /* state0 += state1, state3 = rotl32(state3 ^ state0, 8) */ + add state0.4s, state0.4s, state1.4s + eor tmp.16b, state3.16b, state0.16b + shl state3.4s, tmp.4s, #8 + sri state3.4s, tmp.4s, #24 + + /* state2 += state3, state1 = rotl32(state1 ^ state2, 7) */ + add state2.4s, state2.4s, state3.4s + eor tmp.16b, state1.16b, state2.16b + shl state1.4s, tmp.4s, #7 + sri state1.4s, tmp.4s, #25 + + /* state1[0,1,2,3] = state1[1,2,3,0] */ + ext state1.16b, state1.16b, state1.16b, #4 + /* state2[0,1,2,3] = state2[2,3,0,1] */ + ext state2.16b, state2.16b, state2.16b, #8 + /* state3[0,1,2,3] = state3[1,2,3,0] */ + ext state3.16b, state3.16b, state3.16b, #12 + + /* state0 += state1, state3 = rotl32(state3 ^ state0, 16) */ + add state0.4s, state0.4s, state1.4s + eor state3.16b, state3.16b, state0.16b + rev32 state3.8h, state3.8h + + /* state2 += state3, state1 = rotl32(s |