diff options
Diffstat (limited to 'arch/arm64/kernel/vdso')
| -rw-r--r-- | arch/arm64/kernel/vdso/.gitignore | 1 | ||||
| -rw-r--r-- | arch/arm64/kernel/vdso/Makefile | 75 | ||||
| -rwxr-xr-x | arch/arm64/kernel/vdso/gen_vdso_offsets.sh | 5 | ||||
| -rw-r--r-- | arch/arm64/kernel/vdso/gettimeofday.S | 328 | ||||
| -rw-r--r-- | arch/arm64/kernel/vdso/note.S | 19 | ||||
| -rw-r--r-- | arch/arm64/kernel/vdso/sigreturn.S | 87 | ||||
| -rw-r--r-- | arch/arm64/kernel/vdso/vdso.S | 32 | ||||
| -rw-r--r-- | arch/arm64/kernel/vdso/vdso.lds.S | 52 | ||||
| -rw-r--r-- | arch/arm64/kernel/vdso/vgettimeofday.c | 25 |
9 files changed, 184 insertions, 440 deletions
diff --git a/arch/arm64/kernel/vdso/.gitignore b/arch/arm64/kernel/vdso/.gitignore index f8b69d84238e..652e31d82582 100644 --- a/arch/arm64/kernel/vdso/.gitignore +++ b/arch/arm64/kernel/vdso/.gitignore @@ -1 +1,2 @@ +# SPDX-License-Identifier: GPL-2.0-only vdso.lds diff --git a/arch/arm64/kernel/vdso/Makefile b/arch/arm64/kernel/vdso/Makefile index 62c84f7cb01b..619e2dc7ee14 100644 --- a/arch/arm64/kernel/vdso/Makefile +++ b/arch/arm64/kernel/vdso/Makefile @@ -1,3 +1,4 @@ +# SPDX-License-Identifier: GPL-2.0 # # Building a vDSO image for AArch64. # @@ -5,33 +6,63 @@ # Heavily based on the vDSO Makefiles for other archs. # -obj-vdso := gettimeofday.o note.o sigreturn.o +# Absolute relocation type $(ARCH_REL_TYPE_ABS) needs to be defined before +# the inclusion of generic Makefile. +ARCH_REL_TYPE_ABS := R_AARCH64_JUMP_SLOT|R_AARCH64_GLOB_DAT|R_AARCH64_ABS64 +include $(srctree)/lib/vdso/Makefile + +obj-vdso := vgettimeofday.o note.o sigreturn.o # Build rules targets := $(obj-vdso) vdso.so vdso.so.dbg obj-vdso := $(addprefix $(obj)/, $(obj-vdso)) -ccflags-y := -shared -fno-common -fno-builtin -ccflags-y += -nostdlib -Wl,-soname=linux-vdso.so.1 \ - $(call cc-ldoption, -Wl$(comma)--hash-style=sysv) +btildflags-$(CONFIG_ARM64_BTI_KERNEL) += -z force-bti + +# -Bsymbolic has been added for consistency with arm, the compat vDSO and +# potential future proofing if we end up with internal calls to the exported +# routines, as x86 does (see 6f121e548f83 ("x86, vdso: Reimplement vdso.so +# preparation in build-time C")). +ldflags-y := -shared -soname=linux-vdso.so.1 --hash-style=sysv \ + -Bsymbolic --build-id=sha1 -n $(btildflags-y) + +ifdef CONFIG_LD_ORPHAN_WARN + ldflags-y += --orphan-handling=warn +endif + +ldflags-y += -T + +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) $(CC_FLAGS_CFI) \ + -Wmissing-prototypes -Wmissing-declarations +KASAN_SANITIZE := n +KCSAN_SANITIZE := n +UBSAN_SANITIZE := n +OBJECT_FILES_NON_STANDARD := y +KCOV_INSTRUMENT := n + +CFLAGS_vgettimeofday.o = -O2 -mcmodel=tiny -fasynchronous-unwind-tables + +ifneq ($(c-gettimeofday-y),) + CFLAGS_vgettimeofday.o += -include $(c-gettimeofday-y) +endif # Disable gcov profiling for VDSO code GCOV_PROFILE := n -# Workaround for bare-metal (ELF) toolchains that neglect to pass -shared -# down to collect2, resulting in silent corruption of the vDSO image. -ccflags-y += -Wl,-shared - -obj-y += vdso.o -extra-y += vdso.lds +targets += vdso.lds CPPFLAGS_vdso.lds += -P -C -U$(ARCH) -# Force dependency (incbin is bad) -$(obj)/vdso.o : $(obj)/vdso.so - # Link rule for the .so file, .lds has to be first -$(obj)/vdso.so.dbg: $(src)/vdso.lds $(obj-vdso) - $(call if_changed,vdsold) +$(obj)/vdso.so.dbg: $(obj)/vdso.lds $(obj-vdso) FORCE + $(call if_changed,vdsold_and_vdso_check) # Strip rule for the .so file $(obj)/%.so: OBJCOPYFLAGS := -S @@ -41,22 +72,14 @@ $(obj)/%.so: $(obj)/%.so.dbg FORCE # Generate VDSO offsets using helper script gen-vdsosym := $(srctree)/$(src)/gen_vdso_offsets.sh quiet_cmd_vdsosym = VDSOSYM $@ -define cmd_vdsosym - $(NM) $< | $(gen-vdsosym) | LC_ALL=C sort > $@ -endef + cmd_vdsosym = $(NM) $< | $(gen-vdsosym) | LC_ALL=C sort > $@ include/generated/vdso-offsets.h: $(obj)/vdso.so.dbg FORCE $(call if_changed,vdsosym) -# Assembly rules for the .S files -$(obj-vdso): %.o: %.S FORCE - $(call if_changed_dep,vdsoas) - # Actual build commands -quiet_cmd_vdsold = VDSOL $@ - cmd_vdsold = $(CC) $(c_flags) -Wl,-n -Wl,-T $^ -o $@ -quiet_cmd_vdsoas = VDSOA $@ - cmd_vdsoas = $(CC) $(a_flags) -c -o $@ $< +quiet_cmd_vdsold_and_vdso_check = LD $@ + cmd_vdsold_and_vdso_check = $(cmd_ld); $(cmd_vdso_check) # Install commands for the unstripped file quiet_cmd_vdso_install = INSTALL $@ diff --git a/arch/arm64/kernel/vdso/gen_vdso_offsets.sh b/arch/arm64/kernel/vdso/gen_vdso_offsets.sh index 01924ff071ad..0387209d65b1 100755 --- a/arch/arm64/kernel/vdso/gen_vdso_offsets.sh +++ b/arch/arm64/kernel/vdso/gen_vdso_offsets.sh @@ -1,4 +1,5 @@ #!/bin/sh +# SPDX-License-Identifier: GPL-2.0 # # Match symbols in the DSO that look like VDSO_*; produce a header file @@ -7,9 +8,9 @@ # Doing this inside the Makefile will break the $(filter-out) function, # causing Kbuild to rebuild the vdso-offsets header file every time. # -# Author: Will Deacon <will.deacon@arm.com +# Author: Will Deacon <will.deacon@arm.com> # LC_ALL=C sed -n -e 's/^00*/0/' -e \ -'s/^\([0-9a-fA-F]*\) . VDSO_\([a-zA-Z0-9_]*\)$/\#define vdso_offset_\2\t0x\1/p' +'s/^\([0-9a-fA-F]*\) . VDSO_\([a-zA-Z0-9_]*\)$/\#define vdso_offset_\2 0x\1/p' diff --git a/arch/arm64/kernel/vdso/gettimeofday.S b/arch/arm64/kernel/vdso/gettimeofday.S deleted file mode 100644 index 76320e920965..000000000000 --- a/arch/arm64/kernel/vdso/gettimeofday.S +++ /dev/null @@ -1,328 +0,0 @@ -/* - * Userspace implementations of gettimeofday() and friends. - * - * Copyright (C) 2012 ARM Limited - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 as - * published by the Free Software Foundation. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program. If not, see <http://www.gnu.org/licenses/>. - * - * Author: Will Deacon <will.deacon@arm.com> - */ - -#include <linux/linkage.h> -#include <asm/asm-offsets.h> -#include <asm/unistd.h> - -#define NSEC_PER_SEC_LO16 0xca00 -#define NSEC_PER_SEC_HI16 0x3b9a - -vdso_data .req x6 -seqcnt .req w7 -w_tmp .req w8 -x_tmp .req x8 - -/* - * Conventions for macro arguments: - * - An argument is write-only if its name starts with "res". - * - All other arguments are read-only, unless otherwise specified. - */ - - .macro seqcnt_acquire -9999: ldr seqcnt, [vdso_data, #VDSO_TB_SEQ_COUNT] - tbnz seqcnt, #0, 9999b - dmb ishld - .endm - - .macro seqcnt_check fail - dmb ishld - ldr w_tmp, [vdso_data, #VDSO_TB_SEQ_COUNT] - cmp w_tmp, seqcnt - b.ne \fail - .endm - - .macro syscall_check fail - ldr w_tmp, [vdso_data, #VDSO_USE_SYSCALL] - cbnz w_tmp, \fail - .endm - - .macro get_nsec_per_sec res - mov \res, #NSEC_PER_SEC_LO16 - movk \res, #NSEC_PER_SEC_HI16, lsl #16 - .endm - - /* - * Returns the clock delta, in nanoseconds left-shifted by the clock - * shift. - */ - .macro get_clock_shifted_nsec res, cycle_last, mult - /* Read the virtual counter. */ - isb - mrs x_tmp, cntvct_el0 - /* Calculate cycle delta and convert to ns. */ - sub \res, x_tmp, \cycle_last - /* We can only guarantee 56 bits of precision. */ - movn x_tmp, #0xff00, lsl #48 - and \res, x_tmp, \res - mul \res, \res, \mult - .endm - - /* - * Returns in res_{sec,nsec} the REALTIME timespec, based on the - * "wall time" (xtime) and the clock_mono delta. - */ - .macro get_ts_realtime res_sec, res_nsec, \ - clock_nsec, xtime_sec, xtime_nsec, nsec_to_sec - add \res_nsec, \clock_nsec, \xtime_nsec - udiv x_tmp, \res_nsec, \nsec_to_sec - add \res_sec, \xtime_sec, x_tmp - msub \res_nsec, x_tmp, \nsec_to_sec, \res_nsec - .endm - - /* - * Returns in res_{sec,nsec} the timespec based on the clock_raw delta, - * used for CLOCK_MONOTONIC_RAW. - */ - .macro get_ts_clock_raw res_sec, res_nsec, clock_nsec, nsec_to_sec - udiv \res_sec, \clock_nsec, \nsec_to_sec - msub \res_nsec, \res_sec, \nsec_to_sec, \clock_nsec - .endm - - /* sec and nsec are modified in place. */ - .macro add_ts sec, nsec, ts_sec, ts_nsec, nsec_to_sec - /* Add timespec. */ - add \sec, \sec, \ts_sec - add \nsec, \nsec, \ts_nsec - - /* Normalise the new timespec. */ - cmp \nsec, \nsec_to_sec - b.lt 9999f - sub \nsec, \nsec, \nsec_to_sec - add \sec, \sec, #1 -9999: - cmp \nsec, #0 - b.ge 9998f - add \nsec, \nsec, \nsec_to_sec - sub \sec, \sec, #1 -9998: - .endm - - .macro clock_gettime_return, shift=0 - .if \shift == 1 - lsr x11, x11, x12 - .endif - stp x10, x11, [x1, #TSPEC_TV_SEC] - mov x0, xzr - ret - .endm - - .macro jump_slot jumptable, index, label - .if (. - \jumptable) != 4 * (\index) - .error "Jump slot index mismatch" - .endif - b \label - .endm - - .text - -/* int __kernel_gettimeofday(struct timeval *tv, struct timezone *tz); */ -ENTRY(__kernel_gettimeofday) - .cfi_startproc - adr vdso_data, _vdso_data - /* If tv is NULL, skip to the timezone code. */ - cbz x0, 2f - - /* Compute the time of day. */ -1: seqcnt_acquire - syscall_check fail=4f - ldr x10, [vdso_data, #VDSO_CS_CYCLE_LAST] - /* w11 = cs_mono_mult, w12 = cs_shift */ - ldp w11, w12, [vdso_data, #VDSO_CS_MONO_MULT] - ldp x13, x14, [vdso_data, #VDSO_XTIME_CLK_SEC] - seqcnt_check fail=1b - - get_nsec_per_sec res=x9 - lsl x9, x9, x12 - - get_clock_shifted_nsec res=x15, cycle_last=x10, mult=x11 - get_ts_realtime res_sec=x10, res_nsec=x11, \ - clock_nsec=x15, xtime_sec=x13, xtime_nsec=x14, nsec_to_sec=x9 - - /* Convert ns to us. */ - mov x13, #1000 - lsl x13, x13, x12 - udiv x11, x11, x13 - stp x10, x11, [x0, #TVAL_TV_SEC] -2: - /* If tz is NULL, return 0. */ - cbz x1, 3f - ldp w4, w5, [vdso_data, #VDSO_TZ_MINWEST] - stp w4, w5, [x1, #TZ_MINWEST] -3: - mov x0, xzr - ret -4: - /* Syscall fallback. */ - mov x8, #__NR_gettimeofday - svc #0 - ret - .cfi_endproc -ENDPROC(__kernel_gettimeofday) - -#define JUMPSLOT_MAX CLOCK_MONOTONIC_COARSE - -/* int __kernel_clock_gettime(clockid_t clock_id, struct timespec *tp); */ -ENTRY(__kernel_clock_gettime) - .cfi_startproc - cmp w0, #JUMPSLOT_MAX - b.hi syscall - adr vdso_data, _vdso_data - adr x_tmp, jumptable - add x_tmp, x_tmp, w0, uxtw #2 - br x_tmp - - ALIGN -jumptable: - jump_slot jumptable, CLOCK_REALTIME, realtime - jump_slot jumptable, CLOCK_MONOTONIC, monotonic - b syscall - b syscall - jump_slot jumptable, CLOCK_MONOTONIC_RAW, monotonic_raw - jump_slot jumptable, CLOCK_REALTIME_COARSE, realtime_coarse - jump_slot jumptable, CLOCK_MONOTONIC_COARSE, monotonic_coarse - - .if (. - jumptable) != 4 * (JUMPSLOT_MAX + 1) - .error "Wrong jumptable size" - .endif - - ALIGN -realtime: - seqcnt_acquire - syscall_check fail=syscall - ldr x10, [vdso_data, #VDSO_CS_CYCLE_LAST] - /* w11 = cs_mono_mult, w12 = cs_shift */ - ldp w11, w12, [vdso_data, #VDSO_CS_MONO_MULT] - ldp x13, x14, [vdso_data, #VDSO_XTIME_CLK_SEC] - seqcnt_check fail=realtime - - /* All computations are done with left-shifted nsecs. */ - get_nsec_per_sec res=x9 - lsl x9, x9, x12 - - get_clock_shifted_nsec res=x15, cycle_last=x10, mult=x11 - get_ts_realtime res_sec=x10, res_nsec=x11, \ - clock_nsec=x15, xtime_sec=x13, xtime_nsec=x14, nsec_to_sec=x9 - clock_gettime_return, shift=1 - - ALIGN -monotonic: - seqcnt_acquire - syscall_check fail=syscall - ldr x10, [vdso_data, #VDSO_CS_CYCLE_LAST] - /* w11 = cs_mono_mult, w12 = cs_shift */ - ldp w11, w12, [vdso_data, #VDSO_CS_MONO_MULT] - ldp x13, x14, [vdso_data, #VDSO_XTIME_CLK_SEC] - ldp x3, x4, [vdso_data, #VDSO_WTM_CLK_SEC] - seqcnt_check fail=monotonic - - /* All computations are done with left-shifted nsecs. */ - lsl x4, x4, x12 - get_nsec_per_sec res=x9 - lsl x9, x9, x12 - - get_clock_shifted_nsec res=x15, cycle_last=x10, mult=x11 - get_ts_realtime res_sec=x10, res_nsec=x11, \ - clock_nsec=x15, xtime_sec=x13, xtime_nsec=x14, nsec_to_sec=x9 - - add_ts sec=x10, nsec=x11, ts_sec=x3, ts_nsec=x4, nsec_to_sec=x9 - clock_gettime_return, shift=1 - - ALIGN -monotonic_raw: - seqcnt_acquire - syscall_check fail=syscall - ldr x10, [vdso_data, #VDSO_CS_CYCLE_LAST] - /* w11 = cs_raw_mult, w12 = cs_shift */ - ldp w12, w11, [vdso_data, #VDSO_CS_SHIFT] - ldp x13, x14, [vdso_data, #VDSO_RAW_TIME_SEC] - seqcnt_check fail=monotonic_raw - - /* All computations are done with left-shifted nsecs. */ - get_nsec_per_sec res=x9 - lsl x9, x9, x12 - - get_clock_shifted_nsec res=x15, cycle_last=x10, mult=x11 - get_ts_clock_raw res_sec=x10, res_nsec=x11, \ - clock_nsec=x15, nsec_to_sec=x9 - - add_ts sec=x10, nsec=x11, ts_sec=x13, ts_nsec=x14, nsec_to_sec=x9 - clock_gettime_return, shift=1 - - ALIGN -realtime_coarse: - seqcnt_acquire - ldp x10, x11, [vdso_data, #VDSO_XTIME_CRS_SEC] - seqcnt_check fail=realtime_coarse - clock_gettime_return - - ALIGN -monotonic_coarse: - seqcnt_acquire - ldp x10, x11, [vdso_data, #VDSO_XTIME_CRS_SEC] - ldp x13, x14, [vdso_data, #VDSO_WTM_CLK_SEC] - seqcnt_check fail=monotonic_coarse - - /* Computations are done in (non-shifted) nsecs. */ - get_nsec_per_sec res=x9 - add_ts sec=x10, nsec=x11, ts_sec=x13, ts_nsec=x14, nsec_to_sec=x9 - clock_gettime_return - - ALIGN -syscall: /* Syscall fallback. */ - mov x8, #__NR_clock_gettime - svc #0 - ret - .cfi_endproc -ENDPROC(__kernel_clock_gettime) - -/* int __kernel_clock_getres(clockid_t clock_id, struct timespec *res); */ -ENTRY(__kernel_clock_getres) - .cfi_startproc - cmp w0, #CLOCK_REALTIME - ccmp w0, #CLOCK_MONOTONIC, #0x4, ne - ccmp w0, #CLOCK_MONOTONIC_RAW, #0x4, ne - b.ne 1f - - ldr x2, 5f - b 2f -1: - cmp w0, #CLOCK_REALTIME_COARSE - ccmp w0, #CLOCK_MONOTONIC_COARSE, #0x4, ne - b.ne 4f - ldr x2, 6f -2: - cbz w1, 3f - stp xzr, x2, [x1] - -3: /* res == NULL. */ - mov w0, wzr - ret - -4: /* Syscall fallback. */ - mov x8, #__NR_clock_getres - svc #0 - ret -5: - .quad CLOCK_REALTIME_RES -6: - .quad CLOCK_COARSE_RES - .cfi_endproc -ENDPROC(__kernel_clock_getres) diff --git a/arch/arm64/kernel/vdso/note.S b/arch/arm64/kernel/vdso/note.S index b82c85e5d972..3d4e82290c80 100644 --- a/arch/arm64/kernel/vdso/note.S +++ b/arch/arm64/kernel/vdso/note.S @@ -1,18 +1,7 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ /* * Copyright (C) 2012 ARM Limited * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 as - * published by the Free Software Foundation. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program. If not, see <http://www.gnu.org/licenses/>. - * * Author: Will Deacon <will.deacon@arm.com> * * This supplies .note.* sections to go into the PT_NOTE inside the vDSO text. @@ -22,7 +11,13 @@ #include <linux/uts.h> #include <linux/version.h> #include <linux/elfnote.h> +#include <linux/build-salt.h> +#include <asm/assembler.h> ELFNOTE_START(Linux, 0, "a") .long LINUX_VERSION_CODE ELFNOTE_END + +BUILD_SALT + +emit_aarch64_feature_1_and diff --git a/arch/arm64/kernel/vdso/sigreturn.S b/arch/arm64/kernel/vdso/sigreturn.S index 20d98effa7dd..0e18729abc3b 100644 --- a/arch/arm64/kernel/vdso/sigreturn.S +++ b/arch/arm64/kernel/vdso/sigreturn.S @@ -1,37 +1,80 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ /* * Sigreturn trampoline for returning from a signal when the SA_RESTORER - * flag is not set. + * flag is not set. It serves primarily as a hall of shame for crappy + * unwinders and features an exciting but mysterious NOP instruction. * - * Copyright (C) 2012 ARM Limited - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 as - * published by the Free Software Foundation. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. + * It's also fragile as hell, so please think twice before changing anything + * in here. * - * You should have received a copy of the GNU General Public License - * along with this program. If not, see <http://www.gnu.org/licenses/>. + * Copyright (C) 2012 ARM Limited * * Author: Will Deacon <will.deacon@arm.com> */ #include <linux/linkage.h> +#include <asm/assembler.h> #include <asm/unistd.h> .text - nop -ENTRY(__kernel_rt_sigreturn) - .cfi_startproc - .cfi_signal_frame - .cfi_def_cfa x29, 0 - .cfi_offset x29, 0 * 8 - .cfi_offset x30, 1 * 8 +/* + * NOTE!!! You may notice that all of the .cfi directives in this file have + * been commented out. This is because they have been shown to trigger segfaults + * in libgcc when unwinding out of a SIGCANCEL handler to invoke pthread + * cleanup handlers during the thread cancellation dance. By omitting the + * directives, we trigger an arm64-specific fallback path in the unwinder which + * recognises the signal frame and restores many of the registers directly from + * the sigcontext. Re-enabling the cfi directives here therefore needs to be + * much more comprehensive to reduce the risk of further regressions. + */ + +/* Ensure that the mysterious NOP can be associated with a function. */ +// .cfi_startproc + +/* + * .cfi_signal_frame causes the corresponding Frame Description Entry (FDE) in + * the .eh_frame section to be annotated as a signal frame. This allows DWARF + * unwinders (e.g. libstdc++) to implement _Unwind_GetIPInfo() and identify + * the next frame using the unmodified return address instead of subtracting 1, + * which may yield the wrong FDE. + */ +// .cfi_signal_frame + +/* + * Tell the unwinder where to locate the frame record linking back to the + * interrupted context. We don't provide unwind info for registers other than + * the frame pointer and the link register here; in practice, this is likely to + * be insufficient for unwinding in C/C++ based runtimes, especially without a + * means to restore the stack pointer. Thankfully, unwinders and debuggers + * already have baked-in strategies for attempting to unwind out of signals. + */ +// .cfi_def_cfa x29, 0 +// .cfi_offset x29, 0 * 8 +// .cfi_offset x30, 1 * 8 + +/* + * This mysterious NOP is required for some unwinders (e.g. libc++) that + * unconditionally subtract one from the result of _Unwind_GetIP() in order to + * identify the calling function. + * Hack borrowed from arch/powerpc/kernel/vdso64/sigtramp.S. + */ + nop // Mysterious NOP + +/* + * GDB, libgcc and libunwind rely on being able to identify the sigreturn + * instruction sequence to unwind from signal handlers. We cannot, therefore, + * use SYM_FUNC_START() here, as it will emit a BTI C instruction and break the + * unwinder. Thankfully, this function is only ever called from a RET and so + * omitting the landing pad is perfectly fine. + */ +SYM_CODE_START(__kernel_rt_sigreturn) +// PLEASE DO NOT MODIFY mov x8, #__NR_rt_sigreturn +// PLEASE DO NOT MODIFY svc #0 - .cfi_endproc -ENDPROC(__kernel_rt_sigreturn) +// PLEASE DO NOT MODIFY +// .cfi_endproc +SYM_CODE_END(__kernel_rt_sigreturn) + +emit_aarch64_feature_1_and diff --git a/arch/arm64/kernel/vdso/vdso.S b/arch/arm64/kernel/vdso/vdso.S deleted file mode 100644 index 82379a70ef03..000000000000 --- a/arch/arm64/kernel/vdso/vdso.S +++ /dev/null @@ -1,32 +0,0 @@ -/* - * Copyright (C) 2012 ARM Limited - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 as - * published by the Free Software Foundation. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program. If not, see <http://www.gnu.org/licenses/>. - * - * Author: Will Deacon <will.deacon@arm.com> - */ - -#include <linux/init.h> -#include <linux/linkage.h> -#include <linux/const.h> -#include <asm/page.h> - - .globl vdso_start, vdso_end - .section .rodata - .balign PAGE_SIZE -vdso_start: - .incbin "arch/arm64/kernel/vdso/vdso.so" - .balign PAGE_SIZE -vdso_end: - - .previous diff --git a/arch/arm64/kernel/vdso/vdso.lds.S b/arch/arm64/kernel/vdso/vdso.lds.S index beca249bc2f3..6028f1fe2d1c 100644 --- a/arch/arm64/kernel/vdso/vdso.lds.S +++ b/arch/arm64/kernel/vdso/vdso.lds.S @@ -1,20 +1,9 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ /* * GNU linker script for the VDSO library. * * Copyright (C) 2012 ARM Limited * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 as - * published by the Free Software Foundation. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program. If not, see <http://www.gnu.org/licenses/>. - * * Author: Will Deacon <will.deacon@arm.com> * Heavily based on the vDSO linker scripts for other archs. */ @@ -22,13 +11,17 @@ #include <linux/const.h> #include <asm/page.h> #include <asm/vdso.h> +#include <asm-generic/vmlinux.lds.h> OUTPUT_FORMAT("elf64-littleaarch64", "elf64-bigaarch64", "elf64-littleaarch64") OUTPUT_ARCH(aarch64) SECTIONS { - PROVIDE(_vdso_data = . - PAGE_SIZE); + PROVIDE(_vdso_data = . - __VVAR_PAGES * PAGE_SIZE); +#ifdef CONFIG_TIME_NS + PROVIDE(_timens_data = _vdso_data + PAGE_SIZE); +#endif . = VDSO_LBASE + SIZEOF_HEADERS; .hash : { *(.hash) } :text @@ -39,6 +32,13 @@ SECTIONS .gnu.version_d : { *(.gnu.version_d) } .gnu.version_r : { *(.gnu.version_r) } + /* + * Discard .note.gnu.property sections which are unused and have + * different alignment requirement from vDSO note sections. + */ + /DISCARD/ : { + *(.note.GNU-stack .note.gnu.property) + } .note : { *(.note.*) } :text :note . = ALIGN(16); @@ -48,20 +48,37 @@ SECTIONS PROVIDE (_etext = .); PROVIDE (etext = .); - .eh_frame_hdr : { *(.eh_frame_hdr) } :text :eh_frame_hdr - .eh_frame : { KEEP (*(.eh_frame)) } :text + . = ALIGN(4); + .altinstructions : { + __alt_instructions = .; + *(.altinstructions) + __alt_instructions_end = .; + } .dynamic : { *(.dynamic) } :text :dynamic - .rodata : { *(.rodata*) } :text + .rela.dyn : ALIGN(8) { *(.rela .rela*) } + + .rodata : { + *(.rodata*) + *(.got) + *(.got.plt) + *(.plt) + *(.plt.*) + *(.iplt) + *(.igot .igot.plt) + } :text _end = .; PROVIDE(end = .); + DWARF_DEBUG + ELF_DETAILS + /DISCARD/ : { - *(.note.GNU-stack) *(.data .data.* .gnu.linkonce.d.* .sdata*) *(.bss .sbss .dynbss .dynsbss) + *(.eh_frame .eh_frame_hdr) } } @@ -74,7 +91,6 @@ PHDRS text PT_LOAD FLAGS(5) FILEHDR PHDRS; /* PF_R|PF_X */ dynamic PT_DYNAMIC FLAGS(4); /* PF_R */ note PT_NOTE FLAGS(4); /* PF_R */ - eh_frame_hdr PT_GNU_EH_FRAME; } /* diff --git a/arch/arm64/kernel/vdso/vgettimeofday.c b/arch/arm64/kernel/vdso/vgettimeofday.c new file mode 100644 index 000000000000..4236cf34d7d9 --- /dev/null +++ b/arch/arm64/kernel/vdso/vgettimeofday.c @@ -0,0 +1,25 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * ARM64 userspace implementations of gettimeofday() and similar. + * + * Copyright (C) 2018 ARM Limited + * + */ + +int __kernel_clock_gettime(clockid_t clock, + struct __kernel_timespec *ts) +{ + return __cvdso_clock_gettime(clock, ts); +} + +int __kernel_gettimeofday(struct __kernel_old_timeval *tv, + struct timezone *tz) +{ + return __cvdso_gettimeofday(tv, tz); +} + +int __kernel_clock_getres(clockid_t clock_id, + struct __kernel_timespec *res) +{ + return __cvdso_clock_getres(clock_id, res); +} |