Resguardo inicial

linux-7.2.3/arch/arm64/kernel/vdso/.gitignore

@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-only
+vdso.lds

linux-7.2.3/arch/arm64/kernel/vdso/Makefile

@@ -0,0 +1,82 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Building a vDSO image for AArch64.
+#
+# Author: Will Deacon <will.deacon@arm.com>
+# Heavily based on the vDSO Makefiles for other archs.
+#
+
+# Include the generic Makefile to check the built vdso.
+include $(srctree)/lib/vdso/Makefile.include
+
+obj-vdso := vgettimeofday.o note.o sigreturn.o vgetrandom.o vgetrandom-chacha.o
+
+# Build rules
+targets := $(obj-vdso) vdso.so vdso.so.dbg
+obj-vdso := $(addprefix $(obj)/, $(obj-vdso))
+
+btildflags-$(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 \
+	     -Bsymbolic --build-id=sha1 -n $(btildflags-y)
+
+ifdef CONFIG_LD_ORPHAN_WARN
+  ldflags-y += --orphan-handling=$(CONFIG_LD_ORPHAN_WARN_LEVEL)
+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 to make possible to build the kernel with CONFIG_WERROR enabled.
+CC_FLAGS_REMOVE_VDSO := $(CC_FLAGS_FTRACE) -Os $(CC_FLAGS_SCS) \
+			$(RANDSTRUCT_CFLAGS) $(KSTACK_ERASE_CFLAGS) \
+			$(GCC_PLUGINS_CFLAGS) \
+			$(CC_FLAGS_LTO) $(CC_FLAGS_CFI) \
+			-Wmissing-prototypes -Wmissing-declarations
+
+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)
+
+# Link rule for the .so file, .lds has to be first
+$(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
+$(obj)/%.so: $(obj)/%.so.dbg FORCE
+	$(call if_changed,objcopy)
+
+# Generate VDSO offsets using helper script
+gen-vdsosym := $(src)/gen_vdso_offsets.sh
+quiet_cmd_vdsosym = VDSOSYM $@
+      cmd_vdsosym = $(NM) $< | $(gen-vdsosym) | LC_ALL=C sort > $@
+
+include/generated/vdso-offsets.h: $(obj)/vdso.so.dbg FORCE
+	$(call if_changed,vdsosym)
+
+# Actual build commands
+quiet_cmd_vdsold_and_vdso_check = LD      $@
+      cmd_vdsold_and_vdso_check = $(cmd_ld); $(cmd_vdso_check)

linux-7.2.3/arch/arm64/kernel/vdso/gen_vdso_offsets.sh

@@ -0,0 +1,16 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+
+#
+# Match symbols in the DSO that look like VDSO_*; produce a header file
+# of constant offsets into the shared object.
+#
+# 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>
+#
+
+LC_ALL=C
+sed -n -e 's/^00*/0/' -e \
+'s/^\([0-9a-fA-F]*\) . VDSO_\([a-zA-Z0-9_]*\)$/\#define vdso_offset_\2 0x\1/p'

linux-7.2.3/arch/arm64/kernel/vdso/note.S

@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2012 ARM Limited
+ *
+ * Author: Will Deacon <will.deacon@arm.com>
+ *
+ * This supplies .note.* sections to go into the PT_NOTE inside the vDSO text.
+ * Here we can supply some information useful to userland.
+ */
+
+#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

linux-7.2.3/arch/arm64/kernel/vdso/sigreturn.S

@@ -0,0 +1,80 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Sigreturn trampoline for returning from a signal when the SA_RESTORER
+ * flag is not set. It serves primarily as a hall of shame for crappy
+ * unwinders and features an exciting but mysterious NOP instruction.
+ *
+ * It's also fragile as hell, so please think twice before changing anything
+ * in here.
+ *
+ * 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
+
+/*
+ * 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
+//	PLEASE DO NOT MODIFY
+//	.cfi_endproc
+SYM_CODE_END(__kernel_rt_sigreturn)
+
+emit_aarch64_feature_1_and

linux-7.2.3/arch/arm64/kernel/vdso/vdso.lds.S

@@ -0,0 +1,114 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * GNU linker script for the VDSO library.
+*
+ * Copyright (C) 2012 ARM Limited
+ *
+ * Author: Will Deacon <will.deacon@arm.com>
+ * Heavily based on the vDSO linker scripts for other archs.
+ */
+
+#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)
+
+SECTIONS
+{
+	VDSO_VVAR_SYMS
+
+	. = SIZEOF_HEADERS;
+
+	.hash		: { *(.hash) }			:text
+	.gnu.hash	: { *(.gnu.hash) }
+	.dynsym		: { *(.dynsym) }
+	.dynstr		: { *(.dynstr) }
+	.gnu.version	: { *(.gnu.version) }
+	.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)
+		*(.ARM.attributes)
+	}
+	.note		: { *(.note.*) }		:text	:note
+
+	. = ALIGN(16);
+
+	.text		: { *(.text*) }			:text	=0xd503201f
+	PROVIDE (__etext = .);
+	PROVIDE (_etext = .);
+	PROVIDE (etext = .);
+
+	. = ALIGN(4);
+	.altinstructions : {
+		*(.altinstructions)
+	}
+
+	.dynamic	: { *(.dynamic) }		:text	:dynamic
+
+	.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/	: {
+		*(.data .data.* .gnu.linkonce.d.* .sdata*)
+		*(.bss .sbss .dynbss .dynsbss)
+		*(.eh_frame .eh_frame_hdr)
+	}
+}
+
+/*
+ * We must supply the ELF program headers explicitly to get just one
+ * PT_LOAD segment, and set the flags explicitly to make segments read-only.
+ */
+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 */
+}
+
+/*
+ * This controls what symbols we export from the DSO.
+ */
+VERSION
+{
+	LINUX_2.6.39 {
+	global:
+		__kernel_rt_sigreturn;
+		__kernel_gettimeofday;
+		__kernel_clock_gettime;
+		__kernel_clock_getres;
+		__kernel_getrandom;
+	local: *;
+	};
+}
+
+/*
+ * Make the sigreturn code visible to the kernel.
+ */
+VDSO_sigtramp		= __kernel_rt_sigreturn;

linux-7.2.3/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(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[3,0,1,2] */
+	ext		state1.16b, state1.16b, state1.16b, #12
+	/* 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, #4
+
+	subs		w4, w4, #2
+	b.ne		.Ldoubleround
+
+	/* output0 = state0 + state0 */
+	add		state0.4s, state0.4s, copy0.4s
+	/* output1 = state1 + state1 */
+	add		state1.4s, state1.4s, copy1.4s
+	/* output2 = state2 + state2 */
+	add		state2.4s, state2.4s, copy2.4s
+	/* output2 = state3 + state3 */
+	add		state3.4s, state3.4s, copy3.4s
+	st1		{ state0.16b - state3.16b }, [x0]
+
+	/*
+	 * ++copy3.counter, the 'add' clears the upper half of the SIMD register
+	 * which is the expected behaviour here.
+	 */
+	add		copy3_d, copy3_d, one_d
+
+	/* output += 64, --nblocks */
+	add		x0, x0, 64
+	subs		x3, x3, #1
+	b.ne		.Lblock
+
+	/* counter = copy3.counter */
+	st1		{ copy3.2s }, [x2]
+
+	/* Zero out the potentially sensitive regs, in case nothing uses these again. */
+	movi		state0.16b, #0
+	movi		state1.16b, #0
+	movi		state2.16b, #0
+	movi		state3.16b, #0
+	movi		copy1.16b, #0
+	movi		copy2.16b, #0
+	ret
+SYM_FUNC_END(__arch_chacha20_blocks_nostack)
+
+emit_aarch64_feature_1_and

linux-7.2.3/arch/arm64/kernel/vdso/vgetrandom.c

@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <uapi/asm-generic/errno.h>
+
+typeof(__cvdso_getrandom) __kernel_getrandom;
+
+ssize_t __kernel_getrandom(void *buffer, size_t len, unsigned int flags, void *opaque_state, size_t opaque_len)
+{
+	if (alternative_has_cap_likely(ARM64_HAS_FPSIMD))
+		return __cvdso_getrandom(buffer, len, flags, opaque_state, opaque_len);
+
+	if (unlikely(opaque_len == ~0UL && !buffer && !len && !flags))
+		return -ENOSYS;
+	return getrandom_syscall(buffer, len, flags);
+}

linux-7.2.3/arch/arm64/kernel/vdso/vgettimeofday.c

@@ -0,0 +1,29 @@
+// 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);
+int __kernel_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz);
+int __kernel_clock_getres(clockid_t clock_id, struct __kernel_timespec *res);
+
+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);
+}