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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
commit | ace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch) | |
tree | b2d64bc10158fdd5497876388cd68142ca374ed3 /lib/ubsan.c | |
parent | Initial commit. (diff) | |
download | linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip |
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'lib/ubsan.c')
-rw-r--r-- | lib/ubsan.c | 454 |
1 files changed, 454 insertions, 0 deletions
diff --git a/lib/ubsan.c b/lib/ubsan.c new file mode 100644 index 0000000000..3f90810f9f --- /dev/null +++ b/lib/ubsan.c @@ -0,0 +1,454 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * UBSAN error reporting functions + * + * Copyright (c) 2014 Samsung Electronics Co., Ltd. + * Author: Andrey Ryabinin <ryabinin.a.a@gmail.com> + */ + +#include <linux/bitops.h> +#include <linux/bug.h> +#include <linux/ctype.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/types.h> +#include <linux/sched.h> +#include <linux/uaccess.h> +#include <linux/ubsan.h> +#include <kunit/test-bug.h> + +#include "ubsan.h" + +#ifdef CONFIG_UBSAN_TRAP +/* + * Only include matches for UBSAN checks that are actually compiled in. + * The mappings of struct SanitizerKind (the -fsanitize=xxx args) to + * enum SanitizerHandler (the traps) in Clang is in clang/lib/CodeGen/. + */ +const char *report_ubsan_failure(struct pt_regs *regs, u32 check_type) +{ + switch (check_type) { +#ifdef CONFIG_UBSAN_BOUNDS + /* + * SanitizerKind::ArrayBounds and SanitizerKind::LocalBounds + * emit SanitizerHandler::OutOfBounds. + */ + case ubsan_out_of_bounds: + return "UBSAN: array index out of bounds"; +#endif +#ifdef CONFIG_UBSAN_SHIFT + /* + * SanitizerKind::ShiftBase and SanitizerKind::ShiftExponent + * emit SanitizerHandler::ShiftOutOfBounds. + */ + case ubsan_shift_out_of_bounds: + return "UBSAN: shift out of bounds"; +#endif +#ifdef CONFIG_UBSAN_DIV_ZERO + /* + * SanitizerKind::IntegerDivideByZero emits + * SanitizerHandler::DivremOverflow. + */ + case ubsan_divrem_overflow: + return "UBSAN: divide/remainder overflow"; +#endif +#ifdef CONFIG_UBSAN_UNREACHABLE + /* + * SanitizerKind::Unreachable emits + * SanitizerHandler::BuiltinUnreachable. + */ + case ubsan_builtin_unreachable: + return "UBSAN: unreachable code"; +#endif +#if defined(CONFIG_UBSAN_BOOL) || defined(CONFIG_UBSAN_ENUM) + /* + * SanitizerKind::Bool and SanitizerKind::Enum emit + * SanitizerHandler::LoadInvalidValue. + */ + case ubsan_load_invalid_value: + return "UBSAN: loading invalid value"; +#endif +#ifdef CONFIG_UBSAN_ALIGNMENT + /* + * SanitizerKind::Alignment emits SanitizerHandler::TypeMismatch + * or SanitizerHandler::AlignmentAssumption. + */ + case ubsan_alignment_assumption: + return "UBSAN: alignment assumption"; + case ubsan_type_mismatch: + return "UBSAN: type mismatch"; +#endif + default: + return "UBSAN: unrecognized failure code"; + } +} + +#else +static const char * const type_check_kinds[] = { + "load of", + "store to", + "reference binding to", + "member access within", + "member call on", + "constructor call on", + "downcast of", + "downcast of" +}; + +#define REPORTED_BIT 31 + +#if (BITS_PER_LONG == 64) && defined(__BIG_ENDIAN) +#define COLUMN_MASK (~(1U << REPORTED_BIT)) +#define LINE_MASK (~0U) +#else +#define COLUMN_MASK (~0U) +#define LINE_MASK (~(1U << REPORTED_BIT)) +#endif + +#define VALUE_LENGTH 40 + +static bool was_reported(struct source_location *location) +{ + return test_and_set_bit(REPORTED_BIT, &location->reported); +} + +static bool suppress_report(struct source_location *loc) +{ + return current->in_ubsan || was_reported(loc); +} + +static bool type_is_int(struct type_descriptor *type) +{ + return type->type_kind == type_kind_int; +} + +static bool type_is_signed(struct type_descriptor *type) +{ + WARN_ON(!type_is_int(type)); + return type->type_info & 1; +} + +static unsigned type_bit_width(struct type_descriptor *type) +{ + return 1 << (type->type_info >> 1); +} + +static bool is_inline_int(struct type_descriptor *type) +{ + unsigned inline_bits = sizeof(unsigned long)*8; + unsigned bits = type_bit_width(type); + + WARN_ON(!type_is_int(type)); + + return bits <= inline_bits; +} + +static s_max get_signed_val(struct type_descriptor *type, void *val) +{ + if (is_inline_int(type)) { + unsigned extra_bits = sizeof(s_max)*8 - type_bit_width(type); + unsigned long ulong_val = (unsigned long)val; + + return ((s_max)ulong_val) << extra_bits >> extra_bits; + } + + if (type_bit_width(type) == 64) + return *(s64 *)val; + + return *(s_max *)val; +} + +static bool val_is_negative(struct type_descriptor *type, void *val) +{ + return type_is_signed(type) && get_signed_val(type, val) < 0; +} + +static u_max get_unsigned_val(struct type_descriptor *type, void *val) +{ + if (is_inline_int(type)) + return (unsigned long)val; + + if (type_bit_width(type) == 64) + return *(u64 *)val; + + return *(u_max *)val; +} + +static void val_to_string(char *str, size_t size, struct type_descriptor *type, + void *value) +{ + if (type_is_int(type)) { + if (type_bit_width(type) == 128) { +#if defined(CONFIG_ARCH_SUPPORTS_INT128) + u_max val = get_unsigned_val(type, value); + + scnprintf(str, size, "0x%08x%08x%08x%08x", + (u32)(val >> 96), + (u32)(val >> 64), + (u32)(val >> 32), + (u32)(val)); +#else + WARN_ON(1); +#endif + } else if (type_is_signed(type)) { + scnprintf(str, size, "%lld", + (s64)get_signed_val(type, value)); + } else { + scnprintf(str, size, "%llu", + (u64)get_unsigned_val(type, value)); + } + } +} + +static void ubsan_prologue(struct source_location *loc, const char *reason) +{ + current->in_ubsan++; + + pr_err("========================================" + "========================================\n"); + pr_err("UBSAN: %s in %s:%d:%d\n", reason, loc->file_name, + loc->line & LINE_MASK, loc->column & COLUMN_MASK); + + kunit_fail_current_test("%s in %s", reason, loc->file_name); +} + +static void ubsan_epilogue(void) +{ + dump_stack(); + pr_err("========================================" + "========================================\n"); + + current->in_ubsan--; + + check_panic_on_warn("UBSAN"); +} + +void __ubsan_handle_divrem_overflow(void *_data, void *lhs, void *rhs) +{ + struct overflow_data *data = _data; + char rhs_val_str[VALUE_LENGTH]; + + if (suppress_report(&data->location)) + return; + + ubsan_prologue(&data->location, "division-overflow"); + + val_to_string(rhs_val_str, sizeof(rhs_val_str), data->type, rhs); + + if (type_is_signed(data->type) && get_signed_val(data->type, rhs) == -1) + pr_err("division of %s by -1 cannot be represented in type %s\n", + rhs_val_str, data->type->type_name); + else + pr_err("division by zero\n"); + + ubsan_epilogue(); +} +EXPORT_SYMBOL(__ubsan_handle_divrem_overflow); + +static void handle_null_ptr_deref(struct type_mismatch_data_common *data) +{ + if (suppress_report(data->location)) + return; + + ubsan_prologue(data->location, "null-ptr-deref"); + + pr_err("%s null pointer of type %s\n", + type_check_kinds[data->type_check_kind], + data->type->type_name); + + ubsan_epilogue(); +} + +static void handle_misaligned_access(struct type_mismatch_data_common *data, + unsigned long ptr) +{ + if (suppress_report(data->location)) + return; + + ubsan_prologue(data->location, "misaligned-access"); + + pr_err("%s misaligned address %p for type %s\n", + type_check_kinds[data->type_check_kind], + (void *)ptr, data->type->type_name); + pr_err("which requires %ld byte alignment\n", data->alignment); + + ubsan_epilogue(); +} + +static void handle_object_size_mismatch(struct type_mismatch_data_common *data, + unsigned long ptr) +{ + if (suppress_report(data->location)) + return; + + ubsan_prologue(data->location, "object-size-mismatch"); + pr_err("%s address %p with insufficient space\n", + type_check_kinds[data->type_check_kind], + (void *) ptr); + pr_err("for an object of type %s\n", data->type->type_name); + ubsan_epilogue(); +} + +static void ubsan_type_mismatch_common(struct type_mismatch_data_common *data, + unsigned long ptr) +{ + unsigned long flags = user_access_save(); + + if (!ptr) + handle_null_ptr_deref(data); + else if (data->alignment && !IS_ALIGNED(ptr, data->alignment)) + handle_misaligned_access(data, ptr); + else + handle_object_size_mismatch(data, ptr); + + user_access_restore(flags); +} + +void __ubsan_handle_type_mismatch(struct type_mismatch_data *data, + void *ptr) +{ + struct type_mismatch_data_common common_data = { + .location = &data->location, + .type = data->type, + .alignment = data->alignment, + .type_check_kind = data->type_check_kind + }; + + ubsan_type_mismatch_common(&common_data, (unsigned long)ptr); +} +EXPORT_SYMBOL(__ubsan_handle_type_mismatch); + +void __ubsan_handle_type_mismatch_v1(void *_data, void *ptr) +{ + struct type_mismatch_data_v1 *data = _data; + struct type_mismatch_data_common common_data = { + .location = &data->location, + .type = data->type, + .alignment = 1UL << data->log_alignment, + .type_check_kind = data->type_check_kind + }; + + ubsan_type_mismatch_common(&common_data, (unsigned long)ptr); +} +EXPORT_SYMBOL(__ubsan_handle_type_mismatch_v1); + +void __ubsan_handle_out_of_bounds(void *_data, void *index) +{ + struct out_of_bounds_data *data = _data; + char index_str[VALUE_LENGTH]; + + if (suppress_report(&data->location)) + return; + + ubsan_prologue(&data->location, "array-index-out-of-bounds"); + + val_to_string(index_str, sizeof(index_str), data->index_type, index); + pr_err("index %s is out of range for type %s\n", index_str, + data->array_type->type_name); + ubsan_epilogue(); +} +EXPORT_SYMBOL(__ubsan_handle_out_of_bounds); + +void __ubsan_handle_shift_out_of_bounds(void *_data, void *lhs, void *rhs) +{ + struct shift_out_of_bounds_data *data = _data; + struct type_descriptor *rhs_type = data->rhs_type; + struct type_descriptor *lhs_type = data->lhs_type; + char rhs_str[VALUE_LENGTH]; + char lhs_str[VALUE_LENGTH]; + unsigned long ua_flags = user_access_save(); + + if (suppress_report(&data->location)) + goto out; + + ubsan_prologue(&data->location, "shift-out-of-bounds"); + + val_to_string(rhs_str, sizeof(rhs_str), rhs_type, rhs); + val_to_string(lhs_str, sizeof(lhs_str), lhs_type, lhs); + + if (val_is_negative(rhs_type, rhs)) + pr_err("shift exponent %s is negative\n", rhs_str); + + else if (get_unsigned_val(rhs_type, rhs) >= + type_bit_width(lhs_type)) + pr_err("shift exponent %s is too large for %u-bit type %s\n", + rhs_str, + type_bit_width(lhs_type), + lhs_type->type_name); + else if (val_is_negative(lhs_type, lhs)) + pr_err("left shift of negative value %s\n", + lhs_str); + else + pr_err("left shift of %s by %s places cannot be" + " represented in type %s\n", + lhs_str, rhs_str, + lhs_type->type_name); + + ubsan_epilogue(); +out: + user_access_restore(ua_flags); +} +EXPORT_SYMBOL(__ubsan_handle_shift_out_of_bounds); + + +void __ubsan_handle_builtin_unreachable(void *_data) +{ + struct unreachable_data *data = _data; + ubsan_prologue(&data->location, "unreachable"); + pr_err("calling __builtin_unreachable()\n"); + ubsan_epilogue(); + panic("can't return from __builtin_unreachable()"); +} +EXPORT_SYMBOL(__ubsan_handle_builtin_unreachable); + +void __ubsan_handle_load_invalid_value(void *_data, void *val) +{ + struct invalid_value_data *data = _data; + char val_str[VALUE_LENGTH]; + unsigned long ua_flags = user_access_save(); + + if (suppress_report(&data->location)) + goto out; + + ubsan_prologue(&data->location, "invalid-load"); + + val_to_string(val_str, sizeof(val_str), data->type, val); + + pr_err("load of value %s is not a valid value for type %s\n", + val_str, data->type->type_name); + + ubsan_epilogue(); +out: + user_access_restore(ua_flags); +} +EXPORT_SYMBOL(__ubsan_handle_load_invalid_value); + +void __ubsan_handle_alignment_assumption(void *_data, unsigned long ptr, + unsigned long align, + unsigned long offset) +{ + struct alignment_assumption_data *data = _data; + unsigned long real_ptr; + + if (suppress_report(&data->location)) + return; + + ubsan_prologue(&data->location, "alignment-assumption"); + + if (offset) + pr_err("assumption of %lu byte alignment (with offset of %lu byte) for pointer of type %s failed", + align, offset, data->type->type_name); + else + pr_err("assumption of %lu byte alignment for pointer of type %s failed", + align, data->type->type_name); + + real_ptr = ptr - offset; + pr_err("%saddress is %lu aligned, misalignment offset is %lu bytes", + offset ? "offset " : "", BIT(real_ptr ? __ffs(real_ptr) : 0), + real_ptr & (align - 1)); + + ubsan_epilogue(); +} +EXPORT_SYMBOL(__ubsan_handle_alignment_assumption); + +#endif /* !CONFIG_UBSAN_TRAP */ |