From a8c55407a7230798eb157ed2cf5398a6a2b123b6 Mon Sep 17 00:00:00 2001 From: Andy Shevchenko Date: Fri, 27 Jan 2023 17:51:35 +0200 Subject: lib/string: Use strchr() in strpbrk() Use strchr() instead of open coding it as it's done elsewhere in the same file. Either we will have similar to what it was or possibly better performance in case architecture implements its own strchr(). Memory wise on x86_64 bloat-o-meter shows the following Function old new delta strsep 111 102 -9 Total: Before=2763, After=2754, chg -0.33% Signed-off-by: Andy Shevchenko Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20230127155135.27153-1-andriy.shevchenko@linux.intel.com --- lib/string.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) (limited to 'lib') diff --git a/lib/string.c b/lib/string.c index 4fb566ea610f..3d55ef890106 100644 --- a/lib/string.c +++ b/lib/string.c @@ -480,13 +480,11 @@ EXPORT_SYMBOL(strcspn); */ char *strpbrk(const char *cs, const char *ct) { - const char *sc1, *sc2; + const char *sc; - for (sc1 = cs; *sc1 != '\0'; ++sc1) { - for (sc2 = ct; *sc2 != '\0'; ++sc2) { - if (*sc1 == *sc2) - return (char *)sc1; - } + for (sc = cs; *sc != '\0'; ++sc) { + if (strchr(ct, *sc)) + return (char *)sc; } return NULL; } -- cgit v1.2.3 From 25b84002afb9dc9a91a7ea67166879c13ad82422 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Thu, 2 Feb 2023 22:07:49 +0000 Subject: arm64: Support Clang UBSAN trap codes for better reporting When building with CONFIG_UBSAN_TRAP=y on arm64, Clang encodes the UBSAN check (handler) type in the esr. Extract this and actually report these traps as coming from the specific UBSAN check that tripped. Before: Internal error: BRK handler: 00000000f20003e8 [#1] PREEMPT SMP After: Internal error: UBSAN: shift out of bounds: 00000000f2005514 [#1] PREEMPT SMP Acked-by: Mark Rutland Reviewed-by: Ard Biesheuvel Acked-by: Mukesh Ojha Reviewed-by: Fangrui Song Cc: Catalin Marinas Cc: Will Deacon Cc: John Stultz Cc: Yongqin Liu Cc: Sami Tolvanen Cc: Yury Norov Cc: Andrey Konovalov Cc: Marco Elver Cc: linux-arm-kernel@lists.infradead.org Cc: llvm@lists.linux.dev Signed-off-by: Kees Cook --- arch/arm64/include/asm/brk-imm.h | 3 ++ arch/arm64/kernel/traps.c | 21 +++++++++++++ include/linux/ubsan.h | 9 ++++++ lib/Makefile | 2 -- lib/ubsan.c | 68 ++++++++++++++++++++++++++++++++++++++++ lib/ubsan.h | 32 +++++++++++++++++++ 6 files changed, 133 insertions(+), 2 deletions(-) create mode 100644 include/linux/ubsan.h (limited to 'lib') diff --git a/arch/arm64/include/asm/brk-imm.h b/arch/arm64/include/asm/brk-imm.h index 6e000113e508..1abdcd508a11 100644 --- a/arch/arm64/include/asm/brk-imm.h +++ b/arch/arm64/include/asm/brk-imm.h @@ -17,6 +17,7 @@ * 0x401: for compile time BRK instruction * 0x800: kernel-mode BUG() and WARN() traps * 0x9xx: tag-based KASAN trap (allowed values 0x900 - 0x9ff) + * 0x55xx: Undefined Behavior Sanitizer traps ('U' << 8) * 0x8xxx: Control-Flow Integrity traps */ #define KPROBES_BRK_IMM 0x004 @@ -28,6 +29,8 @@ #define BUG_BRK_IMM 0x800 #define KASAN_BRK_IMM 0x900 #define KASAN_BRK_MASK 0x0ff +#define UBSAN_BRK_IMM 0x5500 +#define UBSAN_BRK_MASK 0x00ff #define CFI_BRK_IMM_TARGET GENMASK(4, 0) #define CFI_BRK_IMM_TYPE GENMASK(9, 5) diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c index 4c0caa589e12..87f42eb1c950 100644 --- a/arch/arm64/kernel/traps.c +++ b/arch/arm64/kernel/traps.c @@ -26,6 +26,7 @@ #include #include #include +#include #include #include @@ -1074,6 +1075,19 @@ static struct break_hook kasan_break_hook = { }; #endif +#ifdef CONFIG_UBSAN_TRAP +static int ubsan_handler(struct pt_regs *regs, unsigned long esr) +{ + die(report_ubsan_failure(regs, esr & UBSAN_BRK_MASK), regs, esr); + return DBG_HOOK_HANDLED; +} + +static struct break_hook ubsan_break_hook = { + .fn = ubsan_handler, + .imm = UBSAN_BRK_IMM, + .mask = UBSAN_BRK_MASK, +}; +#endif #define esr_comment(esr) ((esr) & ESR_ELx_BRK64_ISS_COMMENT_MASK) @@ -1091,6 +1105,10 @@ int __init early_brk64(unsigned long addr, unsigned long esr, #ifdef CONFIG_KASAN_SW_TAGS if ((esr_comment(esr) & ~KASAN_BRK_MASK) == KASAN_BRK_IMM) return kasan_handler(regs, esr) != DBG_HOOK_HANDLED; +#endif +#ifdef CONFIG_UBSAN_TRAP + if ((esr_comment(esr) & ~UBSAN_BRK_MASK) == UBSAN_BRK_IMM) + return ubsan_handler(regs, esr) != DBG_HOOK_HANDLED; #endif return bug_handler(regs, esr) != DBG_HOOK_HANDLED; } @@ -1104,6 +1122,9 @@ void __init trap_init(void) register_kernel_break_hook(&fault_break_hook); #ifdef CONFIG_KASAN_SW_TAGS register_kernel_break_hook(&kasan_break_hook); +#endif +#ifdef CONFIG_UBSAN_TRAP + register_kernel_break_hook(&ubsan_break_hook); #endif debug_traps_init(); } diff --git a/include/linux/ubsan.h b/include/linux/ubsan.h new file mode 100644 index 000000000000..bff7445498de --- /dev/null +++ b/include/linux/ubsan.h @@ -0,0 +1,9 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _LINUX_UBSAN_H +#define _LINUX_UBSAN_H + +#ifdef CONFIG_UBSAN_TRAP +const char *report_ubsan_failure(struct pt_regs *regs, u32 check_type); +#endif + +#endif diff --git a/lib/Makefile b/lib/Makefile index 4d9461bfea42..81b988bf9448 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -340,9 +340,7 @@ quiet_cmd_build_OID_registry = GEN $@ clean-files += oid_registry_data.c obj-$(CONFIG_UCS2_STRING) += ucs2_string.o -ifneq ($(CONFIG_UBSAN_TRAP),y) obj-$(CONFIG_UBSAN) += ubsan.o -endif UBSAN_SANITIZE_ubsan.o := n KASAN_SANITIZE_ubsan.o := n diff --git a/lib/ubsan.c b/lib/ubsan.c index 60c7099857a0..6620e0719c9d 100644 --- a/lib/ubsan.c +++ b/lib/ubsan.c @@ -14,10 +14,76 @@ #include #include #include +#include #include #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", @@ -384,3 +450,5 @@ void __ubsan_handle_alignment_assumption(void *_data, unsigned long ptr, ubsan_epilogue(); } EXPORT_SYMBOL(__ubsan_handle_alignment_assumption); + +#endif /* !CONFIG_UBSAN_TRAP */ diff --git a/lib/ubsan.h b/lib/ubsan.h index 9a0b71c5ff9f..cc5cb94895a6 100644 --- a/lib/ubsan.h +++ b/lib/ubsan.h @@ -2,6 +2,38 @@ #ifndef _LIB_UBSAN_H #define _LIB_UBSAN_H +/* + * ABI defined by Clang's UBSAN enum SanitizerHandler: + * https://github.com/llvm/llvm-project/blob/release/16.x/clang/lib/CodeGen/CodeGenFunction.h#L113 + */ +enum ubsan_checks { + ubsan_add_overflow, + ubsan_builtin_unreachable, + ubsan_cfi_check_fail, + ubsan_divrem_overflow, + ubsan_dynamic_type_cache_miss, + ubsan_float_cast_overflow, + ubsan_function_type_mismatch, + ubsan_implicit_conversion, + ubsan_invalid_builtin, + ubsan_invalid_objc_cast, + ubsan_load_invalid_value, + ubsan_missing_return, + ubsan_mul_overflow, + ubsan_negate_overflow, + ubsan_nullability_arg, + ubsan_nullability_return, + ubsan_nonnull_arg, + ubsan_nonnull_return, + ubsan_out_of_bounds, + ubsan_pointer_overflow, + ubsan_shift_out_of_bounds, + ubsan_sub_overflow, + ubsan_type_mismatch, + ubsan_alignment_assumption, + ubsan_vla_bound_not_positive, +}; + enum { type_kind_int = 0, type_kind_float = 1, -- cgit v1.2.3