Merge 15201a8789 into 0fc810ae3a

The barrier_nospec() in 64-bit copy_from_user() is slow. Instead use
pointer masking to force the user pointer to all 1's for an invalid
address.

The kernel test robot reports a 2.6% improvement in the per_thread_ops
benchmark [1].

This is a variation on a patch originally by Josh Poimboeuf [2].

Link: https://lore.kernel.org/202410281344.d02c72a2-oliver.sang@intel.com [1]
Link: https://lore.kernel.org/5b887fe4c580214900e21f6c61095adf9a142735.1730166635.git.jpoimboe@kernel.org [2]
Tested-and-reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

CODE_OF_CONDUCT.md

@@ -0,0 +1,128 @@
+# Contributor Covenant Code of Conduct
+
+## Our Pledge
+
+We as members, contributors, and leaders pledge to make participation in our
+community a harassment-free experience for everyone, regardless of age, body
+size, visible or invisible disability, ethnicity, sex characteristics, gender
+identity and expression, level of experience, education, socio-economic status,
+nationality, personal appearance, race, religion, or sexual identity
+and orientation.
+
+We pledge to act and interact in ways that contribute to an open, welcoming,
+diverse, inclusive, and healthy community.
+
+## Our Standards
+
+Examples of behavior that contributes to a positive environment for our
+community include:
+
+* Demonstrating empathy and kindness toward other people
+* Being respectful of differing opinions, viewpoints, and experiences
+* Giving and gracefully accepting constructive feedback
+* Accepting responsibility and apologizing to those affected by our mistakes,
+  and learning from the experience
+* Focusing on what is best not just for us as individuals, but for the
+  overall community
+
+Examples of unacceptable behavior include:
+
+* The use of sexualized language or imagery, and sexual attention or
+  advances of any kind
+* Trolling, insulting or derogatory comments, and personal or political attacks
+* Public or private harassment
+* Publishing others' private information, such as a physical or email
+  address, without their explicit permission
+* Other conduct which could reasonably be considered inappropriate in a
+  professional setting
+
+## Enforcement Responsibilities
+
+Community leaders are responsible for clarifying and enforcing our standards of
+acceptable behavior and will take appropriate and fair corrective action in
+response to any behavior that they deem inappropriate, threatening, offensive,
+or harmful.
+
+Community leaders have the right and responsibility to remove, edit, or reject
+comments, commits, code, wiki edits, issues, and other contributions that are
+not aligned to this Code of Conduct, and will communicate reasons for moderation
+decisions when appropriate.
+
+## Scope
+
+This Code of Conduct applies within all community spaces, and also applies when
+an individual is officially representing the community in public spaces.
+Examples of representing our community include using an official e-mail address,
+posting via an official social media account, or acting as an appointed
+representative at an online or offline event.
+
+## Enforcement
+
+Instances of abusive, harassing, or otherwise unacceptable behavior may be
+reported to the community leaders responsible for enforcement at
+torvalds@osdl.org.
+All complaints will be reviewed and investigated promptly and fairly.
+
+All community leaders are obligated to respect the privacy and security of the
+reporter of any incident.
+
+## Enforcement Guidelines
+
+Community leaders will follow these Community Impact Guidelines in determining
+the consequences for any action they deem in violation of this Code of Conduct:
+
+### 1. Correction
+
+**Community Impact**: Use of inappropriate language or other behavior deemed
+unprofessional or unwelcome in the community.
+
+**Consequence**: A private, written warning from community leaders, providing
+clarity around the nature of the violation and an explanation of why the
+behavior was inappropriate. A public apology may be requested.
+
+### 2. Warning
+
+**Community Impact**: A violation through a single incident or series
+of actions.
+
+**Consequence**: A warning with consequences for continued behavior. No
+interaction with the people involved, including unsolicited interaction with
+those enforcing the Code of Conduct, for a specified period of time. This
+includes avoiding interactions in community spaces as well as external channels
+like social media. Violating these terms may lead to a temporary or
+permanent ban.
+
+### 3. Temporary Ban
+
+**Community Impact**: A serious violation of community standards, including
+sustained inappropriate behavior.
+
+**Consequence**: A temporary ban from any sort of interaction or public
+communication with the community for a specified period of time. No public or
+private interaction with the people involved, including unsolicited interaction
+with those enforcing the Code of Conduct, is allowed during this period.
+Violating these terms may lead to a permanent ban.
+
+### 4. Permanent Ban
+
+**Community Impact**: Demonstrating a pattern of violation of community
+standards, including sustained inappropriate behavior,  harassment of an
+individual, or aggression toward or disparagement of classes of individuals.
+
+**Consequence**: A permanent ban from any sort of public interaction within
+the community.
+
+## Attribution
+
+This Code of Conduct is adapted from the [Contributor Covenant][homepage],
+version 2.0, available at
+https://www.contributor-covenant.org/version/2/0/code_of_conduct.html.
+
+Community Impact Guidelines were inspired by [Mozilla's code of conduct
+enforcement ladder](https://github.com/mozilla/diversity).
+
+[homepage]: https://www.contributor-covenant.org
+
+For answers to common questions about this code of conduct, see the FAQ at
+https://www.contributor-covenant.org/faq. Translations are available at
+https://www.contributor-covenant.org/translations.

include/linux/uaccess.h

@@ -38,6 +38,7 @@
 #else
  #define can_do_masked_user_access() 0
  #define masked_user_access_begin(src) NULL
+ #define mask_user_address(src) (src)
 #endif
 
 /*
@@ -159,18 +160,26 @@ _inline_copy_from_user(void *to, const void __user *from, unsigned long n)
 {
 	unsigned long res = n;
 	might_fault();
-	if (!should_fail_usercopy() && likely(access_ok(from, n))) {
+	if (should_fail_usercopy())
+		goto fail;
+	if (can_do_masked_user_access())
+		from = mask_user_address(from);
+	else {
+		if (!access_ok(from, n))
+			goto fail;
 		/*
 		 * Ensure that bad access_ok() speculation will not
 		 * lead to nasty side effects *after* the copy is
 		 * finished:
 		 */
 		barrier_nospec();
+	}
 	instrument_copy_from_user_before(to, from, n);
 	res = raw_copy_from_user(to, from, n);
 	instrument_copy_from_user_after(to, from, n, res);
-	}
-	if (unlikely(res))
+	if (likely(!res))
+		return 0;
+fail:
 	memset(to + (n - res), 0, res);
 	return res;
 }

tools/arch/arm64/include/asm/cputype.h

@@ -94,6 +94,7 @@
 #define ARM_CPU_PART_NEOVERSE_V3	0xD84
 #define ARM_CPU_PART_CORTEX_X925	0xD85
 #define ARM_CPU_PART_CORTEX_A725	0xD87
+#define ARM_CPU_PART_NEOVERSE_N3	0xD8E
 
 #define APM_CPU_PART_XGENE		0x000
 #define APM_CPU_VAR_POTENZA		0x00
@@ -176,6 +177,7 @@
 #define MIDR_NEOVERSE_V3 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_NEOVERSE_V3)
 #define MIDR_CORTEX_X925 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_X925)
 #define MIDR_CORTEX_A725 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_A725)
+#define MIDR_NEOVERSE_N3 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_NEOVERSE_N3)
 #define MIDR_THUNDERX	MIDR_CPU_MODEL(ARM_CPU_IMP_CAVIUM, CAVIUM_CPU_PART_THUNDERX)
 #define MIDR_THUNDERX_81XX MIDR_CPU_MODEL(ARM_CPU_IMP_CAVIUM, CAVIUM_CPU_PART_THUNDERX_81XX)
 #define MIDR_THUNDERX_83XX MIDR_CPU_MODEL(ARM_CPU_IMP_CAVIUM, CAVIUM_CPU_PART_THUNDERX_83XX)

tools/arch/x86/include/asm/msr-index.h

@@ -36,6 +36,20 @@
 #define EFER_FFXSR		(1<<_EFER_FFXSR)
 #define EFER_AUTOIBRS		(1<<_EFER_AUTOIBRS)
 
+/*
+ * Architectural memory types that are common to MTRRs, PAT, VMX MSRs, etc.
+ * Most MSRs support/allow only a subset of memory types, but the values
+ * themselves are common across all relevant MSRs.
+ */
+#define X86_MEMTYPE_UC		0ull	/* Uncacheable, a.k.a. Strong Uncacheable */
+#define X86_MEMTYPE_WC		1ull	/* Write Combining */
+/* RESERVED			2 */
+/* RESERVED			3 */
+#define X86_MEMTYPE_WT		4ull	/* Write Through */
+#define X86_MEMTYPE_WP		5ull	/* Write Protected */
+#define X86_MEMTYPE_WB		6ull	/* Write Back */
+#define X86_MEMTYPE_UC_MINUS	7ull	/* Weak Uncacheabled (PAT only) */
+
 /* FRED MSRs */
 #define MSR_IA32_FRED_RSP0	0x1cc			/* Level 0 stack pointer */
 #define MSR_IA32_FRED_RSP1	0x1cd			/* Level 1 stack pointer */
@@ -365,6 +379,12 @@
 
 #define MSR_IA32_CR_PAT			0x00000277
 
+#define PAT_VALUE(p0, p1, p2, p3, p4, p5, p6, p7)			\
+	((X86_MEMTYPE_ ## p0)      | (X86_MEMTYPE_ ## p1 << 8)  |	\
+	(X86_MEMTYPE_ ## p2 << 16) | (X86_MEMTYPE_ ## p3 << 24) |	\
+	(X86_MEMTYPE_ ## p4 << 32) | (X86_MEMTYPE_ ## p5 << 40) |	\
+	(X86_MEMTYPE_ ## p6 << 48) | (X86_MEMTYPE_ ## p7 << 56))
+
 #define MSR_IA32_DEBUGCTLMSR		0x000001d9
 #define MSR_IA32_LASTBRANCHFROMIP	0x000001db
 #define MSR_IA32_LASTBRANCHTOIP		0x000001dc
@@ -1159,15 +1179,6 @@
 #define MSR_IA32_VMX_VMFUNC             0x00000491
 #define MSR_IA32_VMX_PROCBASED_CTLS3	0x00000492
 
-/* VMX_BASIC bits and bitmasks */
-#define VMX_BASIC_VMCS_SIZE_SHIFT	32
-#define VMX_BASIC_TRUE_CTLS		(1ULL << 55)
-#define VMX_BASIC_64		0x0001000000000000LLU
-#define VMX_BASIC_MEM_TYPE_SHIFT	50
-#define VMX_BASIC_MEM_TYPE_MASK	0x003c000000000000LLU
-#define VMX_BASIC_MEM_TYPE_WB	6LLU
-#define VMX_BASIC_INOUT		0x0040000000000000LLU
-
 /* Resctrl MSRs: */
 /* - Intel: */
 #define MSR_IA32_L3_QOS_CFG		0xc81
@@ -1185,11 +1196,6 @@
 #define MSR_IA32_SMBA_BW_BASE		0xc0000280
 #define MSR_IA32_EVT_CFG_BASE		0xc0000400
 
-/* MSR_IA32_VMX_MISC bits */
-#define MSR_IA32_VMX_MISC_INTEL_PT                 (1ULL << 14)
-#define MSR_IA32_VMX_MISC_VMWRITE_SHADOW_RO_FIELDS (1ULL << 29)
-#define MSR_IA32_VMX_MISC_PREEMPTION_TIMER_SCALE   0x1F
-
 /* AMD-V MSRs */
 #define MSR_VM_CR                       0xc0010114
 #define MSR_VM_IGNNE                    0xc0010115

tools/arch/x86/include/uapi/asm/kvm.h

@@ -439,6 +439,7 @@ struct kvm_sync_regs {
 #define KVM_X86_QUIRK_MISC_ENABLE_NO_MWAIT	(1 << 4)
 #define KVM_X86_QUIRK_FIX_HYPERCALL_INSN	(1 << 5)
 #define KVM_X86_QUIRK_MWAIT_NEVER_UD_FAULTS	(1 << 6)
+#define KVM_X86_QUIRK_SLOT_ZAP_ALL		(1 << 7)
 
 #define KVM_STATE_NESTED_FORMAT_VMX	0
 #define KVM_STATE_NESTED_FORMAT_SVM	1

tools/arch/x86/include/uapi/asm/unistd_32.h

@@ -11,6 +11,9 @@
 #ifndef __NR_getpgid
 #define __NR_getpgid 132
 #endif
+#ifndef __NR_capget
+#define __NR_capget 184
+#endif
 #ifndef __NR_gettid
 #define __NR_gettid 224
 #endif

tools/arch/x86/include/uapi/asm/unistd_64.h

@@ -11,6 +11,9 @@
 #ifndef __NR_getpgid
 #define __NR_getpgid 121
 #endif
+#ifndef __NR_capget
+#define __NR_capget 125
+#endif
 #ifndef __NR_gettid
 #define __NR_gettid 186
 #endif

tools/include/linux/bits.h

@@ -36,4 +36,19 @@
 #define GENMASK_ULL(h, l) \
 	(GENMASK_INPUT_CHECK(h, l) + __GENMASK_ULL(h, l))
 
+#if !defined(__ASSEMBLY__)
+/*
+ * Missing asm support
+ *
+ * __GENMASK_U128() depends on _BIT128() which would not work
+ * in the asm code, as it shifts an 'unsigned __init128' data
+ * type instead of direct representation of 128 bit constants
+ * such as long and unsigned long. The fundamental problem is
+ * that a 128 bit constant will get silently truncated by the
+ * gcc compiler.
+ */
+#define GENMASK_U128(h, l) \
+	(GENMASK_INPUT_CHECK(h, l) + __GENMASK_U128(h, l))
+#endif
+
 #endif	/* __LINUX_BITS_H */

tools/include/linux/unaligned.h

@@ -9,16 +9,7 @@
 #pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wpacked"
 #pragma GCC diagnostic ignored "-Wattributes"
-
-#define __get_unaligned_t(type, ptr) ({						\
-	const struct { type x; } __packed *__pptr = (typeof(__pptr))(ptr);	\
-	__pptr->x;								\
-})
-
-#define __put_unaligned_t(type, val, ptr) do {					\
-	struct { type x; } __packed *__pptr = (typeof(__pptr))(ptr);		\
-	__pptr->x = (val);							\
-} while (0)
+#include <vdso/unaligned.h>
 
 #define get_unaligned(ptr)	__get_unaligned_t(typeof(*(ptr)), (ptr))
 #define put_unaligned(val, ptr) __put_unaligned_t(typeof(*(ptr)), (val), (ptr))

tools/include/uapi/linux/bits.h

@@ -12,4 +12,7 @@
         (((~_ULL(0)) - (_ULL(1) << (l)) + 1) & \
          (~_ULL(0) >> (__BITS_PER_LONG_LONG - 1 - (h))))
 
+#define __GENMASK_U128(h, l) \
+	((_BIT128((h)) << 1) - (_BIT128(l)))
+
 #endif /* _UAPI_LINUX_BITS_H */

tools/include/uapi/linux/const.h

@@ -28,6 +28,23 @@
 #define _BITUL(x)	(_UL(1) << (x))
 #define _BITULL(x)	(_ULL(1) << (x))
 
+#if !defined(__ASSEMBLY__)
+/*
+ * Missing asm support
+ *
+ * __BIT128() would not work in the asm code, as it shifts an
+ * 'unsigned __init128' data type as direct representation of
+ * 128 bit constants is not supported in the gcc compiler, as
+ * they get silently truncated.
+ *
+ * TODO: Please revisit this implementation when gcc compiler
+ * starts representing 128 bit constants directly like long
+ * and unsigned long etc. Subsequently drop the comment for
+ * GENMASK_U128() which would then start supporting asm code.
+ */
+#define _BIT128(x)	((unsigned __int128)(1) << (x))
+#endif
+
 #define __ALIGN_KERNEL(x, a)		__ALIGN_KERNEL_MASK(x, (__typeof__(x))(a) - 1)
 #define __ALIGN_KERNEL_MASK(x, mask)	(((x) + (mask)) & ~(mask))
 

tools/include/vdso/unaligned.h

@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __VDSO_UNALIGNED_H
+#define __VDSO_UNALIGNED_H
+
+#define __get_unaligned_t(type, ptr) ({						\
+	const struct { type x; } __packed *__pptr = (typeof(__pptr))(ptr);	\
+	__pptr->x;								\
+})
+
+#define __put_unaligned_t(type, val, ptr) do {					\
+	struct { type x; } __packed *__pptr = (typeof(__pptr))(ptr);		\
+	__pptr->x = (val);							\
+} while (0)
+
+#endif /* __VDSO_UNALIGNED_H */

tools/perf/Makefile.config

@@ -704,8 +704,8 @@ ifeq ($(BUILD_BPF_SKEL),1)
     BUILD_BPF_SKEL := 0
   else
     CLANG_VERSION := $(shell $(CLANG) --version | head -1 | sed 's/.*clang version \([[:digit:]]\+.[[:digit:]]\+.[[:digit:]]\+\).*/\1/g')
-    ifeq ($(call version-lt3,$(CLANG_VERSION),16.0.6),1)
-      $(warning Warning: Disabled BPF skeletons as at least $(CLANG) version 16.0.6 is reported to be a working setup with the current of BPF based perf features)
+    ifeq ($(call version-lt3,$(CLANG_VERSION),12.0.1),1)
+      $(warning Warning: Disabled BPF skeletons as reliable BTF generation needs at least $(CLANG) version 12.0.1)
       BUILD_BPF_SKEL := 0
     endif
   endif

tools/perf/builtin-trace.c

@@ -1399,7 +1399,7 @@ static const struct syscall_fmt syscall_fmts[] = {
 	  .arg = { [2] = { .scnprintf = SCA_WAITID_OPTIONS, /* options */ }, }, },
 	{ .name	    = "waitid",	    .errpid = true,
 	  .arg = { [3] = { .scnprintf = SCA_WAITID_OPTIONS, /* options */ }, }, },
-	{ .name	    = "write",	    .errpid = true,
+	{ .name	    = "write",
 	  .arg = { [1] = { .scnprintf = SCA_BUF /* buf */, .from_user = true, }, }, },
 };
 

tools/perf/check-headers.sh

@@ -22,6 +22,7 @@ FILES=(
   "include/vdso/bits.h"
   "include/linux/const.h"
   "include/vdso/const.h"
+  "include/vdso/unaligned.h"
   "include/linux/hash.h"
   "include/linux/list-sort.h"
   "include/uapi/linux/hw_breakpoint.h"

tools/perf/tests/shell/base_probe/test_adding_blacklisted.sh

@@ -19,35 +19,74 @@
 TEST_RESULT=0
 
 # skip if not supported
-BLACKFUNC=`head -n 1 /sys/kernel/debug/kprobes/blacklist 2> /dev/null | cut -f2`
-if [ -z "$BLACKFUNC" ]; then
+BLACKFUNC_LIST=`head -n 5 /sys/kernel/debug/kprobes/blacklist 2> /dev/null | cut -f2`
+if [ -z "$BLACKFUNC_LIST" ]; then
 	print_overall_skipped
 	exit 0
 fi
 
+# try to find vmlinux with DWARF debug info
+VMLINUX_FILE=$(perf probe -v random_probe |& grep "Using.*for symbols" | sed -r 's/^Using (.*) for symbols$/\1/')
+
 # remove all previously added probes
 clear_all_probes
 
 
 ### adding blacklisted function
+REGEX_SCOPE_FAIL="Failed to find scope of probe point"
+REGEX_SKIP_MESSAGE=" is blacklisted function, skip it\."
+REGEX_NOT_FOUND_MESSAGE="Probe point \'$RE_EVENT\' not found."
+REGEX_ERROR_MESSAGE="Error: Failed to add events."
+REGEX_INVALID_ARGUMENT="Failed to write event: Invalid argument"
+REGEX_SYMBOL_FAIL="Failed to find symbol at $RE_ADDRESS"
+REGEX_OUT_SECTION="$RE_EVENT is out of \.\w+, skip it"
+REGEX_MISSING_DECL_LINE="A function DIE doesn't have decl_line. Maybe broken DWARF?"
+
+BLACKFUNC=""
+SKIP_DWARF=0
+
+for BLACKFUNC in $BLACKFUNC_LIST; do
+	echo "Probing $BLACKFUNC"
 
 	# functions from blacklist should be skipped by perf probe
 	! $CMD_PERF probe $BLACKFUNC > $LOGS_DIR/adding_blacklisted.log 2> $LOGS_DIR/adding_blacklisted.err
 	PERF_EXIT_CODE=$?
 
-REGEX_SCOPE_FAIL="Failed to find scope of probe point"
-REGEX_SKIP_MESSAGE=" is blacklisted function, skip it\."
-REGEX_NOT_FOUND_MESSAGE="Probe point \'$BLACKFUNC\' not found."
-REGEX_ERROR_MESSAGE="Error: Failed to add events."
-REGEX_INVALID_ARGUMENT="Failed to write event: Invalid argument"
-REGEX_SYMBOL_FAIL="Failed to find symbol at $RE_ADDRESS"
-REGEX_OUT_SECTION="$BLACKFUNC is out of \.\w+, skip it"
+	# check for bad DWARF polluting the result
+	../common/check_all_patterns_found.pl "$REGEX_MISSING_DECL_LINE" >/dev/null < $LOGS_DIR/adding_blacklisted.err
+
+	if [ $? -eq 0 ]; then
+		SKIP_DWARF=1
+		echo "Result polluted by broken DWARF, trying another probe"
+
+		# confirm that the broken DWARF comes from assembler
+		if [ -n "$VMLINUX_FILE" ]; then
+			readelf -wi "$VMLINUX_FILE" |
+			awk -v probe="$BLACKFUNC" '/DW_AT_language/ { comp_lang = $0 }
+						   $0 ~ probe { if (comp_lang) { print comp_lang }; exit }' |
+			grep -q "MIPS assembler"
+
+			CHECK_EXIT_CODE=$?
+			if [ $CHECK_EXIT_CODE -ne 0 ]; then
+				SKIP_DWARF=0 # broken DWARF while available
+				break
+			fi
+		fi
+	else
 		../common/check_all_lines_matched.pl "$REGEX_SKIP_MESSAGE" "$REGEX_NOT_FOUND_MESSAGE" "$REGEX_ERROR_MESSAGE" "$REGEX_SCOPE_FAIL" "$REGEX_INVALID_ARGUMENT" "$REGEX_SYMBOL_FAIL" "$REGEX_OUT_SECTION" < $LOGS_DIR/adding_blacklisted.err
 		CHECK_EXIT_CODE=$?
 
+		SKIP_DWARF=0
+		break
+	fi
+done
+
+if [ $SKIP_DWARF -eq 1 ]; then
+	print_testcase_skipped "adding blacklisted function $BLACKFUNC"
+else
 	print_results $PERF_EXIT_CODE $CHECK_EXIT_CODE "adding blacklisted function $BLACKFUNC"
 	(( TEST_RESULT += $? ))
-
+fi
 
 ### listing not-added probe
 

tools/perf/util/bpf_skel/augmented_raw_syscalls.bpf.c

@@ -288,6 +288,10 @@ int sys_enter_rename(struct syscall_enter_args *args)
 	augmented_args->arg.size = PERF_ALIGN(oldpath_len + 1, sizeof(u64));
 	len += augmented_args->arg.size;
 
+	/* Every read from userspace is limited to value size */
+	if (augmented_args->arg.size > sizeof(augmented_args->arg.value))
+		return 1; /* Failure: don't filter */
+
 	struct augmented_arg *arg2 = (void *)&augmented_args->arg.value + augmented_args->arg.size;
 
 	newpath_len = augmented_arg__read_str(arg2, newpath_arg, sizeof(augmented_args->arg.value));
@@ -315,6 +319,10 @@ int sys_enter_renameat2(struct syscall_enter_args *args)
 	augmented_args->arg.size = PERF_ALIGN(oldpath_len + 1, sizeof(u64));
 	len += augmented_args->arg.size;
 
+	/* Every read from userspace is limited to value size */
+	if (augmented_args->arg.size > sizeof(augmented_args->arg.value))
+		return 1; /* Failure: don't filter */
+
 	struct augmented_arg *arg2 = (void *)&augmented_args->arg.value + augmented_args->arg.size;
 
 	newpath_len = augmented_arg__read_str(arg2, newpath_arg, sizeof(augmented_args->arg.value));
@@ -423,8 +431,9 @@ static bool pid_filter__has(struct pids_filtered *pids, pid_t pid)
 static int augment_sys_enter(void *ctx, struct syscall_enter_args *args)
 {
 	bool augmented, do_output = false;
-	int zero = 0, size, aug_size, index, output = 0,
+	int zero = 0, size, aug_size, index,
 	    value_size = sizeof(struct augmented_arg) - offsetof(struct augmented_arg, value);
+	u64 output = 0; /* has to be u64, otherwise it won't pass the verifier */
 	unsigned int nr, *beauty_map;
 	struct beauty_payload_enter *payload;
 	void *arg, *payload_offset;
@@ -477,6 +486,8 @@ static int augment_sys_enter(void *ctx, struct syscall_enter_args *args)
 				augmented = true;
 		} else if (size < 0 && size >= -6) { /* buffer */
 			index = -(size + 1);
+			barrier_var(index); // Prevent clang (noticed with v18) from removing the &= 7 trick.
+			index &= 7;	    // Satisfy the bounds checking with the verifier in some kernels.
 			aug_size = args->args[index];
 
 			if (aug_size > TRACE_AUG_MAX_BUF)
@@ -488,10 +499,17 @@ static int augment_sys_enter(void *ctx, struct syscall_enter_args *args)
 			}
 		}
 
+		/* Augmented data size is limited to sizeof(augmented_arg->unnamed union with value field) */
+		if (aug_size > value_size)
+			aug_size = value_size;
+
 		/* write data to payload */
 		if (augmented) {
 			int written = offsetof(struct augmented_arg, value) + aug_size;
 
+			if (written < 0 || written > sizeof(struct augmented_arg))
+				return 1;
+
 			((struct augmented_arg *)payload_offset)->size = aug_size;
 			output += written;
 			payload_offset += written;
@@ -499,7 +517,7 @@ static int augment_sys_enter(void *ctx, struct syscall_enter_args *args)
 		}
 	}
 
-	if (!do_output)
+	if (!do_output || (sizeof(struct syscall_enter_args) + output) > sizeof(struct beauty_payload_enter))
 		return 1;
 
 	return augmented__beauty_output(ctx, payload, sizeof(struct syscall_enter_args) + output);

tools/perf/util/cap.c

@@ -7,13 +7,9 @@
 #include "debug.h"
 #include <errno.h>
 #include <string.h>
-#include <unistd.h>
 #include <linux/capability.h>
 #include <sys/syscall.h>
-
-#ifndef SYS_capget
-#define SYS_capget 90
-#endif
+#include <unistd.h>
 
 #define MAX_LINUX_CAPABILITY_U32S _LINUX_CAPABILITY_U32S_3
 
@@ -21,9 +17,9 @@ bool perf_cap__capable(int cap, bool *used_root)
 {
 	struct __user_cap_header_struct header = {
 		.version = _LINUX_CAPABILITY_VERSION_3,
-		.pid = getpid(),
+		.pid = 0,
 	};
-	struct __user_cap_data_struct data[MAX_LINUX_CAPABILITY_U32S];
+	struct __user_cap_data_struct data[MAX_LINUX_CAPABILITY_U32S] = {};
 	__u32 cap_val;
 
 	*used_root = false;

tools/perf/util/python.c

@@ -19,6 +19,7 @@
 #include "util/bpf-filter.h"
 #include "util/env.h"
 #include "util/kvm-stat.h"
+#include "util/stat.h"
 #include "util/kwork.h"
 #include "util/sample.h"
 #include "util/lock-contention.h"
@@ -1355,6 +1356,7 @@ PyMODINIT_FUNC PyInit_perf(void)
 
 unsigned int scripting_max_stack = PERF_MAX_STACK_DEPTH;
 
+#ifdef HAVE_KVM_STAT_SUPPORT
 bool kvm_entry_event(struct evsel *evsel __maybe_unused)
 {
 	return false;
@@ -1384,6 +1386,7 @@ void exit_event_decode_key(struct perf_kvm_stat *kvm __maybe_unused,
 			   char *decode __maybe_unused)
 {
 }
+#endif // HAVE_KVM_STAT_SUPPORT
 
 int find_scripts(char **scripts_array  __maybe_unused, char **scripts_path_array  __maybe_unused,
 		int num  __maybe_unused, int pathlen __maybe_unused)

tools/perf/util/syscalltbl.c

@@ -46,6 +46,11 @@ static const char *const *syscalltbl_native = syscalltbl_mips_n64;
 #include <asm/syscalls.c>
 const int syscalltbl_native_max_id = SYSCALLTBL_LOONGARCH_MAX_ID;
 static const char *const *syscalltbl_native = syscalltbl_loongarch;
+#else
+const int syscalltbl_native_max_id = 0;
+static const char *const syscalltbl_native[] = {
+	[0] = "unknown",
+};
 #endif
 
 struct syscall {
@@ -182,6 +187,11 @@ int syscalltbl__id(struct syscalltbl *tbl, const char *name)
 	return audit_name_to_syscall(name, tbl->audit_machine);
 }
 
+int syscalltbl__id_at_idx(struct syscalltbl *tbl __maybe_unused, int idx)
+{
+	return idx;
+}
+
 int syscalltbl__strglobmatch_next(struct syscalltbl *tbl __maybe_unused,
 				  const char *syscall_glob __maybe_unused, int *idx __maybe_unused)
 {