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linux/tools/lib/bpf/bpf_tracing.h
Jose E. Marchesi a9e7715ce8 libbpf: Avoid casts from pointers to enums in bpf_tracing.h 
[Differences from V1:
  - Do not introduce a global typedef, as this is a public header.
  - Keep the void* casts in BPF_KPROBE_READ_RET_IP and
    BPF_KRETPROBE_READ_RET_IP, as these are necessary
    for converting to a const void* argument of
    bpf_probe_read_kernel.]

The BPF_PROG, BPF_KPROBE and BPF_KSYSCALL macros defined in
tools/lib/bpf/bpf_tracing.h use a clever hack in order to provide a
convenient way to define entry points for BPF programs as if they were
normal C functions that get typed actual arguments, instead of as
elements in a single "context" array argument.

For example, PPF_PROGS allows writing:

  SEC("struct_ops/cwnd_event")
  void BPF_PROG(cwnd_event, struct sock *sk, enum tcp_ca_event event)
  {
        bbr_cwnd_event(sk, event);
        dctcp_cwnd_event(sk, event);
        cubictcp_cwnd_event(sk, event);
  }

That expands into a pair of functions:

  void ____cwnd_event (unsigned long long *ctx, struct sock *sk, enum tcp_ca_event event)
  {
        bbr_cwnd_event(sk, event);
        dctcp_cwnd_event(sk, event);
        cubictcp_cwnd_event(sk, event);
  }

  void cwnd_event (unsigned long long *ctx)
  {
        _Pragma("GCC diagnostic push")
        _Pragma("GCC diagnostic ignored \"-Wint-conversion\"")
        return ____cwnd_event(ctx, (void*)ctx[0], (void*)ctx[1]);
        _Pragma("GCC diagnostic pop")
  }

Note how the 64-bit unsigned integers in the incoming CTX get casted
to a void pointer, and then implicitly converted to whatever type of
the actual argument in the wrapped function.  In this case:

  Arg1: unsigned long long -> void * -> struct sock *
  Arg2: unsigned long long -> void * -> enum tcp_ca_event

The behavior of GCC and clang when facing such conversions differ:

  pointer -> pointer

    Allowed by the C standard.
    GCC: no warning nor error.
    clang: no warning nor error.

  pointer -> integer type

    [C standard says the result of this conversion is implementation
     defined, and it may lead to unaligned pointer etc.]

    GCC: error: integer from pointer without a cast [-Wint-conversion]
    clang: error: incompatible pointer to integer conversion [-Wint-conversion]

  pointer -> enumerated type

    GCC: error: incompatible types in assigment (*)
    clang: error: incompatible pointer to integer conversion [-Wint-conversion]

These macros work because converting pointers to pointers is allowed,
and converting pointers to integers also works provided a suitable
integer type even if it is implementation defined, much like casting a
pointer to uintptr_t is guaranteed to work by the C standard.  The
conversion errors emitted by both compilers by default are silenced by
the pragmas.

However, the GCC error marked with (*) above when assigning a pointer
to an enumerated value is not associated with the -Wint-conversion
warning, and it is not possible to turn it off.

This is preventing building the BPF kernel selftests with GCC.

This patch fixes this by avoiding intermediate casts to void*,
replaced with casts to `unsigned long long', which is an integer type
capable of safely store a BPF pointer, much like the standard
uintptr_t.

Testing performed in bpf-next master:
  - vmtest.sh -- ./test_verifier
  - vmtest.sh -- ./test_progs
  - make M=samples/bpf
No regressions.

Signed-off-by: Jose E. Marchesi <jose.marchesi@oracle.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240502170925.3194-1-jose.marchesi@oracle.com
2024-05-02 22:58:58 -07:00

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/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
#ifndef __BPF_TRACING_H__
#define __BPF_TRACING_H__
#include "bpf_helpers.h"
/* Scan the ARCH passed in from ARCH env variable (see Makefile) */
#if defined(__TARGET_ARCH_x86)
#define bpf_target_x86
#define bpf_target_defined
#elif defined(__TARGET_ARCH_s390)
#define bpf_target_s390
#define bpf_target_defined
#elif defined(__TARGET_ARCH_arm)
#define bpf_target_arm
#define bpf_target_defined
#elif defined(__TARGET_ARCH_arm64)
#define bpf_target_arm64
#define bpf_target_defined
#elif defined(__TARGET_ARCH_mips)
#define bpf_target_mips
#define bpf_target_defined
#elif defined(__TARGET_ARCH_powerpc)
#define bpf_target_powerpc
#define bpf_target_defined
#elif defined(__TARGET_ARCH_sparc)
#define bpf_target_sparc
#define bpf_target_defined
#elif defined(__TARGET_ARCH_riscv)
#define bpf_target_riscv
#define bpf_target_defined
#elif defined(__TARGET_ARCH_arc)
#define bpf_target_arc
#define bpf_target_defined
#elif defined(__TARGET_ARCH_loongarch)
#define bpf_target_loongarch
#define bpf_target_defined
#else
/* Fall back to what the compiler says */
#if defined(__x86_64__)
#define bpf_target_x86
#define bpf_target_defined
#elif defined(__s390__)
#define bpf_target_s390
#define bpf_target_defined
#elif defined(__arm__)
#define bpf_target_arm
#define bpf_target_defined
#elif defined(__aarch64__)
#define bpf_target_arm64
#define bpf_target_defined
#elif defined(__mips__)
#define bpf_target_mips
#define bpf_target_defined
#elif defined(__powerpc__)
#define bpf_target_powerpc
#define bpf_target_defined
#elif defined(__sparc__)
#define bpf_target_sparc
#define bpf_target_defined
#elif defined(__riscv) && __riscv_xlen == 64
#define bpf_target_riscv
#define bpf_target_defined
#elif defined(__arc__)
#define bpf_target_arc
#define bpf_target_defined
#elif defined(__loongarch__)
#define bpf_target_loongarch
#define bpf_target_defined
#endif /* no compiler target */
#endif
#ifndef __BPF_TARGET_MISSING
#define __BPF_TARGET_MISSING "GCC error \"Must specify a BPF target arch via __TARGET_ARCH_xxx\""
#endif
#if defined(bpf_target_x86)
/*
* https://en.wikipedia.org/wiki/X86_calling_conventions#System_V_AMD64_ABI
*/
#if defined(__KERNEL__) || defined(__VMLINUX_H__)
#define __PT_PARM1_REG di
#define __PT_PARM2_REG si
#define __PT_PARM3_REG dx
#define __PT_PARM4_REG cx
#define __PT_PARM5_REG r8
#define __PT_PARM6_REG r9
/*
* Syscall uses r10 for PARM4. See arch/x86/entry/entry_64.S:entry_SYSCALL_64
* comments in Linux sources. And refer to syscall(2) manpage.
*/
#define __PT_PARM1_SYSCALL_REG __PT_PARM1_REG
#define __PT_PARM2_SYSCALL_REG __PT_PARM2_REG
#define __PT_PARM3_SYSCALL_REG __PT_PARM3_REG
#define __PT_PARM4_SYSCALL_REG r10
#define __PT_PARM5_SYSCALL_REG __PT_PARM5_REG
#define __PT_PARM6_SYSCALL_REG __PT_PARM6_REG
#define __PT_RET_REG sp
#define __PT_FP_REG bp
#define __PT_RC_REG ax
#define __PT_SP_REG sp
#define __PT_IP_REG ip
#else
#ifdef __i386__
/* i386 kernel is built with -mregparm=3 */
#define __PT_PARM1_REG eax
#define __PT_PARM2_REG edx
#define __PT_PARM3_REG ecx
/* i386 syscall ABI is very different, refer to syscall(2) manpage */
#define __PT_PARM1_SYSCALL_REG ebx
#define __PT_PARM2_SYSCALL_REG ecx
#define __PT_PARM3_SYSCALL_REG edx
#define __PT_PARM4_SYSCALL_REG esi
#define __PT_PARM5_SYSCALL_REG edi
#define __PT_PARM6_SYSCALL_REG ebp
#define __PT_RET_REG esp
#define __PT_FP_REG ebp
#define __PT_RC_REG eax
#define __PT_SP_REG esp
#define __PT_IP_REG eip
#else /* __i386__ */
#define __PT_PARM1_REG rdi
#define __PT_PARM2_REG rsi
#define __PT_PARM3_REG rdx
#define __PT_PARM4_REG rcx
#define __PT_PARM5_REG r8
#define __PT_PARM6_REG r9
#define __PT_PARM1_SYSCALL_REG __PT_PARM1_REG
#define __PT_PARM2_SYSCALL_REG __PT_PARM2_REG
#define __PT_PARM3_SYSCALL_REG __PT_PARM3_REG
#define __PT_PARM4_SYSCALL_REG r10
#define __PT_PARM5_SYSCALL_REG __PT_PARM5_REG
#define __PT_PARM6_SYSCALL_REG __PT_PARM6_REG
#define __PT_RET_REG rsp
#define __PT_FP_REG rbp
#define __PT_RC_REG rax
#define __PT_SP_REG rsp
#define __PT_IP_REG rip
#endif /* __i386__ */
#endif /* __KERNEL__ || __VMLINUX_H__ */
#elif defined(bpf_target_s390)
/*
* https://github.com/IBM/s390x-abi/releases/download/v1.6/lzsabi_s390x.pdf
*/
struct pt_regs___s390 {
unsigned long orig_gpr2;
};
/* s390 provides user_pt_regs instead of struct pt_regs to userspace */
#define __PT_REGS_CAST(x) ((const user_pt_regs *)(x))
#define __PT_PARM1_REG gprs[2]
#define __PT_PARM2_REG gprs[3]
#define __PT_PARM3_REG gprs[4]
#define __PT_PARM4_REG gprs[5]
#define __PT_PARM5_REG gprs[6]
#define __PT_PARM1_SYSCALL_REG orig_gpr2
#define __PT_PARM2_SYSCALL_REG __PT_PARM2_REG
#define __PT_PARM3_SYSCALL_REG __PT_PARM3_REG
#define __PT_PARM4_SYSCALL_REG __PT_PARM4_REG
#define __PT_PARM5_SYSCALL_REG __PT_PARM5_REG
#define __PT_PARM6_SYSCALL_REG gprs[7]
#define PT_REGS_PARM1_SYSCALL(x) PT_REGS_PARM1_CORE_SYSCALL(x)
#define PT_REGS_PARM1_CORE_SYSCALL(x) \
BPF_CORE_READ((const struct pt_regs___s390 *)(x), __PT_PARM1_SYSCALL_REG)
#define __PT_RET_REG gprs[14]
#define __PT_FP_REG gprs[11] /* Works only with CONFIG_FRAME_POINTER */
#define __PT_RC_REG gprs[2]
#define __PT_SP_REG gprs[15]
#define __PT_IP_REG psw.addr
#elif defined(bpf_target_arm)
/*
* https://github.com/ARM-software/abi-aa/blob/main/aapcs32/aapcs32.rst#machine-registers
*/
#define __PT_PARM1_REG uregs[0]
#define __PT_PARM2_REG uregs[1]
#define __PT_PARM3_REG uregs[2]
#define __PT_PARM4_REG uregs[3]
#define __PT_PARM1_SYSCALL_REG __PT_PARM1_REG
#define __PT_PARM2_SYSCALL_REG __PT_PARM2_REG
#define __PT_PARM3_SYSCALL_REG __PT_PARM3_REG
#define __PT_PARM4_SYSCALL_REG __PT_PARM4_REG
#define __PT_PARM5_SYSCALL_REG uregs[4]
#define __PT_PARM6_SYSCALL_REG uregs[5]
#define __PT_PARM7_SYSCALL_REG uregs[6]
#define __PT_RET_REG uregs[14]
#define __PT_FP_REG uregs[11] /* Works only with CONFIG_FRAME_POINTER */
#define __PT_RC_REG uregs[0]
#define __PT_SP_REG uregs[13]
#define __PT_IP_REG uregs[12]
#elif defined(bpf_target_arm64)
/*
* https://github.com/ARM-software/abi-aa/blob/main/aapcs64/aapcs64.rst#machine-registers
*/
struct pt_regs___arm64 {
unsigned long orig_x0;
};
/* arm64 provides struct user_pt_regs instead of struct pt_regs to userspace */
#define __PT_REGS_CAST(x) ((const struct user_pt_regs *)(x))
#define __PT_PARM1_REG regs[0]
#define __PT_PARM2_REG regs[1]
#define __PT_PARM3_REG regs[2]
#define __PT_PARM4_REG regs[3]
#define __PT_PARM5_REG regs[4]
#define __PT_PARM6_REG regs[5]
#define __PT_PARM7_REG regs[6]
#define __PT_PARM8_REG regs[7]
#define __PT_PARM1_SYSCALL_REG orig_x0
#define __PT_PARM2_SYSCALL_REG __PT_PARM2_REG
#define __PT_PARM3_SYSCALL_REG __PT_PARM3_REG
#define __PT_PARM4_SYSCALL_REG __PT_PARM4_REG
#define __PT_PARM5_SYSCALL_REG __PT_PARM5_REG
#define __PT_PARM6_SYSCALL_REG __PT_PARM6_REG
#define PT_REGS_PARM1_SYSCALL(x) PT_REGS_PARM1_CORE_SYSCALL(x)
#define PT_REGS_PARM1_CORE_SYSCALL(x) \
BPF_CORE_READ((const struct pt_regs___arm64 *)(x), __PT_PARM1_SYSCALL_REG)
#define __PT_RET_REG regs[30]
#define __PT_FP_REG regs[29] /* Works only with CONFIG_FRAME_POINTER */
#define __PT_RC_REG regs[0]
#define __PT_SP_REG sp
#define __PT_IP_REG pc
#elif defined(bpf_target_mips)
/*
* N64 ABI is assumed right now.
* https://en.wikipedia.org/wiki/MIPS_architecture#Calling_conventions
*/
#define __PT_PARM1_REG regs[4]
#define __PT_PARM2_REG regs[5]
#define __PT_PARM3_REG regs[6]
#define __PT_PARM4_REG regs[7]
#define __PT_PARM5_REG regs[8]
#define __PT_PARM6_REG regs[9]
#define __PT_PARM7_REG regs[10]
#define __PT_PARM8_REG regs[11]
#define __PT_PARM1_SYSCALL_REG __PT_PARM1_REG
#define __PT_PARM2_SYSCALL_REG __PT_PARM2_REG
#define __PT_PARM3_SYSCALL_REG __PT_PARM3_REG
#define __PT_PARM4_SYSCALL_REG __PT_PARM4_REG
#define __PT_PARM5_SYSCALL_REG __PT_PARM5_REG /* only N32/N64 */
#define __PT_PARM6_SYSCALL_REG __PT_PARM6_REG /* only N32/N64 */
#define __PT_RET_REG regs[31]
#define __PT_FP_REG regs[30] /* Works only with CONFIG_FRAME_POINTER */
#define __PT_RC_REG regs[2]
#define __PT_SP_REG regs[29]
#define __PT_IP_REG cp0_epc
#elif defined(bpf_target_powerpc)
/*
* http://refspecs.linux-foundation.org/elf/elfspec_ppc.pdf (page 3-14,
* section "Function Calling Sequence")
*/
#define __PT_PARM1_REG gpr[3]
#define __PT_PARM2_REG gpr[4]
#define __PT_PARM3_REG gpr[5]
#define __PT_PARM4_REG gpr[6]
#define __PT_PARM5_REG gpr[7]
#define __PT_PARM6_REG gpr[8]
#define __PT_PARM7_REG gpr[9]
#define __PT_PARM8_REG gpr[10]
/* powerpc does not select ARCH_HAS_SYSCALL_WRAPPER. */
#define PT_REGS_SYSCALL_REGS(ctx) ctx
#define __PT_PARM1_SYSCALL_REG orig_gpr3
#define __PT_PARM2_SYSCALL_REG __PT_PARM2_REG
#define __PT_PARM3_SYSCALL_REG __PT_PARM3_REG
#define __PT_PARM4_SYSCALL_REG __PT_PARM4_REG
#define __PT_PARM5_SYSCALL_REG __PT_PARM5_REG
#define __PT_PARM6_SYSCALL_REG __PT_PARM6_REG
#if !defined(__arch64__)
#define __PT_PARM7_SYSCALL_REG __PT_PARM7_REG /* only powerpc (not powerpc64) */
#endif
#define __PT_RET_REG regs[31]
#define __PT_FP_REG __unsupported__
#define __PT_RC_REG gpr[3]
#define __PT_SP_REG sp
#define __PT_IP_REG nip
#elif defined(bpf_target_sparc)
/*
* https://en.wikipedia.org/wiki/Calling_convention#SPARC
*/
#define __PT_PARM1_REG u_regs[UREG_I0]
#define __PT_PARM2_REG u_regs[UREG_I1]
#define __PT_PARM3_REG u_regs[UREG_I2]
#define __PT_PARM4_REG u_regs[UREG_I3]
#define __PT_PARM5_REG u_regs[UREG_I4]
#define __PT_PARM6_REG u_regs[UREG_I5]
#define __PT_PARM1_SYSCALL_REG __PT_PARM1_REG
#define __PT_PARM2_SYSCALL_REG __PT_PARM2_REG
#define __PT_PARM3_SYSCALL_REG __PT_PARM3_REG
#define __PT_PARM4_SYSCALL_REG __PT_PARM4_REG
#define __PT_PARM5_SYSCALL_REG __PT_PARM5_REG
#define __PT_PARM6_SYSCALL_REG __PT_PARM6_REG
#define __PT_RET_REG u_regs[UREG_I7]
#define __PT_FP_REG __unsupported__
#define __PT_RC_REG u_regs[UREG_I0]
#define __PT_SP_REG u_regs[UREG_FP]
/* Should this also be a bpf_target check for the sparc case? */
#if defined(__arch64__)
#define __PT_IP_REG tpc
#else
#define __PT_IP_REG pc
#endif
#elif defined(bpf_target_riscv)
/*
* https://github.com/riscv-non-isa/riscv-elf-psabi-doc/blob/master/riscv-cc.adoc#risc-v-calling-conventions
*/
/* riscv provides struct user_regs_struct instead of struct pt_regs to userspace */
#define __PT_REGS_CAST(x) ((const struct user_regs_struct *)(x))
#define __PT_PARM1_REG a0
#define __PT_PARM2_REG a1
#define __PT_PARM3_REG a2
#define __PT_PARM4_REG a3
#define __PT_PARM5_REG a4
#define __PT_PARM6_REG a5
#define __PT_PARM7_REG a6
#define __PT_PARM8_REG a7
#define __PT_PARM1_SYSCALL_REG __PT_PARM1_REG
#define __PT_PARM2_SYSCALL_REG __PT_PARM2_REG
#define __PT_PARM3_SYSCALL_REG __PT_PARM3_REG
#define __PT_PARM4_SYSCALL_REG __PT_PARM4_REG
#define __PT_PARM5_SYSCALL_REG __PT_PARM5_REG
#define __PT_PARM6_SYSCALL_REG __PT_PARM6_REG
#define __PT_RET_REG ra
#define __PT_FP_REG s0
#define __PT_RC_REG a0
#define __PT_SP_REG sp
#define __PT_IP_REG pc
#elif defined(bpf_target_arc)
/*
* Section "Function Calling Sequence" (page 24):
* https://raw.githubusercontent.com/wiki/foss-for-synopsys-dwc-arc-processors/toolchain/files/ARCv2_ABI.pdf
*/
/* arc provides struct user_regs_struct instead of struct pt_regs to userspace */
#define __PT_REGS_CAST(x) ((const struct user_regs_struct *)(x))
#define __PT_PARM1_REG scratch.r0
#define __PT_PARM2_REG scratch.r1
#define __PT_PARM3_REG scratch.r2
#define __PT_PARM4_REG scratch.r3
#define __PT_PARM5_REG scratch.r4
#define __PT_PARM6_REG scratch.r5
#define __PT_PARM7_REG scratch.r6
#define __PT_PARM8_REG scratch.r7
/* arc does not select ARCH_HAS_SYSCALL_WRAPPER. */
#define PT_REGS_SYSCALL_REGS(ctx) ctx
#define __PT_PARM1_SYSCALL_REG __PT_PARM1_REG
#define __PT_PARM2_SYSCALL_REG __PT_PARM2_REG
#define __PT_PARM3_SYSCALL_REG __PT_PARM3_REG
#define __PT_PARM4_SYSCALL_REG __PT_PARM4_REG
#define __PT_PARM5_SYSCALL_REG __PT_PARM5_REG
#define __PT_PARM6_SYSCALL_REG __PT_PARM6_REG
#define __PT_RET_REG scratch.blink
#define __PT_FP_REG scratch.fp
#define __PT_RC_REG scratch.r0
#define __PT_SP_REG scratch.sp
#define __PT_IP_REG scratch.ret
#elif defined(bpf_target_loongarch)
/*
* https://docs.kernel.org/loongarch/introduction.html
* https://loongson.github.io/LoongArch-Documentation/LoongArch-ELF-ABI-EN.html
*/
/* loongarch provides struct user_pt_regs instead of struct pt_regs to userspace */
#define __PT_REGS_CAST(x) ((const struct user_pt_regs *)(x))
#define __PT_PARM1_REG regs[4]
#define __PT_PARM2_REG regs[5]
#define __PT_PARM3_REG regs[6]
#define __PT_PARM4_REG regs[7]
#define __PT_PARM5_REG regs[8]
#define __PT_PARM6_REG regs[9]
#define __PT_PARM7_REG regs[10]
#define __PT_PARM8_REG regs[11]
/* loongarch does not select ARCH_HAS_SYSCALL_WRAPPER. */
#define PT_REGS_SYSCALL_REGS(ctx) ctx
#define __PT_PARM1_SYSCALL_REG __PT_PARM1_REG
#define __PT_PARM2_SYSCALL_REG __PT_PARM2_REG
#define __PT_PARM3_SYSCALL_REG __PT_PARM3_REG
#define __PT_PARM4_SYSCALL_REG __PT_PARM4_REG
#define __PT_PARM5_SYSCALL_REG __PT_PARM5_REG
#define __PT_PARM6_SYSCALL_REG __PT_PARM6_REG
#define __PT_RET_REG regs[1]
#define __PT_FP_REG regs[22]
#define __PT_RC_REG regs[4]
#define __PT_SP_REG regs[3]
#define __PT_IP_REG csr_era
#endif
#if defined(bpf_target_defined)
struct pt_regs;
/* allow some architectures to override `struct pt_regs` */
#ifndef __PT_REGS_CAST
#define __PT_REGS_CAST(x) (x)
#endif
/*
* Different architectures support different number of arguments passed
* through registers. i386 supports just 3, some arches support up to 8.
*/
#ifndef __PT_PARM4_REG
#define __PT_PARM4_REG __unsupported__
#endif
#ifndef __PT_PARM5_REG
#define __PT_PARM5_REG __unsupported__
#endif
#ifndef __PT_PARM6_REG
#define __PT_PARM6_REG __unsupported__
#endif
#ifndef __PT_PARM7_REG
#define __PT_PARM7_REG __unsupported__
#endif
#ifndef __PT_PARM8_REG
#define __PT_PARM8_REG __unsupported__
#endif
/*
* Similarly, syscall-specific conventions might differ between function call
* conventions within each architecutre. All supported architectures pass
* either 6 or 7 syscall arguments in registers.
*
* See syscall(2) manpage for succinct table with information on each arch.
*/
#ifndef __PT_PARM7_SYSCALL_REG
#define __PT_PARM7_SYSCALL_REG __unsupported__
#endif
#define PT_REGS_PARM1(x) (__PT_REGS_CAST(x)->__PT_PARM1_REG)
#define PT_REGS_PARM2(x) (__PT_REGS_CAST(x)->__PT_PARM2_REG)
#define PT_REGS_PARM3(x) (__PT_REGS_CAST(x)->__PT_PARM3_REG)
#define PT_REGS_PARM4(x) (__PT_REGS_CAST(x)->__PT_PARM4_REG)
#define PT_REGS_PARM5(x) (__PT_REGS_CAST(x)->__PT_PARM5_REG)
#define PT_REGS_PARM6(x) (__PT_REGS_CAST(x)->__PT_PARM6_REG)
#define PT_REGS_PARM7(x) (__PT_REGS_CAST(x)->__PT_PARM7_REG)
#define PT_REGS_PARM8(x) (__PT_REGS_CAST(x)->__PT_PARM8_REG)
#define PT_REGS_RET(x) (__PT_REGS_CAST(x)->__PT_RET_REG)
#define PT_REGS_FP(x) (__PT_REGS_CAST(x)->__PT_FP_REG)
#define PT_REGS_RC(x) (__PT_REGS_CAST(x)->__PT_RC_REG)
#define PT_REGS_SP(x) (__PT_REGS_CAST(x)->__PT_SP_REG)
#define PT_REGS_IP(x) (__PT_REGS_CAST(x)->__PT_IP_REG)
#define PT_REGS_PARM1_CORE(x) BPF_CORE_READ(__PT_REGS_CAST(x), __PT_PARM1_REG)
#define PT_REGS_PARM2_CORE(x) BPF_CORE_READ(__PT_REGS_CAST(x), __PT_PARM2_REG)
#define PT_REGS_PARM3_CORE(x) BPF_CORE_READ(__PT_REGS_CAST(x), __PT_PARM3_REG)
#define PT_REGS_PARM4_CORE(x) BPF_CORE_READ(__PT_REGS_CAST(x), __PT_PARM4_REG)
#define PT_REGS_PARM5_CORE(x) BPF_CORE_READ(__PT_REGS_CAST(x), __PT_PARM5_REG)
#define PT_REGS_PARM6_CORE(x) BPF_CORE_READ(__PT_REGS_CAST(x), __PT_PARM6_REG)
#define PT_REGS_PARM7_CORE(x) BPF_CORE_READ(__PT_REGS_CAST(x), __PT_PARM7_REG)
#define PT_REGS_PARM8_CORE(x) BPF_CORE_READ(__PT_REGS_CAST(x), __PT_PARM8_REG)
#define PT_REGS_RET_CORE(x) BPF_CORE_READ(__PT_REGS_CAST(x), __PT_RET_REG)
#define PT_REGS_FP_CORE(x) BPF_CORE_READ(__PT_REGS_CAST(x), __PT_FP_REG)
#define PT_REGS_RC_CORE(x) BPF_CORE_READ(__PT_REGS_CAST(x), __PT_RC_REG)
#define PT_REGS_SP_CORE(x) BPF_CORE_READ(__PT_REGS_CAST(x), __PT_SP_REG)
#define PT_REGS_IP_CORE(x) BPF_CORE_READ(__PT_REGS_CAST(x), __PT_IP_REG)
#if defined(bpf_target_powerpc)
#define BPF_KPROBE_READ_RET_IP(ip, ctx) ({ (ip) = (ctx)->link; })
#define BPF_KRETPROBE_READ_RET_IP BPF_KPROBE_READ_RET_IP
#elif defined(bpf_target_sparc)
#define BPF_KPROBE_READ_RET_IP(ip, ctx) ({ (ip) = PT_REGS_RET(ctx); })
#define BPF_KRETPROBE_READ_RET_IP BPF_KPROBE_READ_RET_IP
#else
#define BPF_KPROBE_READ_RET_IP(ip, ctx) \
({ bpf_probe_read_kernel(&(ip), sizeof(ip), (void *)PT_REGS_RET(ctx)); })
#define BPF_KRETPROBE_READ_RET_IP(ip, ctx) \
({ bpf_probe_read_kernel(&(ip), sizeof(ip), (void *)(PT_REGS_FP(ctx) + sizeof(ip))); })
#endif
#ifndef PT_REGS_PARM1_SYSCALL
#define PT_REGS_PARM1_SYSCALL(x) (__PT_REGS_CAST(x)->__PT_PARM1_SYSCALL_REG)
#define PT_REGS_PARM1_CORE_SYSCALL(x) BPF_CORE_READ(__PT_REGS_CAST(x), __PT_PARM1_SYSCALL_REG)
#endif
#ifndef PT_REGS_PARM2_SYSCALL
#define PT_REGS_PARM2_SYSCALL(x) (__PT_REGS_CAST(x)->__PT_PARM2_SYSCALL_REG)
#define PT_REGS_PARM2_CORE_SYSCALL(x) BPF_CORE_READ(__PT_REGS_CAST(x), __PT_PARM2_SYSCALL_REG)
#endif
#ifndef PT_REGS_PARM3_SYSCALL
#define PT_REGS_PARM3_SYSCALL(x) (__PT_REGS_CAST(x)->__PT_PARM3_SYSCALL_REG)
#define PT_REGS_PARM3_CORE_SYSCALL(x) BPF_CORE_READ(__PT_REGS_CAST(x), __PT_PARM3_SYSCALL_REG)
#endif
#ifndef PT_REGS_PARM4_SYSCALL
#define PT_REGS_PARM4_SYSCALL(x) (__PT_REGS_CAST(x)->__PT_PARM4_SYSCALL_REG)
#define PT_REGS_PARM4_CORE_SYSCALL(x) BPF_CORE_READ(__PT_REGS_CAST(x), __PT_PARM4_SYSCALL_REG)
#endif
#ifndef PT_REGS_PARM5_SYSCALL
#define PT_REGS_PARM5_SYSCALL(x) (__PT_REGS_CAST(x)->__PT_PARM5_SYSCALL_REG)
#define PT_REGS_PARM5_CORE_SYSCALL(x) BPF_CORE_READ(__PT_REGS_CAST(x), __PT_PARM5_SYSCALL_REG)
#endif
#ifndef PT_REGS_PARM6_SYSCALL
#define PT_REGS_PARM6_SYSCALL(x) (__PT_REGS_CAST(x)->__PT_PARM6_SYSCALL_REG)
#define PT_REGS_PARM6_CORE_SYSCALL(x) BPF_CORE_READ(__PT_REGS_CAST(x), __PT_PARM6_SYSCALL_REG)
#endif
#ifndef PT_REGS_PARM7_SYSCALL
#define PT_REGS_PARM7_SYSCALL(x) (__PT_REGS_CAST(x)->__PT_PARM7_SYSCALL_REG)
#define PT_REGS_PARM7_CORE_SYSCALL(x) BPF_CORE_READ(__PT_REGS_CAST(x), __PT_PARM7_SYSCALL_REG)
#endif
#else /* defined(bpf_target_defined) */
#define PT_REGS_PARM1(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
#define PT_REGS_PARM2(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
#define PT_REGS_PARM3(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
#define PT_REGS_PARM4(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
#define PT_REGS_PARM5(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
#define PT_REGS_PARM6(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
#define PT_REGS_PARM7(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
#define PT_REGS_PARM8(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
#define PT_REGS_RET(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
#define PT_REGS_FP(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
#define PT_REGS_RC(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
#define PT_REGS_SP(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
#define PT_REGS_IP(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
#define PT_REGS_PARM1_CORE(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
#define PT_REGS_PARM2_CORE(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
#define PT_REGS_PARM3_CORE(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
#define PT_REGS_PARM4_CORE(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
#define PT_REGS_PARM5_CORE(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
#define PT_REGS_PARM6_CORE(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
#define PT_REGS_PARM7_CORE(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
#define PT_REGS_PARM8_CORE(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
#define PT_REGS_RET_CORE(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
#define PT_REGS_FP_CORE(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
#define PT_REGS_RC_CORE(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
#define PT_REGS_SP_CORE(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
#define PT_REGS_IP_CORE(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
#define BPF_KPROBE_READ_RET_IP(ip, ctx) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
#define BPF_KRETPROBE_READ_RET_IP(ip, ctx) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
#define PT_REGS_PARM1_SYSCALL(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
#define PT_REGS_PARM2_SYSCALL(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
#define PT_REGS_PARM3_SYSCALL(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
#define PT_REGS_PARM4_SYSCALL(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
#define PT_REGS_PARM5_SYSCALL(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
#define PT_REGS_PARM6_SYSCALL(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
#define PT_REGS_PARM7_SYSCALL(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
#define PT_REGS_PARM1_CORE_SYSCALL(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
#define PT_REGS_PARM2_CORE_SYSCALL(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
#define PT_REGS_PARM3_CORE_SYSCALL(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
#define PT_REGS_PARM4_CORE_SYSCALL(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
#define PT_REGS_PARM5_CORE_SYSCALL(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
#define PT_REGS_PARM6_CORE_SYSCALL(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
#define PT_REGS_PARM7_CORE_SYSCALL(x) ({ _Pragma(__BPF_TARGET_MISSING); 0l; })
#endif /* defined(bpf_target_defined) */
/*
* When invoked from a syscall handler kprobe, returns a pointer to a
* struct pt_regs containing syscall arguments and suitable for passing to
* PT_REGS_PARMn_SYSCALL() and PT_REGS_PARMn_CORE_SYSCALL().
*/
#ifndef PT_REGS_SYSCALL_REGS
/* By default, assume that the arch selects ARCH_HAS_SYSCALL_WRAPPER. */
#define PT_REGS_SYSCALL_REGS(ctx) ((struct pt_regs *)PT_REGS_PARM1(ctx))
#endif
#ifndef ___bpf_concat
#define ___bpf_concat(a, b) a ## b
#endif
#ifndef ___bpf_apply
#define ___bpf_apply(fn, n) ___bpf_concat(fn, n)
#endif
#ifndef ___bpf_nth
#define ___bpf_nth(_, _1, _2, _3, _4, _5, _6, _7, _8, _9, _a, _b, _c, N, ...) N
#endif
#ifndef ___bpf_narg
#define ___bpf_narg(...) ___bpf_nth(_, ##__VA_ARGS__, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0)
#endif
#define ___bpf_ctx_cast0() ctx
#define ___bpf_ctx_cast1(x) ___bpf_ctx_cast0(), ctx[0]
#define ___bpf_ctx_cast2(x, args...) ___bpf_ctx_cast1(args), ctx[1]
#define ___bpf_ctx_cast3(x, args...) ___bpf_ctx_cast2(args), ctx[2]
#define ___bpf_ctx_cast4(x, args...) ___bpf_ctx_cast3(args), ctx[3]
#define ___bpf_ctx_cast5(x, args...) ___bpf_ctx_cast4(args), ctx[4]
#define ___bpf_ctx_cast6(x, args...) ___bpf_ctx_cast5(args), ctx[5]
#define ___bpf_ctx_cast7(x, args...) ___bpf_ctx_cast6(args), ctx[6]
#define ___bpf_ctx_cast8(x, args...) ___bpf_ctx_cast7(args), ctx[7]
#define ___bpf_ctx_cast9(x, args...) ___bpf_ctx_cast8(args), ctx[8]
#define ___bpf_ctx_cast10(x, args...) ___bpf_ctx_cast9(args), ctx[9]
#define ___bpf_ctx_cast11(x, args...) ___bpf_ctx_cast10(args), ctx[10]
#define ___bpf_ctx_cast12(x, args...) ___bpf_ctx_cast11(args), ctx[11]
#define ___bpf_ctx_cast(args...) ___bpf_apply(___bpf_ctx_cast, ___bpf_narg(args))(args)
/*
* BPF_PROG is a convenience wrapper for generic tp_btf/fentry/fexit and
* similar kinds of BPF programs, that accept input arguments as a single
* pointer to untyped u64 array, where each u64 can actually be a typed
* pointer or integer of different size. Instead of requring user to write
* manual casts and work with array elements by index, BPF_PROG macro
* allows user to declare a list of named and typed input arguments in the
* same syntax as for normal C function. All the casting is hidden and
* performed transparently, while user code can just assume working with
* function arguments of specified type and name.
*
* Original raw context argument is preserved as well as 'ctx' argument.
* This is useful when using BPF helpers that expect original context
* as one of the parameters (e.g., for bpf_perf_event_output()).
*/
#define BPF_PROG(name, args...) \
name(unsigned long long *ctx); \
static __always_inline typeof(name(0)) \
____##name(unsigned long long *ctx, ##args); \
typeof(name(0)) name(unsigned long long *ctx) \
{ \
_Pragma("GCC diagnostic push") \
_Pragma("GCC diagnostic ignored \"-Wint-conversion\"") \
return ____##name(___bpf_ctx_cast(args)); \
_Pragma("GCC diagnostic pop") \
} \
static __always_inline typeof(name(0)) \
____##name(unsigned long long *ctx, ##args)
#ifndef ___bpf_nth2
#define ___bpf_nth2(_, _1, _2, _3, _4, _5, _6, _7, _8, _9, _10, _11, _12, _13, \
_14, _15, _16, _17, _18, _19, _20, _21, _22, _23, _24, N, ...) N
#endif
#ifndef ___bpf_narg2
#define ___bpf_narg2(...) \
___bpf_nth2(_, ##__VA_ARGS__, 12, 12, 11, 11, 10, 10, 9, 9, 8, 8, 7, 7, \
6, 6, 5, 5, 4, 4, 3, 3, 2, 2, 1, 1, 0)
#endif
#define ___bpf_treg_cnt(t) \
__builtin_choose_expr(sizeof(t) == 1, 1, \
__builtin_choose_expr(sizeof(t) == 2, 1, \
__builtin_choose_expr(sizeof(t) == 4, 1, \
__builtin_choose_expr(sizeof(t) == 8, 1, \
__builtin_choose_expr(sizeof(t) == 16, 2, \
(void)0)))))
#define ___bpf_reg_cnt0() (0)
#define ___bpf_reg_cnt1(t, x) (___bpf_reg_cnt0() + ___bpf_treg_cnt(t))
#define ___bpf_reg_cnt2(t, x, args...) (___bpf_reg_cnt1(args) + ___bpf_treg_cnt(t))
#define ___bpf_reg_cnt3(t, x, args...) (___bpf_reg_cnt2(args) + ___bpf_treg_cnt(t))
#define ___bpf_reg_cnt4(t, x, args...) (___bpf_reg_cnt3(args) + ___bpf_treg_cnt(t))
#define ___bpf_reg_cnt5(t, x, args...) (___bpf_reg_cnt4(args) + ___bpf_treg_cnt(t))
#define ___bpf_reg_cnt6(t, x, args...) (___bpf_reg_cnt5(args) + ___bpf_treg_cnt(t))
#define ___bpf_reg_cnt7(t, x, args...) (___bpf_reg_cnt6(args) + ___bpf_treg_cnt(t))
#define ___bpf_reg_cnt8(t, x, args...) (___bpf_reg_cnt7(args) + ___bpf_treg_cnt(t))
#define ___bpf_reg_cnt9(t, x, args...) (___bpf_reg_cnt8(args) + ___bpf_treg_cnt(t))
#define ___bpf_reg_cnt10(t, x, args...) (___bpf_reg_cnt9(args) + ___bpf_treg_cnt(t))
#define ___bpf_reg_cnt11(t, x, args...) (___bpf_reg_cnt10(args) + ___bpf_treg_cnt(t))
#define ___bpf_reg_cnt12(t, x, args...) (___bpf_reg_cnt11(args) + ___bpf_treg_cnt(t))
#define ___bpf_reg_cnt(args...) ___bpf_apply(___bpf_reg_cnt, ___bpf_narg2(args))(args)
#define ___bpf_union_arg(t, x, n) \
__builtin_choose_expr(sizeof(t) == 1, ({ union { __u8 z[1]; t x; } ___t = { .z = {ctx[n]}}; ___t.x; }), \
__builtin_choose_expr(sizeof(t) == 2, ({ union { __u16 z[1]; t x; } ___t = { .z = {ctx[n]} }; ___t.x; }), \
__builtin_choose_expr(sizeof(t) == 4, ({ union { __u32 z[1]; t x; } ___t = { .z = {ctx[n]} }; ___t.x; }), \
__builtin_choose_expr(sizeof(t) == 8, ({ union { __u64 z[1]; t x; } ___t = {.z = {ctx[n]} }; ___t.x; }), \
__builtin_choose_expr(sizeof(t) == 16, ({ union { __u64 z[2]; t x; } ___t = {.z = {ctx[n], ctx[n + 1]} }; ___t.x; }), \
(void)0)))))
#define ___bpf_ctx_arg0(n, args...)
#define ___bpf_ctx_arg1(n, t, x) , ___bpf_union_arg(t, x, n - ___bpf_reg_cnt1(t, x))
#define ___bpf_ctx_arg2(n, t, x, args...) , ___bpf_union_arg(t, x, n - ___bpf_reg_cnt2(t, x, args)) ___bpf_ctx_arg1(n, args)
#define ___bpf_ctx_arg3(n, t, x, args...) , ___bpf_union_arg(t, x, n - ___bpf_reg_cnt3(t, x, args)) ___bpf_ctx_arg2(n, args)
#define ___bpf_ctx_arg4(n, t, x, args...) , ___bpf_union_arg(t, x, n - ___bpf_reg_cnt4(t, x, args)) ___bpf_ctx_arg3(n, args)
#define ___bpf_ctx_arg5(n, t, x, args...) , ___bpf_union_arg(t, x, n - ___bpf_reg_cnt5(t, x, args)) ___bpf_ctx_arg4(n, args)
#define ___bpf_ctx_arg6(n, t, x, args...) , ___bpf_union_arg(t, x, n - ___bpf_reg_cnt6(t, x, args)) ___bpf_ctx_arg5(n, args)
#define ___bpf_ctx_arg7(n, t, x, args...) , ___bpf_union_arg(t, x, n - ___bpf_reg_cnt7(t, x, args)) ___bpf_ctx_arg6(n, args)
#define ___bpf_ctx_arg8(n, t, x, args...) , ___bpf_union_arg(t, x, n - ___bpf_reg_cnt8(t, x, args)) ___bpf_ctx_arg7(n, args)
#define ___bpf_ctx_arg9(n, t, x, args...) , ___bpf_union_arg(t, x, n - ___bpf_reg_cnt9(t, x, args)) ___bpf_ctx_arg8(n, args)
#define ___bpf_ctx_arg10(n, t, x, args...) , ___bpf_union_arg(t, x, n - ___bpf_reg_cnt10(t, x, args)) ___bpf_ctx_arg9(n, args)
#define ___bpf_ctx_arg11(n, t, x, args...) , ___bpf_union_arg(t, x, n - ___bpf_reg_cnt11(t, x, args)) ___bpf_ctx_arg10(n, args)
#define ___bpf_ctx_arg12(n, t, x, args...) , ___bpf_union_arg(t, x, n - ___bpf_reg_cnt12(t, x, args)) ___bpf_ctx_arg11(n, args)
#define ___bpf_ctx_arg(args...) ___bpf_apply(___bpf_ctx_arg, ___bpf_narg2(args))(___bpf_reg_cnt(args), args)
#define ___bpf_ctx_decl0()
#define ___bpf_ctx_decl1(t, x) , t x
#define ___bpf_ctx_decl2(t, x, args...) , t x ___bpf_ctx_decl1(args)
#define ___bpf_ctx_decl3(t, x, args...) , t x ___bpf_ctx_decl2(args)
#define ___bpf_ctx_decl4(t, x, args...) , t x ___bpf_ctx_decl3(args)
#define ___bpf_ctx_decl5(t, x, args...) , t x ___bpf_ctx_decl4(args)
#define ___bpf_ctx_decl6(t, x, args...) , t x ___bpf_ctx_decl5(args)
#define ___bpf_ctx_decl7(t, x, args...) , t x ___bpf_ctx_decl6(args)
#define ___bpf_ctx_decl8(t, x, args...) , t x ___bpf_ctx_decl7(args)
#define ___bpf_ctx_decl9(t, x, args...) , t x ___bpf_ctx_decl8(args)
#define ___bpf_ctx_decl10(t, x, args...) , t x ___bpf_ctx_decl9(args)
#define ___bpf_ctx_decl11(t, x, args...) , t x ___bpf_ctx_decl10(args)
#define ___bpf_ctx_decl12(t, x, args...) , t x ___bpf_ctx_decl11(args)
#define ___bpf_ctx_decl(args...) ___bpf_apply(___bpf_ctx_decl, ___bpf_narg2(args))(args)
/*
* BPF_PROG2 is an enhanced version of BPF_PROG in order to handle struct
* arguments. Since each struct argument might take one or two u64 values
* in the trampoline stack, argument type size is needed to place proper number
* of u64 values for each argument. Therefore, BPF_PROG2 has different
* syntax from BPF_PROG. For example, for the following BPF_PROG syntax:
*
* int BPF_PROG(test2, int a, int b) { ... }
*
* the corresponding BPF_PROG2 syntax is:
*
* int BPF_PROG2(test2, int, a, int, b) { ... }
*
* where type and the corresponding argument name are separated by comma.
*
* Use BPF_PROG2 macro if one of the arguments might be a struct/union larger
* than 8 bytes:
*
* int BPF_PROG2(test_struct_arg, struct bpf_testmod_struct_arg_1, a, int, b,
* int, c, int, d, struct bpf_testmod_struct_arg_2, e, int, ret)
* {
* // access a, b, c, d, e, and ret directly
* ...
* }
*/
#define BPF_PROG2(name, args...) \
name(unsigned long long *ctx); \
static __always_inline typeof(name(0)) \
____##name(unsigned long long *ctx ___bpf_ctx_decl(args)); \
typeof(name(0)) name(unsigned long long *ctx) \
{ \
return ____##name(ctx ___bpf_ctx_arg(args)); \
} \
static __always_inline typeof(name(0)) \
____##name(unsigned long long *ctx ___bpf_ctx_decl(args))
struct pt_regs;
#define ___bpf_kprobe_args0() ctx
#define ___bpf_kprobe_args1(x) ___bpf_kprobe_args0(), (unsigned long long)PT_REGS_PARM1(ctx)
#define ___bpf_kprobe_args2(x, args...) ___bpf_kprobe_args1(args), (unsigned long long)PT_REGS_PARM2(ctx)
#define ___bpf_kprobe_args3(x, args...) ___bpf_kprobe_args2(args), (unsigned long long)PT_REGS_PARM3(ctx)
#define ___bpf_kprobe_args4(x, args...) ___bpf_kprobe_args3(args), (unsigned long long)PT_REGS_PARM4(ctx)
#define ___bpf_kprobe_args5(x, args...) ___bpf_kprobe_args4(args), (unsigned long long)PT_REGS_PARM5(ctx)
#define ___bpf_kprobe_args6(x, args...) ___bpf_kprobe_args5(args), (unsigned long long)PT_REGS_PARM6(ctx)
#define ___bpf_kprobe_args7(x, args...) ___bpf_kprobe_args6(args), (unsigned long long)PT_REGS_PARM7(ctx)
#define ___bpf_kprobe_args8(x, args...) ___bpf_kprobe_args7(args), (unsigned long long)PT_REGS_PARM8(ctx)
#define ___bpf_kprobe_args(args...) ___bpf_apply(___bpf_kprobe_args, ___bpf_narg(args))(args)
/*
* BPF_KPROBE serves the same purpose for kprobes as BPF_PROG for
* tp_btf/fentry/fexit BPF programs. It hides the underlying platform-specific
* low-level way of getting kprobe input arguments from struct pt_regs, and
* provides a familiar typed and named function arguments syntax and
* semantics of accessing kprobe input paremeters.
*
* Original struct pt_regs* context is preserved as 'ctx' argument. This might
* be necessary when using BPF helpers like bpf_perf_event_output().
*/
#define BPF_KPROBE(name, args...) \
name(struct pt_regs *ctx); \
static __always_inline typeof(name(0)) \
____##name(struct pt_regs *ctx, ##args); \
typeof(name(0)) name(struct pt_regs *ctx) \
{ \
_Pragma("GCC diagnostic push") \
_Pragma("GCC diagnostic ignored \"-Wint-conversion\"") \
return ____##name(___bpf_kprobe_args(args)); \
_Pragma("GCC diagnostic pop") \
} \
static __always_inline typeof(name(0)) \
____##name(struct pt_regs *ctx, ##args)
#define ___bpf_kretprobe_args0() ctx
#define ___bpf_kretprobe_args1(x) ___bpf_kretprobe_args0(), (unsigned long long)PT_REGS_RC(ctx)
#define ___bpf_kretprobe_args(args...) ___bpf_apply(___bpf_kretprobe_args, ___bpf_narg(args))(args)
/*
* BPF_KRETPROBE is similar to BPF_KPROBE, except, it only provides optional
* return value (in addition to `struct pt_regs *ctx`), but no input
* arguments, because they will be clobbered by the time probed function
* returns.
*/
#define BPF_KRETPROBE(name, args...) \
name(struct pt_regs *ctx); \
static __always_inline typeof(name(0)) \
____##name(struct pt_regs *ctx, ##args); \
typeof(name(0)) name(struct pt_regs *ctx) \
{ \
_Pragma("GCC diagnostic push") \
_Pragma("GCC diagnostic ignored \"-Wint-conversion\"") \
return ____##name(___bpf_kretprobe_args(args)); \
_Pragma("GCC diagnostic pop") \
} \
static __always_inline typeof(name(0)) ____##name(struct pt_regs *ctx, ##args)
/* If kernel has CONFIG_ARCH_HAS_SYSCALL_WRAPPER, read pt_regs directly */
#define ___bpf_syscall_args0() ctx
#define ___bpf_syscall_args1(x) ___bpf_syscall_args0(), (unsigned long long)PT_REGS_PARM1_SYSCALL(regs)
#define ___bpf_syscall_args2(x, args...) ___bpf_syscall_args1(args), (unsigned long long)PT_REGS_PARM2_SYSCALL(regs)
#define ___bpf_syscall_args3(x, args...) ___bpf_syscall_args2(args), (unsigned long long)PT_REGS_PARM3_SYSCALL(regs)
#define ___bpf_syscall_args4(x, args...) ___bpf_syscall_args3(args), (unsigned long long)PT_REGS_PARM4_SYSCALL(regs)
#define ___bpf_syscall_args5(x, args...) ___bpf_syscall_args4(args), (unsigned long long)PT_REGS_PARM5_SYSCALL(regs)
#define ___bpf_syscall_args6(x, args...) ___bpf_syscall_args5(args), (unsigned long long)PT_REGS_PARM6_SYSCALL(regs)
#define ___bpf_syscall_args7(x, args...) ___bpf_syscall_args6(args), (unsigned long long)PT_REGS_PARM7_SYSCALL(regs)
#define ___bpf_syscall_args(args...) ___bpf_apply(___bpf_syscall_args, ___bpf_narg(args))(args)
/* If kernel doesn't have CONFIG_ARCH_HAS_SYSCALL_WRAPPER, we have to BPF_CORE_READ from pt_regs */
#define ___bpf_syswrap_args0() ctx
#define ___bpf_syswrap_args1(x) ___bpf_syswrap_args0(), (unsigned long long)PT_REGS_PARM1_CORE_SYSCALL(regs)
#define ___bpf_syswrap_args2(x, args...) ___bpf_syswrap_args1(args), (unsigned long long)PT_REGS_PARM2_CORE_SYSCALL(regs)
#define ___bpf_syswrap_args3(x, args...) ___bpf_syswrap_args2(args), (unsigned long long)PT_REGS_PARM3_CORE_SYSCALL(regs)
#define ___bpf_syswrap_args4(x, args...) ___bpf_syswrap_args3(args), (unsigned long long)PT_REGS_PARM4_CORE_SYSCALL(regs)
#define ___bpf_syswrap_args5(x, args...) ___bpf_syswrap_args4(args), (unsigned long long)PT_REGS_PARM5_CORE_SYSCALL(regs)
#define ___bpf_syswrap_args6(x, args...) ___bpf_syswrap_args5(args), (unsigned long long)PT_REGS_PARM6_CORE_SYSCALL(regs)
#define ___bpf_syswrap_args7(x, args...) ___bpf_syswrap_args6(args), (unsigned long long)PT_REGS_PARM7_CORE_SYSCALL(regs)
#define ___bpf_syswrap_args(args...) ___bpf_apply(___bpf_syswrap_args, ___bpf_narg(args))(args)
/*
* BPF_KSYSCALL is a variant of BPF_KPROBE, which is intended for
* tracing syscall functions, like __x64_sys_close. It hides the underlying
* platform-specific low-level way of getting syscall input arguments from
* struct pt_regs, and provides a familiar typed and named function arguments
* syntax and semantics of accessing syscall input parameters.
*
* Original struct pt_regs * context is preserved as 'ctx' argument. This might
* be necessary when using BPF helpers like bpf_perf_event_output().
*
* At the moment BPF_KSYSCALL does not transparently handle all the calling
* convention quirks for the following syscalls:
*
* - mmap(): __ARCH_WANT_SYS_OLD_MMAP.
* - clone(): CONFIG_CLONE_BACKWARDS, CONFIG_CLONE_BACKWARDS2 and
* CONFIG_CLONE_BACKWARDS3.
* - socket-related syscalls: __ARCH_WANT_SYS_SOCKETCALL.
* - compat syscalls.
*
* This may or may not change in the future. User needs to take extra measures
* to handle such quirks explicitly, if necessary.
*
* This macro relies on BPF CO-RE support and virtual __kconfig externs.
*/
#define BPF_KSYSCALL(name, args...) \
name(struct pt_regs *ctx); \
extern _Bool LINUX_HAS_SYSCALL_WRAPPER __kconfig; \
static __always_inline typeof(name(0)) \
____##name(struct pt_regs *ctx, ##args); \
typeof(name(0)) name(struct pt_regs *ctx) \
{ \
struct pt_regs *regs = LINUX_HAS_SYSCALL_WRAPPER \
? (struct pt_regs *)PT_REGS_PARM1(ctx) \
: ctx; \
_Pragma("GCC diagnostic push") \
_Pragma("GCC diagnostic ignored \"-Wint-conversion\"") \
if (LINUX_HAS_SYSCALL_WRAPPER) \
return ____##name(___bpf_syswrap_args(args)); \
else \
return ____##name(___bpf_syscall_args(args)); \
_Pragma("GCC diagnostic pop") \
} \
static __always_inline typeof(name(0)) \
____##name(struct pt_regs *ctx, ##args)
#define BPF_KPROBE_SYSCALL BPF_KSYSCALL
/* BPF_UPROBE and BPF_URETPROBE are identical to BPF_KPROBE and BPF_KRETPROBE,
* but are named way less confusingly for SEC("uprobe") and SEC("uretprobe")
* use cases.
*/
#define BPF_UPROBE(name, args...) BPF_KPROBE(name, ##args)
#define BPF_URETPROBE(name, args...) BPF_KRETPROBE(name, ##args)
#endif
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