From 8d836581f9b1f57ceaa2b47654754ef1260b410b Mon Sep 17 00:00:00 2001 From: Niklas Cassel Date: Wed, 16 Sep 2026 15:00:32 +0200 Subject: ata: libata-scsi: fix ata_dsm_trim_pages() kernel-doc make htmldocs fails with: Documentation/driver-api/libata:604: ./drivers/ata/libata-scsi.c:2301: ERROR: Unexpected indentation. [docutils] The Return: section of ata_dsm_trim_pages() ends its first sentence with a colon and continues with an indented bullet list. reStructuredText requires a blank line before an indented block, so docutils chokes on the list. Simply adding the missing blank line does not work either: Return: is a kernel-doc "special section", which is terminated by the first blank line, so the bullet list would end up in the Description section, detached from the sentence introducing it. Spell the two bounds out as prose instead, so that the Return: section stays self-contained. Documentation-only change. Fixes: e64e6b5dc867 ("ata: libata-scsi: scale DSM TRIM payload by MAX PAGES PER DSM COMMAND") Reported-by: Thomas Huth Closes: https://lore.kernel.org/linux-ide/b0a0b8e8-cc4f-4c7b-8bc5-fee0712d405a@redhat.com/ Reviewed-by: Damien Le Moal Reviewed-by: Thomas Huth Link: https://lore.kernel.org/r/20260916130031.29990-2-cassel@kernel.org Signed-off-by: Niklas Cassel --- samples/seccomp/bpf-direct.c | 191 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 191 insertions(+) create mode 100644 samples/seccomp/bpf-direct.c (limited to 'samples/seccomp/bpf-direct.c') diff --git a/samples/seccomp/bpf-direct.c b/samples/seccomp/bpf-direct.c new file mode 100644 index 000000000..c09e4a17a --- /dev/null +++ b/samples/seccomp/bpf-direct.c @@ -0,0 +1,191 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Seccomp filter example for x86 (32-bit and 64-bit) with BPF macros + * + * Copyright (c) 2012 The Chromium OS Authors + * Author: Will Drewry + * + * The code may be used by anyone for any purpose, + * and can serve as a starting point for developing + * applications using prctl(PR_SET_SECCOMP, 2, ...). + */ +#if defined(__i386__) || defined(__x86_64__) +#define SUPPORTED_ARCH 1 +#endif + +#if defined(SUPPORTED_ARCH) +#define __USE_GNU 1 +#define _GNU_SOURCE 1 + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define syscall_arg(_n) (offsetof(struct seccomp_data, args[_n])) +#define syscall_nr (offsetof(struct seccomp_data, nr)) + +#if defined(__i386__) +#define REG_RESULT REG_EAX +#define REG_SYSCALL REG_EAX +#define REG_ARG0 REG_EBX +#define REG_ARG1 REG_ECX +#define REG_ARG2 REG_EDX +#define REG_ARG3 REG_ESI +#define REG_ARG4 REG_EDI +#define REG_ARG5 REG_EBP +#elif defined(__x86_64__) +#define REG_RESULT REG_RAX +#define REG_SYSCALL REG_RAX +#define REG_ARG0 REG_RDI +#define REG_ARG1 REG_RSI +#define REG_ARG2 REG_RDX +#define REG_ARG3 REG_R10 +#define REG_ARG4 REG_R8 +#define REG_ARG5 REG_R9 +#endif + +#ifndef PR_SET_NO_NEW_PRIVS +#define PR_SET_NO_NEW_PRIVS 38 +#endif + +#ifndef SYS_SECCOMP +#define SYS_SECCOMP 1 +#endif + +static void emulator(int nr, siginfo_t *info, void *void_context) +{ + ucontext_t *ctx = (ucontext_t *)(void_context); + int syscall; + char *buf; + ssize_t bytes; + size_t len; + if (info->si_code != SYS_SECCOMP) + return; + if (!ctx) + return; + syscall = ctx->uc_mcontext.gregs[REG_SYSCALL]; + buf = (char *) ctx->uc_mcontext.gregs[REG_ARG1]; + len = (size_t) ctx->uc_mcontext.gregs[REG_ARG2]; + + if (syscall != __NR_write) + return; + if (ctx->uc_mcontext.gregs[REG_ARG0] != STDERR_FILENO) + return; + /* Redirect stderr messages to stdout. Doesn't handle EINTR, etc */ + ctx->uc_mcontext.gregs[REG_RESULT] = -1; + if (write(STDOUT_FILENO, "[ERR] ", 6) > 0) { + bytes = write(STDOUT_FILENO, buf, len); + ctx->uc_mcontext.gregs[REG_RESULT] = bytes; + } + return; +} + +static int install_emulator(void) +{ + struct sigaction act; + sigset_t mask; + memset(&act, 0, sizeof(act)); + sigemptyset(&mask); + sigaddset(&mask, SIGSYS); + + act.sa_sigaction = &emulator; + act.sa_flags = SA_SIGINFO; + if (sigaction(SIGSYS, &act, NULL) < 0) { + perror("sigaction"); + return -1; + } + if (sigprocmask(SIG_UNBLOCK, &mask, NULL)) { + perror("sigprocmask"); + return -1; + } + return 0; +} + +static int install_filter(void) +{ + struct sock_filter filter[] = { + /* Grab the system call number */ + BPF_STMT(BPF_LD+BPF_W+BPF_ABS, syscall_nr), + /* Jump table for the allowed syscalls */ + BPF_JUMP(BPF_JMP+BPF_JEQ+BPF_K, __NR_rt_sigreturn, 0, 1), + BPF_STMT(BPF_RET+BPF_K, SECCOMP_RET_ALLOW), +#ifdef __NR_sigreturn + BPF_JUMP(BPF_JMP+BPF_JEQ+BPF_K, __NR_sigreturn, 0, 1), + BPF_STMT(BPF_RET+BPF_K, SECCOMP_RET_ALLOW), +#endif + BPF_JUMP(BPF_JMP+BPF_JEQ+BPF_K, __NR_exit_group, 0, 1), + BPF_STMT(BPF_RET+BPF_K, SECCOMP_RET_ALLOW), + BPF_JUMP(BPF_JMP+BPF_JEQ+BPF_K, __NR_exit, 0, 1), + BPF_STMT(BPF_RET+BPF_K, SECCOMP_RET_ALLOW), + BPF_JUMP(BPF_JMP+BPF_JEQ+BPF_K, __NR_read, 1, 0), + BPF_JUMP(BPF_JMP+BPF_JEQ+BPF_K, __NR_write, 3, 2), + + /* Check that read is only using stdin. */ + BPF_STMT(BPF_LD+BPF_W+BPF_ABS, syscall_arg(0)), + BPF_JUMP(BPF_JMP+BPF_JEQ+BPF_K, STDIN_FILENO, 4, 0), + BPF_STMT(BPF_RET+BPF_K, SECCOMP_RET_KILL), + + /* Check that write is only using stdout */ + BPF_STMT(BPF_LD+BPF_W+BPF_ABS, syscall_arg(0)), + BPF_JUMP(BPF_JMP+BPF_JEQ+BPF_K, STDOUT_FILENO, 1, 0), + /* Trap attempts to write to stderr */ + BPF_JUMP(BPF_JMP+BPF_JEQ+BPF_K, STDERR_FILENO, 1, 2), + + BPF_STMT(BPF_RET+BPF_K, SECCOMP_RET_ALLOW), + BPF_STMT(BPF_RET+BPF_K, SECCOMP_RET_TRAP), + BPF_STMT(BPF_RET+BPF_K, SECCOMP_RET_KILL), + }; + struct sock_fprog prog = { + .len = (unsigned short)(sizeof(filter)/sizeof(filter[0])), + .filter = filter, + }; + + if (prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) { + perror("prctl(NO_NEW_PRIVS)"); + return 1; + } + + + if (prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog)) { + perror("prctl"); + return 1; + } + return 0; +} + +#define payload(_c) (_c), sizeof((_c)) +int main(int argc, char **argv) +{ + char buf[4096]; + ssize_t bytes = 0; + if (install_emulator()) + return 1; + if (install_filter()) + return 1; + syscall(__NR_write, STDOUT_FILENO, + payload("OHAI! WHAT IS YOUR NAME? ")); + bytes = syscall(__NR_read, STDIN_FILENO, buf, sizeof(buf)); + syscall(__NR_write, STDOUT_FILENO, payload("HELLO, ")); + syscall(__NR_write, STDOUT_FILENO, buf, bytes); + syscall(__NR_write, STDERR_FILENO, + payload("Error message going to STDERR\n")); + return 0; +} +#else /* SUPPORTED_ARCH */ +/* + * This sample is x86-only. Since kernel samples are compiled with the + * host toolchain, a non-x86 host will result in using only the main() + * below. + */ +int main(void) +{ + return 1; +} +#endif /* SUPPORTED_ARCH */ -- cgit v1.3.1