// SPDX-License-Identifier: GPL-2.0-only /* * Copyright ( c ) 2020 Collabora Ltd . * * Test code for syscall user dispatch #define _GNU_SOURCE#include <sys/prctl.h>#include <sys/sysinfo.h>#include <sys/syscall.h>#include <signal.h>#include <stdbool.h>#include <stdlib.h>#include <asm /unistd.h>#include "../kselftest_harness.h" #ifndef PR_SET_SYSCALL_USER_DISPATCH# define PR_SET_SYSCALL_USER_DISPATCH 59 # define PR_SYS_DISPATCH_OFF 0 # define SYSCALL_DISPATCH_FILTER_ALLOW 0 # define SYSCALL_DISPATCH_FILTER_BLOCK 1 #endif #ifndef PR_SYS_DISPATCH_EXCLUSIVE_ON# define PR_SYS_DISPATCH_EXCLUSIVE_ON 1 # define PR_SYS_DISPATCH_INCLUSIVE_ON 2 #endif #ifndef SYS_USER_DISPATCH# define SYS_USER_DISPATCH 2 #endif #ifdef __NR_syscalls# define MAGIC_SYSCALL_1 (__NR_syscalls + 1 ) /* Bad Linux syscall number */ #else # define MAGIC_SYSCALL_1 (0 xff00) /* Bad Linux syscall number */ #endif #define SYSCALL_DISPATCH_ON(x) ((x) = SYSCALL_DISPATCH_FILTER_BLOCK)#define SYSCALL_DISPATCH_OFF(x) ((x) = SYSCALL_DISPATCH_FILTER_ALLOW)/* Test Summary: * * - dispatch_trigger_sigsys : Verify if PR_SET_SYSCALL_USER_DISPATCH is * able to trigger SIGSYS on a syscall . * * - bad_selector : Test that a bad selector value triggers SIGSYS with * si_errno EINVAL . * * - bad_prctl_param : Test that the API correctly rejects invalid * parameters on prctl * * - dispatch_and_return : Test that a syscall is selectively dispatched * to userspace depending on the value of selector . * * - disable_dispatch : Test that the PR_SYS_DISPATCH_OFF correctly * disables the dispatcher * * - direct_dispatch_range : Test that a syscall within the allowed range * can bypass the dispatcher . char sel = SYSCALL_DISPATCH_FILTER_ALLOW;struct sysinfo info;int ret;0 , ret);0 , 0 , &sel);0 , ret) {"Kernel does not support CONFIG_SYSCALL_USER_DISPATCH" );true ) {"Unreachable!" );static void prctl_valid(struct __test_metadata *_metadata,unsigned long op, unsigned long off,unsigned long size, void *sel)0 , prctl(PR_SET_SYSCALL_USER_DISPATCH, op, off, size, sel));static void prctl_invalid(struct __test_metadata *_metadata,unsigned long op, unsigned long off,unsigned long size, void *sel, int err)1 , prctl(PR_SET_SYSCALL_USER_DISPATCH, op, off, size, sel));char sel = SYSCALL_DISPATCH_FILTER_ALLOW;int op;/* Invalid op */ 1 ;0 , 0 , &sel, EINVAL);/* PR_SYS_DISPATCH_OFF */ /* offset != 0 */ 0 x1, 0 x0, 0 , EINVAL);/* len != 0 */ 0 x0, 0 xff, 0 , EINVAL);/* sel != NULL */ 0 x0, 0 x0, &sel, EINVAL);/* Valid parameter */ 0 x0, 0 x0, 0 x0);/* PR_SYS_DISPATCH_EXCLUSIVE_ON */ /* Dispatcher region is bad (offset > 0 && len == 0) */ 0 x1, 0 x0, &sel, EINVAL);1 L, 0 x0, &sel, EINVAL);/* Invalid selector */ 0 x0, 0 x1, (void *) -1 , EFAULT);/* * Dispatcher range overflows unsigned long 1 , -1 L, &sel, EINVAL);/* * Allowed range overflows usigned long 1 L, 0 x1, &sel, EINVAL);/* 0 len should fail for PR_SYS_DISPATCH_INCLUSIVE_ON */ 1 , 0 , 0 , EINVAL);/* Range wrap-around should fail */ 1 L, 2 , 0 , EINVAL);/* Normal range shouldn't fail */ 2 , 3 , 0 );/* Invalid selector */ 2 , 3 , (void *) -1 , EFAULT);/* * Use global selector for handle_sigsys tests , to avoid passing * selector to signal handler char glob_sel;int nr_syscalls_emulated;int si_code;int si_errno;unsigned long syscall_addr;static void handle_sigsys(int sig, siginfo_t *info, void *ucontext)unsigned long )info->si_call_addr;if (info->si_syscall == MAGIC_SYSCALL_1)/* In preparation for sigreturn. */ /* * The tests for argument handling assume that ` syscall ( x ) = = x ` . This * is a NOP on x86 because the syscall number is passed in % rax , which * happens to also be the function ABI return register . Other * architectures may need to swizzle the arguments around . #if defined (__riscv)/* REG_A7 is not defined in libc headers */ # define REG_A7 (REG_A0 + 7 )#endif int setup_sigsys_handler(void )struct sigaction act;0 , sizeof (act));return sigaction(SIGSYS, &act, NULL);long ret;0 ;0 ;0 ;0 ;0 , setup_sigsys_handler());/* Make sure selector is good prior to prctl. */ 0 , 0 , &glob_sel);0 , ret) {"Kernel does not support CONFIG_SYSCALL_USER_DISPATCH" );/* MAGIC_SYSCALL_1 doesn't exist. */ 1 , ret) {"Dispatch triggered unexpectedly" );/* MAGIC_SYSCALL_1 should be emulated. */ 0 ;"Failed to intercept syscall" );1 , nr_syscalls_emulated) {"Failed to emulate syscall" );"Bad si_code in SIGSYS" );0 , si_errno) {"Bad si_errno in SIGSYS" );long ret;struct sigaction act;struct sysinfo info;0 ;0 ;0 ;0 , sizeof (act));0 , ret);/* Make sure selector is good prior to prctl. */ 0 , 0 , &glob_sel);0 , ret) {"Kernel does not support CONFIG_SYSCALL_USER_DISPATCH" );1 ;/* Even though it is ready to catch SIGSYS, the signal is * supposed to be uncatchable . true ) {"Unreachable!" );int ret;struct sysinfo info;char sel = 0 ;0 , 0 , &sel);0 , ret) {"Kernel does not support CONFIG_SYSCALL_USER_DISPATCH" );/* MAGIC_SYSCALL_1 doesn't exist. */ 0 , 0 , 0 );0 , ret) {"Failed to unset syscall user dispatch" );/* Shouldn't have any effect... */ 0 , ret) {"Dispatch triggered unexpectedly" );int ret = 0 ;struct sysinfo info;char sel = SYSCALL_DISPATCH_FILTER_ALLOW;/* * Instead of calculating libc addresses ; allow the entire * memory map and lock the selector . 0 , -1 L, &sel);0 , ret) {"Kernel does not support CONFIG_SYSCALL_USER_DISPATCH" );0 , ret) {"Dispatch triggered unexpectedly" );static void test_range(struct __test_metadata *_metadata,unsigned long op, unsigned long off,unsigned long size, bool dispatch)0 ;0 , prctl(PR_SET_SYSCALL_USER_DISPATCH, op, off, size, &glob_sel));if (dispatch) {1 );else {1 );0 );0 , setup_sigsys_handler());0 , 0 , true );1 , false );100 , 200 , false );1 , 100 , true );100 , 100 , true );1 , true );1 , 1 , false );1 , 1 , false );
Messung V0.5 in Prozent C=91 H=92 G=91
¤ Dauer der Verarbeitung: 0.11 Sekunden
(vorverarbeitet am 2026-10-12)
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