From 785dc4eb7fd74e3b7f4eac468457b633117e1aea Mon Sep 17 00:00:00 2001 From: Gabriel Krisman Bertazi Date: Mon, 16 Nov 2020 12:42:04 -0500 Subject: [PATCH] audit: Migrate to use SYSCALL_WORK flag On architectures using the generic syscall entry code the architecture independent syscall work is moved to flags in thread_info::syscall_work. This removes architecture dependencies and frees up TIF bits. Define SYSCALL_WORK_SYSCALL_AUDIT, use it in the generic entry code and convert the code which uses the TIF specific helper functions to use the new *_syscall_work() helpers which either resolve to the new mode for users of the generic entry code or to the TIF based functions for the other architectures. Signed-off-by: Gabriel Krisman Bertazi Signed-off-by: Thomas Gleixner Reviewed-by: Andy Lutomirski Link: https://lore.kernel.org/r/20201116174206.2639648-9-krisman@collabora.com --- include/asm-generic/syscall.h | 23 ++++++++++++++--------- include/linux/entry-common.h | 18 ++++++------------ include/linux/thread_info.h | 2 ++ kernel/auditsc.c | 4 ++-- 4 files changed, 24 insertions(+), 23 deletions(-) diff --git a/include/asm-generic/syscall.h b/include/asm-generic/syscall.h index ed94e5658d0c..524218ae3825 100644 --- a/include/asm-generic/syscall.h +++ b/include/asm-generic/syscall.h @@ -43,9 +43,9 @@ int syscall_get_nr(struct task_struct *task, struct pt_regs *regs); * @regs: task_pt_regs() of @task * * It's only valid to call this when @task is stopped for system - * call exit tracing (due to %SYSCALL_WORK_SYSCALL_TRACE or TIF_SYSCALL_AUDIT), - * after tracehook_report_syscall_entry() returned nonzero to prevent - * the system call from taking place. + * call exit tracing (due to %SYSCALL_WORK_SYSCALL_TRACE or + * %SYSCALL_WORK_SYSCALL_AUDIT), after tracehook_report_syscall_entry() + * returned nonzero to prevent the system call from taking place. * * This rolls back the register state in @regs so it's as if the * system call instruction was a no-op. The registers containing @@ -63,7 +63,8 @@ void syscall_rollback(struct task_struct *task, struct pt_regs *regs); * Returns 0 if the system call succeeded, or -ERRORCODE if it failed. * * It's only valid to call this when @task is stopped for tracing on exit - * from a system call, due to %SYSCALL_WORK_SYSCALL_TRACE or %TIF_SYSCALL_AUDIT. + * from a system call, due to %SYSCALL_WORK_SYSCALL_TRACE or + * %SYSCALL_WORK_SYSCALL_AUDIT. */ long syscall_get_error(struct task_struct *task, struct pt_regs *regs); @@ -76,7 +77,8 @@ long syscall_get_error(struct task_struct *task, struct pt_regs *regs); * This value is meaningless if syscall_get_error() returned nonzero. * * It's only valid to call this when @task is stopped for tracing on exit - * from a system call, due to %SYSCALL_WORK_SYSCALL_TRACE or %TIF_SYSCALL_AUDIT. + * from a system call, due to %SYSCALL_WORK_SYSCALL_TRACE or + * %SYSCALL_WORK_SYSCALL_AUDIT. */ long syscall_get_return_value(struct task_struct *task, struct pt_regs *regs); @@ -93,7 +95,8 @@ long syscall_get_return_value(struct task_struct *task, struct pt_regs *regs); * code; the user sees a failed system call with this errno code. * * It's only valid to call this when @task is stopped for tracing on exit - * from a system call, due to %SYSCALL_WORK_SYSCALL_TRACE or %TIF_SYSCALL_AUDIT. + * from a system call, due to %SYSCALL_WORK_SYSCALL_TRACE or + * %SYSCALL_WORK_SYSCALL_AUDIT. */ void syscall_set_return_value(struct task_struct *task, struct pt_regs *regs, int error, long val); @@ -108,7 +111,8 @@ void syscall_set_return_value(struct task_struct *task, struct pt_regs *regs, * @args[0], and so on. * * It's only valid to call this when @task is stopped for tracing on - * entry to a system call, due to %SYSCALL_WORK_SYSCALL_TRACE or %TIF_SYSCALL_AUDIT. + * entry to a system call, due to %SYSCALL_WORK_SYSCALL_TRACE or + * %SYSCALL_WORK_SYSCALL_AUDIT. */ void syscall_get_arguments(struct task_struct *task, struct pt_regs *regs, unsigned long *args); @@ -123,7 +127,8 @@ void syscall_get_arguments(struct task_struct *task, struct pt_regs *regs, * The first argument gets value @args[0], and so on. * * It's only valid to call this when @task is stopped for tracing on - * entry to a system call, due to %SYSCALL_WORK_SYSCALL_TRACE or %TIF_SYSCALL_AUDIT. + * entry to a system call, due to %SYSCALL_WORK_SYSCALL_TRACE or + * %SYSCALL_WORK_SYSCALL_AUDIT. */ void syscall_set_arguments(struct task_struct *task, struct pt_regs *regs, const unsigned long *args); @@ -135,7 +140,7 @@ void syscall_set_arguments(struct task_struct *task, struct pt_regs *regs, * Returns the AUDIT_ARCH_* based on the system call convention in use. * * It's only valid to call this when @task is stopped on entry to a system - * call, due to %SYSCALL_WORK_SYSCALL_TRACE, %TIF_SYSCALL_AUDIT, or + * call, due to %SYSCALL_WORK_SYSCALL_TRACE, %SYSCALL_WORK_SYSCALL_AUDIT, or * %SYSCALL_WORK_SECCOMP. * * Architectures which permit CONFIG_HAVE_ARCH_SECCOMP_FILTER must diff --git a/include/linux/entry-common.h b/include/linux/entry-common.h index b30f82bed92b..d7b96f42817f 100644 --- a/include/linux/entry-common.h +++ b/include/linux/entry-common.h @@ -13,10 +13,6 @@ * Define dummy _TIF work flags if not defined by the architecture or for * disabled functionality. */ -#ifndef _TIF_SYSCALL_AUDIT -# define _TIF_SYSCALL_AUDIT (0) -#endif - #ifndef _TIF_PATCH_PENDING # define _TIF_PATCH_PENDING (0) #endif @@ -36,9 +32,7 @@ # define ARCH_SYSCALL_ENTER_WORK (0) #endif -#define SYSCALL_ENTER_WORK \ - (_TIF_SYSCALL_AUDIT | \ - ARCH_SYSCALL_ENTER_WORK) +#define SYSCALL_ENTER_WORK ARCH_SYSCALL_ENTER_WORK /* * TIF flags handled in syscall_exit_to_user_mode() @@ -47,16 +41,16 @@ # define ARCH_SYSCALL_EXIT_WORK (0) #endif -#define SYSCALL_EXIT_WORK \ - (_TIF_SYSCALL_AUDIT | \ - ARCH_SYSCALL_EXIT_WORK) +#define SYSCALL_EXIT_WORK ARCH_SYSCALL_EXIT_WORK #define SYSCALL_WORK_ENTER (SYSCALL_WORK_SECCOMP | \ SYSCALL_WORK_SYSCALL_TRACEPOINT | \ SYSCALL_WORK_SYSCALL_TRACE | \ - SYSCALL_WORK_SYSCALL_EMU) + SYSCALL_WORK_SYSCALL_EMU | \ + SYSCALL_WORK_SYSCALL_AUDIT) #define SYSCALL_WORK_EXIT (SYSCALL_WORK_SYSCALL_TRACEPOINT | \ - SYSCALL_WORK_SYSCALL_TRACE) + SYSCALL_WORK_SYSCALL_TRACE | \ + SYSCALL_WORK_SYSCALL_AUDIT) /* * TIF flags handled in exit_to_user_mode_loop() diff --git a/include/linux/thread_info.h b/include/linux/thread_info.h index 85b8a4216168..317363212ae9 100644 --- a/include/linux/thread_info.h +++ b/include/linux/thread_info.h @@ -40,12 +40,14 @@ enum syscall_work_bit { SYSCALL_WORK_BIT_SYSCALL_TRACEPOINT, SYSCALL_WORK_BIT_SYSCALL_TRACE, SYSCALL_WORK_BIT_SYSCALL_EMU, + SYSCALL_WORK_BIT_SYSCALL_AUDIT, }; #define SYSCALL_WORK_SECCOMP BIT(SYSCALL_WORK_BIT_SECCOMP) #define SYSCALL_WORK_SYSCALL_TRACEPOINT BIT(SYSCALL_WORK_BIT_SYSCALL_TRACEPOINT) #define SYSCALL_WORK_SYSCALL_TRACE BIT(SYSCALL_WORK_BIT_SYSCALL_TRACE) #define SYSCALL_WORK_SYSCALL_EMU BIT(SYSCALL_WORK_BIT_SYSCALL_EMU) +#define SYSCALL_WORK_SYSCALL_AUDIT BIT(SYSCALL_WORK_BIT_SYSCALL_AUDIT) #include diff --git a/kernel/auditsc.c b/kernel/auditsc.c index 8dba8f0983b5..c00aa5837965 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -952,7 +952,7 @@ int audit_alloc(struct task_struct *tsk) state = audit_filter_task(tsk, &key); if (state == AUDIT_DISABLED) { - clear_tsk_thread_flag(tsk, TIF_SYSCALL_AUDIT); + clear_task_syscall_work(tsk, SYSCALL_AUDIT); return 0; } @@ -964,7 +964,7 @@ int audit_alloc(struct task_struct *tsk) context->filterkey = key; audit_set_context(tsk, context); - set_tsk_thread_flag(tsk, TIF_SYSCALL_AUDIT); + set_task_syscall_work(tsk, SYSCALL_AUDIT); return 0; }