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| author | Eric W. Biederman <ebiederm@xmission.com> | 2021-06-23 16:44:32 -0500 |
|---|---|---|
| committer | Eric W. Biederman <ebiederm@xmission.com> | 2021-08-26 10:30:12 -0500 |
| commit | 307d522f5eb86cd6ac8c905f5b0577dedac54ec5 (patch) | |
| tree | 826a8de8128133767b650120882b4edea7ee728b /kernel/signal.c | |
| parent | a3616a3c02722d1edb95acc7fceade242f6553ba (diff) | |
| download | linux-307d522f5eb86cd6ac8c905f5b0577dedac54ec5.tar.gz | |
signal/seccomp: Refactor seccomp signal and coredump generation
Factor out force_sig_seccomp from the seccomp signal generation and
place it in kernel/signal.c. The function force_sig_seccomp takes a
parameter force_coredump to indicate that the sigaction field should
be reset to SIGDFL so that a coredump will be generated when the
signal is delivered.
force_sig_seccomp is then used to replace both seccomp_send_sigsys
and seccomp_init_siginfo.
force_sig_info_to_task gains an extra parameter to force using
the default signal action.
With this change seccomp is no longer a special case and there
becomes exactly one place do_coredump is called from.
Further it no longer becomes necessary for __seccomp_filter
to call do_group_exit.
Acked-by: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/87r1gr6qc4.fsf_-_@disp2133
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Diffstat (limited to 'kernel/signal.c')
| -rw-r--r-- | kernel/signal.c | 30 |
1 files changed, 26 insertions, 4 deletions
diff --git a/kernel/signal.c b/kernel/signal.c index a3229add4455..fbf941b80dd4 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -54,6 +54,7 @@ #include <asm/unistd.h> #include <asm/siginfo.h> #include <asm/cacheflush.h> +#include <asm/syscall.h> /* for syscall_get_* */ /* * SLAB caches for signal bits. @@ -1322,7 +1323,7 @@ int do_send_sig_info(int sig, struct kernel_siginfo *info, struct task_struct *p * that is why we also clear SIGNAL_UNKILLABLE. */ static int -force_sig_info_to_task(struct kernel_siginfo *info, struct task_struct *t) +force_sig_info_to_task(struct kernel_siginfo *info, struct task_struct *t, bool sigdfl) { unsigned long int flags; int ret, blocked, ignored; @@ -1333,7 +1334,7 @@ force_sig_info_to_task(struct kernel_siginfo *info, struct task_struct *t) action = &t->sighand->action[sig-1]; ignored = action->sa.sa_handler == SIG_IGN; blocked = sigismember(&t->blocked, sig); - if (blocked || ignored) { + if (blocked || ignored || sigdfl) { action->sa.sa_handler = SIG_DFL; if (blocked) { sigdelset(&t->blocked, sig); @@ -1354,7 +1355,7 @@ force_sig_info_to_task(struct kernel_siginfo *info, struct task_struct *t) int force_sig_info(struct kernel_siginfo *info) { - return force_sig_info_to_task(info, current); + return force_sig_info_to_task(info, current, false); } /* @@ -1685,7 +1686,7 @@ int force_sig_fault_to_task(int sig, int code, void __user *addr info.si_flags = flags; info.si_isr = isr; #endif - return force_sig_info_to_task(&info, t); + return force_sig_info_to_task(&info, t, false); } int force_sig_fault(int sig, int code, void __user *addr @@ -1793,6 +1794,27 @@ int force_sig_perf(void __user *addr, u32 type, u64 sig_data) return force_sig_info(&info); } +/** + * force_sig_seccomp - signals the task to allow in-process syscall emulation + * @syscall: syscall number to send to userland + * @reason: filter-supplied reason code to send to userland (via si_errno) + * + * Forces a SIGSYS with a code of SYS_SECCOMP and related sigsys info. + */ +int force_sig_seccomp(int syscall, int reason, bool force_coredump) +{ + struct kernel_siginfo info; + + clear_siginfo(&info); + info.si_signo = SIGSYS; + info.si_code = SYS_SECCOMP; + info.si_call_addr = (void __user *)KSTK_EIP(current); + info.si_errno = reason; + info.si_arch = syscall_get_arch(current); + info.si_syscall = syscall; + return force_sig_info_to_task(&info, current, force_coredump); +} + /* For the crazy architectures that include trap information in * the errno field, instead of an actual errno value. */ |