diff options
| author | Will Drewry <wad@chromium.org> | 2012-02-09 12:01:37 -0600 |
|---|---|---|
| committer | John Rigby <john.rigby@linaro.org> | 2012-06-20 12:33:04 -0600 |
| commit | 959540e0ae69fddc4c3e410c26b38eabf40d9778 (patch) | |
| tree | 87601a109795e2c83f55696e3898608b28c523cb /kernel | |
| parent | d8f0f1a89b239953877671f6b84c3851935d100f (diff) | |
UBUNTU: SAUCE: SECCOMP: seccomp: Add SECCOMP_RET_TRAP
Adds a new return value to seccomp filters that triggers a SIGSYS to be
delivered with the new SYS_SECCOMP si_code.
This allows in-process system call emulation, including just specifying
an errno or cleanly dumping core, rather than just dying.
v15: - use audit_seccomp/skip
- pad out error spacing; clean up switch (indan@nul.nu)
v14: - n/a
v13: - rebase on to 88ebdda6159ffc15699f204c33feb3e431bf9bdc
v12: - rebase on to linux-next
v11: - clarify the comment (indan@nul.nu)
- s/sigtrap/sigsys
v10: - use SIGSYS, syscall_get_arch, updates arch/Kconfig
note suggested-by (though original suggestion had other behaviors)
v9: - changes to SIGILL
v8: - clean up based on changes to dependent patches
v7: - introduction
Suggested-by: Markus Gutschke <markus@chromium.org>
Suggested-by: Julien Tinnes <jln@chromium.org>
Signed-off-by: Will Drewry <wad@chromium.org>
Signed-off-by: Kees Cook <kees@ubuntu.com>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/seccomp.c | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/kernel/seccomp.c b/kernel/seccomp.c index 118368fce85..1a6146d9f75 100644 --- a/kernel/seccomp.c +++ b/kernel/seccomp.c @@ -329,6 +329,26 @@ void put_seccomp_filter(struct task_struct *tsk) kfree(freeme); } } + +/** + * seccomp_send_sigsys - 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. + */ +static void seccomp_send_sigsys(int syscall, int reason) +{ + struct siginfo info; + memset(&info, 0, sizeof(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, task_pt_regs(current)); + info.si_syscall = syscall; + force_sig_info(SIGSYS, &info, current); +} #endif /* CONFIG_SECCOMP_FILTER */ /* @@ -386,6 +406,12 @@ int __secure_computing_int(int this_syscall) syscall_set_return_value(current, task_pt_regs(current), -data, 0); goto skip; + case SECCOMP_RET_TRAP: + /* Show the handler the original registers. */ + syscall_rollback(current, task_pt_regs(current)); + /* Let the filter pass back 16 bits of data. */ + seccomp_send_sigsys(this_syscall, data); + goto skip; case SECCOMP_RET_ALLOW: return 0; case SECCOMP_RET_KILL: |