kernel.git/arch/um/kernel/skas/syscall.c, branch linux-5.3.y

um: Support time travel mode

2019-07-02T21:27:36Z

Sometimes it can be useful to run with "time travel" inside the UML instance, for example for testing. For example, some tests for the wireless subsystem and userspace are based on hwsim, a virtual wireless adapter. Some tests can take a long time to run because they e.g. wait for 120 seconds to elapse for some regulatory checks. This obviously goes faster if it need not actually wait that long, but time inside the test environment just "bumps up" when there's nothing to do. Add CONFIG_UML_TIME_TRAVEL_SUPPORT to enable code to support such modes at runtime, selected on the command line: * just "time-travel", in which time inside the UML instance can move faster than real time, if there's nothing to do * "time-travel=inf-cpu" in which time also moves slower and any CPU processing takes no time at all, which allows to implement consistent behaviour regardless of host CPU load (or speed) or debug overhead. An additional "time-travel-start=" parameter is also supported in this case to start the wall clock at this time (in unix epoch). With this enabled, the test mentioned above goes from a runtime of about 140 seconds (with startup overhead and all) to being CPU bound and finishing in 15 seconds (on my slow laptop). Signed-off-by: Johannes Berg Signed-off-by: Richard Weinberger

um/ptrace: Fix the syscall number update after a ptrace

2016-09-07T16:25:04Z

Update the syscall number after each PTRACE_SETREGS on ORIG_*AX. This is needed to get the potentially altered syscall number in the seccomp filters after RET_TRACE. This fix four seccomp_bpf tests: > [ RUN ] TRACE_syscall.skip_after_RET_TRACE > seccomp_bpf.c:1560:TRACE_syscall.skip_after_RET_TRACE:Expected -1 (18446744073709551615) == syscall(39) (26) > seccomp_bpf.c:1561:TRACE_syscall.skip_after_RET_TRACE:Expected 1 (1) == (*__errno_location ()) (22) > [ FAIL ] TRACE_syscall.skip_after_RET_TRACE > [ RUN ] TRACE_syscall.kill_after_RET_TRACE > TRACE_syscall.kill_after_RET_TRACE: Test exited normally instead of by signal (code: 1) > [ FAIL ] TRACE_syscall.kill_after_RET_TRACE > [ RUN ] TRACE_syscall.skip_after_ptrace > seccomp_bpf.c:1622:TRACE_syscall.skip_after_ptrace:Expected -1 (18446744073709551615) == syscall(39) (26) > seccomp_bpf.c:1623:TRACE_syscall.skip_after_ptrace:Expected 1 (1) == (*__errno_location ()) (22) > [ FAIL ] TRACE_syscall.skip_after_ptrace > [ RUN ] TRACE_syscall.kill_after_ptrace > TRACE_syscall.kill_after_ptrace: Test exited normally instead of by signal (code: 1) > [ FAIL ] TRACE_syscall.kill_after_ptrace Fixes: 26703c636c1f ("um/ptrace: run seccomp after ptrace") Signed-off-by: Mickaël Salaün Acked-by: Kees Cook Cc: Jeff Dike Cc: Richard Weinberger Cc: James Morris Cc: user-mode-linux-devel@lists.sourceforge.net Signed-off-by: James Morris Signed-off-by: Kees Cook

um/ptrace: Fix the syscall_trace_leave call

2016-09-07T16:25:04Z

Keep the same semantic as before the commit 26703c636c1f: deallocate audit context and fake a proper syscall exit. This fix a kernel panic triggered by the seccomp_bpf test: > [ RUN ] global.ERRNO_valid > BUG: failure at kernel/auditsc.c:1504/__audit_syscall_entry()! > Kernel panic - not syncing: BUG! Fixes: 26703c636c1f ("um/ptrace: run seccomp after ptrace") Signed-off-by: Mickaël Salaün Acked-by: Kees Cook Cc: Jeff Dike Cc: Richard Weinberger Cc: James Morris Cc: user-mode-linux-devel@lists.sourceforge.net Signed-off-by: James Morris Signed-off-by: Kees Cook

um/ptrace: run seccomp after ptrace

2016-06-14T17:54:47Z

Close the hole where ptrace can change a syscall out from under seccomp. Signed-off-by: Kees Cook Cc: Jeff Dike Cc: Richard Weinberger Cc: user-mode-linux-devel@lists.sourceforge.net

seccomp: Add a seccomp_data parameter secure_computing()

2016-06-14T17:54:39Z

Currently, if arch code wants to supply seccomp_data directly to seccomp (which is generally much faster than having seccomp do it using the syscall_get_xyz() API), it has to use the two-phase seccomp hooks. Add it to the easy hooks, too. Cc: linux-arch@vger.kernel.org Signed-off-by: Andy Lutomirski Signed-off-by: Kees Cook

um: Add seccomp support

2016-01-10T20:49:49Z

This brings SECCOMP_MODE_STRICT and SECCOMP_MODE_FILTER support through prctl(2) and seccomp(2) to User-mode Linux for i386 and x86_64 subarchitectures. secure_computing() is called first in handle_syscall() so that the syscall emulation will be aborted quickly if matching a seccomp rule. This is inspired from Meredydd Luff's patch (https://gerrit.chromium.org/gerrit/21425). Signed-off-by: Mickaël Salaün Cc: Jeff Dike Cc: Richard Weinberger Cc: Ingo Molnar Cc: Kees Cook Cc: Andy Lutomirski Cc: Will Drewry Cc: Chris Metcalf Cc: Michael Ellerman Cc: James Hogan Cc: Meredydd Luff Cc: David Drysdale Signed-off-by: Richard Weinberger Acked-by: Kees Cook

um: Fix ptrace GETREGS/SETREGS bugs

2016-01-10T20:49:48Z

This fix two related bugs: * PTRACE_GETREGS doesn't get the right orig_ax (syscall) value * PTRACE_SETREGS can't set the orig_ax value (erased by initial value) Get rid of the now useless and error-prone get_syscall(). Fix inconsistent behavior in the ptrace implementation for i386 when updating orig_eax automatically update the syscall number as well. This is now updated in handle_syscall(). Signed-off-by: Mickaël Salaün Cc: Jeff Dike Cc: Richard Weinberger Cc: Thomas Gleixner Cc: Kees Cook Cc: Andy Lutomirski Cc: Will Drewry Cc: Thomas Meyer Cc: Nicolas Iooss Cc: Anton Ivanov Cc: Meredydd Luff Cc: David Drysdale Signed-off-by: Richard Weinberger Acked-by: Kees Cook

um: Get rid of open coded NR_SYSCALLS

2015-11-06T21:49:10Z

We can use __NR_syscall_max. Signed-off-by: Richard Weinberger

um: Store syscall number after syscall_trace_enter()

2015-11-06T21:49:09Z

To support changing syscall numbers we have to store it after syscall_trace_enter(). Signed-off-by: Richard Weinberger

um: Handle tracehook_report_syscall_entry() result

2015-05-31T20:59:03Z

tracehook_report_syscall_entry() is allowed to fail, in case of failure we have to abort the current syscall. Signed-off-by: Richard Weinberger