Messages in this thread |  | | Date | Tue, 17 Feb 2015 21:01:19 -0600 | From | Mike Strosaker <> | Subject | Re: [PATCH v3 1/3] powerpc: Don't force ENOSYS as error on syscall fail |
| |
This patch failed to build using pseries_le_defconfig. With the change noted below in entry_64.S, the build succeeded and seccomp mode 2 worked correctly.
Best, Mike Strosaker
On 02/13/2015 02:22 AM, Bogdan Purcareata wrote: > In certain scenarios - e.g. seccomp filtering with ERRNO as default action - > the system call fails for other reasons than the syscall not being available. > The seccomp filter can be configured to store a user-defined error code on > return from a blacklisted syscall. Don't always set ENOSYS on > do_syscall_trace_enter failure. > > Delegate setting ENOSYS in case of failure, where appropriate, to > do_syscall_trace_enter. > > v3: > - keep setting ENOSYS in the syscall entry assembly for scenarios without > syscall tracing > > v2: > - move setting ENOSYS as errno from the syscall entry assembly to > do_syscall_trace_enter, only in the specific case > > Signed-off-by: Bogdan Purcareata <bogdan.purcareata@freescale.com> > --- > arch/powerpc/kernel/entry_32.S | 7 ++++++- > arch/powerpc/kernel/entry_64.S | 5 +++-- > arch/powerpc/kernel/ptrace.c | 4 +++- > 3 files changed, 12 insertions(+), 4 deletions(-) > > diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S > index 46fc0f4..b2f88cd 100644 > --- a/arch/powerpc/kernel/entry_32.S > +++ b/arch/powerpc/kernel/entry_32.S > @@ -333,12 +333,12 @@ _GLOBAL(DoSyscall) > lwz r11,TI_FLAGS(r10) > andi. r11,r11,_TIF_SYSCALL_DOTRACE > bne- syscall_dotrace > -syscall_dotrace_cont: > cmplwi 0,r0,NR_syscalls > lis r10,sys_call_table@h > ori r10,r10,sys_call_table@l > slwi r0,r0,2 > bge- 66f > +syscall_dotrace_cont: > lwzx r10,r10,r0 /* Fetch system call handler [ptr] */ > mtlr r10 > addi r9,r1,STACK_FRAME_OVERHEAD > @@ -457,6 +457,11 @@ syscall_dotrace: > lwz r7,GPR7(r1) > lwz r8,GPR8(r1) > REST_NVGPRS(r1) > + cmplwi 0,r0,NR_syscalls > + lis r10,sys_call_table@h > + ori r10,r10,sys_call_table@l > + slwi r0,r0,2 > + bge- ret_from_syscall > b syscall_dotrace_cont > > syscall_exit_work: > diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S > index d180caf2..0d22fa8 100644 > --- a/arch/powerpc/kernel/entry_64.S > +++ b/arch/powerpc/kernel/entry_64.S > @@ -144,7 +144,6 @@ END_FW_FTR_SECTION_IFSET(FW_FEATURE_SPLPAR) > ld r10,TI_FLAGS(r11) > andi. r11,r10,_TIF_SYSCALL_DOTRACE > bne syscall_dotrace > -.Lsyscall_dotrace_cont: > cmpldi 0,r0,NR_syscalls > bge- syscall_enosys > > @@ -253,7 +252,9 @@ syscall_dotrace: > addi r9,r1,STACK_FRAME_OVERHEAD > CURRENT_THREAD_INFO(r10, r1) > ld r10,TI_FLAGS(r10) > - b .Lsyscall_dotrace_cont > + cmpldi 0,r0,NR_syscalls > + bge- syscall_exit
Shouldn't this be .Lsyscall_exit?
> + b system_call > > syscall_enosys: > li r3,-ENOSYS > diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c > index f21897b..2edae06 100644 > --- a/arch/powerpc/kernel/ptrace.c > +++ b/arch/powerpc/kernel/ptrace.c > @@ -1775,13 +1775,15 @@ long do_syscall_trace_enter(struct pt_regs *regs) > secure_computing_strict(regs->gpr[0]); > > if (test_thread_flag(TIF_SYSCALL_TRACE) && > - tracehook_report_syscall_entry(regs)) > + tracehook_report_syscall_entry(regs)) { > /* > * Tracing decided this syscall should not happen. > * We'll return a bogus call number to get an ENOSYS > * error, but leave the original number in regs->gpr[0]. > */ > ret = -1L; > + syscall_set_return_value(current, regs, ENOSYS, 0); > + } > > if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT))) > trace_sys_enter(regs, regs->gpr[0]); >
|  |