From 062ab57b2f8439ab506645cf6f29432e7c61497c Mon Sep 17 00:00:00 2001 From: Al Viro Date: Tue, 28 Sep 2010 18:50:17 +0100 Subject: MIPS: Don't block signals if we'd failed to setup a sigframe Signed-off-by: Al Viro Cc: linux-kernel@vger.kernel.org Cc: linux-arch@vger.kernel.org Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/1696/ Signed-off-by: Ralf Baechle --- arch/mips/kernel/signal.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'arch/mips/kernel') diff --git a/arch/mips/kernel/signal.c b/arch/mips/kernel/signal.c index 2099d5a4c4b..b3273aeaeed 100644 --- a/arch/mips/kernel/signal.c +++ b/arch/mips/kernel/signal.c @@ -575,6 +575,9 @@ static int handle_signal(unsigned long sig, siginfo_t *info, ret = abi->setup_frame(vdso + abi->signal_return_offset, ka, regs, sig, oldset); + if (ret) + return ret; + spin_lock_irq(¤t->sighand->siglock); sigorsets(¤t->blocked, ¤t->blocked, &ka->sa.sa_mask); if (!(ka->sa.sa_flags & SA_NODEFER)) -- cgit v1.2.3-70-g09d2 From e5b377a8fb7b05f27647698ac739a0504cb2bf80 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Tue, 28 Sep 2010 18:50:27 +0100 Subject: MIPS: secure_computing, syscall audit: syscall number should in r2, not r0. As it is, audit_syscall_entry() and secure_computing() get the bogus value (0, in fact) Signed-off-by: Al Viro Cc: linux-kernel@vger.kernel.org Cc: linux-arch@vger.kernel.org Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/1697/ Signed-off-by: Ralf Baechle --- arch/mips/kernel/ptrace.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/mips/kernel') diff --git a/arch/mips/kernel/ptrace.c b/arch/mips/kernel/ptrace.c index c51b95ff864..c8777333e19 100644 --- a/arch/mips/kernel/ptrace.c +++ b/arch/mips/kernel/ptrace.c @@ -536,7 +536,7 @@ asmlinkage void do_syscall_trace(struct pt_regs *regs, int entryexit) { /* do the secure computing check first */ if (!entryexit) - secure_computing(regs->regs[0]); + secure_computing(regs->regs[2]); if (unlikely(current->audit_context) && entryexit) audit_syscall_exit(AUDITSC_RESULT(regs->regs[2]), @@ -565,7 +565,7 @@ asmlinkage void do_syscall_trace(struct pt_regs *regs, int entryexit) out: if (unlikely(current->audit_context) && !entryexit) - audit_syscall_entry(audit_arch(), regs->regs[0], + audit_syscall_entry(audit_arch(), regs->regs[2], regs->regs[4], regs->regs[5], regs->regs[6], regs->regs[7]); } -- cgit v1.2.3-70-g09d2 From 8f5a00eb422ed86e77bb8f67e08b9fe6d30f679a Mon Sep 17 00:00:00 2001 From: Al Viro Date: Tue, 28 Sep 2010 18:50:37 +0100 Subject: MIPS: Sanitize restart logics Put the original syscall number into ->regs[0] when we leave syscall with error. Use it in restart logics. Everything else will have it 0 since we pass through SAVE_SOME on all the ways in. Note that in places like bad_stack and inllegal_syscall we leave it 0 - it's not restartable. Signed-off-by: Al Viro Cc: linux-kernel@vger.kernel.org Cc: linux-arch@vger.kernel.org Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/1698/ Signed-off-by: Ralf Baechle --- arch/mips/kernel/branch.c | 1 - arch/mips/kernel/scall32-o32.S | 9 ++++----- arch/mips/kernel/scall64-64.S | 7 ++++--- arch/mips/kernel/scall64-n32.S | 6 ++++-- arch/mips/kernel/scall64-o32.S | 7 ++++--- arch/mips/kernel/signal.c | 37 ++++++++++++++++++------------------- arch/mips/kernel/unaligned.c | 2 -- 7 files changed, 34 insertions(+), 35 deletions(-) (limited to 'arch/mips/kernel') diff --git a/arch/mips/kernel/branch.c b/arch/mips/kernel/branch.c index 0176ed015c8..32103cc2a25 100644 --- a/arch/mips/kernel/branch.c +++ b/arch/mips/kernel/branch.c @@ -40,7 +40,6 @@ int __compute_return_epc(struct pt_regs *regs) return -EFAULT; } - regs->regs[0] = 0; switch (insn.i_format.opcode) { /* * jr and jalr are in r_format format. diff --git a/arch/mips/kernel/scall32-o32.S b/arch/mips/kernel/scall32-o32.S index 17202bbe843..73a061e8553 100644 --- a/arch/mips/kernel/scall32-o32.S +++ b/arch/mips/kernel/scall32-o32.S @@ -63,9 +63,9 @@ stack_done: sw t0, PT_R7(sp) # set error flag beqz t0, 1f + lw t1, PT_R2(sp) # syscall number negu v0 # error - sw v0, PT_R0(sp) # set flag for syscall - # restarting + sw t1, PT_R0(sp) # save it for syscall restarting 1: sw v0, PT_R2(sp) # result o32_syscall_exit: @@ -104,9 +104,9 @@ syscall_trace_entry: sw t0, PT_R7(sp) # set error flag beqz t0, 1f + lw t1, PT_R2(sp) # syscall number negu v0 # error - sw v0, PT_R0(sp) # set flag for syscall - # restarting + sw t1, PT_R0(sp) # save it for syscall restarting 1: sw v0, PT_R2(sp) # result j syscall_exit @@ -170,7 +170,6 @@ stackargs: */ bad_stack: negu v0 # error - sw v0, PT_R0(sp) sw v0, PT_R2(sp) li t0, 1 # set error flag sw t0, PT_R7(sp) diff --git a/arch/mips/kernel/scall64-64.S b/arch/mips/kernel/scall64-64.S index a8a6c596eb0..eb0bb73172c 100644 --- a/arch/mips/kernel/scall64-64.S +++ b/arch/mips/kernel/scall64-64.S @@ -66,9 +66,9 @@ NESTED(handle_sys64, PT_SIZE, sp) sd t0, PT_R7(sp) # set error flag beqz t0, 1f + ld t1, PT_R2(sp) # syscall number dnegu v0 # error - sd v0, PT_R0(sp) # set flag for syscall - # restarting + sd t1, PT_R0(sp) # save it for syscall restarting 1: sd v0, PT_R2(sp) # result n64_syscall_exit: @@ -109,8 +109,9 @@ syscall_trace_entry: sd t0, PT_R7(sp) # set error flag beqz t0, 1f + ld t1, PT_R2(sp) # syscall number dnegu v0 # error - sd v0, PT_R0(sp) # set flag for syscall restarting + sd t1, PT_R0(sp) # save it for syscall restarting 1: sd v0, PT_R2(sp) # result j syscall_exit diff --git a/arch/mips/kernel/scall64-n32.S b/arch/mips/kernel/scall64-n32.S index a3d66137731..4da3fafaa31 100644 --- a/arch/mips/kernel/scall64-n32.S +++ b/arch/mips/kernel/scall64-n32.S @@ -65,8 +65,9 @@ NESTED(handle_sysn32, PT_SIZE, sp) sd t0, PT_R7(sp) # set error flag beqz t0, 1f + ld t1, PT_R2(sp) # syscall number dnegu v0 # error - sd v0, PT_R0(sp) # set flag for syscall restarting + sd t1, PT_R0(sp) # save it for syscall restarting 1: sd v0, PT_R2(sp) # result local_irq_disable # make sure need_resched and @@ -106,8 +107,9 @@ n32_syscall_trace_entry: sd t0, PT_R7(sp) # set error flag beqz t0, 1f + ld t1, PT_R2(sp) # syscall number dnegu v0 # error - sd v0, PT_R0(sp) # set flag for syscall restarting + sd t1, PT_R0(sp) # save it for syscall restarting 1: sd v0, PT_R2(sp) # result j syscall_exit diff --git a/arch/mips/kernel/scall64-o32.S b/arch/mips/kernel/scall64-o32.S index 813689ef238..7ce0a368562 100644 --- a/arch/mips/kernel/scall64-o32.S +++ b/arch/mips/kernel/scall64-o32.S @@ -93,8 +93,9 @@ NESTED(handle_sys, PT_SIZE, sp) sd t0, PT_R7(sp) # set error flag beqz t0, 1f + ld t1, PT_R2(sp) # syscall number dnegu v0 # error - sd v0, PT_R0(sp) # flag for syscall restarting + sd t1, PT_R0(sp) # save it for syscall restarting 1: sd v0, PT_R2(sp) # result o32_syscall_exit: @@ -142,8 +143,9 @@ trace_a_syscall: sd t0, PT_R7(sp) # set error flag beqz t0, 1f + ld t1, PT_R2(sp) # syscall number dnegu v0 # error - sd v0, PT_R0(sp) # set flag for syscall restarting + sd t1, PT_R0(sp) # save it for syscall restarting 1: sd v0, PT_R2(sp) # result j syscall_exit @@ -155,7 +157,6 @@ trace_a_syscall: */ bad_stack: dnegu v0 # error - sd v0, PT_R0(sp) sd v0, PT_R2(sp) li t0, 1 # set error flag sd t0, PT_R7(sp) diff --git a/arch/mips/kernel/signal.c b/arch/mips/kernel/signal.c index b3273aeaeed..604f077bb5b 100644 --- a/arch/mips/kernel/signal.c +++ b/arch/mips/kernel/signal.c @@ -550,23 +550,26 @@ static int handle_signal(unsigned long sig, siginfo_t *info, struct mips_abi *abi = current->thread.abi; void *vdso = current->mm->context.vdso; - switch(regs->regs[0]) { - case ERESTART_RESTARTBLOCK: - case ERESTARTNOHAND: - regs->regs[2] = EINTR; - break; - case ERESTARTSYS: - if (!(ka->sa.sa_flags & SA_RESTART)) { + if (regs->regs[0]) { + switch(regs->regs[2]) { + case ERESTART_RESTARTBLOCK: + case ERESTARTNOHAND: regs->regs[2] = EINTR; break; + case ERESTARTSYS: + if (!(ka->sa.sa_flags & SA_RESTART)) { + regs->regs[2] = EINTR; + break; + } + /* fallthrough */ + case ERESTARTNOINTR: + regs->regs[7] = regs->regs[26]; + regs->regs[2] = regs->regs[0]; + regs->cp0_epc -= 4; } - /* fallthrough */ - case ERESTARTNOINTR: /* Userland will reload $v0. */ - regs->regs[7] = regs->regs[26]; - regs->cp0_epc -= 8; - } - regs->regs[0] = 0; /* Don't deal with this again. */ + regs->regs[0] = 0; /* Don't deal with this again. */ + } if (sig_uses_siginfo(ka)) ret = abi->setup_rt_frame(vdso + abi->rt_signal_return_offset, @@ -625,17 +628,13 @@ static void do_signal(struct pt_regs *regs) return; } - /* - * Who's code doesn't conform to the restartable syscall convention - * dies here!!! The li instruction, a single machine instruction, - * must directly be followed by the syscall instruction. - */ if (regs->regs[0]) { if (regs->regs[2] == ERESTARTNOHAND || regs->regs[2] == ERESTARTSYS || regs->regs[2] == ERESTARTNOINTR) { + regs->regs[2] = regs->regs[0]; regs->regs[7] = regs->regs[26]; - regs->cp0_epc -= 8; + regs->cp0_epc -= 4; } if (regs->regs[2] == ERESTART_RESTARTBLOCK) { regs->regs[2] = current->thread.abi->restart; diff --git a/arch/mips/kernel/unaligned.c b/arch/mips/kernel/unaligned.c index 69b039ca8d8..33d5a5ce4a2 100644 --- a/arch/mips/kernel/unaligned.c +++ b/arch/mips/kernel/unaligned.c @@ -109,8 +109,6 @@ static void emulate_load_store_insn(struct pt_regs *regs, unsigned long value; unsigned int res; - regs->regs[0] = 0; - /* * This load never faults. */ -- cgit v1.2.3-70-g09d2 From 5b89c0044e048842245193b200b61e5f998abd9a Mon Sep 17 00:00:00 2001 From: Al Viro Date: Tue, 28 Sep 2010 18:50:47 +0100 Subject: MIPS: Fix error values in case of bad_stack We want EFAULT, not - Signed-off-by: Al Viro Cc: linux-kernel@vger.kernel.org Cc: linux-arch@vger.kernel.org Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/1699/ Signed-off-by: Ralf Baechle --- arch/mips/kernel/scall32-o32.S | 2 +- arch/mips/kernel/scall64-o32.S | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/mips/kernel') diff --git a/arch/mips/kernel/scall32-o32.S b/arch/mips/kernel/scall32-o32.S index 73a061e8553..84b41797fae 100644 --- a/arch/mips/kernel/scall32-o32.S +++ b/arch/mips/kernel/scall32-o32.S @@ -169,7 +169,7 @@ stackargs: * We probably should handle this case a bit more drastic. */ bad_stack: - negu v0 # error + li v0, EFAULT sw v0, PT_R2(sp) li t0, 1 # set error flag sw t0, PT_R7(sp) diff --git a/arch/mips/kernel/scall64-o32.S b/arch/mips/kernel/scall64-o32.S index 7ce0a368562..d2bc285413d 100644 --- a/arch/mips/kernel/scall64-o32.S +++ b/arch/mips/kernel/scall64-o32.S @@ -156,7 +156,7 @@ trace_a_syscall: * The stackpointer for a call with more than 4 arguments is bad. */ bad_stack: - dnegu v0 # error + li v0, EFAULT sd v0, PT_R2(sp) li t0, 1 # set error flag sd t0, PT_R7(sp) -- cgit v1.2.3-70-g09d2 From 4bfb8c5c87bd167640ef5789b22e058e339df804 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Tue, 28 Sep 2010 18:50:57 +0100 Subject: MIPS: do_sigaltstack() expects userland pointers o32 compat does the right thing, native and n32 compat do not... Signed-off-by: Al Viro Cc: linux-kernel@vger.kernel.org Cc: linux-arch@vger.kernel.org Cc: linux-mips@linux-mips.org Patchwork: http://patchwork.linux-mips.org/patch/1700/ Signed-off-by: Ralf Baechle --- arch/mips/kernel/signal.c | 5 +---- arch/mips/kernel/signal_n32.c | 5 +++++ 2 files changed, 6 insertions(+), 4 deletions(-) (limited to 'arch/mips/kernel') diff --git a/arch/mips/kernel/signal.c b/arch/mips/kernel/signal.c index 604f077bb5b..5922342bca3 100644 --- a/arch/mips/kernel/signal.c +++ b/arch/mips/kernel/signal.c @@ -390,7 +390,6 @@ asmlinkage void sys_rt_sigreturn(nabi_no_regargs struct pt_regs regs) { struct rt_sigframe __user *frame; sigset_t set; - stack_t st; int sig; frame = (struct rt_sigframe __user *) regs.regs[29]; @@ -411,11 +410,9 @@ asmlinkage void sys_rt_sigreturn(nabi_no_regargs struct pt_regs regs) else if (sig) force_sig(sig, current); - if (__copy_from_user(&st, &frame->rs_uc.uc_stack, sizeof(st))) - goto badframe; /* It is more difficult to avoid calling this function than to call it and ignore errors. */ - do_sigaltstack((stack_t __user *)&st, NULL, regs.regs[29]); + do_sigaltstack(&frame->rs_uc.uc_stack, NULL, regs.regs[29]); /* * Don't let your children do this ... diff --git a/arch/mips/kernel/signal_n32.c b/arch/mips/kernel/signal_n32.c index 2c5df818c65..ee24d814d5b 100644 --- a/arch/mips/kernel/signal_n32.c +++ b/arch/mips/kernel/signal_n32.c @@ -109,6 +109,7 @@ asmlinkage int sysn32_rt_sigsuspend(nabi_no_regargs struct pt_regs regs) asmlinkage void sysn32_rt_sigreturn(nabi_no_regargs struct pt_regs regs) { struct rt_sigframe_n32 __user *frame; + mm_segment_t old_fs; sigset_t set; stack_t st; s32 sp; @@ -143,7 +144,11 @@ asmlinkage void sysn32_rt_sigreturn(nabi_no_regargs struct pt_regs regs) /* It is more difficult to avoid calling this function than to call it and ignore errors. */ + old_fs = get_fs(); + set_fs(KERNEL_DS); do_sigaltstack((stack_t __user *)&st, NULL, regs.regs[29]); + set_fs(old_fs); + /* * Don't let your children do this ... -- cgit v1.2.3-70-g09d2