From c6a2f4679331206ef5d353fc9a6cda2fa4aef8c6 Mon Sep 17 00:00:00 2001 From: Atsushi Nemoto Date: Sat, 10 Mar 2007 01:03:48 +0900 Subject: [PATCH] [MIPS] Check FCSR for pending interrupts, alternative version Commit 6d6671066a311703bca1b91645bb1e04cc983387 is incomplete and misses non-r4k CPUs. This patch reverts the commit and fixes in other way. o Do FCSR checking in caller of restore_fp_context. o Send SIGFPE if the signal handler set any FPU exception bits. Signed-off-by: Atsushi Nemoto Signed-off-by: Ralf Baechle --- arch/mips/kernel/r4k_fpu.S | 16 ----------- arch/mips/kernel/signal-common.h | 3 +++ arch/mips/kernel/signal.c | 46 +++++++++++++++++++++++++++++--- arch/mips/kernel/signal32.c | 27 ++++++++++++++++--- arch/mips/kernel/signal_n32.c | 6 ++++- 5 files changed, 75 insertions(+), 23 deletions(-) diff --git a/arch/mips/kernel/r4k_fpu.S b/arch/mips/kernel/r4k_fpu.S index 59c1577ecbb..dbd42adc52e 100644 --- a/arch/mips/kernel/r4k_fpu.S +++ b/arch/mips/kernel/r4k_fpu.S @@ -114,14 +114,6 @@ LEAF(_save_fp_context32) */ LEAF(_restore_fp_context) EX lw t0, SC_FPC_CSR(a0) - - /* Fail if the CSR has exceptions pending */ - srl t1, t0, 5 - and t1, t0 - andi t1, 0x1f << 7 - bnez t1, fault - nop - #ifdef CONFIG_64BIT EX ldc1 $f1, SC_FPREGS+8(a0) EX ldc1 $f3, SC_FPREGS+24(a0) @@ -165,14 +157,6 @@ LEAF(_restore_fp_context) LEAF(_restore_fp_context32) /* Restore an o32 sigcontext. */ EX lw t0, SC32_FPC_CSR(a0) - - /* Fail if the CSR has exceptions pending */ - srl t1, t0, 5 - and t1, t0 - andi t1, 0x1f << 7 - bnez t1, fault - nop - EX ldc1 $f0, SC32_FPREGS+0(a0) EX ldc1 $f2, SC32_FPREGS+16(a0) EX ldc1 $f4, SC32_FPREGS+32(a0) diff --git a/arch/mips/kernel/signal-common.h b/arch/mips/kernel/signal-common.h index fdbdbdc65b5..297dfcb9752 100644 --- a/arch/mips/kernel/signal-common.h +++ b/arch/mips/kernel/signal-common.h @@ -31,4 +31,7 @@ extern void __user *get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, */ extern int install_sigtramp(unsigned int __user *tramp, unsigned int syscall); +/* Check and clear pending FPU exceptions in saved CSR */ +extern int fpcsr_pending(unsigned int __user *fpcsr); + #endif /* __SIGNAL_COMMON_H */ diff --git a/arch/mips/kernel/signal.c b/arch/mips/kernel/signal.c index f091786187a..bf094fc4c7e 100644 --- a/arch/mips/kernel/signal.c +++ b/arch/mips/kernel/signal.c @@ -124,6 +124,37 @@ int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc) return err; } +int fpcsr_pending(unsigned int __user *fpcsr) +{ + int err, sig = 0; + unsigned int csr, enabled; + + err = __get_user(csr, fpcsr); + enabled = FPU_CSR_UNI_X | ((csr & FPU_CSR_ALL_E) << 5); + /* + * If the signal handler set some FPU exceptions, clear it and + * send SIGFPE. + */ + if (csr & enabled) { + csr &= ~enabled; + err |= __put_user(csr, fpcsr); + sig = SIGFPE; + } + return err ?: sig; +} + +static int +check_and_restore_fp_context(struct sigcontext __user *sc) +{ + int err, sig; + + err = sig = fpcsr_pending(&sc->sc_fpc_csr); + if (err > 0) + err = 0; + err |= restore_fp_context(sc); + return err ?: sig; +} + int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc) { unsigned int used_math; @@ -162,7 +193,8 @@ int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc) if (used_math()) { /* restore fpu context if we have used it before */ own_fpu(); - err |= restore_fp_context(sc); + if (!err) + err = check_and_restore_fp_context(sc); } else { /* signal handler may have used FPU. Give it up. */ lose_fpu(); @@ -332,6 +364,7 @@ asmlinkage void sys_sigreturn(nabi_no_regargs struct pt_regs regs) { struct sigframe __user *frame; sigset_t blocked; + int sig; frame = (struct sigframe __user *) regs.regs[29]; if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) @@ -345,8 +378,11 @@ asmlinkage void sys_sigreturn(nabi_no_regargs struct pt_regs regs) recalc_sigpending(); spin_unlock_irq(¤t->sighand->siglock); - if (restore_sigcontext(®s, &frame->sf_sc)) + sig = restore_sigcontext(®s, &frame->sf_sc); + if (sig < 0) goto badframe; + else if (sig) + force_sig(sig, current); /* * Don't let your children do this ... @@ -368,6 +404,7 @@ 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]; if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) @@ -381,8 +418,11 @@ asmlinkage void sys_rt_sigreturn(nabi_no_regargs struct pt_regs regs) recalc_sigpending(); spin_unlock_irq(¤t->sighand->siglock); - if (restore_sigcontext(®s, &frame->rs_uc.uc_mcontext)) + sig = restore_sigcontext(®s, &frame->rs_uc.uc_mcontext); + if (sig < 0) goto badframe; + else if (sig) + force_sig(sig, current); if (__copy_from_user(&st, &frame->rs_uc.uc_stack, sizeof(st))) goto badframe; diff --git a/arch/mips/kernel/signal32.c b/arch/mips/kernel/signal32.c index 19bbef00195..20013b6fe72 100644 --- a/arch/mips/kernel/signal32.c +++ b/arch/mips/kernel/signal32.c @@ -220,6 +220,18 @@ static int setup_sigcontext32(struct pt_regs *regs, return err; } +static int +check_and_restore_fp_context32(struct sigcontext32 __user *sc) +{ + int err, sig; + + err = sig = fpcsr_pending(&sc->sc_fpc_csr); + if (err > 0) + err = 0; + err |= restore_fp_context32(sc); + return err ?: sig; +} + static int restore_sigcontext32(struct pt_regs *regs, struct sigcontext32 __user *sc) { @@ -255,7 +267,8 @@ static int restore_sigcontext32(struct pt_regs *regs, if (used_math()) { /* restore fpu context if we have used it before */ own_fpu(); - err |= restore_fp_context32(sc); + if (!err) + err = check_and_restore_fp_context32(sc); } else { /* signal handler may have used FPU. Give it up. */ lose_fpu(); @@ -508,6 +521,7 @@ asmlinkage void sys32_sigreturn(nabi_no_regargs struct pt_regs regs) { struct sigframe32 __user *frame; sigset_t blocked; + int sig; frame = (struct sigframe32 __user *) regs.regs[29]; if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) @@ -521,8 +535,11 @@ asmlinkage void sys32_sigreturn(nabi_no_regargs struct pt_regs regs) recalc_sigpending(); spin_unlock_irq(¤t->sighand->siglock); - if (restore_sigcontext32(®s, &frame->sf_sc)) + sig = restore_sigcontext32(®s, &frame->sf_sc); + if (sig < 0) goto badframe; + else if (sig) + force_sig(sig, current); /* * Don't let your children do this ... @@ -545,6 +562,7 @@ asmlinkage void sys32_rt_sigreturn(nabi_no_regargs struct pt_regs regs) sigset_t set; stack_t st; s32 sp; + int sig; frame = (struct rt_sigframe32 __user *) regs.regs[29]; if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) @@ -558,8 +576,11 @@ asmlinkage void sys32_rt_sigreturn(nabi_no_regargs struct pt_regs regs) recalc_sigpending(); spin_unlock_irq(¤t->sighand->siglock); - if (restore_sigcontext32(®s, &frame->rs_uc.uc_mcontext)) + sig = restore_sigcontext32(®s, &frame->rs_uc.uc_mcontext); + if (sig < 0) goto badframe; + else if (sig) + force_sig(sig, current); /* The ucontext contains a stack32_t, so we must convert! */ if (__get_user(sp, &frame->rs_uc.uc_stack.ss_sp)) diff --git a/arch/mips/kernel/signal_n32.c b/arch/mips/kernel/signal_n32.c index ecf1f7ecaad..a9202fa9598 100644 --- a/arch/mips/kernel/signal_n32.c +++ b/arch/mips/kernel/signal_n32.c @@ -127,6 +127,7 @@ asmlinkage void sysn32_rt_sigreturn(nabi_no_regargs struct pt_regs regs) sigset_t set; stack_t st; s32 sp; + int sig; frame = (struct rt_sigframe_n32 __user *) regs.regs[29]; if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) @@ -140,8 +141,11 @@ asmlinkage void sysn32_rt_sigreturn(nabi_no_regargs struct pt_regs regs) recalc_sigpending(); spin_unlock_irq(¤t->sighand->siglock); - if (restore_sigcontext(®s, &frame->rs_uc.uc_mcontext)) + sig = restore_sigcontext(®s, &frame->rs_uc.uc_mcontext); + if (sig < 0) goto badframe; + else if (sig) + force_sig(sig, current); /* The ucontext contains a stack32_t, so we must convert! */ if (__get_user(sp, &frame->rs_uc.uc_stack.ss_sp)) -- 2.20.1