From c6a2f4679331206ef5d353fc9a6cda2fa4aef8c6 Mon Sep 17 00:00:00 2001 From: Atsushi Nemoto Date: Sat, 10 Mar 2007 01:03:48 +0900 Subject: [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/signal.c | 46 +++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 43 insertions(+), 3 deletions(-) (limited to 'arch/mips/kernel/signal.c') diff --git a/arch/mips/kernel/signal.c b/arch/mips/kernel/signal.c index f091786187a6..bf094fc4c7eb 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; -- cgit v1.2.1 From 53dc80287da43b75df2fe2658651d3c5160dad8e Mon Sep 17 00:00:00 2001 From: Atsushi Nemoto Date: Sat, 10 Mar 2007 01:07:45 +0900 Subject: [MIPS] FPU ownership management & preemption fixes Signed-off-by: Atsushi Nemoto Signed-off-by: Ralf Baechle --- arch/mips/kernel/signal.c | 29 ++++++++++++----------------- 1 file changed, 12 insertions(+), 17 deletions(-) (limited to 'arch/mips/kernel/signal.c') diff --git a/arch/mips/kernel/signal.c b/arch/mips/kernel/signal.c index bf094fc4c7eb..8c3c5a5789b0 100644 --- a/arch/mips/kernel/signal.c +++ b/arch/mips/kernel/signal.c @@ -82,6 +82,7 @@ int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc) { int err = 0; int i; + unsigned int used_math; err |= __put_user(regs->cp0_epc, &sc->sc_pc); @@ -104,22 +105,18 @@ int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc) err |= __put_user(rddsp(DSP_MASK), &sc->sc_dsp); } - err |= __put_user(!!used_math(), &sc->sc_used_math); + used_math = !!used_math(); + err |= __put_user(used_math, &sc->sc_used_math); - if (used_math()) { + if (used_math) { /* * Save FPU state to signal context. Signal handler * will "inherit" current FPU state. */ - preempt_disable(); - - if (!is_fpu_owner()) { - own_fpu(); - restore_fp(current); - } + own_fpu(1); + enable_fp_in_kernel(); err |= save_fp_context(sc); - - preempt_enable(); + disable_fp_in_kernel(); } return err; } @@ -188,20 +185,18 @@ int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc) err |= __get_user(used_math, &sc->sc_used_math); conditional_used_math(used_math); - preempt_disable(); - - if (used_math()) { + if (used_math) { /* restore fpu context if we have used it before */ - own_fpu(); + own_fpu(0); + enable_fp_in_kernel(); if (!err) err = check_and_restore_fp_context(sc); + disable_fp_in_kernel(); } else { /* signal handler may have used FPU. Give it up. */ - lose_fpu(); + lose_fpu(0); } - preempt_enable(); - return err; } -- cgit v1.2.1