diff options
| author | Leonid Yegoshin <Leonid.Yegoshin@imgtec.com> | 2013-12-12 16:57:19 +0000 |
|---|---|---|
| committer | Ralf Baechle <ralf@linux-mips.org> | 2014-03-26 23:09:17 +0100 |
| commit | ca750649e08ce37bd3873e1026dc245811adf7a8 (patch) | |
| tree | 20da25ff255abacaf73da7c9009063fd5a316027 | |
| parent | c2d85bc1041c38bebf982a0d16242c3189ca1152 (diff) | |
MIPS: kernel: signal: Prevent save/restore FPU context in user memory
EVA does not have FPU specific instructions for reading or writing
FPU registers from userspace memory.
Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
| -rw-r--r-- | arch/mips/kernel/signal.c | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/arch/mips/kernel/signal.c b/arch/mips/kernel/signal.c index fd61700409bc..33133d3df3e5 100644 --- a/arch/mips/kernel/signal.c +++ b/arch/mips/kernel/signal.c @@ -6,6 +6,7 @@ * Copyright (C) 1991, 1992 Linus Torvalds * Copyright (C) 1994 - 2000 Ralf Baechle * Copyright (C) 1999, 2000 Silicon Graphics, Inc. + * Copyright (C) 2014, Imagination Technologies Ltd. */ #include <linux/cache.h> #include <linux/context_tracking.h> @@ -140,6 +141,7 @@ static int protected_save_fp_context(struct sigcontext __user *sc, { int err; bool save_msa = cpu_has_msa && (used_math & USEDMATH_MSA); +#ifndef CONFIG_EVA while (1) { lock_fpu_owner(); if (is_fpu_owner()) { @@ -162,6 +164,17 @@ static int protected_save_fp_context(struct sigcontext __user *sc, if (err) break; /* really bad sigcontext */ } +#else + /* + * EVA does not have FPU EVA instructions so saving fpu context directly + * does not work. + */ + disable_msa(); + lose_fpu(1); + err = save_fp_context(sc); /* this might fail */ + if (save_msa && !err) + err = copy_msa_to_sigcontext(sc); +#endif return err; } @@ -170,6 +183,7 @@ static int protected_restore_fp_context(struct sigcontext __user *sc, { int err, tmp __maybe_unused; bool restore_msa = cpu_has_msa && (used_math & USEDMATH_MSA); +#ifndef CONFIG_EVA while (1) { lock_fpu_owner(); if (is_fpu_owner()) { @@ -197,6 +211,17 @@ static int protected_restore_fp_context(struct sigcontext __user *sc, if (err) break; /* really bad sigcontext */ } +#else + /* + * EVA does not have FPU EVA instructions so restoring fpu context + * directly does not work. + */ + enable_msa(); + lose_fpu(0); + err = restore_fp_context(sc); /* this might fail */ + if (restore_msa && !err) + err = copy_msa_from_sigcontext(sc); +#endif return err; } @@ -685,6 +710,7 @@ asmlinkage void do_notify_resume(struct pt_regs *regs, void *unused, } #ifdef CONFIG_SMP +#ifndef CONFIG_EVA static int smp_save_fp_context(struct sigcontext __user *sc) { return raw_cpu_has_fpu @@ -698,10 +724,12 @@ static int smp_restore_fp_context(struct sigcontext __user *sc) ? _restore_fp_context(sc) : copy_fp_from_sigcontext(sc); } +#endif /* CONFIG_EVA */ #endif static int signal_setup(void) { +#ifndef CONFIG_EVA #ifdef CONFIG_SMP /* For now just do the cpu_has_fpu check when the functions are invoked */ save_fp_context = smp_save_fp_context; @@ -714,6 +742,10 @@ static int signal_setup(void) save_fp_context = copy_fp_from_sigcontext; restore_fp_context = copy_fp_to_sigcontext; } +#endif /* CONFIG_SMP */ +#else + save_fp_context = copy_fp_from_sigcontext;; + restore_fp_context = copy_fp_to_sigcontext; #endif return 0; |