diff options
Diffstat (limited to 'recipes/linux/linux-omap-psp-2.6.32/0032-ARM-VFP-preserve-the-HW-context-when-calling-signal-.patch')
| -rw-r--r-- | recipes/linux/linux-omap-psp-2.6.32/0032-ARM-VFP-preserve-the-HW-context-when-calling-signal-.patch | 211 |
1 files changed, 211 insertions, 0 deletions
diff --git a/recipes/linux/linux-omap-psp-2.6.32/0032-ARM-VFP-preserve-the-HW-context-when-calling-signal-.patch b/recipes/linux/linux-omap-psp-2.6.32/0032-ARM-VFP-preserve-the-HW-context-when-calling-signal-.patch new file mode 100644 index 0000000000..90db80a3d5 --- /dev/null +++ b/recipes/linux/linux-omap-psp-2.6.32/0032-ARM-VFP-preserve-the-HW-context-when-calling-signal-.patch @@ -0,0 +1,211 @@ +From fb730244df2f3bd3f51b6f052c4c0dbe2e1428f4 Mon Sep 17 00:00:00 2001 +From: Imre Deak <imre.deak@nokia.com> +Date: Thu, 4 Feb 2010 21:38:30 +0200 +Subject: [PATCH 32/32] ARM: VFP: preserve the HW context when calling signal handlers + +ARM: VFP: preserve the HW context when calling signal handlers + +Signal handlers can use floating point, so prevent them to corrupt +the main thread's VFP context. So far there were two signal stack +frame formats defined based on the VFP implementation, but the user +struct used for ptrace covers all posibilities, so use it for the +signal stack too. This patch extends the user struct and leaves +its magic number the same, in the hope that user space code does +not depend on its size and can parse the original regs w/o +problems. + +Support to save / restore the exception registers was added by +Will Deacon. + +Signed-off-by: Imre Deak <imre.deak@nokia.com> +Signed-off-by: Will Deacon <will.deacon@arm.com> +Signed-off-by: Bryan Wu <bryan.wu@canonical.com> +--- + arch/arm/include/asm/ucontext.h | 19 +++----- + arch/arm/include/asm/user.h | 3 + + arch/arm/kernel/signal.c | 91 +++++++++++++++++++++++++++++++++++++-- + 3 files changed, 97 insertions(+), 16 deletions(-) + +diff --git a/arch/arm/include/asm/ucontext.h b/arch/arm/include/asm/ucontext.h +index bf65e9f..1c3236b 100644 +--- a/arch/arm/include/asm/ucontext.h ++++ b/arch/arm/include/asm/ucontext.h +@@ -59,23 +59,18 @@ struct iwmmxt_sigframe { + #endif /* CONFIG_IWMMXT */ + + #ifdef CONFIG_VFP +-#if __LINUX_ARM_ARCH__ < 6 +-/* For ARM pre-v6, we use fstmiax and fldmiax. This adds one extra +- * word after the registers, and a word of padding at the end for +- * alignment. */ + #define VFP_MAGIC 0x56465001 +-#define VFP_STORAGE_SIZE 152 +-#else +-#define VFP_MAGIC 0x56465002 +-#define VFP_STORAGE_SIZE 144 +-#endif + + struct vfp_sigframe + { + unsigned long magic; + unsigned long size; +- union vfp_state storage; +-}; ++ struct user_vfp ufp; ++} __attribute__((__aligned__(8))); ++ ++/* 8 byte for magic and size, 272 byte for ufp */ ++#define VFP_STORAGE_SIZE sizeof(struct vfp_sigframe) ++ + #endif /* CONFIG_VFP */ + + /* +@@ -91,7 +86,7 @@ struct aux_sigframe { + #ifdef CONFIG_IWMMXT + struct iwmmxt_sigframe iwmmxt; + #endif +-#if 0 && defined CONFIG_VFP /* Not yet saved. */ ++#ifdef CONFIG_VFP + struct vfp_sigframe vfp; + #endif + /* Something that isn't a valid magic number for any coprocessor. */ +diff --git a/arch/arm/include/asm/user.h b/arch/arm/include/asm/user.h +index df95e05..ea7e44d 100644 +--- a/arch/arm/include/asm/user.h ++++ b/arch/arm/include/asm/user.h +@@ -88,6 +88,9 @@ struct user{ + struct user_vfp { + unsigned long long fpregs[32]; + unsigned long fpscr; ++ unsigned long fpexc; ++ unsigned long fpinst; ++ unsigned long fpinst2; + }; + + #endif /* _ARM_USER_H */ +diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c +index e7714f3..6a36851 100644 +--- a/arch/arm/kernel/signal.c ++++ b/arch/arm/kernel/signal.c +@@ -18,6 +18,7 @@ + #include <asm/cacheflush.h> + #include <asm/ucontext.h> + #include <asm/unistd.h> ++#include <asm/vfp.h> + + #include "ptrace.h" + #include "signal.h" +@@ -175,6 +176,88 @@ static int restore_iwmmxt_context(struct iwmmxt_sigframe *frame) + + #endif + ++#ifdef CONFIG_VFP ++ ++static int preserve_vfp_context(struct vfp_sigframe __user *frame) ++{ ++ struct thread_info *thread = current_thread_info(); ++ struct vfp_hard_struct *h = &thread->vfpstate.hard; ++ const unsigned long magic = VFP_MAGIC; ++ const unsigned long size = VFP_STORAGE_SIZE; ++ int err = 0; ++ ++ vfp_sync_state(thread); ++ __put_user_error(magic, &frame->magic, err); ++ __put_user_error(size, &frame->size, err); ++ ++ /* ++ * Copy the floating point registers. There can be unused ++ * registers see asm/hwcap.h for details. ++ */ ++ err |= __copy_to_user(&frame->ufp.fpregs, &h->fpregs, ++ sizeof(h->fpregs)); ++ /* ++ * Copy the status and control register. ++ */ ++ __put_user_error(h->fpscr, &frame->ufp.fpscr, err); ++ ++ /* ++ * Copy the exception registers. ++ */ ++ __put_user_error(h->fpexc, &frame->ufp.fpexc, err); ++ __put_user_error(h->fpinst, &frame->ufp.fpinst, err); ++ __put_user_error(h->fpinst2, &frame->ufp.fpinst2, err); ++ ++ return err ? -EFAULT : 0; ++} ++ ++static int restore_vfp_context(struct vfp_sigframe __user *frame) ++{ ++ struct thread_info *thread = current_thread_info(); ++ struct vfp_hard_struct *h = &thread->vfpstate.hard; ++ unsigned long magic; ++ unsigned long size; ++ unsigned long fpexc; ++ int err = 0; ++ ++ vfp_sync_state(thread); ++ __get_user_error(magic, &frame->magic, err); ++ __get_user_error(size, &frame->size, err); ++ ++ if (err) ++ return -EFAULT; ++ if (magic != VFP_MAGIC || size != VFP_STORAGE_SIZE) ++ return -EINVAL; ++ ++ /* ++ * Copy the floating point registers. There can be unused ++ * registers see asm/hwcap.h for details. ++ */ ++ err |= __copy_from_user(&h->fpregs, &frame->ufp.fpregs, ++ sizeof(h->fpregs)); ++ /* ++ * Copy the status and control register. ++ */ ++ __get_user_error(h->fpscr, &frame->ufp.fpscr, err); ++ ++ /* ++ * Sanitise and restore the exception registers. ++ */ ++ __get_user_error(fpexc, &frame->ufp.fpexc, err); ++ /* Ensure the VFP is enabled. */ ++ fpexc |= FPEXC_EN; ++ /* Ensure FPINST2 is invalid and the exception flag is cleared. */ ++ fpexc &= ~(FPEXC_EX | FPEXC_FP2V); ++ h->fpexc = fpexc; ++ ++ __get_user_error(h->fpinst, &frame->ufp.fpinst, err); ++ __get_user_error(h->fpinst2, &frame->ufp.fpinst2, err); ++ ++ return err ? -EFAULT : 0; ++} ++ ++#endif ++ + /* + * Do a signal return; undo the signal stack. These are aligned to 64-bit. + */ +@@ -233,8 +316,8 @@ static int restore_sigframe(struct pt_regs *regs, struct sigframe __user *sf) + err |= restore_iwmmxt_context(&aux->iwmmxt); + #endif + #ifdef CONFIG_VFP +-// if (err == 0) +-// err |= vfp_restore_state(&sf->aux.vfp); ++ if (err == 0) ++ err |= restore_vfp_context(&aux->vfp); + #endif + + return err; +@@ -348,8 +431,8 @@ setup_sigframe(struct sigframe __user *sf, struct pt_regs *regs, sigset_t *set) + err |= preserve_iwmmxt_context(&aux->iwmmxt); + #endif + #ifdef CONFIG_VFP +-// if (err == 0) +-// err |= vfp_save_state(&sf->aux.vfp); ++ if (err == 0) ++ err |= preserve_vfp_context(&aux->vfp); + #endif + __put_user_error(0, &aux->end_magic, err); + +-- +1.6.6.1 + |