diff mbox

[RFC,v5,33/38] powerpc: Deliver SEGV signal on pkey violation

Message ID 1499289735-14220-34-git-send-email-linuxram@us.ibm.com (mailing list archive)
State Superseded
Headers show

Commit Message

Ram Pai July 5, 2017, 9:22 p.m. UTC 
The value of the AMR register at the time of exception
is made available in gp_regs[PT_AMR] of the siginfo.

The value of the pkey, whose protection got violated,
is made available in si_pkey field of the siginfo structure.

Signed-off-by: Ram Pai <linuxram@us.ibm.com>
---
 arch/powerpc/include/uapi/asm/ptrace.h |    3 ++-
 arch/powerpc/kernel/signal_32.c        |    5 +++++
 arch/powerpc/kernel/signal_64.c        |    4 ++++
 arch/powerpc/kernel/traps.c            |   14 ++++++++++++++
 4 files changed, 25 insertions(+), 1 deletions(-)

Comments

Anshuman Khandual July 10, 2017, 3:08 a.m. UTC | #1 
On 07/06/2017 02:52 AM, Ram Pai wrote:
> The value of the AMR register at the time of exception
> is made available in gp_regs[PT_AMR] of the siginfo.
> 
> The value of the pkey, whose protection got violated,
> is made available in si_pkey field of the siginfo structure.
> 
> Signed-off-by: Ram Pai <linuxram@us.ibm.com>
> ---
>  arch/powerpc/include/uapi/asm/ptrace.h |    3 ++-
>  arch/powerpc/kernel/signal_32.c        |    5 +++++
>  arch/powerpc/kernel/signal_64.c        |    4 ++++
>  arch/powerpc/kernel/traps.c            |   14 ++++++++++++++
>  4 files changed, 25 insertions(+), 1 deletions(-)
> 
> diff --git a/arch/powerpc/include/uapi/asm/ptrace.h b/arch/powerpc/include/uapi/asm/ptrace.h
> index 8036b38..7ec2428 100644
> --- a/arch/powerpc/include/uapi/asm/ptrace.h
> +++ b/arch/powerpc/include/uapi/asm/ptrace.h
> @@ -108,8 +108,9 @@ struct pt_regs {
>  #define PT_DAR	41
>  #define PT_DSISR 42
>  #define PT_RESULT 43
> -#define PT_DSCR 44
>  #define PT_REGS_COUNT 44
> +#define PT_DSCR 44
> +#define PT_AMR	45

Why PT_DSCR was moved down ? This change is redundant here.
diff mbox

Patch

diff --git a/arch/powerpc/include/uapi/asm/ptrace.h b/arch/powerpc/include/uapi/asm/ptrace.h
index 8036b38..7ec2428 100644
--- a/arch/powerpc/include/uapi/asm/ptrace.h
+++ b/arch/powerpc/include/uapi/asm/ptrace.h
@@ -108,8 +108,9 @@  struct pt_regs {
 #define PT_DAR	41
 #define PT_DSISR 42
 #define PT_RESULT 43
-#define PT_DSCR 44
 #define PT_REGS_COUNT 44
+#define PT_DSCR 44
+#define PT_AMR	45
 
 #define PT_FPR0	48	/* each FP reg occupies 2 slots in this space */
 
diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index 97bb138..9c4a7f3 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -500,6 +500,11 @@  static int save_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
 				   (unsigned long) &frame->tramp[2]);
 	}
 
+#ifdef CONFIG_PPC64_MEMORY_PROTECTION_KEYS
+	if (__put_user(get_paca()->paca_amr, &frame->mc_gregs[PT_AMR]))
+		return 1;
+#endif /*  CONFIG_PPC64_MEMORY_PROTECTION_KEYS */
+
 	return 0;
 }
 
diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c
index c83c115..86a4262 100644
--- a/arch/powerpc/kernel/signal_64.c
+++ b/arch/powerpc/kernel/signal_64.c
@@ -174,6 +174,10 @@  static long setup_sigcontext(struct sigcontext __user *sc,
 	if (set != NULL)
 		err |=  __put_user(set->sig[0], &sc->oldmask);
 
+#ifdef CONFIG_PPC64_MEMORY_PROTECTION_KEYS
+	err |= __put_user(get_paca()->paca_amr, &sc->gp_regs[PT_AMR]);
+#endif /*  CONFIG_PPC64_MEMORY_PROTECTION_KEYS */
+
 	return err;
 }
 
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index d4e545d..cc0a8c4 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -20,6 +20,7 @@ 
 #include <linux/sched/debug.h>
 #include <linux/kernel.h>
 #include <linux/mm.h>
+#include <linux/pkeys.h>
 #include <linux/stddef.h>
 #include <linux/unistd.h>
 #include <linux/ptrace.h>
@@ -247,6 +248,14 @@  void user_single_step_siginfo(struct task_struct *tsk,
 	info->si_addr = (void __user *)regs->nip;
 }
 
+#ifdef CONFIG_PPC64_MEMORY_PROTECTION_KEYS
+static void fill_sig_info_pkey(int si_code, siginfo_t *info, unsigned long addr)
+{
+	WARN_ON(si_code != SEGV_PKUERR);
+	info->si_pkey = get_paca()->paca_pkey;
+}
+#endif /* CONFIG_PPC64_MEMORY_PROTECTION_KEYS */
+
 void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr)
 {
 	siginfo_t info;
@@ -274,6 +283,11 @@  void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr)
 	info.si_signo = signr;
 	info.si_code = code;
 	info.si_addr = (void __user *) addr;
+
+#ifdef CONFIG_PPC64_MEMORY_PROTECTION_KEYS
+	fill_sig_info_pkey(code, &info, addr);
+#endif /* CONFIG_PPC64_MEMORY_PROTECTION_KEYS */
+
 	force_sig_info(signr, &info, current);
 }