| Message ID | 1500177424-13695-36-git-send-email-linuxram@us.ibm.com (mailing list archive) |
|---|---|
| State | RFC |
| Headers | show |
Ram Pai <linuxram@us.ibm.com> writes: > diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c > index d4e545d..fe1e7c7 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 +248,15 @@ 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) > +{ > + if (si_code != SEGV_PKUERR) > + return; Given that SEGV_PKUERR is a signal specific si_code this test is insufficient to detect an pkey error. You also need to check that signr == SIGSEGV > + 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 +284,11 @@ 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); > } Eric
On Sat, Aug 19, 2017 at 02:09:58PM -0500, Eric W. Biederman wrote: > Ram Pai <linuxram@us.ibm.com> writes: > > > diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c > > index d4e545d..fe1e7c7 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 +248,15 @@ 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) > > +{ > > + if (si_code != SEGV_PKUERR) > > + return; > > Given that SEGV_PKUERR is a signal specific si_code this test is > insufficient to detect an pkey error. You also need to check > that signr == SIGSEGV true. will make it a more precise check. Thanks RP
diff --git a/arch/powerpc/include/uapi/asm/ptrace.h b/arch/powerpc/include/uapi/asm/ptrace.h index 8036b38..fc9c9c0 100644 --- a/arch/powerpc/include/uapi/asm/ptrace.h +++ b/arch/powerpc/include/uapi/asm/ptrace.h @@ -110,6 +110,7 @@ struct pt_regs { #define PT_RESULT 43 #define PT_DSCR 44 #define PT_REGS_COUNT 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..fe1e7c7 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 +248,15 @@ 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) +{ + if (si_code != SEGV_PKUERR) + return; + 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 +284,11 @@ 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); }
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 | 1 + arch/powerpc/kernel/signal_32.c | 5 +++++ arch/powerpc/kernel/signal_64.c | 4 ++++ arch/powerpc/kernel/traps.c | 15 +++++++++++++++ 4 files changed, 25 insertions(+), 0 deletions(-)