Re: [RFC v6 35/62] powerpc: Deliver SEGV signal on pkey violation
From: Eric W. Biederman <hidden>
Date: 2017-08-19 19:10:14
Ram Pai [off-list ref] writes:
quoted hunk
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
quoted hunk
+ 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