diff options
| -rw-r--r-- | arch/x86_64/kernel/process.c | 8 | ||||
| -rw-r--r-- | include/asm-x86_64/pda.h | 7 | ||||
| -rw-r--r-- | include/linux/sched.h | 5 | ||||
| -rw-r--r-- | kernel/fork.c | 5 |
4 files changed, 24 insertions, 1 deletions
diff --git a/arch/x86_64/kernel/process.c b/arch/x86_64/kernel/process.c index 9e9a70e50c72..fba8dfeda67c 100644 --- a/arch/x86_64/kernel/process.c +++ b/arch/x86_64/kernel/process.c @@ -625,6 +625,14 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p) unlazy_fpu(prev_p); write_pda(kernelstack, task_stack_page(next_p) + THREAD_SIZE - PDA_STACKOFFSET); +#ifdef CONFIG_CC_STACKPROTECTOR + write_pda(stack_canary, next_p->stack_canary); + /* + * Build time only check to make sure the stack_canary is at + * offset 40 in the pda; this is a gcc ABI requirement + */ + BUILD_BUG_ON(offsetof(struct x8664_pda, stack_canary) != 40); +#endif /* * Now maybe reload the debug registers and handle I/O bitmaps diff --git a/include/asm-x86_64/pda.h b/include/asm-x86_64/pda.h index 6794ffaae433..e7773e0af865 100644 --- a/include/asm-x86_64/pda.h +++ b/include/asm-x86_64/pda.h @@ -16,7 +16,12 @@ struct x8664_pda { unsigned long oldrsp; /* 24 user rsp for system call */ int irqcount; /* 32 Irq nesting counter. Starts with -1 */ int cpunumber; /* 36 Logical CPU number */ - char *irqstackptr; /* 40 top of irqstack */ +#ifdef CONFIG_CC_STACKPROTECTOR + unsigned long stack_canary; /* 40 stack canary value */ + /* gcc-ABI: this canary MUST be at + offset 40!!! */ +#endif + char *irqstackptr; int nodenumber; /* number of current node */ unsigned int __softirq_pending; unsigned int __nmi_count; /* number of NMI on this CPUs */ diff --git a/include/linux/sched.h b/include/linux/sched.h index 807556c5bcd2..9d4aa7f95bc8 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -819,6 +819,11 @@ struct task_struct { unsigned did_exec:1; pid_t pid; pid_t tgid; + +#ifdef CONFIG_CC_STACKPROTECTOR + /* Canary value for the -fstack-protector gcc feature */ + unsigned long stack_canary; +#endif /* * pointers to (original) parent process, youngest child, younger sibling, * older sibling, respectively. (p->father can be replaced with diff --git a/kernel/fork.c b/kernel/fork.c index f9b014e3e700..a0dad84567c9 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -45,6 +45,7 @@ #include <linux/cn_proc.h> #include <linux/delayacct.h> #include <linux/taskstats_kern.h> +#include <linux/random.h> #include <asm/pgtable.h> #include <asm/pgalloc.h> @@ -175,6 +176,10 @@ static struct task_struct *dup_task_struct(struct task_struct *orig) tsk->thread_info = ti; setup_thread_stack(tsk, orig); +#ifdef CONFIG_CC_STACKPROTECTOR + tsk->stack_canary = get_random_int(); +#endif + /* One for us, one for whoever does the "release_task()" (usually parent) */ atomic_set(&tsk->usage,2); atomic_set(&tsk->fs_excl, 0); |