diff options
| author | Madhavan Srinivasan <maddy@linux.vnet.ibm.com> | 2017-08-20 23:28:24 +0530 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2018-01-19 22:36:54 +1100 |
| commit | a8a4b03ab95f3e99196b0a4dd40804620ea77e74 (patch) | |
| tree | 210d0a819712c7301180bdf862d56f09d41bb12c /arch | |
| parent | 7a074fc08389f43b448ebef74bf56ba0f6f087d9 (diff) | |
powerpc: Hard wire PT_SOFTE value to 1 in ptrace & signals
We have always had softe in pt_regs, and accessible via PT_SOFTE, even
though it is not userspace state.
The value userspace sees should always be 1, because we should never
be in userspace with interrupts soft disabled.
In a subsequent patch we will be changing the semantics of the kernel
softe value, so hard wire the value to 1 to retain the existing
semantics. As far as we know nothing ever looks at it, but better safe
than sorry.
Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
[mpe: Split out of larger patch, write change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/powerpc/kernel/ptrace.c | 12 | ||||
| -rw-r--r-- | arch/powerpc/kernel/signal_32.c | 8 | ||||
| -rw-r--r-- | arch/powerpc/kernel/signal_64.c | 3 |
3 files changed, 23 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c index f52ad5bb7109..bd2c49475473 100644 --- a/arch/powerpc/kernel/ptrace.c +++ b/arch/powerpc/kernel/ptrace.c @@ -283,6 +283,18 @@ int ptrace_get_reg(struct task_struct *task, int regno, unsigned long *data) if (regno == PT_DSCR) return get_user_dscr(task, data); +#ifdef CONFIG_PPC64 + /* + * softe copies paca->soft_enabled variable state. Since soft_enabled is + * no more used as a flag, lets force usr to alway see the softe value as 1 + * which means interrupts are not soft disabled. + */ + if (regno == PT_SOFTE) { + *data = 1; + return 0; + } +#endif + if (regno < (sizeof(struct pt_regs) / sizeof(unsigned long))) { *data = ((unsigned long *)task->thread.regs)[regno]; return 0; diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c index 9ffd73296f64..a30c6562ed66 100644 --- a/arch/powerpc/kernel/signal_32.c +++ b/arch/powerpc/kernel/signal_32.c @@ -111,12 +111,20 @@ static inline int save_general_regs(struct pt_regs *regs, { elf_greg_t64 *gregs = (elf_greg_t64 *)regs; int i; + /* Force usr to alway see softe as 1 (interrupts enabled) */ + elf_greg_t64 softe = 0x1; WARN_ON(!FULL_REGS(regs)); for (i = 0; i <= PT_RESULT; i ++) { if (i == 14 && !FULL_REGS(regs)) i = 32; + if ( i == PT_SOFTE) { + if(__put_user((unsigned int)softe, &frame->mc_gregs[i])) + return -EFAULT; + else + continue; + } if (__put_user((unsigned int)gregs[i], &frame->mc_gregs[i])) return -EFAULT; } diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c index 4b9ca3570344..2705fba544ad 100644 --- a/arch/powerpc/kernel/signal_64.c +++ b/arch/powerpc/kernel/signal_64.c @@ -110,6 +110,8 @@ static long setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs = tsk->thread.regs; unsigned long msr = regs->msr; long err = 0; + /* Force usr to alway see softe as 1 (interrupts enabled) */ + unsigned long softe = 0x1; BUG_ON(tsk != current); @@ -169,6 +171,7 @@ static long setup_sigcontext(struct sigcontext __user *sc, WARN_ON(!FULL_REGS(regs)); err |= __copy_to_user(&sc->gp_regs, regs, GP_REGS_SIZE); err |= __put_user(msr, &sc->gp_regs[PT_MSR]); + err |= __put_user(softe, &sc->gp_regs[PT_SOFTE]); err |= __put_user(signr, &sc->signal); err |= __put_user(handler, &sc->handler); if (set != NULL) |