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author | Linus Torvalds <torvalds@linux-foundation.org> | 2019-11-02 19:00:26 +0100 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-11-02 19:00:26 +0100 |
commit | 969a5197da89454c41d95e2404e2e9d91ad73ba6 (patch) | |
tree | bcecf84affacc307f8a3ab2c3d740d18cd916783 /arch | |
parent | Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net (diff) | |
parent | s390/idle: fix cpu idle time calculation (diff) | |
download | linux-969a5197da89454c41d95e2404e2e9d91ad73ba6.tar.xz linux-969a5197da89454c41d95e2404e2e9d91ad73ba6.zip |
Merge tag 's390-5.4-6' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 fixes from Vasily Gorbik:
- Fix cpu idle time accounting
- Fix stack unwinder case when both pt_regs and sp are specified
- Fix information leak via cmm timeout proc handler
* tag 's390-5.4-6' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
s390/idle: fix cpu idle time calculation
s390/unwind: fix mixing regs and sp
s390/cmm: fix information leak in cmm_timeout_handler()
Diffstat (limited to 'arch')
-rw-r--r-- | arch/s390/include/asm/unwind.h | 1 | ||||
-rw-r--r-- | arch/s390/kernel/idle.c | 29 | ||||
-rw-r--r-- | arch/s390/kernel/unwind_bc.c | 18 | ||||
-rw-r--r-- | arch/s390/mm/cmm.c | 12 |
4 files changed, 42 insertions, 18 deletions
diff --git a/arch/s390/include/asm/unwind.h b/arch/s390/include/asm/unwind.h index d827b5b9a32c..eaaefeceef6f 100644 --- a/arch/s390/include/asm/unwind.h +++ b/arch/s390/include/asm/unwind.h @@ -35,6 +35,7 @@ struct unwind_state { struct task_struct *task; struct pt_regs *regs; unsigned long sp, ip; + bool reuse_sp; int graph_idx; bool reliable; bool error; diff --git a/arch/s390/kernel/idle.c b/arch/s390/kernel/idle.c index b9d8fe45737a..8f8456816d83 100644 --- a/arch/s390/kernel/idle.c +++ b/arch/s390/kernel/idle.c @@ -69,18 +69,26 @@ DEVICE_ATTR(idle_count, 0444, show_idle_count, NULL); static ssize_t show_idle_time(struct device *dev, struct device_attribute *attr, char *buf) { + unsigned long long now, idle_time, idle_enter, idle_exit, in_idle; struct s390_idle_data *idle = &per_cpu(s390_idle, dev->id); - unsigned long long now, idle_time, idle_enter, idle_exit; unsigned int seq; do { - now = get_tod_clock(); seq = read_seqcount_begin(&idle->seqcount); idle_time = READ_ONCE(idle->idle_time); idle_enter = READ_ONCE(idle->clock_idle_enter); idle_exit = READ_ONCE(idle->clock_idle_exit); } while (read_seqcount_retry(&idle->seqcount, seq)); - idle_time += idle_enter ? ((idle_exit ? : now) - idle_enter) : 0; + in_idle = 0; + now = get_tod_clock(); + if (idle_enter) { + if (idle_exit) { + in_idle = idle_exit - idle_enter; + } else if (now > idle_enter) { + in_idle = now - idle_enter; + } + } + idle_time += in_idle; return sprintf(buf, "%llu\n", idle_time >> 12); } DEVICE_ATTR(idle_time_us, 0444, show_idle_time, NULL); @@ -88,17 +96,24 @@ DEVICE_ATTR(idle_time_us, 0444, show_idle_time, NULL); u64 arch_cpu_idle_time(int cpu) { struct s390_idle_data *idle = &per_cpu(s390_idle, cpu); - unsigned long long now, idle_enter, idle_exit; + unsigned long long now, idle_enter, idle_exit, in_idle; unsigned int seq; do { - now = get_tod_clock(); seq = read_seqcount_begin(&idle->seqcount); idle_enter = READ_ONCE(idle->clock_idle_enter); idle_exit = READ_ONCE(idle->clock_idle_exit); } while (read_seqcount_retry(&idle->seqcount, seq)); - - return cputime_to_nsecs(idle_enter ? ((idle_exit ?: now) - idle_enter) : 0); + in_idle = 0; + now = get_tod_clock(); + if (idle_enter) { + if (idle_exit) { + in_idle = idle_exit - idle_enter; + } else if (now > idle_enter) { + in_idle = now - idle_enter; + } + } + return cputime_to_nsecs(in_idle); } void arch_cpu_idle_enter(void) diff --git a/arch/s390/kernel/unwind_bc.c b/arch/s390/kernel/unwind_bc.c index 8fc9daae47a2..a8204f952315 100644 --- a/arch/s390/kernel/unwind_bc.c +++ b/arch/s390/kernel/unwind_bc.c @@ -46,10 +46,15 @@ bool unwind_next_frame(struct unwind_state *state) regs = state->regs; if (unlikely(regs)) { - sp = READ_ONCE_NOCHECK(regs->gprs[15]); - if (unlikely(outside_of_stack(state, sp))) { - if (!update_stack_info(state, sp)) - goto out_err; + if (state->reuse_sp) { + sp = state->sp; + state->reuse_sp = false; + } else { + sp = READ_ONCE_NOCHECK(regs->gprs[15]); + if (unlikely(outside_of_stack(state, sp))) { + if (!update_stack_info(state, sp)) + goto out_err; + } } sf = (struct stack_frame *) sp; ip = READ_ONCE_NOCHECK(sf->gprs[8]); @@ -107,9 +112,9 @@ void __unwind_start(struct unwind_state *state, struct task_struct *task, { struct stack_info *info = &state->stack_info; unsigned long *mask = &state->stack_mask; + bool reliable, reuse_sp; struct stack_frame *sf; unsigned long ip; - bool reliable; memset(state, 0, sizeof(*state)); state->task = task; @@ -134,10 +139,12 @@ void __unwind_start(struct unwind_state *state, struct task_struct *task, if (regs) { ip = READ_ONCE_NOCHECK(regs->psw.addr); reliable = true; + reuse_sp = true; } else { sf = (struct stack_frame *) sp; ip = READ_ONCE_NOCHECK(sf->gprs[8]); reliable = false; + reuse_sp = false; } #ifdef CONFIG_FUNCTION_GRAPH_TRACER @@ -151,5 +158,6 @@ void __unwind_start(struct unwind_state *state, struct task_struct *task, state->sp = sp; state->ip = ip; state->reliable = reliable; + state->reuse_sp = reuse_sp; } EXPORT_SYMBOL_GPL(__unwind_start); diff --git a/arch/s390/mm/cmm.c b/arch/s390/mm/cmm.c index 510a18299196..a51c892f14f3 100644 --- a/arch/s390/mm/cmm.c +++ b/arch/s390/mm/cmm.c @@ -298,16 +298,16 @@ static int cmm_timeout_handler(struct ctl_table *ctl, int write, } if (write) { - len = *lenp; - if (copy_from_user(buf, buffer, - len > sizeof(buf) ? sizeof(buf) : len)) + len = min(*lenp, sizeof(buf)); + if (copy_from_user(buf, buffer, len)) return -EFAULT; - buf[sizeof(buf) - 1] = '\0'; + buf[len - 1] = '\0'; cmm_skip_blanks(buf, &p); nr = simple_strtoul(p, &p, 0); cmm_skip_blanks(p, &p); seconds = simple_strtoul(p, &p, 0); cmm_set_timeout(nr, seconds); + *ppos += *lenp; } else { len = sprintf(buf, "%ld %ld\n", cmm_timeout_pages, cmm_timeout_seconds); @@ -315,9 +315,9 @@ static int cmm_timeout_handler(struct ctl_table *ctl, int write, len = *lenp; if (copy_to_user(buffer, buf, len)) return -EFAULT; + *lenp = len; + *ppos += len; } - *lenp = len; - *ppos += len; return 0; } |