[PATCH 4.19 63/91] Revert "drivers core: Use sysfs_emit and sysfs_emit_at for show(device *...) functions"

4.19-stable review patch. If anyone has any objections, please let me know.

------------------

From: Greg Kroah-Hartman gregkh@linuxfoundation.org

This reverts commit 3ce2cd63e8ee037644db0cbea65e6c40ab6cc178 which is commit aa838896d87af561a33ecefea1caa4c15a68bc47 upstream.

Ben writes: When I looked into the referenced security issue, it seemed to only be exploitable through wakelock names, and in the upstream kernel only after commit c8377adfa781 "PM / wakeup: Show wakeup sources stats in sysfs" (first included in 5.4). So I would be interested to know if and why a fix was needed for 4.19.

More importantly, this backported version uniformly converts to sysfs_emit(), but there are 3 places sysfs_emit_at() must be used instead:

Reported-by: Ben Hutchings ben@decadent.org.uk Link: https://lore.kernel.org/r/95831df76c41a53bc3e1ac8ece64915dd63763a1.camel@dec... Cc: Joe Perches joe@perches.com Cc: Brennan Lamoreaux blamoreaux@vmware.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/base/arch_topology.c | 2 - drivers/base/cacheinfo.c | 18 +++++------ drivers/base/core.c | 8 ++--- drivers/base/cpu.c | 34 ++++++++++----------- drivers/base/firmware_loader/fallback.c | 2 - drivers/base/memory.c | 24 +++++++-------- drivers/base/node.c | 34 ++++++++++----------- drivers/base/platform.c | 2 - drivers/base/power/sysfs.c | 50 ++++++++++++++++---------------- drivers/base/soc.c | 8 ++--- 10 files changed, 91 insertions(+), 91 deletions(-)

--- a/drivers/base/arch_topology.c +++ b/drivers/base/arch_topology.c @@ -44,7 +44,7 @@ static ssize_t cpu_capacity_show(struct { struct cpu *cpu = container_of(dev, struct cpu, dev);

- return sysfs_emit(buf, "%lu\n", topology_get_cpu_scale(NULL, cpu->dev.id)); + return sprintf(buf, "%lu\n", topology_get_cpu_scale(NULL, cpu->dev.id)); }

static ssize_t cpu_capacity_store(struct device *dev, --- a/drivers/base/cacheinfo.c +++ b/drivers/base/cacheinfo.c @@ -372,7 +372,7 @@ static ssize_t size_show(struct device * { struct cacheinfo *this_leaf = dev_get_drvdata(dev);

- return sysfs_emit(buf, "%uK\n", this_leaf->size >> 10); + return sprintf(buf, "%uK\n", this_leaf->size >> 10); }

static ssize_t shared_cpumap_show_func(struct device *dev, bool list, char *buf) @@ -402,11 +402,11 @@ static ssize_t type_show(struct device *

switch (this_leaf->type) { case CACHE_TYPE_DATA: - return sysfs_emit(buf, "Data\n"); + return sprintf(buf, "Data\n"); case CACHE_TYPE_INST: - return sysfs_emit(buf, "Instruction\n"); + return sprintf(buf, "Instruction\n"); case CACHE_TYPE_UNIFIED: - return sysfs_emit(buf, "Unified\n"); + return sprintf(buf, "Unified\n"); default: return -EINVAL; } @@ -420,11 +420,11 @@ static ssize_t allocation_policy_show(st int n = 0;

if ((ci_attr & CACHE_READ_ALLOCATE) && (ci_attr & CACHE_WRITE_ALLOCATE)) - n = sysfs_emit(buf, "ReadWriteAllocate\n"); + n = sprintf(buf, "ReadWriteAllocate\n"); else if (ci_attr & CACHE_READ_ALLOCATE) - n = sysfs_emit(buf, "ReadAllocate\n"); + n = sprintf(buf, "ReadAllocate\n"); else if (ci_attr & CACHE_WRITE_ALLOCATE) - n = sysfs_emit(buf, "WriteAllocate\n"); + n = sprintf(buf, "WriteAllocate\n"); return n; }

@@ -436,9 +436,9 @@ static ssize_t write_policy_show(struct int n = 0;

if (ci_attr & CACHE_WRITE_THROUGH) - n = sysfs_emit(buf, "WriteThrough\n"); + n = sprintf(buf, "WriteThrough\n"); else if (ci_attr & CACHE_WRITE_BACK) - n = sysfs_emit(buf, "WriteBack\n"); + n = sprintf(buf, "WriteBack\n"); return n; }

--- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -994,7 +994,7 @@ ssize_t device_show_ulong(struct device char *buf) { struct dev_ext_attribute *ea = to_ext_attr(attr); - return sysfs_emit(buf, "%lx\n", *(unsigned long *)(ea->var)); + return snprintf(buf, PAGE_SIZE, "%lx\n", *(unsigned long *)(ea->var)); } EXPORT_SYMBOL_GPL(device_show_ulong);

@@ -1019,7 +1019,7 @@ ssize_t device_show_int(struct device *d { struct dev_ext_attribute *ea = to_ext_attr(attr);

- return sysfs_emit(buf, "%d\n", *(int *)(ea->var)); + return snprintf(buf, PAGE_SIZE, "%d\n", *(int *)(ea->var)); } EXPORT_SYMBOL_GPL(device_show_int);

@@ -1040,7 +1040,7 @@ ssize_t device_show_bool(struct device * { struct dev_ext_attribute *ea = to_ext_attr(attr);

- return sysfs_emit(buf, "%d\n", *(bool *)(ea->var)); + return snprintf(buf, PAGE_SIZE, "%d\n", *(bool *)(ea->var)); } EXPORT_SYMBOL_GPL(device_show_bool);

@@ -1273,7 +1273,7 @@ static ssize_t online_show(struct device device_lock(dev); val = !dev->offline; device_unlock(dev); - return sysfs_emit(buf, "%u\n", val); + return sprintf(buf, "%u\n", val); }

static ssize_t online_store(struct device *dev, struct device_attribute *attr, --- a/drivers/base/cpu.c +++ b/drivers/base/cpu.c @@ -156,7 +156,7 @@ static ssize_t show_crash_notes(struct d * operation should be safe. No locking required. */ addr = per_cpu_ptr_to_phys(per_cpu_ptr(crash_notes, cpunum)); - rc = sysfs_emit(buf, "%Lx\n", addr); + rc = sprintf(buf, "%Lx\n", addr); return rc; } static DEVICE_ATTR(crash_notes, 0400, show_crash_notes, NULL); @@ -167,7 +167,7 @@ static ssize_t show_crash_notes_size(str { ssize_t rc;

- rc = sysfs_emit(buf, "%zu\n", sizeof(note_buf_t)); + rc = sprintf(buf, "%zu\n", sizeof(note_buf_t)); return rc; } static DEVICE_ATTR(crash_notes_size, 0400, show_crash_notes_size, NULL); @@ -264,7 +264,7 @@ static ssize_t print_cpus_offline(struct nr_cpu_ids, total_cpus-1); }

- n += sysfs_emit(&buf[n], "\n"); + n += snprintf(&buf[n], len - n, "\n"); return n; } static DEVICE_ATTR(offline, 0444, print_cpus_offline, NULL); @@ -272,7 +272,7 @@ static DEVICE_ATTR(offline, 0444, print_ static ssize_t print_cpus_isolated(struct device *dev, struct device_attribute *attr, char *buf) { - int n = 0; + int n = 0, len = PAGE_SIZE-2; cpumask_var_t isolated;

if (!alloc_cpumask_var(&isolated, GFP_KERNEL)) @@ -280,7 +280,7 @@ static ssize_t print_cpus_isolated(struc

cpumask_andnot(isolated, cpu_possible_mask, housekeeping_cpumask(HK_FLAG_DOMAIN)); - n = sysfs_emit(buf, "%*pbl\n", cpumask_pr_args(isolated)); + n = scnprintf(buf, len, "%*pbl\n", cpumask_pr_args(isolated));

free_cpumask_var(isolated);

@@ -292,9 +292,9 @@ static DEVICE_ATTR(isolated, 0444, print static ssize_t print_cpus_nohz_full(struct device *dev, struct device_attribute *attr, char *buf) { - int n = 0; + int n = 0, len = PAGE_SIZE-2;

- n = sysfs_emit(buf, "%*pbl\n", cpumask_pr_args(tick_nohz_full_mask)); + n = scnprintf(buf, len, "%*pbl\n", cpumask_pr_args(tick_nohz_full_mask));

return n; } @@ -328,7 +328,7 @@ static ssize_t print_cpu_modalias(struct ssize_t n; u32 i;

- n = sysfs_emit(buf, "cpu:type:" CPU_FEATURE_TYPEFMT ":feature:", + n = sprintf(buf, "cpu:type:" CPU_FEATURE_TYPEFMT ":feature:", CPU_FEATURE_TYPEVAL);

for (i = 0; i < MAX_CPU_FEATURES; i++) @@ -520,56 +520,56 @@ static void __init cpu_dev_register_gene ssize_t __weak cpu_show_meltdown(struct device *dev, struct device_attribute *attr, char *buf) { - return sysfs_emit(buf, "Not affected\n"); + return sprintf(buf, "Not affected\n"); }

ssize_t __weak cpu_show_spectre_v1(struct device *dev, struct device_attribute *attr, char *buf) { - return sysfs_emit(buf, "Not affected\n"); + return sprintf(buf, "Not affected\n"); }

ssize_t __weak cpu_show_spectre_v2(struct device *dev, struct device_attribute *attr, char *buf) { - return sysfs_emit(buf, "Not affected\n"); + return sprintf(buf, "Not affected\n"); }

ssize_t __weak cpu_show_spec_store_bypass(struct device *dev, struct device_attribute *attr, char *buf) { - return sysfs_emit(buf, "Not affected\n"); + return sprintf(buf, "Not affected\n"); }

ssize_t __weak cpu_show_l1tf(struct device *dev, struct device_attribute *attr, char *buf) { - return sysfs_emit(buf, "Not affected\n"); + return sprintf(buf, "Not affected\n"); }

ssize_t __weak cpu_show_mds(struct device *dev, struct device_attribute *attr, char *buf) { - return sysfs_emit(buf, "Not affected\n"); + return sprintf(buf, "Not affected\n"); }

ssize_t __weak cpu_show_tsx_async_abort(struct device *dev, struct device_attribute *attr, char *buf) { - return sysfs_emit(buf, "Not affected\n"); + return sprintf(buf, "Not affected\n"); }

ssize_t __weak cpu_show_itlb_multihit(struct device *dev, struct device_attribute *attr, char *buf) { - return sysfs_emit(buf, "Not affected\n"); + return sprintf(buf, "Not affected\n"); }

ssize_t __weak cpu_show_srbds(struct device *dev, struct device_attribute *attr, char *buf) { - return sysfs_emit(buf, "Not affected\n"); + return sprintf(buf, "Not affected\n"); }

ssize_t __weak cpu_show_mmio_stale_data(struct device *dev, --- a/drivers/base/firmware_loader/fallback.c +++ b/drivers/base/firmware_loader/fallback.c @@ -215,7 +215,7 @@ static ssize_t firmware_loading_show(str loading = fw_sysfs_loading(fw_sysfs->fw_priv); mutex_unlock(&fw_lock);

- return sysfs_emit(buf, "%d\n", loading); + return sprintf(buf, "%d\n", loading); }

/* one pages buffer should be mapped/unmapped only once */ --- a/drivers/base/memory.c +++ b/drivers/base/memory.c @@ -121,7 +121,7 @@ static ssize_t show_mem_start_phys_index unsigned long phys_index;

phys_index = mem->start_section_nr / sections_per_block; - return sysfs_emit(buf, "%08lx\n", phys_index); + return sprintf(buf, "%08lx\n", phys_index); }

/* @@ -145,7 +145,7 @@ static ssize_t show_mem_removable(struct }

out: - return sysfs_emit(buf, "%d\n", ret); + return sprintf(buf, "%d\n", ret); }

/* @@ -163,17 +163,17 @@ static ssize_t show_mem_state(struct dev */ switch (mem->state) { case MEM_ONLINE: - len = sysfs_emit(buf, "online\n"); + len = sprintf(buf, "online\n"); break; case MEM_OFFLINE: - len = sysfs_emit(buf, "offline\n"); + len = sprintf(buf, "offline\n"); break; case MEM_GOING_OFFLINE: - len = sysfs_emit(buf, "going-offline\n"); + len = sprintf(buf, "going-offline\n"); break; default: - len = sysfs_emit(buf, "ERROR-UNKNOWN-%ld\n", - mem->state); + len = sprintf(buf, "ERROR-UNKNOWN-%ld\n", + mem->state); WARN_ON(1); break; } @@ -384,7 +384,7 @@ static ssize_t show_phys_device(struct d struct device_attribute *attr, char *buf) { struct memory_block *mem = to_memory_block(dev); - return sysfs_emit(buf, "%d\n", mem->phys_device); + return sprintf(buf, "%d\n", mem->phys_device); }

#ifdef CONFIG_MEMORY_HOTREMOVE @@ -422,7 +422,7 @@ static ssize_t show_valid_zones(struct d */ if (!test_pages_in_a_zone(start_pfn, start_pfn + nr_pages, &valid_start_pfn, &valid_end_pfn)) - return sysfs_emit(buf, "none\n"); + return sprintf(buf, "none\n"); start_pfn = valid_start_pfn; strcat(buf, page_zone(pfn_to_page(start_pfn))->name); goto out; @@ -456,7 +456,7 @@ static ssize_t print_block_size(struct device *dev, struct device_attribute *attr, char *buf) { - return sysfs_emit(buf, "%lx\n", get_memory_block_size()); + return sprintf(buf, "%lx\n", get_memory_block_size()); }

static DEVICE_ATTR(block_size_bytes, 0444, print_block_size, NULL); @@ -470,9 +470,9 @@ show_auto_online_blocks(struct device *d char *buf) { if (memhp_auto_online) - return sysfs_emit(buf, "online\n"); + return sprintf(buf, "online\n"); else - return sysfs_emit(buf, "offline\n"); + return sprintf(buf, "offline\n"); }

static ssize_t --- a/drivers/base/node.c +++ b/drivers/base/node.c @@ -69,7 +69,7 @@ static ssize_t node_read_meminfo(struct struct sysinfo i;

si_meminfo_node(&i, nid); - n = sysfs_emit(buf, + n = sprintf(buf, "Node %d MemTotal: %8lu kB\n" "Node %d MemFree: %8lu kB\n" "Node %d MemUsed: %8lu kB\n" @@ -96,7 +96,7 @@ static ssize_t node_read_meminfo(struct nid, K(sum_zone_node_page_state(nid, NR_MLOCK)));

#ifdef CONFIG_HIGHMEM - n += sysfs_emit(buf + n, + n += sprintf(buf + n, "Node %d HighTotal: %8lu kB\n" "Node %d HighFree: %8lu kB\n" "Node %d LowTotal: %8lu kB\n" @@ -106,7 +106,7 @@ static ssize_t node_read_meminfo(struct nid, K(i.totalram - i.totalhigh), nid, K(i.freeram - i.freehigh)); #endif - n += sysfs_emit(buf + n, + n += sprintf(buf + n, "Node %d Dirty: %8lu kB\n" "Node %d Writeback: %8lu kB\n" "Node %d FilePages: %8lu kB\n" @@ -162,19 +162,19 @@ static DEVICE_ATTR(meminfo, S_IRUGO, nod static ssize_t node_read_numastat(struct device *dev, struct device_attribute *attr, char *buf) { - return sysfs_emit(buf, - "numa_hit %lu\n" - "numa_miss %lu\n" - "numa_foreign %lu\n" - "interleave_hit %lu\n" - "local_node %lu\n" - "other_node %lu\n", - sum_zone_numa_state(dev->id, NUMA_HIT), - sum_zone_numa_state(dev->id, NUMA_MISS), - sum_zone_numa_state(dev->id, NUMA_FOREIGN), - sum_zone_numa_state(dev->id, NUMA_INTERLEAVE_HIT), - sum_zone_numa_state(dev->id, NUMA_LOCAL), - sum_zone_numa_state(dev->id, NUMA_OTHER)); + return sprintf(buf, + "numa_hit %lu\n" + "numa_miss %lu\n" + "numa_foreign %lu\n" + "interleave_hit %lu\n" + "local_node %lu\n" + "other_node %lu\n", + sum_zone_numa_state(dev->id, NUMA_HIT), + sum_zone_numa_state(dev->id, NUMA_MISS), + sum_zone_numa_state(dev->id, NUMA_FOREIGN), + sum_zone_numa_state(dev->id, NUMA_INTERLEAVE_HIT), + sum_zone_numa_state(dev->id, NUMA_LOCAL), + sum_zone_numa_state(dev->id, NUMA_OTHER)); } static DEVICE_ATTR(numastat, S_IRUGO, node_read_numastat, NULL);

@@ -612,7 +612,7 @@ static ssize_t print_nodes_state(enum no { int n;

- n = sysfs_emit(buf, "%*pbl", + n = scnprintf(buf, PAGE_SIZE - 1, "%*pbl", nodemask_pr_args(&node_states[state])); buf[n++] = '\n'; buf[n] = '\0'; --- a/drivers/base/platform.c +++ b/drivers/base/platform.c @@ -927,7 +927,7 @@ static ssize_t driver_override_show(stru ssize_t len;

device_lock(dev); - len = sysfs_emit(buf, "%s\n", pdev->driver_override); + len = sprintf(buf, "%s\n", pdev->driver_override); device_unlock(dev); return len; } --- a/drivers/base/power/sysfs.c +++ b/drivers/base/power/sysfs.c @@ -101,7 +101,7 @@ static const char ctrl_on[] = "on"; static ssize_t control_show(struct device *dev, struct device_attribute *attr, char *buf) { - return sysfs_emit(buf, "%s\n", + return sprintf(buf, "%s\n", dev->power.runtime_auto ? ctrl_auto : ctrl_on); }

@@ -127,7 +127,7 @@ static ssize_t runtime_active_time_show( int ret; spin_lock_irq(&dev->power.lock); update_pm_runtime_accounting(dev); - ret = sysfs_emit(buf, "%i\n", jiffies_to_msecs(dev->power.active_jiffies)); + ret = sprintf(buf, "%i\n", jiffies_to_msecs(dev->power.active_jiffies)); spin_unlock_irq(&dev->power.lock); return ret; } @@ -140,7 +140,7 @@ static ssize_t runtime_suspended_time_sh int ret; spin_lock_irq(&dev->power.lock); update_pm_runtime_accounting(dev); - ret = sysfs_emit(buf, "%i\n", + ret = sprintf(buf, "%i\n", jiffies_to_msecs(dev->power.suspended_jiffies)); spin_unlock_irq(&dev->power.lock); return ret; @@ -175,7 +175,7 @@ static ssize_t runtime_status_show(struc return -EIO; } } - return sysfs_emit(buf, p); + return sprintf(buf, p); }

static DEVICE_ATTR_RO(runtime_status); @@ -185,7 +185,7 @@ static ssize_t autosuspend_delay_ms_show { if (!dev->power.use_autosuspend) return -EIO; - return sysfs_emit(buf, "%d\n", dev->power.autosuspend_delay); + return sprintf(buf, "%d\n", dev->power.autosuspend_delay); }

static ssize_t autosuspend_delay_ms_store(struct device *dev, @@ -214,11 +214,11 @@ static ssize_t pm_qos_resume_latency_us_ s32 value = dev_pm_qos_requested_resume_latency(dev);

if (value == 0) - return sysfs_emit(buf, "n/a\n"); + return sprintf(buf, "n/a\n"); if (value == PM_QOS_RESUME_LATENCY_NO_CONSTRAINT) value = 0;

- return sysfs_emit(buf, "%d\n", value); + return sprintf(buf, "%d\n", value); }

static ssize_t pm_qos_resume_latency_us_store(struct device *dev, @@ -258,11 +258,11 @@ static ssize_t pm_qos_latency_tolerance_ s32 value = dev_pm_qos_get_user_latency_tolerance(dev);

if (value < 0) - return sysfs_emit(buf, "auto\n"); + return sprintf(buf, "auto\n"); if (value == PM_QOS_LATENCY_ANY) - return sysfs_emit(buf, "any\n"); + return sprintf(buf, "any\n");

- return sysfs_emit(buf, "%d\n", value); + return sprintf(buf, "%d\n", value); }

static ssize_t pm_qos_latency_tolerance_us_store(struct device *dev, @@ -294,8 +294,8 @@ static ssize_t pm_qos_no_power_off_show( struct device_attribute *attr, char *buf) { - return sysfs_emit(buf, "%d\n", !!(dev_pm_qos_requested_flags(dev) - & PM_QOS_FLAG_NO_POWER_OFF)); + return sprintf(buf, "%d\n", !!(dev_pm_qos_requested_flags(dev) + & PM_QOS_FLAG_NO_POWER_OFF)); }

static ssize_t pm_qos_no_power_off_store(struct device *dev, @@ -323,9 +323,9 @@ static const char _disabled[] = "disable static ssize_t wakeup_show(struct device *dev, struct device_attribute *attr, char *buf) { - return sysfs_emit(buf, "%s\n", device_can_wakeup(dev) - ? (device_may_wakeup(dev) ? _enabled : _disabled) - : ""); + return sprintf(buf, "%s\n", device_can_wakeup(dev) + ? (device_may_wakeup(dev) ? _enabled : _disabled) + : ""); }

static ssize_t wakeup_store(struct device *dev, struct device_attribute *attr, @@ -511,7 +511,7 @@ static DEVICE_ATTR_RO(wakeup_prevent_sle static ssize_t runtime_usage_show(struct device *dev, struct device_attribute *attr, char *buf) { - return sysfs_emit(buf, "%d\n", atomic_read(&dev->power.usage_count)); + return sprintf(buf, "%d\n", atomic_read(&dev->power.usage_count)); } static DEVICE_ATTR_RO(runtime_usage);

@@ -519,8 +519,8 @@ static ssize_t runtime_active_kids_show( struct device_attribute *attr, char *buf) { - return sysfs_emit(buf, "%d\n", dev->power.ignore_children ? - 0 : atomic_read(&dev->power.child_count)); + return sprintf(buf, "%d\n", dev->power.ignore_children ? + 0 : atomic_read(&dev->power.child_count)); } static DEVICE_ATTR_RO(runtime_active_kids);

@@ -528,12 +528,12 @@ static ssize_t runtime_enabled_show(stru struct device_attribute *attr, char *buf) { if (dev->power.disable_depth && (dev->power.runtime_auto == false)) - return sysfs_emit(buf, "disabled & forbidden\n"); + return sprintf(buf, "disabled & forbidden\n"); if (dev->power.disable_depth) - return sysfs_emit(buf, "disabled\n"); + return sprintf(buf, "disabled\n"); if (dev->power.runtime_auto == false) - return sysfs_emit(buf, "forbidden\n"); - return sysfs_emit(buf, "enabled\n"); + return sprintf(buf, "forbidden\n"); + return sprintf(buf, "enabled\n"); } static DEVICE_ATTR_RO(runtime_enabled);

@@ -541,9 +541,9 @@ static DEVICE_ATTR_RO(runtime_enabled); static ssize_t async_show(struct device *dev, struct device_attribute *attr, char *buf) { - return sysfs_emit(buf, "%s\n", - device_async_suspend_enabled(dev) ? - _enabled : _disabled); + return sprintf(buf, "%s\n", + device_async_suspend_enabled(dev) ? + _enabled : _disabled); }

static ssize_t async_store(struct device *dev, struct device_attribute *attr, --- a/drivers/base/soc.c +++ b/drivers/base/soc.c @@ -72,13 +72,13 @@ static ssize_t soc_info_get(struct devic struct soc_device *soc_dev = container_of(dev, struct soc_device, dev);

if (attr == &dev_attr_machine) - return sysfs_emit(buf, "%s\n", soc_dev->attr->machine); + return sprintf(buf, "%s\n", soc_dev->attr->machine); if (attr == &dev_attr_family) - return sysfs_emit(buf, "%s\n", soc_dev->attr->family); + return sprintf(buf, "%s\n", soc_dev->attr->family); if (attr == &dev_attr_revision) - return sysfs_emit(buf, "%s\n", soc_dev->attr->revision); + return sprintf(buf, "%s\n", soc_dev->attr->revision); if (attr == &dev_attr_soc_id) - return sysfs_emit(buf, "%s\n", soc_dev->attr->soc_id); + return sprintf(buf, "%s\n", soc_dev->attr->soc_id);

return -EINVAL;