user/sven/linux.git/drivers/acpi/cppc_acpi.c, branch v4.19.226

ACPI: CPPC: Replace cppc_attr with kobj_attribute

2021-05-22T08:59:30Z

[ Upstream commit 2bc6262c6117dd18106d5aa50d53e945b5d99c51 ] All of the CPPC sysfs show functions are called via indirect call in kobj_attr_show(), where they should be of type ssize_t (*show)(struct kobject *kobj, struct kobj_attribute *attr, char *buf); because that is the type of the ->show() member in 'struct kobj_attribute' but they are actually of type ssize_t (*show)(struct kobject *kobj, struct attribute *attr, char *buf); because of the ->show() member in 'struct cppc_attr', resulting in a Control Flow Integrity violation [1]. $ cat /sys/devices/system/cpu/cpu0/acpi_cppc/highest_perf 3400 $ dmesg | grep "CFI failure" [ 175.970559] CFI failure (target: show_highest_perf+0x0/0x8): As far as I can tell, the only difference between 'struct cppc_attr' and 'struct kobj_attribute' aside from the type of the attr parameter is the type of the count parameter in the ->store() member (ssize_t vs. size_t), which does not actually matter because all of these nodes are read-only. Eliminate 'struct cppc_attr' in favor of 'struct kobj_attribute' to fix the violation. [1]: https://lore.kernel.org/r/20210401233216.2540591-1-samitolvanen@google.com/ Fixes: 158c998ea44b ("ACPI / CPPC: add sysfs support to compute delivered performance") Link: https://github.com/ClangBuiltLinux/linux/issues/1343 Signed-off-by: Nathan Chancellor Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin

ACPI: CPPC: Fix reference count leak in acpi_cppc_processor_probe()

2020-06-22T07:05:02Z

commit 4d8be4bc94f74bb7d096e1c2e44457b530d5a170 upstream. kobject_init_and_add() takes reference even when it fails. If this function returns an error, kobject_put() must be called to properly clean up the memory associated with the object. Previous commit "b8eb718348b8" fixed a similar problem. Fixes: 158c998ea44b ("ACPI / CPPC: add sysfs support to compute delivered performance") Signed-off-by: Qiushi Wu Cc: 4.10+ # 4.10+ Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman

ACPI: CPPC: Set pcc_data[pcc_ss_id] to NULL in acpi_cppc_processor_exit()

2019-10-29T08:19:52Z

commit 56a0b978d42f58c7e3ba715cf65af487d427524d upstream. When enabling KASAN and DEBUG_TEST_DRIVER_REMOVE, I find this KASAN warning: [ 20.872057] BUG: KASAN: use-after-free in pcc_data_alloc+0x40/0xb8 [ 20.878226] Read of size 4 at addr ffff00236cdeb684 by task swapper/0/1 [ 20.884826] [ 20.886309] CPU: 19 PID: 1 Comm: swapper/0 Not tainted 5.4.0-rc1-00009-ge7f7df3db5bf-dirty #289 [ 20.894994] Hardware name: Huawei D06 /D06, BIOS Hisilicon D06 UEFI RC0 - V1.16.01 03/15/2019 [ 20.903505] Call trace: [ 20.905942] dump_backtrace+0x0/0x200 [ 20.909593] show_stack+0x14/0x20 [ 20.912899] dump_stack+0xd4/0x130 [ 20.916291] print_address_description.isra.9+0x6c/0x3b8 [ 20.921592] __kasan_report+0x12c/0x23c [ 20.925417] kasan_report+0xc/0x18 [ 20.928808] __asan_load4+0x94/0xb8 [ 20.932286] pcc_data_alloc+0x40/0xb8 [ 20.935938] acpi_cppc_processor_probe+0x4e8/0xb08 [ 20.940717] __acpi_processor_start+0x48/0xb0 [ 20.945062] acpi_processor_start+0x40/0x60 [ 20.949235] really_probe+0x118/0x548 [ 20.952887] driver_probe_device+0x7c/0x148 [ 20.957059] device_driver_attach+0x94/0xa0 [ 20.961231] __driver_attach+0xa4/0x110 [ 20.965055] bus_for_each_dev+0xe8/0x158 [ 20.968966] driver_attach+0x30/0x40 [ 20.972531] bus_add_driver+0x234/0x2f0 [ 20.976356] driver_register+0xbc/0x1d0 [ 20.980182] acpi_processor_driver_init+0x40/0xe4 [ 20.984875] do_one_initcall+0xb4/0x254 [ 20.988700] kernel_init_freeable+0x24c/0x2f8 [ 20.993047] kernel_init+0x10/0x118 [ 20.996524] ret_from_fork+0x10/0x18 [ 21.000087] [ 21.001567] Allocated by task 1: [ 21.004785] save_stack+0x28/0xc8 [ 21.008089] __kasan_kmalloc.isra.9+0xbc/0xd8 [ 21.012435] kasan_kmalloc+0xc/0x18 [ 21.015913] pcc_data_alloc+0x94/0xb8 [ 21.019564] acpi_cppc_processor_probe+0x4e8/0xb08 [ 21.024343] __acpi_processor_start+0x48/0xb0 [ 21.028689] acpi_processor_start+0x40/0x60 [ 21.032860] really_probe+0x118/0x548 [ 21.036512] driver_probe_device+0x7c/0x148 [ 21.040684] device_driver_attach+0x94/0xa0 [ 21.044855] __driver_attach+0xa4/0x110 [ 21.048680] bus_for_each_dev+0xe8/0x158 [ 21.052591] driver_attach+0x30/0x40 [ 21.056155] bus_add_driver+0x234/0x2f0 [ 21.059980] driver_register+0xbc/0x1d0 [ 21.063805] acpi_processor_driver_init+0x40/0xe4 [ 21.068497] do_one_initcall+0xb4/0x254 [ 21.072322] kernel_init_freeable+0x24c/0x2f8 [ 21.076667] kernel_init+0x10/0x118 [ 21.080144] ret_from_fork+0x10/0x18 [ 21.083707] [ 21.085186] Freed by task 1: [ 21.088056] save_stack+0x28/0xc8 [ 21.091360] __kasan_slab_free+0x118/0x180 [ 21.095445] kasan_slab_free+0x10/0x18 [ 21.099183] kfree+0x80/0x268 [ 21.102139] acpi_cppc_processor_exit+0x1a8/0x1b8 [ 21.106832] acpi_processor_stop+0x70/0x80 [ 21.110917] really_probe+0x174/0x548 [ 21.114568] driver_probe_device+0x7c/0x148 [ 21.118740] device_driver_attach+0x94/0xa0 [ 21.122912] __driver_attach+0xa4/0x110 [ 21.126736] bus_for_each_dev+0xe8/0x158 [ 21.130648] driver_attach+0x30/0x40 [ 21.134212] bus_add_driver+0x234/0x2f0 [ 21.0x10/0x18 [ 21.161764] [ 21.163244] The buggy address belongs to the object at ffff00236cdeb600 [ 21.163244] which belongs to the cache kmalloc-256 of size 256 [ 21.175750] The buggy address is located 132 bytes inside of [ 21.175750] 256-byte region [ffff00236cdeb600, ffff00236cdeb700) [ 21.187473] The buggy address belongs to the page: [ 21.192254] page:fffffe008d937a00 refcount:1 mapcount:0 mapping:ffff002370c0fa00 index:0x0 compound_mapcount: 0 [ 21.202331] flags: 0x1ffff00000010200(slab|head) [ 21.206940] raw: 1ffff00000010200 dead000000000100 dead000000000122 ffff002370c0fa00 [ 21.214671] raw: 0000000000000000 00000000802a002a 00000001ffffffff 0000000000000000 [ 21.222400] page dumped because: kasan: bad access detected [ 21.227959] [ 21.229438] Memory state around the buggy address: [ 21.234218] ffff00236cdeb580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 21.241427] ffff00236cdeb600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 21.248637] >ffff00236cdeb680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 21.255845] ^ [ 21.259062] ffff00236cdeb700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 21.266272] ffff00236cdeb780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 21.273480] ================================================================== It seems that global pcc_data[pcc_ss_id] can be freed in acpi_cppc_processor_exit(), but we may later reference this value, so NULLify it when freed. Also remove the useless setting of data "pcc_channel_acquired", which we're about to free. Fixes: 85b1407bf6d2 ("ACPI / CPPC: Make CPPC ACPI driver aware of PCC subspace IDs") Signed-off-by: John Garry Cc: 4.15+ # 4.15+ Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman

ACPI / CPPC: do not require the _PSD method

2019-10-05T11:09:50Z

[ Upstream commit 4c4cdc4c63853fee48c02e25c8605fb65a6c9924 ] According to the ACPI 6.3 specification, the _PSD method is optional when using CPPC. The underlying assumption is that each CPU can change frequency independently from all other CPUs; _PSD is provided to tell the OS that some processors can NOT do that. However, the acpi_get_psd() function returns ENODEV if there is no _PSD method present, or an ACPI error status if an error occurs when evaluating _PSD, if present. This makes _PSD mandatory when using CPPC, in violation of the specification, and only on Linux. This has forced some firmware writers to provide a dummy _PSD, even though it is irrelevant, but only because Linux requires it; other OSPMs follow the spec. We really do not want to have OS specific ACPI tables, though. So, correct acpi_get_psd() so that it does not return an error if there is no _PSD method present, but does return a failure when the method can not be executed properly. This allows _PSD to be optional as it should be. Signed-off-by: Al Stone Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin

ACPI / CPPC: Fix invalid PCC channel status errors

2018-05-10T15:16:22Z

Replace the faulty PCC status register polling code with a iopoll.h macro to fix incorrect reporting of PCC check errors ("PCC check channel failed"). There were potential codepaths where we could incorrectly return PCC channel status as busy even without checking the PCC status register once or not checking the status register before breaking out of the polling loop. For example, if the thread polling PCC status register was preempted and scheduled back after we have crossed the deadline then we can report that the channel is busy even without checking the status register. Signed-off-by: Prashanth Prakash Signed-off-by: Rafael J. Wysocki

ACPI / CPPC: Check for valid PCC subspace only if PCC is used

2018-04-24T10:33:28Z

Changes the behavior where we return error if there are no valid PCC subspace for a given performance domain. The ACPI spec does not mandate the use PCC, so it is possible to have platforms where a PCC subspace may not be present, so we need to check for a valid PCC subspace ID only if the register is a PCC register. Signed-off-by: Prashanth Prakash Signed-off-by: Rafael J. Wysocki

ACPI / CPPC: Add support for CPPC v3

2018-04-24T10:33:28Z

CPPC V3 introduces two new entries to make it easier to convert between abstract processor performance and frequency. The two new entries are lowest frequency and nominal frequency. These are the frequencies corresponding to lowest and nominal abstract performance. Add support to read the new entries and populate them as part of the CPPC performance capabilities which can be used by cpufreq drivers Signed-off-by: Prashanth Prakash Signed-off-by: Rafael J. Wysocki

ACPI / CPPC: Update all pr_(debug/err) messages to log the susbspace id

2018-02-22T21:54:00Z

CPPC dirver is aware of multiple PCC subspace IDs. Enhance the debug and error messages in the driver to print the subspace id. In case of error it will be helpful to find which particular subspace is failing. Signed-off-by: George Cherian Signed-off-by: Rafael J. Wysocki

ACPI / CPPC: Use 64-bit arithmetic instead of 32-bit

2018-02-07T10:15:02Z

Add suffix ULL to constant 500 in order to give the compiler complete information about the proper arithmetic to use. Notice that this constant is used in a context that expects an expression of type u64 (64 bits, unsigned). The expression NUM_RETRIES * cppc_ss->latency at line 578, which at preprocessing time translates to 500 * cppc_ss->latency is currently being evaluated using 32-bit arithmetic. Signed-off-by: Gustavo A. R. Silva Signed-off-by: Rafael J. Wysocki

ACPI: CPPC: remove initial assignment of pcc_ss_data

2017-12-18T11:10:37Z

The initialization of pcc_ss_data from pcc_data[pcc_ss_id] before pcc_ss_id is being range checked could lead to an out-of-bounds array read. This very same initialization is also being performed after the range check on pcc_ss_id, so we can just remove this problematic and also redundant assignment to fix the issue. Detected by cppcheck: warning: Value stored to 'pcc_ss_data' during its initialization is never read Fixes: 85b1407bf6d2 (ACPI / CPPC: Make CPPC ACPI driver aware of PCC subspace IDs) Signed-off-by: Colin Ian King Signed-off-by: Rafael J. Wysocki