diff options
| author | Sudeep Holla <sudeep.holla@arm.com> | 2022-08-08 11:46:40 +0300 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2022-08-23 13:10:24 +0300 |
| commit | e75d18cecbb3805895d8ed64da4f78575ec96043 (patch) | |
| tree | a843a436535e87af07f5f45d7544b76aa5b20bbb /arch | |
| parent | e89d120c4b720e232cc6a94f0fcbd59c15d41489 (diff) | |
| download | linux-e75d18cecbb3805895d8ed64da4f78575ec96043.tar.xz | |
arm64: cacheinfo: Fix incorrect assignment of signed error value to unsigned fw_level
Though acpi_find_last_cache_level() always returned signed value and the
document states it will return any errors caused by lack of a PPTT table,
it never returned negative values before.
Commit 0c80f9e165f8 ("ACPI: PPTT: Leave the table mapped for the runtime usage")
however changed it by returning -ENOENT if no PPTT was found. The value
returned from acpi_find_last_cache_level() is then assigned to unsigned
fw_level.
It will result in the number of cache leaves calculated incorrectly as
a huge value which will then cause the following warning from __alloc_pages
as the order would be great than MAX_ORDER because of incorrect and huge
cache leaves value.
| WARNING: CPU: 0 PID: 1 at mm/page_alloc.c:5407 __alloc_pages+0x74/0x314
| Modules linked in:
| CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.19.0-10393-g7c2a8d3ac4c0 #73
| pstate: 20000005 (nzCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
| pc : __alloc_pages+0x74/0x314
| lr : alloc_pages+0xe8/0x318
| Call trace:
| __alloc_pages+0x74/0x314
| alloc_pages+0xe8/0x318
| kmalloc_order_trace+0x68/0x1dc
| __kmalloc+0x240/0x338
| detect_cache_attributes+0xe0/0x56c
| update_siblings_masks+0x38/0x284
| store_cpu_topology+0x78/0x84
| smp_prepare_cpus+0x48/0x134
| kernel_init_freeable+0xc4/0x14c
| kernel_init+0x2c/0x1b4
| ret_from_fork+0x10/0x20
Fix the same by changing fw_level to be signed integer and return the
error from init_cache_level() early in case of error.
Reported-and-Tested-by: Bruno Goncalves <bgoncalv@redhat.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Link: https://lore.kernel.org/r/20220808084640.3165368-1-sudeep.holla@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm64/kernel/cacheinfo.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/arch/arm64/kernel/cacheinfo.c b/arch/arm64/kernel/cacheinfo.c index 587543c6c51c..97c42be71338 100644 --- a/arch/arm64/kernel/cacheinfo.c +++ b/arch/arm64/kernel/cacheinfo.c @@ -45,7 +45,8 @@ static void ci_leaf_init(struct cacheinfo *this_leaf, int init_cache_level(unsigned int cpu) { - unsigned int ctype, level, leaves, fw_level; + unsigned int ctype, level, leaves; + int fw_level; struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu); for (level = 1, leaves = 0; level <= MAX_CACHE_LEVEL; level++) { @@ -63,6 +64,9 @@ int init_cache_level(unsigned int cpu) else fw_level = acpi_find_last_cache_level(cpu); + if (fw_level < 0) + return fw_level; + if (level < fw_level) { /* * some external caches not specified in CLIDR_EL1 |