summaryrefslogtreecommitdiff
path: root/arch
diff options
context:
space:
mode:
authorSudeep Holla <sudeep.holla@arm.com>2022-08-08 11:46:40 +0300
committerWill Deacon <will@kernel.org>2022-08-23 13:10:24 +0300
commite75d18cecbb3805895d8ed64da4f78575ec96043 (patch)
treea843a436535e87af07f5f45d7544b76aa5b20bbb /arch
parente89d120c4b720e232cc6a94f0fcbd59c15d41489 (diff)
downloadlinux-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.c6
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