In the memory allocation of rp->domains in rapl_detect_domains(), there is an additional memory of struct rapl_domain allocated to prevent the pointer out of bounds called later.

Optimize the code here to save sizeof(struct rapl_domain) bytes of memory.

Test in Intel NUC (i5-1135G7).

Cc: stable@vger.kernel.org Signed-off-by: xiongxin xiongxin@kylinos.cn Tested-by: xiongxin xiongxin@kylinos.cn --- drivers/powercap/intel_rapl_common.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/drivers/powercap/intel_rapl_common.c b/drivers/powercap/intel_rapl_common.c index 8970c7b80884..f8971282498a 100644 --- a/drivers/powercap/intel_rapl_common.c +++ b/drivers/powercap/intel_rapl_common.c @@ -1171,13 +1171,14 @@ static int rapl_package_register_powercap(struct rapl_package *rp) { struct rapl_domain *rd; struct powercap_zone *power_zone = NULL; - int nr_pl, ret; + int nr_pl, ret, i;

/* Update the domain data of the new package */ rapl_update_domain_data(rp);

/* first we register package domain as the parent zone */ - for (rd = rp->domains; rd < rp->domains + rp->nr_domains; rd++) { + for (i = 0; i < rp->nr_domains; i++) { + rd = &rp->domains[i]; if (rd->id == RAPL_DOMAIN_PACKAGE) { nr_pl = find_nr_power_limit(rd); pr_debug("register package domain %s\n", rp->name); @@ -1201,8 +1202,9 @@ static int rapl_package_register_powercap(struct rapl_package *rp) return -ENODEV; } /* now register domains as children of the socket/package */ - for (rd = rp->domains; rd < rp->domains + rp->nr_domains; rd++) { + for (i = 0; i < rp->nr_domains; i++) { struct powercap_zone *parent = rp->power_zone; + rd = &rp->domains[i];

if (rd->id == RAPL_DOMAIN_PACKAGE) continue; @@ -1302,7 +1304,6 @@ static void rapl_detect_powerlimit(struct rapl_domain *rd) */ static int rapl_detect_domains(struct rapl_package *rp, int cpu) { - struct rapl_domain *rd; int i;

for (i = 0; i < RAPL_DOMAIN_MAX; i++) { @@ -1319,15 +1320,15 @@ static int rapl_detect_domains(struct rapl_package *rp, int cpu) } pr_debug("found %d domains on %s\n", rp->nr_domains, rp->name);

- rp->domains = kcalloc(rp->nr_domains + 1, sizeof(struct rapl_domain), + rp->domains = kcalloc(rp->nr_domains, sizeof(struct rapl_domain), GFP_KERNEL); if (!rp->domains) return -ENOMEM;

rapl_init_domains(rp);

- for (rd = rp->domains; rd < rp->domains + rp->nr_domains; rd++) - rapl_detect_powerlimit(rd); + for (i = 0; i < rp->nr_domains; i++) + rapl_detect_powerlimit(&rp->domains[i]);

return 0; }