From 163fa23435cc9c705a71001d4aa15f3f945554a1 Mon Sep 17 00:00:00 2001 From: Kefeng Wang Date: Wed, 3 Jul 2019 16:25:52 +0800 Subject: [PATCH 1/3] percpu: Make pcpu_setup_first_chunk() void function pcpu_setup_first_chunk() will panic or BUG_ON if the are some error and doesn't return any error, hence it can be defined to return void. Reported-by: kbuild test robot Signed-off-by: Kefeng Wang Signed-off-by: Dennis Zhou [Dennis: fixed kbuild warning for pcpu_page_first_chunk()] --- arch/ia64/mm/contig.c | 5 +---- arch/ia64/mm/discontig.c | 5 +---- include/linux/percpu.h | 2 +- mm/percpu.c | 19 +++++++------------ 4 files changed, 10 insertions(+), 21 deletions(-) diff --git a/arch/ia64/mm/contig.c b/arch/ia64/mm/contig.c index d29fb6b9fa33..db09a693f094 100644 --- a/arch/ia64/mm/contig.c +++ b/arch/ia64/mm/contig.c @@ -134,10 +134,7 @@ setup_per_cpu_areas(void) ai->atom_size = PAGE_SIZE; ai->alloc_size = PERCPU_PAGE_SIZE; - rc = pcpu_setup_first_chunk(ai, __per_cpu_start + __per_cpu_offset[0]); - if (rc) - panic("failed to setup percpu area (err=%d)", rc); - + pcpu_setup_first_chunk(ai, __per_cpu_start + __per_cpu_offset[0]); pcpu_free_alloc_info(ai); } #else diff --git a/arch/ia64/mm/discontig.c b/arch/ia64/mm/discontig.c index 05490dd073e6..004dee231874 100644 --- a/arch/ia64/mm/discontig.c +++ b/arch/ia64/mm/discontig.c @@ -245,10 +245,7 @@ void __init setup_per_cpu_areas(void) gi->cpu_map = &cpu_map[unit]; } - rc = pcpu_setup_first_chunk(ai, base); - if (rc) - panic("failed to setup percpu area (err=%d)", rc); - + pcpu_setup_first_chunk(ai, base); pcpu_free_alloc_info(ai); } #endif diff --git a/include/linux/percpu.h b/include/linux/percpu.h index 9909dc0e273a..5e76af742c80 100644 --- a/include/linux/percpu.h +++ b/include/linux/percpu.h @@ -105,7 +105,7 @@ extern struct pcpu_alloc_info * __init pcpu_alloc_alloc_info(int nr_groups, int nr_units); extern void __init pcpu_free_alloc_info(struct pcpu_alloc_info *ai); -extern int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai, +extern void __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai, void *base_addr); #ifdef CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK diff --git a/mm/percpu.c b/mm/percpu.c index 9821241fdede..5a918a4b1da0 100644 --- a/mm/percpu.c +++ b/mm/percpu.c @@ -2267,12 +2267,9 @@ static void pcpu_dump_alloc_info(const char *lvl, * share the same vm, but use offset regions in the area allocation map. * The chunk serving the dynamic region is circulated in the chunk slots * and available for dynamic allocation like any other chunk. - * - * RETURNS: - * 0 on success, -errno on failure. */ -int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai, - void *base_addr) +void __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai, + void *base_addr) { size_t size_sum = ai->static_size + ai->reserved_size + ai->dyn_size; size_t static_size, dyn_size; @@ -2457,7 +2454,6 @@ int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai, /* we're done */ pcpu_base_addr = base_addr; - return 0; } #ifdef CONFIG_SMP @@ -2710,7 +2706,7 @@ int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size, struct pcpu_alloc_info *ai; size_t size_sum, areas_size; unsigned long max_distance; - int group, i, highest_group, rc; + int group, i, highest_group, rc = 0; ai = pcpu_build_alloc_info(reserved_size, dyn_size, atom_size, cpu_distance_fn); @@ -2795,7 +2791,7 @@ int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size, PFN_DOWN(size_sum), ai->static_size, ai->reserved_size, ai->dyn_size, ai->unit_size); - rc = pcpu_setup_first_chunk(ai, base); + pcpu_setup_first_chunk(ai, base); goto out_free; out_free_areas: @@ -2839,7 +2835,7 @@ int __init pcpu_page_first_chunk(size_t reserved_size, int unit_pages; size_t pages_size; struct page **pages; - int unit, i, j, rc; + int unit, i, j, rc = 0; int upa; int nr_g0_units; @@ -2920,7 +2916,7 @@ int __init pcpu_page_first_chunk(size_t reserved_size, unit_pages, psize_str, ai->static_size, ai->reserved_size, ai->dyn_size); - rc = pcpu_setup_first_chunk(ai, vm.addr); + pcpu_setup_first_chunk(ai, vm.addr); goto out_free_ar; enomem: @@ -3014,8 +3010,7 @@ void __init setup_per_cpu_areas(void) ai->groups[0].nr_units = 1; ai->groups[0].cpu_map[0] = 0; - if (pcpu_setup_first_chunk(ai, fc) < 0) - panic("Failed to initialize percpu areas."); + pcpu_setup_first_chunk(ai, fc); pcpu_free_alloc_info(ai); } From 69ab285b682328ef7622f0567f8afebb00b404f3 Mon Sep 17 00:00:00 2001 From: Christophe JAILLET Date: Sun, 21 Jul 2019 11:56:33 +0200 Subject: [PATCH 2/3] percpu: fix typo in pcpu_setup_first_chunk() comment s/perpcu/percpu/ Signed-off-by: Christophe JAILLET Signed-off-by: Dennis Zhou [Dennis: updated title] --- mm/percpu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/percpu.c b/mm/percpu.c index 5a918a4b1da0..7e2aa0305c27 100644 --- a/mm/percpu.c +++ b/mm/percpu.c @@ -2220,7 +2220,7 @@ static void pcpu_dump_alloc_info(const char *lvl, * @base_addr: mapped address * * Initialize the first percpu chunk which contains the kernel static - * perpcu area. This function is to be called from arch percpu area + * percpu area. This function is to be called from arch percpu area * setup path. * * @ai contains all information necessary to initialize the first From 14d3761245551bdfc516abd8214a9f76bfd51435 Mon Sep 17 00:00:00 2001 From: "Gustavo A. R. Silva" Date: Thu, 29 Aug 2019 14:06:05 -0500 Subject: [PATCH 3/3] percpu: Use struct_size() helper One of the more common cases of allocation size calculations is finding the size of a structure that has a zero-sized array at the end, along with memory for some number of elements for that array. For example: struct pcpu_alloc_info { ... struct pcpu_group_info groups[]; }; Make use of the struct_size() helper instead of an open-coded version in order to avoid any potential type mistakes. So, replace the following form: sizeof(*ai) + nr_groups * sizeof(ai->groups[0]) with: struct_size(ai, groups, nr_groups) This code was detected with the help of Coccinelle. Signed-off-by: Gustavo A. R. Silva Signed-off-by: Dennis Zhou --- mm/percpu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/percpu.c b/mm/percpu.c index 7e2aa0305c27..7e06a1e58720 100644 --- a/mm/percpu.c +++ b/mm/percpu.c @@ -2125,7 +2125,7 @@ struct pcpu_alloc_info * __init pcpu_alloc_alloc_info(int nr_groups, void *ptr; int unit; - base_size = ALIGN(sizeof(*ai) + nr_groups * sizeof(ai->groups[0]), + base_size = ALIGN(struct_size(ai, groups, nr_groups), __alignof__(ai->groups[0].cpu_map[0])); ai_size = base_size + nr_units * sizeof(ai->groups[0].cpu_map[0]);