[Xen-devel] [PATCH 16/21] mm/percpu: add checks for the return value of memblock_alloc*()

[Mike Rapoport <rppt@xxxxxxxxxxxxx>]

Add panic() calls if memblock_alloc() returns NULL.

The panic() format duplicates the one used by memblock itself and in order
to avoid explosion with long parameters list replace open coded allocation
size calculations with a local variable.

Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxx>
---
 mm/percpu.c | 73 +++++++++++++++++++++++++++++++++++++++++++++++--------------
 1 file changed, 56 insertions(+), 17 deletions(-)

diff --git a/mm/percpu.c b/mm/percpu.c
index db86282..5998b03 100644
--- a/mm/percpu.c
+++ b/mm/percpu.c
@@ -1086,6 +1086,7 @@ static struct pcpu_chunk * __init 
pcpu_alloc_first_chunk(unsigned long tmp_addr,
        struct pcpu_chunk *chunk;
        unsigned long aligned_addr, lcm_align;
        int start_offset, offset_bits, region_size, region_bits;
+       size_t alloc_size;
 
        /* region calculations */
        aligned_addr = tmp_addr & PAGE_MASK;
@@ -1101,9 +1102,12 @@ static struct pcpu_chunk * __init 
pcpu_alloc_first_chunk(unsigned long tmp_addr,
        region_size = ALIGN(start_offset + map_size, lcm_align);
 
        /* allocate chunk */
-       chunk = memblock_alloc(sizeof(struct pcpu_chunk) +
-                              BITS_TO_LONGS(region_size >> PAGE_SHIFT),
-                              SMP_CACHE_BYTES);
+       alloc_size = sizeof(struct pcpu_chunk) +
+               BITS_TO_LONGS(region_size >> PAGE_SHIFT);
+       chunk = memblock_alloc(alloc_size, SMP_CACHE_BYTES);
+       if (!chunk)
+               panic("%s: Failed to allocate %zu bytes\n", __func__,
+                     alloc_size);
 
        INIT_LIST_HEAD(&chunk->list);
 
@@ -1114,12 +1118,25 @@ static struct pcpu_chunk * __init 
pcpu_alloc_first_chunk(unsigned long tmp_addr,
        chunk->nr_pages = region_size >> PAGE_SHIFT;
        region_bits = pcpu_chunk_map_bits(chunk);
 
-       chunk->alloc_map = memblock_alloc(BITS_TO_LONGS(region_bits) * 
sizeof(chunk->alloc_map[0]),
-                                         SMP_CACHE_BYTES);
-       chunk->bound_map = memblock_alloc(BITS_TO_LONGS(region_bits + 1) * 
sizeof(chunk->bound_map[0]),
-                                         SMP_CACHE_BYTES);
-       chunk->md_blocks = memblock_alloc(pcpu_chunk_nr_blocks(chunk) * 
sizeof(chunk->md_blocks[0]),
-                                         SMP_CACHE_BYTES);
+       alloc_size = BITS_TO_LONGS(region_bits) * sizeof(chunk->alloc_map[0]);
+       chunk->alloc_map = memblock_alloc(alloc_size, SMP_CACHE_BYTES);
+       if (!chunk->alloc_map)
+               panic("%s: Failed to allocate %zu bytes\n", __func__,
+                     alloc_size);
+
+       alloc_size =
+               BITS_TO_LONGS(region_bits + 1) * sizeof(chunk->bound_map[0]);
+       chunk->bound_map = memblock_alloc(alloc_size, SMP_CACHE_BYTES);
+       if (!chunk->bound_map)
+               panic("%s: Failed to allocate %zu bytes\n", __func__,
+                     alloc_size);
+
+       alloc_size = pcpu_chunk_nr_blocks(chunk) * sizeof(chunk->md_blocks[0]);
+       chunk->md_blocks = memblock_alloc(alloc_size, SMP_CACHE_BYTES);
+       if (!chunk->md_blocks)
+               panic("%s: Failed to allocate %zu bytes\n", __func__,
+                     alloc_size);
+
        pcpu_init_md_blocks(chunk);
 
        /* manage populated page bitmap */
@@ -2044,6 +2061,7 @@ int __init pcpu_setup_first_chunk(const struct 
pcpu_alloc_info *ai,
        int group, unit, i;
        int map_size;
        unsigned long tmp_addr;
+       size_t alloc_size;
 
 #define PCPU_SETUP_BUG_ON(cond)        do {                                    
\
        if (unlikely(cond)) {                                           \
@@ -2075,14 +2093,29 @@ int __init pcpu_setup_first_chunk(const struct 
pcpu_alloc_info *ai,
        PCPU_SETUP_BUG_ON(pcpu_verify_alloc_info(ai) < 0);
 
        /* process group information and build config tables accordingly */
-       group_offsets = memblock_alloc(ai->nr_groups * sizeof(group_offsets[0]),
-                                      SMP_CACHE_BYTES);
-       group_sizes = memblock_alloc(ai->nr_groups * sizeof(group_sizes[0]),
-                                    SMP_CACHE_BYTES);
-       unit_map = memblock_alloc(nr_cpu_ids * sizeof(unit_map[0]),
-                                 SMP_CACHE_BYTES);
-       unit_off = memblock_alloc(nr_cpu_ids * sizeof(unit_off[0]),
-                                 SMP_CACHE_BYTES);
+       alloc_size = ai->nr_groups * sizeof(group_offsets[0]);
+       group_offsets = memblock_alloc(alloc_size, SMP_CACHE_BYTES);
+       if (!group_offsets)
+               panic("%s: Failed to allocate %zu bytes\n", __func__,
+                     alloc_size);
+
+       alloc_size = ai->nr_groups * sizeof(group_sizes[0]);
+       group_sizes = memblock_alloc(alloc_size, SMP_CACHE_BYTES);
+       if (!group_sizes)
+               panic("%s: Failed to allocate %zu bytes\n", __func__,
+                     alloc_size);
+
+       alloc_size = nr_cpu_ids * sizeof(unit_map[0]);
+       unit_map = memblock_alloc(alloc_size, SMP_CACHE_BYTES);
+       if (!unit_map)
+               panic("%s: Failed to allocate %zu bytes\n", __func__,
+                     alloc_size);
+
+       alloc_size = nr_cpu_ids * sizeof(unit_off[0]);
+       unit_off = memblock_alloc(alloc_size, SMP_CACHE_BYTES);
+       if (!unit_off)
+               panic("%s: Failed to allocate %zu bytes\n", __func__,
+                     alloc_size);
 
        for (cpu = 0; cpu < nr_cpu_ids; cpu++)
                unit_map[cpu] = UINT_MAX;
@@ -2148,6 +2181,9 @@ int __init pcpu_setup_first_chunk(const struct 
pcpu_alloc_info *ai,
        pcpu_nr_slots = __pcpu_size_to_slot(pcpu_unit_size) + 2;
        pcpu_slot = memblock_alloc(pcpu_nr_slots * sizeof(pcpu_slot[0]),
                                   SMP_CACHE_BYTES);
+       if (!pcpu_slot)
+               panic("%s: Failed to allocate %zu bytes\n", __func__,
+                     pcpu_nr_slots * sizeof(pcpu_slot[0]));
        for (i = 0; i < pcpu_nr_slots; i++)
                INIT_LIST_HEAD(&pcpu_slot[i]);
 
@@ -2602,6 +2638,9 @@ int __init pcpu_page_first_chunk(size_t reserved_size,
        pages_size = PFN_ALIGN(unit_pages * num_possible_cpus() *
                               sizeof(pages[0]));
        pages = memblock_alloc(pages_size, SMP_CACHE_BYTES);
+       if (!pages)
+               panic("%s: Failed to allocate %zu bytes\n", __func__,
+                     pages_size);
 
        /* allocate pages */
        j = 0;
-- 
2.7.4


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