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authorLinus Torvalds <torvalds@linux-foundation.org>2021-09-14 23:23:22 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2021-09-14 23:23:22 +0300
commit77e02cf57b6cff9919949defb7fd9b8ac16399a2 (patch)
tree96d0a1d317e28e7b22165ca419c99f7313e64ea3
parent6a4746ba06191e23d30230738e94334b26590a8a (diff)
downloadlinux-77e02cf57b6cff9919949defb7fd9b8ac16399a2.tar.xz
memblock: introduce saner 'memblock_free_ptr()' interface
The boot-time allocation interface for memblock is a mess, with 'memblock_alloc()' returning a virtual pointer, but then you are supposed to free it with 'memblock_free()' that takes a _physical_ address. Not only is that all kinds of strange and illogical, but it actually causes bugs, when people then use it like a normal allocation function, and it fails spectacularly on a NULL pointer: https://lore.kernel.org/all/20210912140820.GD25450@xsang-OptiPlex-9020/ or just random memory corruption if the debug checks don't catch it: https://lore.kernel.org/all/61ab2d0c-3313-aaab-514c-e15b7aa054a0@suse.cz/ I really don't want to apply patches that treat the symptoms, when the fundamental cause is this horribly confusing interface. I started out looking at just automating a sane replacement sequence, but because of this mix or virtual and physical addresses, and because people have used the "__pa()" macro that can take either a regular kernel pointer, or just the raw "unsigned long" address, it's all quite messy. So this just introduces a new saner interface for freeing a virtual address that was allocated using 'memblock_alloc()', and that was kept as a regular kernel pointer. And then it converts a couple of users that are obvious and easy to test, including the 'xbc_nodes' case in lib/bootconfig.c that caused problems. Reported-by: kernel test robot <oliver.sang@intel.com> Fixes: 40caa127f3c7 ("init: bootconfig: Remove all bootconfig data when the init memory is removed") Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Mike Rapoport <rppt@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--arch/x86/kernel/setup_percpu.c2
-rw-r--r--arch/x86/mm/kasan_init_64.c6
-rw-r--r--arch/x86/mm/numa.c2
-rw-r--r--arch/x86/mm/numa_emulation.c3
-rw-r--r--drivers/base/arch_numa.c2
-rw-r--r--drivers/macintosh/smu.c2
-rw-r--r--include/linux/memblock.h1
-rw-r--r--init/main.c2
-rw-r--r--kernel/printk/printk.c4
-rw-r--r--lib/bootconfig.c2
-rw-r--r--mm/memblock.c16
11 files changed, 27 insertions, 15 deletions
diff --git a/arch/x86/kernel/setup_percpu.c b/arch/x86/kernel/setup_percpu.c
index 78a32b956e81..5afd98559193 100644
--- a/arch/x86/kernel/setup_percpu.c
+++ b/arch/x86/kernel/setup_percpu.c
@@ -135,7 +135,7 @@ static void * __init pcpu_fc_alloc(unsigned int cpu, size_t size, size_t align)
static void __init pcpu_fc_free(void *ptr, size_t size)
{
- memblock_free(__pa(ptr), size);
+ memblock_free_ptr(ptr, size);
}
static int __init pcpu_cpu_distance(unsigned int from, unsigned int to)
diff --git a/arch/x86/mm/kasan_init_64.c b/arch/x86/mm/kasan_init_64.c
index 1a50434c8a4d..ef885370719a 100644
--- a/arch/x86/mm/kasan_init_64.c
+++ b/arch/x86/mm/kasan_init_64.c
@@ -49,8 +49,7 @@ static void __init kasan_populate_pmd(pmd_t *pmd, unsigned long addr,
p = early_alloc(PMD_SIZE, nid, false);
if (p && pmd_set_huge(pmd, __pa(p), PAGE_KERNEL))
return;
- else if (p)
- memblock_free(__pa(p), PMD_SIZE);
+ memblock_free_ptr(p, PMD_SIZE);
}
p = early_alloc(PAGE_SIZE, nid, true);
@@ -86,8 +85,7 @@ static void __init kasan_populate_pud(pud_t *pud, unsigned long addr,
p = early_alloc(PUD_SIZE, nid, false);
if (p && pud_set_huge(pud, __pa(p), PAGE_KERNEL))
return;
- else if (p)
- memblock_free(__pa(p), PUD_SIZE);
+ memblock_free_ptr(p, PUD_SIZE);
}
p = early_alloc(PAGE_SIZE, nid, true);
diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c
index a1b5c71099e6..1e9b93b088db 100644
--- a/arch/x86/mm/numa.c
+++ b/arch/x86/mm/numa.c
@@ -355,7 +355,7 @@ void __init numa_reset_distance(void)
/* numa_distance could be 1LU marking allocation failure, test cnt */
if (numa_distance_cnt)
- memblock_free(__pa(numa_distance), size);
+ memblock_free_ptr(numa_distance, size);
numa_distance_cnt = 0;
numa_distance = NULL; /* enable table creation */
}
diff --git a/arch/x86/mm/numa_emulation.c b/arch/x86/mm/numa_emulation.c
index 737491b13728..e801e30089c4 100644
--- a/arch/x86/mm/numa_emulation.c
+++ b/arch/x86/mm/numa_emulation.c
@@ -517,8 +517,7 @@ void __init numa_emulation(struct numa_meminfo *numa_meminfo, int numa_dist_cnt)
}
/* free the copied physical distance table */
- if (phys_dist)
- memblock_free(__pa(phys_dist), phys_size);
+ memblock_free_ptr(phys_dist, phys_size);
return;
no_emu:
diff --git a/drivers/base/arch_numa.c b/drivers/base/arch_numa.c
index 46c503486e96..00fb4120a5b3 100644
--- a/drivers/base/arch_numa.c
+++ b/drivers/base/arch_numa.c
@@ -264,7 +264,7 @@ void __init numa_free_distance(void)
size = numa_distance_cnt * numa_distance_cnt *
sizeof(numa_distance[0]);
- memblock_free(__pa(numa_distance), size);
+ memblock_free_ptr(numa_distance, size);
numa_distance_cnt = 0;
numa_distance = NULL;
}
diff --git a/drivers/macintosh/smu.c b/drivers/macintosh/smu.c
index 94fb63a7b357..fe63d5ee201b 100644
--- a/drivers/macintosh/smu.c
+++ b/drivers/macintosh/smu.c
@@ -570,7 +570,7 @@ fail_msg_node:
fail_db_node:
of_node_put(smu->db_node);
fail_bootmem:
- memblock_free(__pa(smu), sizeof(struct smu_device));
+ memblock_free_ptr(smu, sizeof(struct smu_device));
smu = NULL;
fail_np:
of_node_put(np);
diff --git a/include/linux/memblock.h b/include/linux/memblock.h
index b066024c62e3..34de69b3b8ba 100644
--- a/include/linux/memblock.h
+++ b/include/linux/memblock.h
@@ -118,6 +118,7 @@ int memblock_mark_nomap(phys_addr_t base, phys_addr_t size);
int memblock_clear_nomap(phys_addr_t base, phys_addr_t size);
void memblock_free_all(void);
+void memblock_free_ptr(void *ptr, size_t size);
void reset_node_managed_pages(pg_data_t *pgdat);
void reset_all_zones_managed_pages(void);
diff --git a/init/main.c b/init/main.c
index 5c9a48df90e1..3f7216934441 100644
--- a/init/main.c
+++ b/init/main.c
@@ -924,7 +924,7 @@ static void __init print_unknown_bootoptions(void)
end += sprintf(end, " %s", *p);
pr_notice("Unknown command line parameters:%s\n", unknown_options);
- memblock_free(__pa(unknown_options), len);
+ memblock_free_ptr(unknown_options, len);
}
asmlinkage __visible void __init __no_sanitize_address start_kernel(void)
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 825277e1e742..a8d0a58deebc 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -1166,9 +1166,9 @@ void __init setup_log_buf(int early)
return;
err_free_descs:
- memblock_free(__pa(new_descs), new_descs_size);
+ memblock_free_ptr(new_descs, new_descs_size);
err_free_log_buf:
- memblock_free(__pa(new_log_buf), new_log_buf_len);
+ memblock_free_ptr(new_log_buf, new_log_buf_len);
}
static bool __read_mostly ignore_loglevel;
diff --git a/lib/bootconfig.c b/lib/bootconfig.c
index f8419cff1147..5ae248b29373 100644
--- a/lib/bootconfig.c
+++ b/lib/bootconfig.c
@@ -792,7 +792,7 @@ void __init xbc_destroy_all(void)
xbc_data = NULL;
xbc_data_size = 0;
xbc_node_num = 0;
- memblock_free(__pa(xbc_nodes), sizeof(struct xbc_node) * XBC_NODE_MAX);
+ memblock_free_ptr(xbc_nodes, sizeof(struct xbc_node) * XBC_NODE_MAX);
xbc_nodes = NULL;
brace_index = 0;
}
diff --git a/mm/memblock.c b/mm/memblock.c
index 0ab5a749bfa6..184dcd2e5d99 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -472,7 +472,7 @@ static int __init_memblock memblock_double_array(struct memblock_type *type,
kfree(old_array);
else if (old_array != memblock_memory_init_regions &&
old_array != memblock_reserved_init_regions)
- memblock_free(__pa(old_array), old_alloc_size);
+ memblock_free_ptr(old_array, old_alloc_size);
/*
* Reserve the new array if that comes from the memblock. Otherwise, we
@@ -796,6 +796,20 @@ int __init_memblock memblock_remove(phys_addr_t base, phys_addr_t size)
}
/**
+ * memblock_free_ptr - free boot memory allocation
+ * @ptr: starting address of the boot memory allocation
+ * @size: size of the boot memory block in bytes
+ *
+ * Free boot memory block previously allocated by memblock_alloc_xx() API.
+ * The freeing memory will not be released to the buddy allocator.
+ */
+void __init_memblock memblock_free_ptr(void *ptr, size_t size)
+{
+ if (ptr)
+ memblock_free(__pa(ptr), size);
+}
+
+/**
* memblock_free - free boot memory block
* @base: phys starting address of the boot memory block
* @size: size of the boot memory block in bytes