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authorLinus Torvalds <torvalds@linux-foundation.org>2021-09-14 13:23:22 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2021-09-14 13:23:22 -0700
commit77e02cf57b6cff9919949defb7fd9b8ac16399a2 (patch)
tree96d0a1d317e28e7b22165ca419c99f7313e64ea3 /arch
parent6a4746ba06191e23d30230738e94334b26590a8a (diff)
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>
Diffstat (limited to 'arch')
-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
4 files changed, 5 insertions, 8 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: