powerpc/msi: Free the bitmap if it was slab allocated
During the MSI bitmap test on boot kmemleak spews the following trace:
unreferenced object 0xc00000016e86c900 (size 64):
comm "swapper/0", pid 1, jiffies 4294893173 (age 518.024s)
hex dump (first 32 bytes):
00 00 01 ff 7f ff 7f 37 00 00 00 00 00 00 00 00
.......7........
ff ff ff ff ff ff ff ff 01 ff ff ff ff
ff ff ff
................
backtrace:
[<c00000000003eebc>] .zalloc_maybe_bootmem+0x3c/0x380
[<c000000000042d6c>] .msi_bitmap_alloc+0x3c/0xb0
[<c000000000a9aff8>] .msi_bitmap_selftest+0x30/0x2b4
[<c0000000000090f4>] .do_one_initcall+0xd4/0x270
[<c000000000a8e250>] .kernel_init_freeable+0x1a0/0x280
[<c000000000009b5c>] .kernel_init+0x1c/0x120
[<c000000000007fbc>] .ret_from_kernel_thread+0x58/0x9c
Add a flag to msi_bitmap for tracking allocations from slab and memblock
so we can properly free/handle memory in msi_bitmap_free().
Signed-off-by: Denis Kirjanov <kda@linux-powerpc.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
[mpe: Reword changelog & use bitmap_from_slab in the if]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
diff --git a/arch/powerpc/include/asm/msi_bitmap.h b/arch/powerpc/include/asm/msi_bitmap.h
index 97ac3f4..1ec7125 100644
--- a/arch/powerpc/include/asm/msi_bitmap.h
+++ b/arch/powerpc/include/asm/msi_bitmap.h
@@ -19,6 +19,7 @@
unsigned long *bitmap;
spinlock_t lock;
unsigned int irq_count;
+ bool bitmap_from_slab;
};
int msi_bitmap_alloc_hwirqs(struct msi_bitmap *bmp, int num);
diff --git a/arch/powerpc/sysdev/msi_bitmap.c b/arch/powerpc/sysdev/msi_bitmap.c
index 73b64c7..1a826f3 100644
--- a/arch/powerpc/sysdev/msi_bitmap.c
+++ b/arch/powerpc/sysdev/msi_bitmap.c
@@ -11,6 +11,7 @@
#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/bitmap.h>
+#include <linux/bootmem.h>
#include <asm/msi_bitmap.h>
#include <asm/setup.h>
@@ -122,7 +123,15 @@
size = BITS_TO_LONGS(irq_count) * sizeof(long);
pr_debug("msi_bitmap: allocator bitmap size is 0x%x bytes\n", size);
- bmp->bitmap = zalloc_maybe_bootmem(size, GFP_KERNEL);
+ bmp->bitmap_from_slab = slab_is_available();
+ if (bmp->bitmap_from_slab)
+ bmp->bitmap = kzalloc(size, GFP_KERNEL);
+ else {
+ bmp->bitmap = memblock_virt_alloc(size, 0);
+ /* the bitmap won't be freed from memblock allocator */
+ kmemleak_not_leak(bmp->bitmap);
+ }
+
if (!bmp->bitmap) {
pr_debug("msi_bitmap: ENOMEM allocating allocator bitmap!\n");
return -ENOMEM;
@@ -138,7 +147,8 @@
void msi_bitmap_free(struct msi_bitmap *bmp)
{
- /* we can't free the bitmap we don't know if it's bootmem etc. */
+ if (bmp->bitmap_from_slab)
+ kfree(bmp->bitmap);
of_node_put(bmp->of_node);
bmp->bitmap = NULL;
}
@@ -203,8 +213,6 @@
/* Clients may WARN_ON bitmap == NULL for "not-allocated" */
WARN_ON(bmp.bitmap != NULL);
-
- kfree(bmp.bitmap);
}
static void __init test_of_node(void)