[PATCH] x86: deflate stack usage in lib/inflate.c
inflate_fixed and huft_build together use around 2.7k of stack. When
using 4k stacks, I saw stack overflows from interrupts arriving while
unpacking the root initrd:
do_IRQ: stack overflow: 384
[<c0106b64>] show_trace_log_lvl+0x1a/0x30
[<c01075e6>] show_trace+0x12/0x14
[<c010763f>] dump_stack+0x16/0x18
[<c0107ca4>] do_IRQ+0x6d/0xd9
[<c010202b>] xen_evtchn_do_upcall+0x6e/0xa2
[<c0106781>] xen_hypervisor_callback+0x25/0x2c
[<c010116c>] xen_restore_fl+0x27/0x29
[<c0330f63>] _spin_unlock_irqrestore+0x4a/0x50
[<c0117aab>] change_page_attr+0x577/0x584
[<c0117b45>] kernel_map_pages+0x8d/0xb4
[<c016a314>] cache_alloc_refill+0x53f/0x632
[<c016a6c2>] __kmalloc+0xc1/0x10d
[<c0463d34>] malloc+0x10/0x12
[<c04641c1>] huft_build+0x2a7/0x5fa
[<c04645a5>] inflate_fixed+0x91/0x136
[<c04657e2>] unpack_to_rootfs+0x5f2/0x8c1
[<c0465acf>] populate_rootfs+0x1e/0xe4
(This was under Xen, but there's no reason it couldn't happen on bare
hardware.)
This patch mallocs the local variables, thereby reducing the stack
usage to sane levels.
Also, up the heap size for the kernel decompressor to deal with the
extra allocation.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Tim Yamin <plasmaroo@gentoo.org>
Cc: Andi Kleen <ak@suse.de>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ian Molton <spyro@f2s.com>
diff --git a/arch/i386/boot/compressed/misc.c b/arch/i386/boot/compressed/misc.c
index 1ce7017..b28505c 100644
--- a/arch/i386/boot/compressed/misc.c
+++ b/arch/i386/boot/compressed/misc.c
@@ -189,7 +189,7 @@
static unsigned long free_mem_ptr;
static unsigned long free_mem_end_ptr;
-#define HEAP_SIZE 0x3000
+#define HEAP_SIZE 0x4000
static char *vidmem = (char *)0xb8000;
static int vidport;