Revision de85422b94ddb23c021126815ea49414047c13dc authored by Stefan Becker on 01 July 2008, 16:19:22 UTC, committed by Greg Kroah-Hartman on 04 July 2008, 01:20:37 UTC
USB: fix interrupt disabling for HCDs with shared interrupt handlers As has been discussed several times on LKML, IRQF_SHARED | IRQF_DISABLED doesn't work reliably, i.e. a shared interrupt handler CAN'T be certain to be called with interrupts disabled. Most USB HCD handlers use IRQF_DISABLED and therefore havoc can break out if they share their interrupt with a handler that doesn't use it. On my test machine the yenta_socket interrupt handler (no IRQF_DISABLED) was registered before ehci_hcd and one uhci_hcd instance. Therefore all usb_hcd_irq() invocations for ehci_hcd and for one uhci_hcd instance happened with interrupts enabled. That led to random lockups as USB core HCD functions that acquire the same spinlock could be called twice from interrupt handlers. This patch updates usb_hcd_irq() to always disable/restore interrupts. usb_add_hcd() will silently remove any IRQF_DISABLED requested from HCD code. Signed-off-by: Stefan Becker <stefan.becker@nokia.com> Cc: stable <stable@kernel.org> Acked-by: David Brownell <david-b@pacbell.net> Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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arc4.c
/*
* Cryptographic API
*
* ARC4 Cipher Algorithm
*
* Jon Oberheide <jon@oberheide.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/crypto.h>
#define ARC4_MIN_KEY_SIZE 1
#define ARC4_MAX_KEY_SIZE 256
#define ARC4_BLOCK_SIZE 1
struct arc4_ctx {
u8 S[256];
u8 x, y;
};
static int arc4_set_key(struct crypto_tfm *tfm, const u8 *in_key,
unsigned int key_len)
{
struct arc4_ctx *ctx = crypto_tfm_ctx(tfm);
int i, j = 0, k = 0;
ctx->x = 1;
ctx->y = 0;
for(i = 0; i < 256; i++)
ctx->S[i] = i;
for(i = 0; i < 256; i++)
{
u8 a = ctx->S[i];
j = (j + in_key[k] + a) & 0xff;
ctx->S[i] = ctx->S[j];
ctx->S[j] = a;
if(++k >= key_len)
k = 0;
}
return 0;
}
static void arc4_crypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
{
struct arc4_ctx *ctx = crypto_tfm_ctx(tfm);
u8 *const S = ctx->S;
u8 x = ctx->x;
u8 y = ctx->y;
u8 a, b;
a = S[x];
y = (y + a) & 0xff;
b = S[y];
S[x] = b;
S[y] = a;
x = (x + 1) & 0xff;
*out++ = *in ^ S[(a + b) & 0xff];
ctx->x = x;
ctx->y = y;
}
static struct crypto_alg arc4_alg = {
.cra_name = "arc4",
.cra_flags = CRYPTO_ALG_TYPE_CIPHER,
.cra_blocksize = ARC4_BLOCK_SIZE,
.cra_ctxsize = sizeof(struct arc4_ctx),
.cra_module = THIS_MODULE,
.cra_list = LIST_HEAD_INIT(arc4_alg.cra_list),
.cra_u = { .cipher = {
.cia_min_keysize = ARC4_MIN_KEY_SIZE,
.cia_max_keysize = ARC4_MAX_KEY_SIZE,
.cia_setkey = arc4_set_key,
.cia_encrypt = arc4_crypt,
.cia_decrypt = arc4_crypt } }
};
static int __init arc4_init(void)
{
return crypto_register_alg(&arc4_alg);
}
static void __exit arc4_exit(void)
{
crypto_unregister_alg(&arc4_alg);
}
module_init(arc4_init);
module_exit(arc4_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("ARC4 Cipher Algorithm");
MODULE_AUTHOR("Jon Oberheide <jon@oberheide.org>");
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