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authorKees Cook <keescook@chromium.org>2017-02-09 15:43:44 -0800
committerKees Cook <keescook@chromium.org>2017-02-13 10:25:52 -0800
commit76d5692a58031696e282384cbd893832bc92bd76 (patch)
tree95d2c1eed40eef5adbce92e1026139e530f97d69 /fs/pstore
parent7089db84e356562f8ba737c29e472cc42d530dbc (diff)
pstore: Correctly initialize spinlock and flags
The ram backend wasn't always initializing its spinlock correctly. Since it was coming from kzalloc memory, though, it was harmless on architectures that initialize unlocked spinlocks to 0 (at least x86 and ARM). This also fixes a possibly ignored flag setting too. When running under CONFIG_DEBUG_SPINLOCK, the following Oops was visible: [ 0.760836] persistent_ram: found existing buffer, size 29988, start 29988 [ 0.765112] persistent_ram: found existing buffer, size 30105, start 30105 [ 0.769435] persistent_ram: found existing buffer, size 118542, start 118542 [ 0.785960] persistent_ram: found existing buffer, size 0, start 0 [ 0.786098] persistent_ram: found existing buffer, size 0, start 0 [ 0.786131] pstore: using zlib compression [ 0.790716] BUG: spinlock bad magic on CPU#0, swapper/0/1 [ 0.790729] lock: 0xffffffc0d1ca9bb0, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0 [ 0.790742] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.10.0-rc2+ #913 [ 0.790747] Hardware name: Google Kevin (DT) [ 0.790750] Call trace: [ 0.790768] [<ffffff900808ae88>] dump_backtrace+0x0/0x2bc [ 0.790780] [<ffffff900808b164>] show_stack+0x20/0x28 [ 0.790794] [<ffffff9008460ee0>] dump_stack+0xa4/0xcc [ 0.790809] [<ffffff9008113cfc>] spin_dump+0xe0/0xf0 [ 0.790821] [<ffffff9008113d3c>] spin_bug+0x30/0x3c [ 0.790834] [<ffffff9008113e28>] do_raw_spin_lock+0x50/0x1b8 [ 0.790846] [<ffffff9008a2d2ec>] _raw_spin_lock_irqsave+0x54/0x6c [ 0.790862] [<ffffff90083ac3b4>] buffer_size_add+0x48/0xcc [ 0.790875] [<ffffff90083acb34>] persistent_ram_write+0x60/0x11c [ 0.790888] [<ffffff90083aab1c>] ramoops_pstore_write_buf+0xd4/0x2a4 [ 0.790900] [<ffffff90083a9d3c>] pstore_console_write+0xf0/0x134 [ 0.790912] [<ffffff900811c304>] console_unlock+0x48c/0x5e8 [ 0.790923] [<ffffff900811da18>] register_console+0x3b0/0x4d4 [ 0.790935] [<ffffff90083aa7d0>] pstore_register+0x1a8/0x234 [ 0.790947] [<ffffff90083ac250>] ramoops_probe+0x6b8/0x7d4 [ 0.790961] [<ffffff90085ca548>] platform_drv_probe+0x7c/0xd0 [ 0.790972] [<ffffff90085c76ac>] driver_probe_device+0x1b4/0x3bc [ 0.790982] [<ffffff90085c7ac8>] __device_attach_driver+0xc8/0xf4 [ 0.790996] [<ffffff90085c4bfc>] bus_for_each_drv+0xb4/0xe4 [ 0.791006] [<ffffff90085c7414>] __device_attach+0xd0/0x158 [ 0.791016] [<ffffff90085c7b18>] device_initial_probe+0x24/0x30 [ 0.791026] [<ffffff90085c648c>] bus_probe_device+0x50/0xe4 [ 0.791038] [<ffffff90085c35b8>] device_add+0x3a4/0x76c [ 0.791051] [<ffffff90087d0e84>] of_device_add+0x74/0x84 [ 0.791062] [<ffffff90087d19b8>] of_platform_device_create_pdata+0xc0/0x100 [ 0.791073] [<ffffff90087d1a2c>] of_platform_device_create+0x34/0x40 [ 0.791086] [<ffffff900903c910>] of_platform_default_populate_init+0x58/0x78 [ 0.791097] [<ffffff90080831fc>] do_one_initcall+0x88/0x160 [ 0.791109] [<ffffff90090010ac>] kernel_init_freeable+0x264/0x31c [ 0.791123] [<ffffff9008a25bd0>] kernel_init+0x18/0x11c [ 0.791133] [<ffffff9008082ec0>] ret_from_fork+0x10/0x50 [ 0.793717] console [pstore-1] enabled [ 0.797845] pstore: Registered ramoops as persistent store backend [ 0.804647] ramoops: attached 0x100000@0xf7edc000, ecc: 0/0 Fixes: 663deb47880f ("pstore: Allow prz to control need for locking") Fixes: 109704492ef6 ("pstore: Make spinlock per zone instead of global") Reported-by: Brian Norris <briannorris@chromium.org> Signed-off-by: Kees Cook <keescook@chromium.org>
Diffstat (limited to 'fs/pstore')
-rw-r--r--fs/pstore/ram_core.c12
1 files changed, 7 insertions, 5 deletions
diff --git a/fs/pstore/ram_core.c b/fs/pstore/ram_core.c
index a857338b7dab..bc927e30bdcc 100644
--- a/fs/pstore/ram_core.c
+++ b/fs/pstore/ram_core.c
@@ -467,8 +467,7 @@ static int persistent_ram_buffer_map(phys_addr_t start, phys_addr_t size,
}
static int persistent_ram_post_init(struct persistent_ram_zone *prz, u32 sig,
- struct persistent_ram_ecc_info *ecc_info,
- unsigned long flags)
+ struct persistent_ram_ecc_info *ecc_info)
{
int ret;
@@ -494,10 +493,9 @@ static int persistent_ram_post_init(struct persistent_ram_zone *prz, u32 sig,
prz->buffer->sig);
}
+ /* Rewind missing or invalid memory area. */
prz->buffer->sig = sig;
persistent_ram_zap(prz);
- prz->buffer_lock = __RAW_SPIN_LOCK_UNLOCKED(buffer_lock);
- prz->flags = flags;
return 0;
}
@@ -533,11 +531,15 @@ struct persistent_ram_zone *persistent_ram_new(phys_addr_t start, size_t size,
goto err;
}
+ /* Initialize general buffer state. */
+ prz->buffer_lock = __RAW_SPIN_LOCK_UNLOCKED(buffer_lock);
+ prz->flags = flags;
+
ret = persistent_ram_buffer_map(start, size, prz, memtype);
if (ret)
goto err;
- ret = persistent_ram_post_init(prz, sig, ecc_info, flags);
+ ret = persistent_ram_post_init(prz, sig, ecc_info);
if (ret)
goto err;