Revision ebff65473f56e6c30de928fd6a4f1ce5ae36e8c5 authored by Shawn Guo on 02 December 2013, 05:26:50 UTC, committed by Mark Brown on 02 December 2013, 11:50:53 UTC
Since devm_card_release() expects parameter 'res' to be a pointer to struct snd_soc_card, devm_snd_soc_register_card() should really pass such a pointer rather than the one to struct device. This bug causes the kernel Oops below with imx-sgtl500 driver when we remove the module. It happens because with 'card' pointing to the wrong structure, card->num_rtd becomes 0 in function soc_remove_dai_links(). Consequently, soc_remove_link_components() and in turn soc_cleanup_codec[platform]_debugfs() will not be called on card removal. It results in that debugfs_card_root is being removed while its child entries debugfs_codec_root and debugfs_platform_root are still there, and thus the kernel Oops. Fix the bug by correcting the parameter 'res' to be the pointer to struct snd_soc_card. $ lsmod Module Size Used by snd_soc_imx_sgtl5000 3506 0 snd_soc_sgtl5000 13677 2 snd_soc_imx_audmux 5324 1 snd_soc_imx_sgtl5000 snd_soc_fsl_ssi 8139 2 imx_pcm_dma 1380 1 snd_soc_fsl_ssi $ rmmod snd_soc_imx_sgtl5000 Unable to handle kernel paging request at virtual address e594025c pgd = be134000 [e594025c] *pgd=00000000 Internal error: Oops: 5 [#1] SMP ARM Modules linked in: snd_soc_imx_sgtl5000(-) snd_soc_sgtl5000 snd_soc_imx_audmux snd_soc_fsl_ssi imx_pcm_dma CPU: 0 PID: 1793 Comm: rmmod Not tainted 3.13.0-rc1 #1570 task: bee28900 ti: bfbec000 task.ti: bfbec000 PC is at debugfs_remove_recursive+0x28/0x154 LR is at snd_soc_unregister_card+0xa0/0xcc pc : [<80252b38>] lr : [<80496ac4>] psr: a0000013 sp : bfbede00 ip : bfbede28 fp : bfbede24 r10: 803281d4 r9 : bfbec000 r8 : 803271ac r7 : bef54440 r6 : 00000004 r5 : bf9a4010 r4 : bf9a4010 r3 : e5940224 r2 : 00000000 r1 : bef54450 r0 : 803271ac Flags: NzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user Control: 10c53c7d Table: 4e13404a DAC: 00000015 Process rmmod (pid: 1793, stack limit = 0xbfbec240) Stack: (0xbfbede00 to 0xbfbee000) de00: 00000000 bf9a4010 bf9a4010 00000004 bef54440 bec89000 bfbede44 bfbede28 de20: 80496ac4 80252b1c 804a4b60 bfbede60 bf9a4010 00000004 bfbede54 bfbede48 de40: 804a4b74 80496a30 bfbede94 bfbede58 80328728 804a4b6c bfbede94 a0000013 de60: bf1b5800 bef54440 00000002 bf9a4010 7f0169f8 bf9a4044 00000081 8000e9c4 de80: bfbec000 00000000 bfbedeac bfbede98 80328cb0 80328618 7f016000 bf9a4010 dea0: bfbedec4 bfbedeb0 8032561c 80328c84 bf9a4010 7f0169f8 bfbedee4 bfbedec8 dec0: 80325e84 803255a8 bee28900 7f0169f8 00000000 78208d30 bfbedefc bfbedee8 dee0: 80325410 80325dd4 beca8100 7f0169f8 bfbedf14 bfbedf00 803264f8 803253c8 df00: 7f01635c 7f016a3c bfbedf24 bfbedf18 80327098 803264d4 bfbedf34 bfbedf28 df20: 7f016370 80327090 bfbedfa4 bfbedf38 80085ef0 7f016368 bfbedf54 5f646e73 df40: 5f636f73 5f786d69 6c746773 30303035 00000000 78208008 bfbedf84 bfbedf68 df60: 800613b0 80061194 fffffffe 78208d00 7efc2f07 00000081 7f016a3c 00000800 df80: bfbedf84 00000000 00000000 fffffffe 78208d00 7efc2f07 00000000 bfbedfa8 dfa0: 8000e800 80085dcc fffffffe 78208d00 78208d30 00000800 a8c82400 a8c82400 dfc0: fffffffe 78208d00 7efc2f07 00000081 00000002 00000000 78208008 00000800 dfe0: 7efc2e1c 7efc2ba8 76f5ca47 76edec7c 80000010 78208d30 00000000 00000000 Backtrace: [<80252b10>] (debugfs_remove_recursive+0x0/0x154) from [<80496ac4>] (snd_soc_unregister_card+0xa0/0xcc) r8:bec89000 r7:bef54440 r6:00000004 r5:bf9a4010 r4:bf9a4010 r3:00000000 [<80496a24>] (snd_soc_unregister_card+0x0/0xcc) from [<804a4b74>] (devm_card_release+0x14/0x18) r6:00000004 r5:bf9a4010 r4:bfbede60 r3:804a4b60 [<804a4b60>] (devm_card_release+0x0/0x18) from [<80328728>] (release_nodes+0x11c/0x1dc) [<8032860c>] (release_nodes+0x0/0x1dc) from [<80328cb0>] (devres_release_all+0x38/0x54) [<80328c78>] (devres_release_all+0x0/0x54) from [<8032561c>] (__device_release_driver+0x80/0xd4) r4:bf9a4010 r3:7f016000 [<8032559c>] (__device_release_driver+0x0/0xd4) from [<80325e84>] (driver_detach+0xbc/0xc0) r5:7f0169f8 r4:bf9a4010 [<80325dc8>] (driver_detach+0x0/0xc0) from [<80325410>] (bus_remove_driver+0x54/0x98) r6:78208d30 r5:00000000 r4:7f0169f8 r3:bee28900 [<803253bc>] (bus_remove_driver+0x0/0x98) from [<803264f8>] (driver_unregister+0x30/0x50) r4:7f0169f8 r3:beca8100 [<803264c8>] (driver_unregister+0x0/0x50) from [<80327098>] (platform_driver_unregister+0x14/0x18) r4:7f016a3c r3:7f01635c [<80327084>] (platform_driver_unregister+0x0/0x18) from [<7f016370>] (imx_sgtl5000_driver_exit+0x14/0x1c [snd_soc_imx_sgtl5000]) [<7f01635c>] (imx_sgtl5000_driver_exit+0x0/0x1c [snd_soc_imx_sgtl5000]) from [<80085ef0>] (SyS_delete_module+0x130/0x18c) [<80085dc0>] (SyS_delete_module+0x0/0x18c) from [<8000e800>] (ret_fast_syscall+0x0/0x48) r6:7efc2f07 r5:78208d00 r4:fffffffe Code: 889da9f8 e5983020 e3530000 089da9f8 (e5933038) ---[ end trace 825e7e125251a225 ]--- Signed-off-by: Shawn Guo <shawn.guo@linaro.org> Signed-off-by: Mark Brown <broonie@linaro.org>
1 parent 8f1ec93
bug.c
/*
Generic support for BUG()
This respects the following config options:
CONFIG_BUG - emit BUG traps. Nothing happens without this.
CONFIG_GENERIC_BUG - enable this code.
CONFIG_GENERIC_BUG_RELATIVE_POINTERS - use 32-bit pointers relative to
the containing struct bug_entry for bug_addr and file.
CONFIG_DEBUG_BUGVERBOSE - emit full file+line information for each BUG
CONFIG_BUG and CONFIG_DEBUG_BUGVERBOSE are potentially user-settable
(though they're generally always on).
CONFIG_GENERIC_BUG is set by each architecture using this code.
To use this, your architecture must:
1. Set up the config options:
- Enable CONFIG_GENERIC_BUG if CONFIG_BUG
2. Implement BUG (and optionally BUG_ON, WARN, WARN_ON)
- Define HAVE_ARCH_BUG
- Implement BUG() to generate a faulting instruction
- NOTE: struct bug_entry does not have "file" or "line" entries
when CONFIG_DEBUG_BUGVERBOSE is not enabled, so you must generate
the values accordingly.
3. Implement the trap
- In the illegal instruction trap handler (typically), verify
that the fault was in kernel mode, and call report_bug()
- report_bug() will return whether it was a false alarm, a warning,
or an actual bug.
- You must implement the is_valid_bugaddr(bugaddr) callback which
returns true if the eip is a real kernel address, and it points
to the expected BUG trap instruction.
Jeremy Fitzhardinge <jeremy@goop.org> 2006
*/
#include <linux/list.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/bug.h>
#include <linux/sched.h>
extern const struct bug_entry __start___bug_table[], __stop___bug_table[];
static inline unsigned long bug_addr(const struct bug_entry *bug)
{
#ifndef CONFIG_GENERIC_BUG_RELATIVE_POINTERS
return bug->bug_addr;
#else
return (unsigned long)bug + bug->bug_addr_disp;
#endif
}
#ifdef CONFIG_MODULES
/* Updates are protected by module mutex */
static LIST_HEAD(module_bug_list);
static const struct bug_entry *module_find_bug(unsigned long bugaddr)
{
struct module *mod;
list_for_each_entry(mod, &module_bug_list, bug_list) {
const struct bug_entry *bug = mod->bug_table;
unsigned i;
for (i = 0; i < mod->num_bugs; ++i, ++bug)
if (bugaddr == bug_addr(bug))
return bug;
}
return NULL;
}
void module_bug_finalize(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs,
struct module *mod)
{
char *secstrings;
unsigned int i;
mod->bug_table = NULL;
mod->num_bugs = 0;
/* Find the __bug_table section, if present */
secstrings = (char *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
for (i = 1; i < hdr->e_shnum; i++) {
if (strcmp(secstrings+sechdrs[i].sh_name, "__bug_table"))
continue;
mod->bug_table = (void *) sechdrs[i].sh_addr;
mod->num_bugs = sechdrs[i].sh_size / sizeof(struct bug_entry);
break;
}
/*
* Strictly speaking this should have a spinlock to protect against
* traversals, but since we only traverse on BUG()s, a spinlock
* could potentially lead to deadlock and thus be counter-productive.
*/
list_add(&mod->bug_list, &module_bug_list);
}
void module_bug_cleanup(struct module *mod)
{
list_del(&mod->bug_list);
}
#else
static inline const struct bug_entry *module_find_bug(unsigned long bugaddr)
{
return NULL;
}
#endif
const struct bug_entry *find_bug(unsigned long bugaddr)
{
const struct bug_entry *bug;
for (bug = __start___bug_table; bug < __stop___bug_table; ++bug)
if (bugaddr == bug_addr(bug))
return bug;
return module_find_bug(bugaddr);
}
enum bug_trap_type report_bug(unsigned long bugaddr, struct pt_regs *regs)
{
const struct bug_entry *bug;
const char *file;
unsigned line, warning;
if (!is_valid_bugaddr(bugaddr))
return BUG_TRAP_TYPE_NONE;
bug = find_bug(bugaddr);
file = NULL;
line = 0;
warning = 0;
if (bug) {
#ifdef CONFIG_DEBUG_BUGVERBOSE
#ifndef CONFIG_GENERIC_BUG_RELATIVE_POINTERS
file = bug->file;
#else
file = (const char *)bug + bug->file_disp;
#endif
line = bug->line;
#endif
warning = (bug->flags & BUGFLAG_WARNING) != 0;
}
if (warning) {
/* this is a WARN_ON rather than BUG/BUG_ON */
printk(KERN_WARNING "------------[ cut here ]------------\n");
if (file)
printk(KERN_WARNING "WARNING: at %s:%u\n",
file, line);
else
printk(KERN_WARNING "WARNING: at %p "
"[verbose debug info unavailable]\n",
(void *)bugaddr);
print_modules();
show_regs(regs);
print_oops_end_marker();
/* Just a warning, don't kill lockdep. */
add_taint(BUG_GET_TAINT(bug), LOCKDEP_STILL_OK);
return BUG_TRAP_TYPE_WARN;
}
printk(KERN_DEFAULT "------------[ cut here ]------------\n");
if (file)
printk(KERN_CRIT "kernel BUG at %s:%u!\n",
file, line);
else
printk(KERN_CRIT "Kernel BUG at %p "
"[verbose debug info unavailable]\n",
(void *)bugaddr);
return BUG_TRAP_TYPE_BUG;
}
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