linux_dsm_epyc7002/arch/powerpc/include/asm/fadump.h
Hari Bathini 1bd6a1c4b8 powerpc/fadump: handle crash memory ranges array index overflow
Crash memory ranges is an array of memory ranges of the crashing kernel
to be exported as a dump via /proc/vmcore file. The size of the array
is set based on INIT_MEMBLOCK_REGIONS, which works alright in most cases
where memblock memory regions count is less than INIT_MEMBLOCK_REGIONS
value. But this count can grow beyond INIT_MEMBLOCK_REGIONS value since
commit 142b45a72e ("memblock: Add array resizing support").

On large memory systems with a few DLPAR operations, the memblock memory
regions count could be larger than INIT_MEMBLOCK_REGIONS value. On such
systems, registering fadump results in crash or other system failures
like below:

  task: c00007f39a290010 ti: c00000000b738000 task.ti: c00000000b738000
  NIP: c000000000047df4 LR: c0000000000f9e58 CTR: c00000000010f180
  REGS: c00000000b73b570 TRAP: 0300   Tainted: G          L   X  (4.4.140+)
  MSR: 8000000000009033 <SF,EE,ME,IR,DR,RI,LE>  CR: 22004484  XER: 20000000
  CFAR: c000000000008500 DAR: 000007a450000000 DSISR: 40000000 SOFTE: 0
  ...
  NIP [c000000000047df4] smp_send_reschedule+0x24/0x80
  LR [c0000000000f9e58] resched_curr+0x138/0x160
  Call Trace:
    resched_curr+0x138/0x160 (unreliable)
    check_preempt_curr+0xc8/0xf0
    ttwu_do_wakeup+0x38/0x150
    try_to_wake_up+0x224/0x4d0
    __wake_up_common+0x94/0x100
    ep_poll_callback+0xac/0x1c0
    __wake_up_common+0x94/0x100
    __wake_up_sync_key+0x70/0xa0
    sock_def_readable+0x58/0xa0
    unix_stream_sendmsg+0x2dc/0x4c0
    sock_sendmsg+0x68/0xa0
    ___sys_sendmsg+0x2cc/0x2e0
    __sys_sendmsg+0x5c/0xc0
    SyS_socketcall+0x36c/0x3f0
    system_call+0x3c/0x100

as array index overflow is not checked for while setting up crash memory
ranges causing memory corruption. To resolve this issue, dynamically
allocate memory for crash memory ranges and resize it incrementally,
in units of pagesize, on hitting array size limit.

Fixes: 2df173d9e8 ("fadump: Initialize elfcore header and add PT_LOAD program headers.")
Cc: stable@vger.kernel.org # v3.4+
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Reviewed-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
[mpe: Just use PAGE_SIZE directly, fixup variable placement]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-08-10 22:12:34 +10:00

219 lines
6.1 KiB
C

/*
* Firmware Assisted dump header file.
*
* 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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
* Copyright 2011 IBM Corporation
* Author: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
*/
#ifndef __PPC64_FA_DUMP_H__
#define __PPC64_FA_DUMP_H__
#ifdef CONFIG_FA_DUMP
/*
* The RMA region will be saved for later dumping when kernel crashes.
* RMA is Real Mode Area, the first block of logical memory address owned
* by logical partition, containing the storage that may be accessed with
* translate off.
*/
#define RMA_START 0x0
#define RMA_END (ppc64_rma_size)
/*
* On some Power systems where RMO is 128MB, it still requires minimum of
* 256MB for kernel to boot successfully. When kdump infrastructure is
* configured to save vmcore over network, we run into OOM issue while
* loading modules related to network setup. Hence we need aditional 64M
* of memory to avoid OOM issue.
*/
#define MIN_BOOT_MEM (((RMA_END < (0x1UL << 28)) ? (0x1UL << 28) : RMA_END) \
+ (0x1UL << 26))
/* The upper limit percentage for user specified boot memory size (25%) */
#define MAX_BOOT_MEM_RATIO 4
#define memblock_num_regions(memblock_type) (memblock.memblock_type.cnt)
/* Firmware provided dump sections */
#define FADUMP_CPU_STATE_DATA 0x0001
#define FADUMP_HPTE_REGION 0x0002
#define FADUMP_REAL_MODE_REGION 0x0011
/* Dump request flag */
#define FADUMP_REQUEST_FLAG 0x00000001
/* FAD commands */
#define FADUMP_REGISTER 1
#define FADUMP_UNREGISTER 2
#define FADUMP_INVALIDATE 3
/* Dump status flag */
#define FADUMP_ERROR_FLAG 0x2000
#define FADUMP_CPU_ID_MASK ((1UL << 32) - 1)
#define CPU_UNKNOWN (~((u32)0))
/* Utility macros */
#define SKIP_TO_NEXT_CPU(reg_entry) \
({ \
while (be64_to_cpu(reg_entry->reg_id) != REG_ID("CPUEND")) \
reg_entry++; \
reg_entry++; \
})
extern int crashing_cpu;
/* Kernel Dump section info */
struct fadump_section {
__be32 request_flag;
__be16 source_data_type;
__be16 error_flags;
__be64 source_address;
__be64 source_len;
__be64 bytes_dumped;
__be64 destination_address;
};
/* ibm,configure-kernel-dump header. */
struct fadump_section_header {
__be32 dump_format_version;
__be16 dump_num_sections;
__be16 dump_status_flag;
__be32 offset_first_dump_section;
/* Fields for disk dump option. */
__be32 dd_block_size;
__be64 dd_block_offset;
__be64 dd_num_blocks;
__be32 dd_offset_disk_path;
/* Maximum time allowed to prevent an automatic dump-reboot. */
__be32 max_time_auto;
};
/*
* Firmware Assisted dump memory structure. This structure is required for
* registering future kernel dump with power firmware through rtas call.
*
* No disk dump option. Hence disk dump path string section is not included.
*/
struct fadump_mem_struct {
struct fadump_section_header header;
/* Kernel dump sections */
struct fadump_section cpu_state_data;
struct fadump_section hpte_region;
struct fadump_section rmr_region;
};
/* Firmware-assisted dump configuration details. */
struct fw_dump {
unsigned long cpu_state_data_size;
unsigned long hpte_region_size;
unsigned long boot_memory_size;
unsigned long reserve_dump_area_start;
unsigned long reserve_dump_area_size;
/* cmd line option during boot */
unsigned long reserve_bootvar;
unsigned long fadumphdr_addr;
unsigned long cpu_notes_buf;
unsigned long cpu_notes_buf_size;
int ibm_configure_kernel_dump;
unsigned long fadump_enabled:1;
unsigned long fadump_supported:1;
unsigned long dump_active:1;
unsigned long dump_registered:1;
};
/*
* Copy the ascii values for first 8 characters from a string into u64
* variable at their respective indexes.
* e.g.
* The string "FADMPINF" will be converted into 0x4641444d50494e46
*/
static inline u64 str_to_u64(const char *str)
{
u64 val = 0;
int i;
for (i = 0; i < sizeof(val); i++)
val = (*str) ? (val << 8) | *str++ : val << 8;
return val;
}
#define STR_TO_HEX(x) str_to_u64(x)
#define REG_ID(x) str_to_u64(x)
#define FADUMP_CRASH_INFO_MAGIC STR_TO_HEX("FADMPINF")
#define REGSAVE_AREA_MAGIC STR_TO_HEX("REGSAVE")
/* The firmware-assisted dump format.
*
* The register save area is an area in the partition's memory used to preserve
* the register contents (CPU state data) for the active CPUs during a firmware
* assisted dump. The dump format contains register save area header followed
* by register entries. Each list of registers for a CPU starts with
* "CPUSTRT" and ends with "CPUEND".
*/
/* Register save area header. */
struct fadump_reg_save_area_header {
__be64 magic_number;
__be32 version;
__be32 num_cpu_offset;
};
/* Register entry. */
struct fadump_reg_entry {
__be64 reg_id;
__be64 reg_value;
};
/* fadump crash info structure */
struct fadump_crash_info_header {
u64 magic_number;
u64 elfcorehdr_addr;
u32 crashing_cpu;
struct pt_regs regs;
struct cpumask online_mask;
};
struct fad_crash_memory_ranges {
unsigned long long base;
unsigned long long size;
};
extern int is_fadump_boot_memory_area(u64 addr, ulong size);
extern int early_init_dt_scan_fw_dump(unsigned long node,
const char *uname, int depth, void *data);
extern int fadump_reserve_mem(void);
extern int setup_fadump(void);
extern int is_fadump_active(void);
extern int should_fadump_crash(void);
extern void crash_fadump(struct pt_regs *, const char *);
extern void fadump_cleanup(void);
#else /* CONFIG_FA_DUMP */
static inline int is_fadump_active(void) { return 0; }
static inline int should_fadump_crash(void) { return 0; }
static inline void crash_fadump(struct pt_regs *regs, const char *str) { }
#endif
#endif