diff options
| author | Mikhail Zaslonko | 2023-05-09 17:38:15 +0200 |
|---|---|---|
| committer | Alexander Gordeev | 2023-06-01 17:07:56 +0200 |
| commit | 9f70bc890ae299a6fdf83bfc99832509fd2f7494 (patch) | |
| tree | 1442c4e540933d2bf2a64aade4725578980142f5 /drivers/s390 | |
| parent | 31e9ccc67ce24f82120e41fcafd841f98838ff5c (diff) | |
s390/zcore: conditionally clear memory on reipl
Currently zcore_reipl_write() always use DIAG308_LOAD_CLEAR to ipl the
system (used by ngdump and zfcpdump to ipl the original kernel after
dumping).
Instead of 'always clear' check OS_INFO_FLAG_REIPL_CLEAR flag and use
either LOAD_CLEAR or LOAD_NORMAL diag308 subcode accordingly.
For that read os_info and check for the valid os_info flags entry
in zcore_reipl_init(). Do not return error on failure (e.g. os_info
checksum error) in order to continue dump processing, considering
that os_info could be corrupted on the panicked system.
Signed-off-by: Mikhail Zaslonko <zaslonko@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Diffstat (limited to 'drivers/s390')
| -rw-r--r-- | drivers/s390/char/zcore.c | 41 |
1 files changed, 40 insertions, 1 deletions
diff --git a/drivers/s390/char/zcore.c b/drivers/s390/char/zcore.c index 599f547310f8..942c73a11ca3 100644 --- a/drivers/s390/char/zcore.c +++ b/drivers/s390/char/zcore.c @@ -51,6 +51,7 @@ static struct dentry *zcore_dir; static struct dentry *zcore_reipl_file; static struct dentry *zcore_hsa_file; static struct ipl_parameter_block *zcore_ipl_block; +static unsigned long os_info_flags; static DEFINE_MUTEX(hsa_buf_mutex); static char hsa_buf[PAGE_SIZE] __aligned(PAGE_SIZE); @@ -139,7 +140,13 @@ static ssize_t zcore_reipl_write(struct file *filp, const char __user *buf, { if (zcore_ipl_block) { diag308(DIAG308_SET, zcore_ipl_block); - diag308(DIAG308_LOAD_CLEAR, NULL); + if (os_info_flags & OS_INFO_FLAG_REIPL_CLEAR) + diag308(DIAG308_LOAD_CLEAR, NULL); + /* Use special diag308 subcode for CCW normal ipl */ + if (zcore_ipl_block->pb0_hdr.pbt == IPL_PBT_CCW) + diag308(DIAG308_LOAD_NORMAL_DUMP, NULL); + else + diag308(DIAG308_LOAD_NORMAL, NULL); } return count; } @@ -212,7 +219,10 @@ static int __init check_sdias(void) */ static int __init zcore_reipl_init(void) { + struct os_info_entry *entry; struct ipib_info ipib_info; + unsigned long os_info_addr; + struct os_info *os_info; int rc; rc = memcpy_hsa_kernel(&ipib_info, __LC_DUMP_REIPL, sizeof(ipib_info)); @@ -234,6 +244,35 @@ static int __init zcore_reipl_init(void) free_page((unsigned long) zcore_ipl_block); zcore_ipl_block = NULL; } + /* + * Read the bit-flags field from os_info flags entry. + * Return zero even for os_info read or entry checksum errors in order + * to continue dump processing, considering that os_info could be + * corrupted on the panicked system. + */ + os_info = (void *)__get_free_page(GFP_KERNEL); + if (!os_info) + return -ENOMEM; + rc = memcpy_hsa_kernel(&os_info_addr, __LC_OS_INFO, sizeof(os_info_addr)); + if (rc) + goto out; + if (os_info_addr < sclp.hsa_size) + rc = memcpy_hsa_kernel(os_info, os_info_addr, PAGE_SIZE); + else + rc = memcpy_real(os_info, os_info_addr, PAGE_SIZE); + if (rc || os_info_csum(os_info) != os_info->csum) + goto out; + entry = &os_info->entry[OS_INFO_FLAGS_ENTRY]; + if (entry->addr && entry->size) { + if (entry->addr < sclp.hsa_size) + rc = memcpy_hsa_kernel(&os_info_flags, entry->addr, sizeof(os_info_flags)); + else + rc = memcpy_real(&os_info_flags, entry->addr, sizeof(os_info_flags)); + if (rc || (__force u32)csum_partial(&os_info_flags, entry->size, 0) != entry->csum) + os_info_flags = 0; + } +out: + free_page((unsigned long)os_info); return 0; } |