diff options
| -rw-r--r-- | arch/powerpc/include/asm/rtas.h | 6 | ||||
| -rw-r--r-- | arch/powerpc/platforms/pseries/Kconfig | 1 | ||||
| -rw-r--r-- | arch/powerpc/platforms/pseries/nvram.c | 171 |
3 files changed, 169 insertions, 9 deletions
diff --git a/arch/powerpc/include/asm/rtas.h b/arch/powerpc/include/asm/rtas.h index 58625d1e780..41f69ae79d4 100644 --- a/arch/powerpc/include/asm/rtas.h +++ b/arch/powerpc/include/asm/rtas.h @@ -249,10 +249,12 @@ extern void pSeries_log_error(char *buf, unsigned int err_type, int fatal); #define ERR_FLAG_ALREADY_LOGGED 0x0 #define ERR_FLAG_BOOT 0x1 /* log was pulled from NVRAM on boot */ #define ERR_TYPE_RTAS_LOG 0x2 /* from rtas event-scan */ -#define ERR_TYPE_KERNEL_PANIC 0x4 /* from panic() */ +#define ERR_TYPE_KERNEL_PANIC 0x4 /* from die()/panic() */ +#define ERR_TYPE_KERNEL_PANIC_GZ 0x8 /* ditto, compressed */ /* All the types and not flags */ -#define ERR_TYPE_MASK (ERR_TYPE_RTAS_LOG | ERR_TYPE_KERNEL_PANIC) +#define ERR_TYPE_MASK \ + (ERR_TYPE_RTAS_LOG | ERR_TYPE_KERNEL_PANIC | ERR_TYPE_KERNEL_PANIC_GZ) #define RTAS_DEBUG KERN_DEBUG "RTAS: " diff --git a/arch/powerpc/platforms/pseries/Kconfig b/arch/powerpc/platforms/pseries/Kconfig index 05cf4769b88..c81f6bb9c10 100644 --- a/arch/powerpc/platforms/pseries/Kconfig +++ b/arch/powerpc/platforms/pseries/Kconfig @@ -15,6 +15,7 @@ config PPC_PSERIES select PPC_UDBG_16550 select PPC_NATIVE select PPC_PCI_CHOICE if EXPERT + select ZLIB_DEFLATE default y config PPC_SPLPAR diff --git a/arch/powerpc/platforms/pseries/nvram.c b/arch/powerpc/platforms/pseries/nvram.c index 00cc3a09488..a76b22844d1 100644 --- a/arch/powerpc/platforms/pseries/nvram.c +++ b/arch/powerpc/platforms/pseries/nvram.c @@ -18,6 +18,8 @@ #include <linux/spinlock.h> #include <linux/slab.h> #include <linux/kmsg_dump.h> +#include <linux/ctype.h> +#include <linux/zlib.h> #include <asm/uaccess.h> #include <asm/nvram.h> #include <asm/rtas.h> @@ -78,8 +80,41 @@ static struct kmsg_dumper nvram_kmsg_dumper = { #define NVRAM_RTAS_READ_TIMEOUT 5 /* seconds */ static unsigned long last_unread_rtas_event; /* timestamp */ -/* We preallocate oops_buf during init to avoid kmalloc during oops/panic. */ -static char *oops_buf; +/* + * For capturing and compressing an oops or panic report... + + * big_oops_buf[] holds the uncompressed text we're capturing. + * + * oops_buf[] holds the compressed text, preceded by a prefix. + * The prefix is just a u16 holding the length of the compressed* text. + * (*Or uncompressed, if compression fails.) oops_buf[] gets written + * to NVRAM. + * + * oops_len points to the prefix. oops_data points to the compressed text. + * + * +- oops_buf + * | +- oops_data + * v v + * +------------+-----------------------------------------------+ + * | length | text | + * | (2 bytes) | (oops_data_sz bytes) | + * +------------+-----------------------------------------------+ + * ^ + * +- oops_len + * + * We preallocate these buffers during init to avoid kmalloc during oops/panic. + */ +static size_t big_oops_buf_sz; +static char *big_oops_buf, *oops_buf; +static u16 *oops_len; +static char *oops_data; +static size_t oops_data_sz; + +/* Compression parameters */ +#define COMPR_LEVEL 6 +#define WINDOW_BITS 12 +#define MEM_LEVEL 4 +static struct z_stream_s stream; static ssize_t pSeries_nvram_read(char *buf, size_t count, loff_t *index) { @@ -387,11 +422,44 @@ static void __init nvram_init_oops_partition(int rtas_partition_exists) sizeof(rtas_log_partition)); } oops_buf = kmalloc(oops_log_partition.size, GFP_KERNEL); + if (!oops_buf) { + pr_err("nvram: No memory for %s partition\n", + oops_log_partition.name); + return; + } + oops_len = (u16*) oops_buf; + oops_data = oops_buf + sizeof(u16); + oops_data_sz = oops_log_partition.size - sizeof(u16); + + /* + * Figure compression (preceded by elimination of each line's <n> + * severity prefix) will reduce the oops/panic report to at most + * 45% of its original size. + */ + big_oops_buf_sz = (oops_data_sz * 100) / 45; + big_oops_buf = kmalloc(big_oops_buf_sz, GFP_KERNEL); + if (big_oops_buf) { + stream.workspace = kmalloc(zlib_deflate_workspacesize( + WINDOW_BITS, MEM_LEVEL), GFP_KERNEL); + if (!stream.workspace) { + pr_err("nvram: No memory for compression workspace; " + "skipping compression of %s partition data\n", + oops_log_partition.name); + kfree(big_oops_buf); + big_oops_buf = NULL; + } + } else { + pr_err("No memory for uncompressed %s data; " + "skipping compression\n", oops_log_partition.name); + stream.workspace = NULL; + } + rc = kmsg_dump_register(&nvram_kmsg_dumper); if (rc != 0) { pr_err("nvram: kmsg_dump_register() failed; returned %d\n", rc); kfree(oops_buf); - return; + kfree(big_oops_buf); + kfree(stream.workspace); } } @@ -473,7 +541,83 @@ static int clobbering_unread_rtas_event(void) NVRAM_RTAS_READ_TIMEOUT); } -/* our kmsg_dump callback */ +/* Squeeze out each line's <n> severity prefix. */ +static size_t elide_severities(char *buf, size_t len) +{ + char *in, *out, *buf_end = buf + len; + /* Assume a <n> at the very beginning marks the start of a line. */ + int newline = 1; + + in = out = buf; + while (in < buf_end) { + if (newline && in+3 <= buf_end && + *in == '<' && isdigit(in[1]) && in[2] == '>') { + in += 3; + newline = 0; + } else { + newline = (*in == '\n'); + *out++ = *in++; + } + } + return out - buf; +} + +/* Derived from logfs_compress() */ +static int nvram_compress(const void *in, void *out, size_t inlen, + size_t outlen) +{ + int err, ret; + + ret = -EIO; + err = zlib_deflateInit2(&stream, COMPR_LEVEL, Z_DEFLATED, WINDOW_BITS, + MEM_LEVEL, Z_DEFAULT_STRATEGY); + if (err != Z_OK) + goto error; + + stream.next_in = in; + stream.avail_in = inlen; + stream.total_in = 0; + stream.next_out = out; + stream.avail_out = outlen; + stream.total_out = 0; + + err = zlib_deflate(&stream, Z_FINISH); + if (err != Z_STREAM_END) + goto error; + + err = zlib_deflateEnd(&stream); + if (err != Z_OK) + goto error; + + if (stream.total_out >= stream.total_in) + goto error; + + ret = stream.total_out; +error: + return ret; +} + +/* Compress the text from big_oops_buf into oops_buf. */ +static int zip_oops(size_t text_len) +{ + int zipped_len = nvram_compress(big_oops_buf, oops_data, text_len, + oops_data_sz); + if (zipped_len < 0) { + pr_err("nvram: compression failed; returned %d\n", zipped_len); + pr_err("nvram: logging uncompressed oops/panic report\n"); + return -1; + } + *oops_len = (u16) zipped_len; + return 0; +} + +/* + * This is our kmsg_dump callback, called after an oops or panic report + * has been written to the printk buffer. We want to capture as much + * of the printk buffer as possible. First, capture as much as we can + * that we think will compress sufficiently to fit in the lnx,oops-log + * partition. If that's too much, go back and capture uncompressed text. + */ static void oops_to_nvram(struct kmsg_dumper *dumper, enum kmsg_dump_reason reason, const char *old_msgs, unsigned long old_len, @@ -482,6 +626,8 @@ static void oops_to_nvram(struct kmsg_dumper *dumper, static unsigned int oops_count = 0; static bool panicking = false; size_t text_len; + unsigned int err_type = ERR_TYPE_KERNEL_PANIC_GZ; + int rc = -1; switch (reason) { case KMSG_DUMP_RESTART: @@ -509,8 +655,19 @@ static void oops_to_nvram(struct kmsg_dumper *dumper, if (clobbering_unread_rtas_event()) return; - text_len = capture_last_msgs(old_msgs, old_len, new_msgs, new_len, - oops_buf, oops_log_partition.size); + if (big_oops_buf) { + text_len = capture_last_msgs(old_msgs, old_len, + new_msgs, new_len, big_oops_buf, big_oops_buf_sz); + text_len = elide_severities(big_oops_buf, text_len); + rc = zip_oops(text_len); + } + if (rc != 0) { + text_len = capture_last_msgs(old_msgs, old_len, + new_msgs, new_len, oops_data, oops_data_sz); + err_type = ERR_TYPE_KERNEL_PANIC; + *oops_len = (u16) text_len; + } + (void) nvram_write_os_partition(&oops_log_partition, oops_buf, - (int) text_len, ERR_TYPE_KERNEL_PANIC, ++oops_count); + (int) (sizeof(*oops_len) + *oops_len), err_type, ++oops_count); } |