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Add 4Kn kernel dump support

Browse source 
(And 4Kn minidump support, but only for amd64.)

Make sure all I/O to the dump device is of the native sector size.  To
that end, we keep a native sector sized buffer associated with dump
devices (di->blockbuf) and use it to pad smaller objects as needed (e.g.
kerneldumpheader).

Add dump_write_pad() as a convenience API to dump smaller objects with
zero padding.  (Rather than pull in NPM leftpad, we wrote our own.)

Savecore(1) has been updated to deal with these dumps.  The format for
512-byte sector dumps should remain backwards compatible.

Minidumps for other architectures are left as an exercise for the
reader.

PR:		194279
Submitted by:	ambrisko@
Reviewed by:	cem (earlier version), rpokala
Tested by:	rpokala (4Kn/512 except 512 fulldump), cem (512 fulldump)
Relnotes:	yes
Sponsored by:	EMC / Isilon Storage Division
Differential Revision:	https://reviews.freebsd.org/D5848
This commit is contained in:
Conrad Meyer 2016-04-15 17:45:12 +00:00
parent 155d72c498
commit 5dc5dab6eb
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=298076
5 changed files with 86 additions and 40 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

33
sbin/savecore/savecore.c
View file

@ -436,7 +436,7 @@ DoFile(const char *savedir, const char *device)
{
xo_handle_t *xostdout, *xoinfo;
static char infoname[PATH_MAX], corename[PATH_MAX], linkname[PATH_MAX];
static char *buf = NULL;
static char *buf = NULL, *temp = NULL;
struct kerneldumpheader kdhf, kdhl;
off_t mediasize, dumpsize, firsthd, lasthd;
FILE *info, *fp;
@ -490,14 +490,29 @@ DoFile(const char *savedir, const char *device)
printf("sectorsize = %u\n", sectorsize);
}
if (sectorsize < sizeof(kdhl)) {
syslog(LOG_ERR,
"Sector size is less the kernel dump header %zu",
sizeof(kdhl));
goto closefd;
}
lasthd = mediasize - sectorsize;
if (temp == NULL) {
temp = malloc(sectorsize);
if (temp == NULL) {
syslog(LOG_ERR, "%m");
return;
}
}
if (lseek(fd, lasthd, SEEK_SET) != lasthd ||
read(fd, &kdhl, sizeof(kdhl)) != sizeof(kdhl)) {
read(fd, temp, sectorsize) != sectorsize) {
syslog(LOG_ERR,
"error reading last dump header at offset %lld in %s: %m",
(long long)lasthd, device);
goto closefd;
}
memcpy(&kdhl, temp, sizeof(kdhl));
istextdump = 0;
if (strncmp(kdhl.magic, TEXTDUMPMAGIC, sizeof kdhl) == 0) {
if (verbose)
@ -567,15 +582,16 @@ DoFile(const char *savedir, const char *device)
goto closefd;
}
dumpsize = dtoh64(kdhl.dumplength);
firsthd = lasthd - dumpsize - sizeof kdhf;
firsthd = lasthd - dumpsize - sectorsize;
if (lseek(fd, firsthd, SEEK_SET) != firsthd ||
read(fd, &kdhf, sizeof(kdhf)) != sizeof(kdhf)) {
read(fd, temp, sectorsize) != sectorsize) {
syslog(LOG_ERR,
"error reading first dump header at offset %lld in %s: %m",
(long long)firsthd, device);
nerr++;
goto closefd;
}
memcpy(&kdhf, temp, sizeof(kdhf));
if (verbose >= 2) {
printf("First dump headers:\n");
@ -586,7 +602,7 @@ DoFile(const char *savedir, const char *device)
printf("\n");
}
if (memcmp(&kdhl, &kdhf, sizeof kdhl)) {
if (memcmp(&kdhl, &kdhf, sizeof(kdhl))) {
syslog(LOG_ERR,
"first and last dump headers disagree on %s", device);
nerr++;
@ -603,7 +619,7 @@ DoFile(const char *savedir, const char *device)
exit(0);
}
if (kdhl.panicstring[0])
if (kdhl.panicstring[0] != '\0')
syslog(LOG_ALERT, "reboot after panic: %*s",
(int)sizeof(kdhl.panicstring), kdhl.panicstring);
else
@ -724,9 +740,10 @@ DoFile(const char *savedir, const char *device)
if (!keep) {
if (verbose)
printf("clearing dump header\n");
memcpy(kdhl.magic, KERNELDUMPMAGIC_CLEARED, sizeof kdhl.magic);
memcpy(kdhl.magic, KERNELDUMPMAGIC_CLEARED, sizeof(kdhl.magic));
memcpy(temp, &kdhl, sizeof(kdhl));
if (lseek(fd, lasthd, SEEK_SET) != lasthd ||
write(fd, &kdhl, sizeof(kdhl)) != sizeof(kdhl))
write(fd, temp, sectorsize) != sectorsize)
syslog(LOG_ERR,
"error while clearing the dump header: %m");
}

16
sys/amd64/amd64/minidump_machdep.c
View file

@ -56,9 +56,6 @@ CTASSERT(sizeof(struct kerneldumpheader) == 512);
*/
#define SIZEOF_METADATA (64*1024)
#define MD_ALIGN(x) (((off_t)(x) + PAGE_MASK) & ~PAGE_MASK)
#define DEV_ALIGN(x) (((off_t)(x) + (DEV_BSIZE-1)) & ~(DEV_BSIZE-1))
uint64_t *vm_page_dump;
int vm_page_dump_size;
@ -222,6 +219,7 @@ minidumpsys(struct dumperinfo *di)
int error;
uint64_t bits;
uint64_t *pml4, *pdp, *pd, *pt, pa;
size_t size;
int i, ii, j, k, n, bit;
int retry_count;
struct minidumphdr mdhdr;
@ -319,12 +317,12 @@ minidumpsys(struct dumperinfo *di)
dumpsize += PAGE_SIZE;
/* Determine dump offset on device. */
if (di->mediasize < SIZEOF_METADATA + dumpsize + sizeof(kdh) * 2) {
if (di->mediasize < SIZEOF_METADATA + dumpsize + di->blocksize * 2) {
error = E2BIG;
goto fail;
}
dumplo = di->mediaoffset + di->mediasize - dumpsize;
dumplo -= sizeof(kdh) * 2;
dumplo -= di->blocksize * 2;
progress = dumpsize;
/* Initialize mdhdr */
@ -344,10 +342,10 @@ minidumpsys(struct dumperinfo *di)
ptoa((uintmax_t)physmem) / 1048576);
/* Dump leader */
error = dump_write(di, &kdh, 0, dumplo, sizeof(kdh));
error = dump_write_pad(di, &kdh, 0, dumplo, sizeof(kdh), &size);
if (error)
goto fail;
dumplo += sizeof(kdh);
dumplo += size;
/* Dump my header */
bzero(&fakepd, sizeof(fakepd));
@ -432,10 +430,10 @@ minidumpsys(struct dumperinfo *di)
goto fail;
/* Dump trailer */
error = dump_write(di, &kdh, 0, dumplo, sizeof(kdh));
error = dump_write_pad(di, &kdh, 0, dumplo, sizeof(kdh), &size);
if (error)
goto fail;
dumplo += sizeof(kdh);
dumplo += size;
/* Signal completion, signoff and exit stage left. */
dump_write(di, NULL, 0, 0, 0);

34
sys/kern/kern_dump.c
View file

@ -55,13 +55,11 @@ CTASSERT(sizeof(struct kerneldumpheader) == 512);
*/
#define SIZEOF_METADATA (64*1024)
#define MD_ALIGN(x) (((off_t)(x) + PAGE_MASK) & ~PAGE_MASK)
#define DEV_ALIGN(x) (((off_t)(x) + (DEV_BSIZE-1)) & ~(DEV_BSIZE-1))
#define MD_ALIGN(x) roundup2((off_t)(x), PAGE_SIZE)
off_t dumplo;
/* Handle buffered writes. */
static char buffer[DEV_BSIZE];
static size_t fragsz;
struct dump_pa dump_map[DUMPSYS_MD_PA_NPAIRS];
@ -125,19 +123,19 @@ dumpsys_buf_write(struct dumperinfo *di, char *ptr, size_t sz)
int error;
while (sz) {
len = DEV_BSIZE - fragsz;
len = di->blocksize - fragsz;
if (len > sz)
len = sz;
bcopy(ptr, buffer + fragsz, len);
memcpy((char *)di->blockbuf + fragsz, ptr, len);
fragsz += len;
ptr += len;
sz -= len;
if (fragsz == DEV_BSIZE) {
error = dump_write(di, buffer, 0, dumplo,
DEV_BSIZE);
if (fragsz == di->blocksize) {
error = dump_write(di, di->blockbuf, 0, dumplo,
di->blocksize);
if (error)
return (error);
dumplo += DEV_BSIZE;
dumplo += di->blocksize;
fragsz = 0;
}
}
@ -152,8 +150,8 @@ dumpsys_buf_flush(struct dumperinfo *di)
if (fragsz == 0)
return (0);
error = dump_write(di, buffer, 0, dumplo, DEV_BSIZE);
dumplo += DEV_BSIZE;
error = dump_write(di, di->blockbuf, 0, dumplo, di->blocksize);
dumplo += di->blocksize;
fragsz = 0;
return (error);
}
@ -286,7 +284,7 @@ dumpsys_generic(struct dumperinfo *di)
Elf_Ehdr ehdr;
uint64_t dumpsize;
off_t hdrgap;
size_t hdrsz;
size_t hdrsz, size;
int error;
#ifndef __powerpc__
@ -324,15 +322,15 @@ dumpsys_generic(struct dumperinfo *di)
hdrsz = ehdr.e_phoff + ehdr.e_phnum * ehdr.e_phentsize;
fileofs = MD_ALIGN(hdrsz);
dumpsize += fileofs;
hdrgap = fileofs - DEV_ALIGN(hdrsz);
hdrgap = fileofs - roundup2((off_t)hdrsz, di->blocksize);
/* Determine dump offset on device. */
if (di->mediasize < SIZEOF_METADATA + dumpsize + sizeof(kdh) * 2) {
if (di->mediasize < SIZEOF_METADATA + dumpsize + di->blocksize * 2) {
error = ENOSPC;
goto fail;
}
dumplo = di->mediaoffset + di->mediasize - dumpsize;
dumplo -= sizeof(kdh) * 2;
dumplo -= di->blocksize * 2;
mkdumpheader(&kdh, KERNELDUMPMAGIC, KERNELDUMP_ARCH_VERSION, dumpsize,
di->blocksize);
@ -341,10 +339,10 @@ dumpsys_generic(struct dumperinfo *di)
ehdr.e_phnum - DUMPSYS_NUM_AUX_HDRS);
/* Dump leader */
error = dump_write(di, &kdh, 0, dumplo, sizeof(kdh));
error = dump_write_pad(di, &kdh, 0, dumplo, sizeof(kdh), &size);
if (error)
goto fail;
dumplo += sizeof(kdh);
dumplo += size;
/* Dump ELF header */
error = dumpsys_buf_write(di, (char*)&ehdr, sizeof(ehdr));
@ -375,7 +373,7 @@ dumpsys_generic(struct dumperinfo *di)
goto fail;
/* Dump trailer */
error = dump_write(di, &kdh, 0, dumplo, sizeof(kdh));
error = dump_write_pad(di, &kdh, 0, dumplo, sizeof(kdh), &size);
if (error)
goto fail;

32
sys/kern/kern_shutdown.c
View file

@ -88,6 +88,8 @@ __FBSDID("$FreeBSD$");
#include <sys/signalvar.h>
static MALLOC_DEFINE(M_DUMPER, "dumper", "dumper block buffer");
#ifndef PANIC_REBOOT_WAIT_TIME
#define PANIC_REBOOT_WAIT_TIME 15 /* default to 15 seconds */
#endif
@ -848,7 +850,9 @@ set_dumper(struct dumperinfo *di, const char *devname, struct thread *td)
return (error);
if (di == NULL) {
bzero(&dumper, sizeof dumper);
if (dumper.blockbuf != NULL)
free(dumper.blockbuf, M_DUMPER);
bzero(&dumper, sizeof(dumper));
dumpdevname[0] = '\0';
return (0);
}
@ -860,6 +864,7 @@ set_dumper(struct dumperinfo *di, const char *devname, struct thread *td)
printf("set_dumper: device name truncated from '%s' -> '%s'\n",
devname, dumpdevname);
}
dumper.blockbuf = malloc(di->blocksize, M_DUMPER, M_WAITOK | M_ZERO);
return (0);
}
@ -880,6 +885,31 @@ dump_write(struct dumperinfo *di, void *virtual, vm_offset_t physical,
return (di->dumper(di->priv, virtual, physical, offset, length));
}
/* Call dumper with bounds checking. */
int
dump_write_pad(struct dumperinfo *di, void *virtual, vm_offset_t physical,
off_t offset, size_t length, size_t *size)
{
char *temp;
int ret;
if (length > di->blocksize)
return (ENOMEM);
*size = di->blocksize;
if (length == di->blocksize)
temp = virtual;
else {
temp = di->blockbuf;
memset(temp + length, 0, di->blocksize - length);
memcpy(temp, virtual, length);
}
ret = dump_write(di, temp, physical, offset, *size);
return (ret);
}
void
mkdumpheader(struct kerneldumpheader *kdh, char *magic, uint32_t archver,
uint64_t dumplen, uint32_t blksz)

11
sys/sys/conf.h
View file

@ -328,15 +328,18 @@ EVENTHANDLER_DECLARE(dev_clone, dev_clone_fn);
struct dumperinfo {
dumper_t *dumper; /* Dumping function. */
void *priv; /* Private parts. */
u_int blocksize; /* Size of block in bytes. */
void *priv; /* Private parts. */
u_int blocksize; /* Size of block in bytes. */
u_int maxiosize; /* Max size allowed for an individual I/O */
off_t mediaoffset; /* Initial offset in bytes. */
off_t mediasize; /* Space available in bytes. */
off_t mediaoffset; /* Initial offset in bytes. */
off_t mediasize; /* Space available in bytes. */
void *blockbuf; /* Buffer for padding shorter dump blocks */
};
int set_dumper(struct dumperinfo *, const char *_devname, struct thread *td);
int dump_write(struct dumperinfo *, void *, vm_offset_t, off_t, size_t);
int dump_write_pad(struct dumperinfo *, void *, vm_offset_t, off_t, size_t,
size_t *);
int doadump(boolean_t);
extern int dumping; /* system is dumping */