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[src/trunk]: src/sys When writing coredumps, don't write zero uninstantiated ...
details: https://anonhg.NetBSD.org/src/rev/7d2126817a55
branches: trunk
changeset: 581575:7d2126817a55
user: matt <matt%NetBSD.org@localhost>
date: Thu Jun 02 17:01:43 2005 +0000
description:
When writing coredumps, don't write zero uninstantiated demand-zero pages.
Also, with ELF core dumps, trim trailing zeroes from sections. These two
changes can shrink coredumps by over 50% in size.
diffstat:
sys/compat/netbsd32/netbsd32_core.c | 6 +-
sys/kern/core_elf32.c | 176 ++++++++++++++++++++---------------
sys/kern/core_netbsd.c | 6 +-
sys/uvm/uvm_extern.h | 6 +-
sys/uvm/uvm_glue.c | 73 +++++++++++---
sys/uvm/uvm_map.c | 6 +-
6 files changed, 169 insertions(+), 104 deletions(-)
diffs (truncated from 495 to 300 lines):
diff -r a2114085a438 -r 7d2126817a55 sys/compat/netbsd32/netbsd32_core.c
--- a/sys/compat/netbsd32/netbsd32_core.c Thu Jun 02 16:54:52 2005 +0000
+++ b/sys/compat/netbsd32/netbsd32_core.c Thu Jun 02 17:01:43 2005 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: netbsd32_core.c,v 1.10 2004/09/17 14:11:24 skrll Exp $ */
+/* $NetBSD: netbsd32_core.c,v 1.11 2005/06/02 17:01:43 matt Exp $ */
/*
* Copyright (c) 1997 Charles D. Cranor and Washington University.
@@ -50,7 +50,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: netbsd32_core.c,v 1.10 2004/09/17 14:11:24 skrll Exp $");
+__KERNEL_RCSID(0, "$NetBSD: netbsd32_core.c,v 1.11 2005/06/02 17:01:43 matt Exp $");
#include <sys/param.h>
#include <sys/systm.h>
@@ -127,7 +127,7 @@
struct coreseg32 cseg;
int flag, error;
- if (us->flags & UVM_COREDUMP_NODUMP)
+ if (us->start == us->realend)
return (0);
if (us->flags & UVM_COREDUMP_STACK)
diff -r a2114085a438 -r 7d2126817a55 sys/kern/core_elf32.c
--- a/sys/kern/core_elf32.c Thu Jun 02 16:54:52 2005 +0000
+++ b/sys/kern/core_elf32.c Thu Jun 02 17:01:43 2005 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: core_elf32.c,v 1.15 2005/05/29 22:24:14 christos Exp $ */
+/* $NetBSD: core_elf32.c,v 1.16 2005/06/02 17:01:43 matt Exp $ */
/*
* Copyright (c) 2001 Wasabi Systems, Inc.
@@ -40,7 +40,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(1, "$NetBSD: core_elf32.c,v 1.15 2005/05/29 22:24:14 christos Exp $");
+__KERNEL_RCSID(1, "$NetBSD: core_elf32.c,v 1.16 2005/06/02 17:01:43 matt Exp $");
/* If not included by core_elf64.c, ELFSIZE won't be defined. */
#ifndef ELFSIZE
@@ -53,6 +53,7 @@
#include <sys/vnode.h>
#include <sys/exec_elf.h>
#include <sys/ptrace.h>
+#include <sys/malloc.h>
#include <machine/reg.h>
@@ -66,7 +67,7 @@
struct ucred *, struct uvm_coredump_state *);
struct writesegs_state {
- off_t offset;
+ Elf_Phdr *psections;
off_t secoff;
};
@@ -88,13 +89,14 @@
{
struct proc *p;
Elf_Ehdr ehdr;
- Elf_Phdr phdr;
+ Elf_Phdr phdr, *psections;
struct countsegs_state cs;
struct writesegs_state ws;
- off_t notestart, secstart;
+ off_t notestart, secstart, offset;
size_t notesize;
- int error;
+ int error, i;
+ psections = NULL;
p = l->l_proc;
/*
* We have to make a total of 3 passes across the map:
@@ -112,15 +114,15 @@
error = uvm_coredump_walkmap(p, vp, cred,
ELFNAMEEND(coredump_countsegs), &cs);
if (error)
- return (error);
+ goto out;
+
+ /* Count the PT_NOTE section. */
+ cs.npsections++;
/* Get the size of the notes. */
error = ELFNAMEEND(coredump_notes)(p, l, vp, cred, ¬esize, 0);
if (error)
- return (error);
-
- /* Count the PT_NOTE section. */
- cs.npsections++;
+ goto out;
memcpy(ehdr.e_ident, ELFMAG, SELFMAG);
#if ELFSIZE == 32
@@ -149,65 +151,95 @@
ehdr.e_shnum = 0;
ehdr.e_shstrndx = 0;
+ offset = 0;
+
/* Write out the ELF header. */
- error = vn_rdwr(UIO_WRITE, vp, (caddr_t)&ehdr,
- (int)sizeof(ehdr), (off_t)0,
+ error = vn_rdwr(UIO_WRITE, vp,
+ (caddr_t)&ehdr, (int)sizeof(ehdr), (off_t)offset,
UIO_SYSSPACE, IO_NODELOCKED|IO_UNIT, cred, NULL, NULL);
+ if (error)
+ goto out;
- ws.offset = ehdr.e_phoff;
- notestart = ws.offset + (sizeof(phdr) * cs.npsections);
- secstart = round_page(notestart + notesize);
+ offset += sizeof(ehdr);
+
+ notestart = offset + sizeof(phdr) * cs.npsections;
+ secstart = notestart + notesize;
+
+ psections = malloc(cs.npsections * sizeof(Elf_Phdr),
+ M_TEMP, M_WAITOK|M_ZERO);
/* Pass 2: now write the P-section headers. */
ws.secoff = secstart;
+ ws.psections = psections;
error = uvm_coredump_walkmap(p, vp, cred,
ELFNAMEEND(coredump_writeseghdrs), &ws);
if (error)
- return (error);
+ goto out;
/* Write out the PT_NOTE header. */
- phdr.p_type = PT_NOTE;
- phdr.p_offset = notestart;
- phdr.p_vaddr = 0;
- phdr.p_paddr = 0;
- phdr.p_filesz = notesize;
- phdr.p_memsz = 0;
- phdr.p_flags = PF_R;
- phdr.p_align = ELFROUNDSIZE;
+ ws.psections->p_type = PT_NOTE;
+ ws.psections->p_offset = notestart;
+ ws.psections->p_vaddr = 0;
+ ws.psections->p_paddr = 0;
+ ws.psections->p_filesz = notesize;
+ ws.psections->p_memsz = 0;
+ ws.psections->p_flags = PF_R;
+ ws.psections->p_align = ELFROUNDSIZE;
error = vn_rdwr(UIO_WRITE, vp,
- (caddr_t)&phdr, sizeof(phdr),
- ws.offset, UIO_SYSSPACE,
+ (caddr_t)psections, cs.npsections * sizeof(Elf_Phdr),
+ offset, UIO_SYSSPACE,
IO_NODELOCKED|IO_UNIT, cred, NULL, NULL);
if (error)
- return (error);
+ goto out;
- ws.offset += sizeof(phdr);
+ offset += cs.npsections * sizeof(Elf_Phdr);
#ifdef DIAGNOSTIC
- if (ws.offset != notestart)
+ if (offset != notestart)
panic("coredump: offset %lld != notestart %lld",
- (long long) ws.offset, (long long) notestart);
+ (long long) offset, (long long) notestart);
#endif
/* Write out the notes. */
- error = ELFNAMEEND(coredump_notes)(p, l, vp, cred, ¬esize, ws.offset);
-
- ws.offset += notesize;
+ error = ELFNAMEEND(coredump_notes)(p, l, vp, cred, ¬esize, offset);
+ if (error)
+ goto out;
#ifdef DIAGNOSTIC
- if (round_page(ws.offset) != secstart)
+ offset += notesize;
+ if (offset != secstart)
panic("coredump: offset %lld != secstart %lld",
- (long long) round_page(ws.offset), (long long) secstart);
+ (long long) offset, (long long) secstart);
#endif
/* Pass 3: finally, write the sections themselves. */
- ws.secoff = secstart;
- error = uvm_coredump_walkmap(p, vp, cred,
- ELFNAMEEND(coredump_writesegs), &ws);
- if (error)
- return (error);
+ for (i = 0; i < cs.npsections - 1; i++) {
+ if (psections[i].p_filesz == 0)
+ continue;
+
+#ifdef DIAGNOSTIC
+ if (offset != psections[i].p_offset)
+ panic("coredump: offset %lld != p_offset[%d] %lld",
+ (long long) offset, i,
+ (long long) psections[i].p_filesz);
+#endif
+ error = vn_rdwr(UIO_WRITE, vp,
+ (caddr_t) psections[i].p_vaddr, psections[i].p_filesz,
+ psections[i].p_offset, UIO_USERSPACE,
+ IO_NODELOCKED|IO_UNIT, cred, NULL, p);
+ if (error)
+ goto out;
+
+#ifdef DIAGNOSTIC
+ offset += psections[i].p_filesz;
+#endif
+ }
+
+ out:
+ if (psections)
+ free(psections, M_TEMP);
return (error);
}
@@ -227,16 +259,40 @@
{
struct writesegs_state *ws = us->cookie;
Elf_Phdr phdr;
- vsize_t size;
+ vsize_t size, realsize;
+ vaddr_t end;
int error;
size = us->end - us->start;
+ realsize = us->realend - us->start;
+ end = us->realend;
+
+ while (realsize > 0) {
+ long buf[1024 / sizeof(long)];
+ size_t slen = realsize > sizeof(buf) ? sizeof(buf) : realsize;
+ const long *ep;
+ int i;
+
+ end -= slen;
+ error = copyin((void *) end, buf, slen);
+ if (error)
+ return (error);
+
+ ep = (const long *) &buf[slen / sizeof(buf[0])];
+ for (i = 0, ep--; buf <= ep; ep--, i++) {
+ if (*ep)
+ break;
+ }
+ realsize -= i * sizeof(buf[0]);
+ if (i * sizeof(buf[0]) < slen)
+ break;
+ }
phdr.p_type = PT_LOAD;
phdr.p_offset = ws->secoff;
phdr.p_vaddr = us->start;
phdr.p_paddr = 0;
- phdr.p_filesz = (us->flags & UVM_COREDUMP_NODUMP) ? 0 : size;
+ phdr.p_filesz = realsize;
phdr.p_memsz = size;
phdr.p_flags = 0;
if (us->prot & VM_PROT_READ)
@@ -247,40 +303,8 @@
phdr.p_flags |= PF_X;
phdr.p_align = PAGE_SIZE;
- error = vn_rdwr(UIO_WRITE, vp,
- (caddr_t)&phdr, sizeof(phdr),
- ws->offset, UIO_SYSSPACE,
- IO_NODELOCKED|IO_UNIT, cred, NULL, NULL);
- if (error)
- return (error);
-
- ws->offset += sizeof(phdr);
ws->secoff += phdr.p_filesz;
-
- return (0);
-}
-
-int
-ELFNAMEEND(coredump_writesegs)(struct proc *p, struct vnode *vp,
- struct ucred *cred, struct uvm_coredump_state *us)
-{
- struct writesegs_state *ws = us->cookie;
- vsize_t size;
- int error;
-
- if (us->flags & UVM_COREDUMP_NODUMP)
- return (0);
-
- size = us->end - us->start;
-
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