Module Name: src
Committed By: dsl
Date: Fri Jan 3 15:15:02 UTC 2014
Modified Files:
src/sys/kern: core_elf32.c core_netbsd.c
src/sys/uvm: uvm_coredump.c uvm_extern.h
Log Message:
Minor changes to the process coredump code.
- Add some extra comments.
- Add some XXX comments because the process state might not be stable,
- Add uvm_coredump_count_segs() to simplify the calling code.
- uvm code now only returns non-empty sections/segments.
- Put the 'iocookie' into the 'cookie' block passed to uvm_coredump_walkmap()
instead of passing it through as an additional parameter.
amd64 can still generate core dumps that gdb can read.
To generate a diff of this commit:
cvs rdiff -u -r1.37 -r1.38 src/sys/kern/core_elf32.c
cvs rdiff -u -r1.19 -r1.20 src/sys/kern/core_netbsd.c
cvs rdiff -u -r1.3 -r1.4 src/sys/uvm/uvm_coredump.c
cvs rdiff -u -r1.186 -r1.187 src/sys/uvm/uvm_extern.h
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/kern/core_elf32.c
diff -u src/sys/kern/core_elf32.c:1.37 src/sys/kern/core_elf32.c:1.38
--- src/sys/kern/core_elf32.c:1.37 Wed Jan 1 18:57:16 2014
+++ src/sys/kern/core_elf32.c Fri Jan 3 15:15:02 2014
@@ -1,4 +1,4 @@
-/* $NetBSD: core_elf32.c,v 1.37 2014/01/01 18:57:16 dsl Exp $ */
+/* $NetBSD: core_elf32.c,v 1.38 2014/01/03 15:15:02 dsl Exp $ */
/*
* Copyright (c) 2001 Wasabi Systems, Inc.
@@ -40,7 +40,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(1, "$NetBSD: core_elf32.c,v 1.37 2014/01/01 18:57:16 dsl Exp $");
+__KERNEL_RCSID(1, "$NetBSD: core_elf32.c,v 1.38 2014/01/03 15:15:02 dsl Exp $");
#ifdef _KERNEL_OPT
#include "opt_coredump.h"
@@ -66,20 +66,13 @@ __KERNEL_RCSID(1, "$NetBSD: core_elf32.c
#ifdef COREDUMP
-struct countsegs_state {
- int npsections;
-};
-
-static int ELFNAMEEND(coredump_countsegs)(struct proc *,
- struct coredump_iostate *, struct uvm_coredump_state *);
-
struct writesegs_state {
Elf_Phdr *psections;
off_t secoff;
};
-static int ELFNAMEEND(coredump_writeseghdrs)(struct proc *,
- struct coredump_iostate *, struct uvm_coredump_state *);
+static int ELFNAMEEND(coredump_getseghdrs)(struct proc *,
+ struct uvm_coredump_state *);
static int ELFNAMEEND(coredump_notes)(struct proc *, struct lwp *,
struct coredump_iostate *, size_t *);
@@ -105,7 +98,7 @@ ELFNAMEEND(coredump)(struct lwp *l, stru
Elf_Ehdr ehdr;
Elf_Phdr phdr, *psections;
size_t psectionssize;
- struct countsegs_state cs;
+ int npsections;
struct writesegs_state ws;
off_t notestart, secstart, offset;
size_t notesize;
@@ -117,7 +110,7 @@ ELFNAMEEND(coredump)(struct lwp *l, stru
* We have to make a total of 3 passes across the map:
*
* 1. Count the number of map entries (the number of
- * PT_LOAD sections).
+ * PT_LOAD sections in the dump).
*
* 2. Write the P-section headers.
*
@@ -125,16 +118,11 @@ ELFNAMEEND(coredump)(struct lwp *l, stru
*/
/* Pass 1: count the entries. */
- cs.npsections = 0;
- error = uvm_coredump_walkmap(p, NULL,
- ELFNAMEEND(coredump_countsegs), &cs);
- if (error)
- goto out;
-
+ npsections = uvm_coredump_count_segs(p);
/* Count the PT_NOTE section. */
- cs.npsections++;
+ npsections++;
- /* Get the size of the notes. */
+ /* Get the size of the notes (mostly all the registers). */
error = ELFNAMEEND(coredump_notes)(p, l, NULL, ¬esize);
if (error)
goto out;
@@ -162,7 +150,7 @@ ELFNAMEEND(coredump)(struct lwp *l, stru
ehdr.e_flags = 0;
ehdr.e_ehsize = sizeof(ehdr);
ehdr.e_phentsize = sizeof(Elf_Phdr);
- ehdr.e_phnum = cs.npsections;
+ ehdr.e_phnum = npsections;
ehdr.e_shentsize = 0;
ehdr.e_shnum = 0;
ehdr.e_shstrndx = 0;
@@ -178,21 +166,20 @@ ELFNAMEEND(coredump)(struct lwp *l, stru
offset = sizeof(ehdr);
- notestart = offset + sizeof(phdr) * cs.npsections;
+ notestart = offset + sizeof(phdr) * npsections;
secstart = notestart + notesize;
- psectionssize = cs.npsections * sizeof(Elf_Phdr);
+ psectionssize = npsections * sizeof(Elf_Phdr);
psections = kmem_zalloc(psectionssize, KM_SLEEP);
- /* Pass 2: now write the P-section headers. */
+ /* Pass 2: now find the P-section headers. */
ws.secoff = secstart;
ws.psections = psections;
- error = uvm_coredump_walkmap(p, cookie,
- ELFNAMEEND(coredump_writeseghdrs), &ws);
+ error = uvm_coredump_walkmap(p, ELFNAMEEND(coredump_getseghdrs), &ws);
if (error)
goto out;
- /* Write out the PT_NOTE header. */
+ /* Add the PT_NOTE header after the P-section headers. */
ws.psections->p_type = PT_NOTE;
ws.psections->p_offset = notestart;
ws.psections->p_vaddr = 0;
@@ -202,13 +189,14 @@ ELFNAMEEND(coredump)(struct lwp *l, stru
ws.psections->p_flags = PF_R;
ws.psections->p_align = ELFROUNDSIZE;
+ /* Write the P-section headers followed by the PT_NOTR header */
error = coredump_write(cookie, UIO_SYSSPACE, psections,
- cs.npsections * sizeof(Elf_Phdr));
+ npsections * sizeof(Elf_Phdr));
if (error)
goto out;
#ifdef DIAGNOSTIC
- offset += cs.npsections * sizeof(Elf_Phdr);
+ offset += npsections * sizeof(Elf_Phdr);
if (offset != notestart)
panic("coredump: offset %lld != notestart %lld",
(long long) offset, (long long) notestart);
@@ -227,7 +215,7 @@ ELFNAMEEND(coredump)(struct lwp *l, stru
#endif
/* Pass 3: finally, write the sections themselves. */
- for (i = 0; i < cs.npsections - 1; i++) {
+ for (i = 0; i < npsections - 1; i++) {
if (psections[i].p_filesz == 0)
continue;
@@ -256,18 +244,7 @@ ELFNAMEEND(coredump)(struct lwp *l, stru
}
static int
-ELFNAMEEND(coredump_countsegs)(struct proc *p,
- struct coredump_iostate *iocookie, struct uvm_coredump_state *us)
-{
- struct countsegs_state *cs = us->cookie;
-
- cs->npsections++;
- return (0);
-}
-
-static int
-ELFNAMEEND(coredump_writeseghdrs)(struct proc *p,
- struct coredump_iostate *iocookie, struct uvm_coredump_state *us)
+ELFNAMEEND(coredump_getseghdrs)(struct proc *p, struct uvm_coredump_state *us)
{
struct writesegs_state *ws = us->cookie;
Elf_Phdr phdr;
@@ -279,6 +256,7 @@ ELFNAMEEND(coredump_writeseghdrs)(struct
realsize = us->realend - us->start;
end = us->realend;
+ /* Don't bother writing out trailing zeros */
while (realsize > 0) {
long buf[1024 / sizeof(long)];
size_t slen = realsize > sizeof(buf) ? sizeof(buf) : realsize;
Index: src/sys/kern/core_netbsd.c
diff -u src/sys/kern/core_netbsd.c:1.19 src/sys/kern/core_netbsd.c:1.20
--- src/sys/kern/core_netbsd.c:1.19 Wed Jan 1 18:57:16 2014
+++ src/sys/kern/core_netbsd.c Fri Jan 3 15:15:02 2014
@@ -1,4 +1,4 @@
-/* $NetBSD: core_netbsd.c,v 1.19 2014/01/01 18:57:16 dsl Exp $ */
+/* $NetBSD: core_netbsd.c,v 1.20 2014/01/03 15:15:02 dsl Exp $ */
/*
* Copyright (c) 1997 Charles D. Cranor and Washington University.
@@ -45,7 +45,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: core_netbsd.c,v 1.19 2014/01/01 18:57:16 dsl Exp $");
+__KERNEL_RCSID(0, "$NetBSD: core_netbsd.c,v 1.20 2014/01/03 15:15:02 dsl Exp $");
#ifdef _KERNEL_OPT
#include "opt_coredump.h"
@@ -70,13 +70,12 @@ __KERNEL_RCSID(0, "$NetBSD: core_netbsd.
#ifdef COREDUMP
struct coredump_state {
+ struct coredump_iostate *iocookie;
struct CORENAME(core) core;
};
-static int CORENAME(coredump_countsegs_netbsd)(struct proc *,
- struct coredump_iostate *, struct uvm_coredump_state *);
static int CORENAME(coredump_writesegs_netbsd)(struct proc *,
- struct coredump_iostate *, struct uvm_coredump_state *);
+ struct uvm_coredump_state *);
int
CORENAME(coredump_netbsd)(struct lwp *l, struct coredump_iostate *iocookie)
@@ -86,6 +85,7 @@ CORENAME(coredump_netbsd)(struct lwp *l,
struct vmspace *vm = p->p_vmspace;
int error;
+ cs.iocookie = iocookie;
cs.core.c_midmag = 0;
strncpy(cs.core.c_name, p->p_comm, MAXCOMLEN);
cs.core.c_nseg = 0;
@@ -99,10 +99,7 @@ CORENAME(coredump_netbsd)(struct lwp *l,
error = CORENAME(cpu_coredump)(l, NULL, &cs.core);
if (error)
return (error);
- error = uvm_coredump_walkmap(p, NULL,
- CORENAME(coredump_countsegs_netbsd), &cs);
- if (error)
- return (error);
+ cs.core.c_nseg = uvm_coredump_count_segs(p);
/* First write out the core header. */
error = coredump_write(iocookie, UIO_SYSSPACE, &cs.core,
@@ -116,33 +113,18 @@ CORENAME(coredump_netbsd)(struct lwp *l,
return (error);
/* Finally, the address space dump */
- return uvm_coredump_walkmap(p, iocookie,
- CORENAME(coredump_writesegs_netbsd), &cs);
-}
-
-static int
-CORENAME(coredump_countsegs_netbsd)(struct proc *p,
- struct coredump_iostate *iocookie, struct uvm_coredump_state *us)
-{
- struct coredump_state *cs = us->cookie;
-
- if (us->start != us->realend)
- cs->core.c_nseg++;
-
- return (0);
+ return uvm_coredump_walkmap(p, CORENAME(coredump_writesegs_netbsd),
+ &cs);
}
static int
CORENAME(coredump_writesegs_netbsd)(struct proc *p,
- struct coredump_iostate *iocookie, struct uvm_coredump_state *us)
+ struct uvm_coredump_state *us)
{
struct coredump_state *cs = us->cookie;
struct CORENAME(coreseg) cseg;
int flag, error;
- if (us->start == us->realend)
- return (0);
-
if (us->flags & UVM_COREDUMP_STACK)
flag = CORE_STACK;
else
@@ -155,12 +137,12 @@ CORENAME(coredump_writesegs_netbsd)(stru
cseg.c_addr = us->start;
cseg.c_size = us->end - us->start;
- error = coredump_write(iocookie, UIO_SYSSPACE,
+ error = coredump_write(cs->iocookie, UIO_SYSSPACE,
&cseg, cs->core.c_seghdrsize);
if (error)
return (error);
- return coredump_write(iocookie, UIO_USERSPACE,
+ return coredump_write(cs->iocookie, UIO_USERSPACE,
(void *)(vaddr_t)us->start, cseg.c_size);
}
Index: src/sys/uvm/uvm_coredump.c
diff -u src/sys/uvm/uvm_coredump.c:1.3 src/sys/uvm/uvm_coredump.c:1.4
--- src/sys/uvm/uvm_coredump.c:1.3 Wed Jan 1 18:57:16 2014
+++ src/sys/uvm/uvm_coredump.c Fri Jan 3 15:15:02 2014
@@ -1,4 +1,4 @@
-/* $NetBSD: uvm_coredump.c,v 1.3 2014/01/01 18:57:16 dsl Exp $ */
+/* $NetBSD: uvm_coredump.c,v 1.4 2014/01/03 15:15:02 dsl Exp $ */
/*
* Copyright (c) 1997 Charles D. Cranor and Washington University.
@@ -62,7 +62,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: uvm_coredump.c,v 1.3 2014/01/01 18:57:16 dsl Exp $");
+__KERNEL_RCSID(0, "$NetBSD: uvm_coredump.c,v 1.4 2014/01/03 15:15:02 dsl Exp $");
/*
* uvm_coredump.c: glue functions for coredump
@@ -77,13 +77,15 @@ __KERNEL_RCSID(0, "$NetBSD: uvm_coredump
/*
* uvm_coredump_walkmap: walk a process's map for the purpose of dumping
* a core file.
+ * XXX: I'm not entirely sure the locking is this function is in anyway
+ * correct. If the process isn't actually stopped then the data passed
+ * to func() is at best stale, and horrid things might happen if the
+ * entry being processed is deleted (dsl).
*/
int
-uvm_coredump_walkmap(struct proc *p, struct coredump_iostate *iocookie,
- int (*func)(struct proc *, struct coredump_iostate *,
- struct uvm_coredump_state *),
- void *cookie)
+uvm_coredump_walkmap(struct proc *p, int (*func)(struct proc *,
+ struct uvm_coredump_state *), void *cookie)
{
struct uvm_coredump_state state;
struct vmspace *vm = p->p_vmspace;
@@ -183,10 +185,13 @@ uvm_coredump_walkmap(struct proc *p, str
amap_unlock(entry->aref.ar_amap);
}
}
-
+ /* Ignore empty sections */
+ if (state.start == state.realend)
+ continue;
+
vm_map_unlock_read(map);
- error = (*func)(p, iocookie, &state);
+ error = (*func)(p, &state);
if (error)
return (error);
vm_map_lock_read(map);
@@ -195,3 +200,20 @@ uvm_coredump_walkmap(struct proc *p, str
return (0);
}
+
+static int
+count_segs(struct proc *p, struct uvm_coredump_state *s)
+{
+ (*(int *)s->cookie)++;
+
+ return 0;
+}
+
+int
+uvm_coredump_count_segs(struct proc *p)
+{
+ int count = 0;
+
+ uvm_coredump_walkmap(p, count_segs, &count);
+ return count;
+}
Index: src/sys/uvm/uvm_extern.h
diff -u src/sys/uvm/uvm_extern.h:1.186 src/sys/uvm/uvm_extern.h:1.187
--- src/sys/uvm/uvm_extern.h:1.186 Wed Jan 1 18:57:16 2014
+++ src/sys/uvm/uvm_extern.h Fri Jan 3 15:15:02 2014
@@ -1,4 +1,4 @@
-/* $NetBSD: uvm_extern.h,v 1.186 2014/01/01 18:57:16 dsl Exp $ */
+/* $NetBSD: uvm_extern.h,v 1.187 2014/01/03 15:15:02 dsl Exp $ */
/*
* Copyright (c) 1997 Charles D. Cranor and Washington University.
@@ -591,10 +591,9 @@ void uvm_proc_fork(struct proc *, stru
void uvm_lwp_fork(struct lwp *, struct lwp *,
void *, size_t, void (*)(void *), void *);
struct coredump_iostate;
-int uvm_coredump_walkmap(struct proc *,
- struct coredump_iostate *,
- int (*)(struct proc *, struct coredump_iostate *,
- struct uvm_coredump_state *), void *);
+int uvm_coredump_walkmap(struct proc *, int (*)(struct proc *,
+ struct uvm_coredump_state *), void *);
+int uvm_coredump_count_segs(struct proc *);
void uvm_proc_exit(struct proc *);
void uvm_lwp_exit(struct lwp *);
void uvm_init_limits(struct proc *);
