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Subject[PATCH] Multithreaded core dump for ia64 and i386 architectures
Date
This is a version of the tcore multi-threaded core dump patch that supports both 
i386 and ia64 architectures.

Its been smoke tested on a 2 way Itanium system as well as a 2 way P4 system.
So far its been very stable on both architectures

This patch applies cleanly to the 2.5.18 kernel.

This multithread core dump differs from my earlier patches in that this patch works
with ia64 kernels, when applied after the Mosberger ia64 port patch. There is only
2 off by 6 line warnings, in ia64/kernel/process.c, when this patch is applied to
the ia64 kernel. This is due to the ia64 port patch adding some lines to that file.

This patch also differs from the earlier patches in that I've removed the proc interface
to enable / disable the multi-threaded core file creation. This is no longer needed as t
he patch is holding up as stable, and its inconvenient to have to enable the feature
that could "just work".

Apply this patch then when a multi-threaded application dumps core, it will create a
core file with the data for all the processes in the thread group. BTW, non-threaded
applications still produce good core files ;)

This code works by "suspending" the other thread group processes, and then adding
extra note sections to the core file with the user register state data. GDB 5.x knows
how to work with these core files with one caveat. You may need to "strip libpthread*"
before loading up the core file and crashing application into gdb. GDB 5.x; x < 2, seems
to have a problem loading symbols for libpthread in this type of use.

The process suspend design does a number of interesting things that are worth
pointing out... again ;)
1) it creates an extra run queue that has no cpu, the phantom cpu.
2) it uses process migration to migrate the processes of the thread group to the phantom
run queue.
3) it removes the down_write from elf_dump_core, to avoid any possibility of deadlocking
with one of the suspended thread processes. This is safe to do as the other thread
process are suspended and cannot free pages while they aren't getting any CPU time.

I will be making one more re-base of this patch for whatever the current 2.5.x is next week,
after I finish the 2.4.x version. I think it would be a good thing for this patch / feature
make it into the kernel, especially a development one.

--mgross

diff -urN -X dontdiff src/linux-2.5.18/arch/i386/kernel/i387.c linux2518/arch/i386/kernel/i387.c
--- src/linux-2.5.18/arch/i386/kernel/i387.c Fri May 24 21:55:31 2002
+++ linux2518/arch/i386/kernel/i387.c Thu Jun 6 15:51:09 2002
@@ -528,3 +528,36 @@

return fpvalid;
}
+
+int dump_task_fpu( struct task_struct *tsk, struct user_i387_struct *fpu )
+{
+ int fpvalid;
+
+ fpvalid = tsk->used_math;
+ if ( fpvalid ) {
+ if (tsk == current) unlazy_fpu( tsk );
+ if ( cpu_has_fxsr ) {
+ copy_fpu_fxsave( tsk, fpu );
+ } else {
+ copy_fpu_fsave( tsk, fpu );
+ }
+ }
+
+ return fpvalid;
+}
+
+int dump_task_extended_fpu( struct task_struct *tsk, struct user_fxsr_struct *fpu )
+{
+ int fpvalid;
+
+ fpvalid = tsk->used_math && cpu_has_fxsr;
+ if ( fpvalid ) {
+ if (tsk == current) unlazy_fpu( tsk );
+ memcpy( fpu, &tsk->thread.i387.fxsave,
+ sizeof(struct user_fxsr_struct) );
+ }
+
+ return fpvalid;
+}
+
+
diff -urN -X dontdiff src/linux-2.5.18/arch/i386/kernel/process.c linux2518/arch/i386/kernel/process.c
--- src/linux-2.5.18/arch/i386/kernel/process.c Fri May 24 21:55:16 2002
+++ linux2518/arch/i386/kernel/process.c Thu Jun 6 15:51:09 2002
@@ -610,6 +610,24 @@

dump->u_fpvalid = dump_fpu (regs, &dump->i387);
}
+/*
+ * Capture the user space registers if the task is not running (in user space)
+ */
+#include <linux/elfcore.h>
+int dump_task_regs(struct task_struct *tsk, elf_gregset_t *regs)
+{
+ struct pt_regs ptregs;
+
+ ptregs = *(struct pt_regs *)((unsigned long)tsk->thread_info + THREAD_SIZE - sizeof(struct pt_regs));
+ ptregs.xcs &= 0xffff;
+ ptregs.xds &= 0xffff;
+ ptregs.xes &= 0xffff;
+ ptregs.xss &= 0xffff;
+
+ elf_core_copy_regs(regs, &ptregs);
+
+ return 1;
+}

/*
* This special macro can be used to load a debugging register
diff -urN -X dontdiff src/linux-2.5.18/arch/ia64/kernel/process.c linux2518/arch/ia64/kernel/process.c
--- src/linux-2.5.18/arch/ia64/kernel/process.c Fri May 24 21:55:26 2002
+++ linux2518/arch/ia64/kernel/process.c Thu Jun 6 15:51:09 2002
@@ -366,6 +366,31 @@
void
do_copy_regs (struct unw_frame_info *info, void *arg)
{
+ do_copy_task_regs(current, info, arg);
+}
+
+void
+do_dump_fpu (struct unw_frame_info *info, void *arg)
+{
+ do_dump_task_fpu(current, info, arg);
+}
+
+void
+ia64_elf_core_copy_regs (struct pt_regs *pt, elf_gregset_t dst)
+{
+ unw_init_running(do_copy_regs, dst);
+}
+
+int
+dump_fpu (struct pt_regs *pt, elf_fpregset_t dst)
+{
+ unw_init_running(do_dump_fpu, dst);
+ return 1; /* f0-f31 are always valid so we always return 1 */
+}
+
+static void
+do_copy_task_regs (struct task_struct *task, struct unw_frame_info *info, void *arg)
+{
unsigned long mask, sp, nat_bits = 0, ip, ar_rnat, urbs_end, cfm;
elf_greg_t *dst = arg;
struct pt_regs *pt;
@@ -380,12 +405,12 @@
unw_get_sp(info, &sp);
pt = (struct pt_regs *) (sp + 16);

- urbs_end = ia64_get_user_rbs_end(current, pt, &cfm);
+ urbs_end = ia64_get_user_rbs_end(task, pt, &cfm);

- if (ia64_sync_user_rbs(current, info->sw, pt->ar_bspstore, urbs_end) < 0)
+ if (ia64_sync_user_rbs(task, info->sw, pt->ar_bspstore, urbs_end) < 0)
return;

- ia64_peek(current, info->sw, urbs_end, (long) ia64_rse_rnat_addr((long *) urbs_end),
+ ia64_peek(task, info->sw, urbs_end, (long) ia64_rse_rnat_addr((long *) urbs_end),
&ar_rnat);

/*
@@ -434,7 +459,7 @@
}

void
-do_dump_fpu (struct unw_frame_info *info, void *arg)
+do_dump_task_fpu (struct task_struct *task, struct unw_frame_info *info, void *arg)
{
elf_fpreg_t *dst = arg;
int i;
@@ -449,22 +474,41 @@
for (i = 2; i < 32; ++i)
unw_get_fr(info, i, dst + i);

- ia64_flush_fph(current);
- if ((current->thread.flags & IA64_THREAD_FPH_VALID) != 0)
- memcpy(dst + 32, current->thread.fph, 96*16);
+ ia64_flush_fph(task);
+ if ((task->thread.flags & IA64_THREAD_FPH_VALID) != 0)
+ memcpy(dst + 32, task->thread.fph, 96*16);
}

-void
-ia64_elf_core_copy_regs (struct pt_regs *pt, elf_gregset_t dst)
+int dump_task_regs(struct task_struct *task, elf_gregset_t *regs)
{
- unw_init_running(do_copy_regs, dst);
+ struct unw_frame_info tcore_info;
+
+ if(current == task) {
+ unw_init_running(do_copy_regs, regs);
+ }
+ else {
+ memset(&tcore_info, 0, sizeof(tcore_info));
+ unw_init_from_blocked_task(&tcore_info, task);
+ do_copy_task_regs(task, &tcore_info, regs);
+ }
+
+ return 1;
}

-int
-dump_fpu (struct pt_regs *pt, elf_fpregset_t dst)
+int dump_task_fpu (struct task_struct *task, elf_fpregset_t *dst)
{
- unw_init_running(do_dump_fpu, dst);
- return 1; /* f0-f31 are always valid so we always return 1 */
+ struct unw_frame_info tcore_info;
+
+ if(current == task) {
+ unw_init_running(do_dump_fpu, dst);
+ }
+ else {
+ memset(&tcore_info, 0, sizeof(tcore_info));
+ unw_init_from_blocked_task(&tcore_info, task);
+ do_dump_task_fpu(task, &tcore_info, dst);
+ }
+
+ return 1;
}

asmlinkage long
diff -urN -X dontdiff src/linux-2.5.18/fs/binfmt_elf.c linux2518/fs/binfmt_elf.c
--- src/linux-2.5.18/fs/binfmt_elf.c Fri May 24 21:55:26 2002
+++ linux2518/fs/binfmt_elf.c Thu Jun 6 15:51:09 2002
@@ -13,6 +13,7 @@

#include <linux/fs.h>
#include <linux/stat.h>
+#include <linux/sched.h>
#include <linux/time.h>
#include <linux/mm.h>
#include <linux/mman.h>
@@ -30,6 +31,7 @@
#include <linux/elfcore.h>
#include <linux/init.h>
#include <linux/highuid.h>
+#include <linux/smp.h>
#include <linux/smp_lock.h>
#include <linux/compiler.h>
#include <linux/highmem.h>
@@ -958,7 +960,7 @@
/* #define DEBUG */

#ifdef DEBUG
-static void dump_regs(const char *str, elf_greg_t *r)
+static void dump_regs(const char *str, elf_gregset_t *r)
{
int i;
static const char *regs[] = { "ebx", "ecx", "edx", "esi", "edi", "ebp",
@@ -1006,6 +1008,158 @@
#define DUMP_SEEK(off) \
if (!dump_seek(file, (off))) \
goto end_coredump;
+
+static inline void fill_elf_header(struct elfhdr *elf, int segs)
+{
+ memcpy(elf->e_ident, ELFMAG, SELFMAG);
+ elf->e_ident[EI_CLASS] = ELF_CLASS;
+ elf->e_ident[EI_DATA] = ELF_DATA;
+ elf->e_ident[EI_VERSION] = EV_CURRENT;
+ memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
+
+ elf->e_type = ET_CORE;
+ elf->e_machine = ELF_ARCH;
+ elf->e_version = EV_CURRENT;
+ elf->e_entry = 0;
+ elf->e_phoff = sizeof(struct elfhdr);
+ elf->e_shoff = 0;
+ elf->e_flags = 0;
+ elf->e_ehsize = sizeof(struct elfhdr);
+ elf->e_phentsize = sizeof(struct elf_phdr);
+ elf->e_phnum = segs;
+ elf->e_shentsize = 0;
+ elf->e_shnum = 0;
+ elf->e_shstrndx = 0;
+ return;
+}
+
+static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, off_t offset)
+{
+ phdr->p_type = PT_NOTE;
+ phdr->p_offset = offset;
+ phdr->p_vaddr = 0;
+ phdr->p_paddr = 0;
+ phdr->p_filesz = sz;
+ phdr->p_memsz = 0;
+ phdr->p_flags = 0;
+ phdr->p_align = 0;
+ return;
+}
+
+static inline void fill_note(struct memelfnote *note, const char *name, int type,
+ unsigned int sz, void *data)
+{
+ note->name = name;
+ note->type = type;
+ note->datasz = sz;
+ note->data = data;
+ return;
+}
+
+/*
+ * fill up all the fields in prstatus from the given task struct, except registers
+ * which need to be filled up seperately.
+ */
+static inline void fill_prstatus(struct elf_prstatus *prstatus, struct task_struct *p, long signr)
+{
+ prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
+ prstatus->pr_sigpend = p->pending.signal.sig[0];
+ prstatus->pr_sighold = p->blocked.sig[0];
+ prstatus->pr_pid = p->pid;
+ prstatus->pr_ppid = p->parent->pid;
+ prstatus->pr_pgrp = p->pgrp;
+ prstatus->pr_sid = p->session;
+ prstatus->pr_utime.tv_sec = CT_TO_SECS(p->times.tms_utime);
+ prstatus->pr_utime.tv_usec = CT_TO_USECS(p->times.tms_utime);
+ prstatus->pr_stime.tv_sec = CT_TO_SECS(p->times.tms_stime);
+ prstatus->pr_stime.tv_usec = CT_TO_USECS(p->times.tms_stime);
+ prstatus->pr_cutime.tv_sec = CT_TO_SECS(p->times.tms_cutime);
+ prstatus->pr_cutime.tv_usec = CT_TO_USECS(p->times.tms_cutime);
+ prstatus->pr_cstime.tv_sec = CT_TO_SECS(p->times.tms_cstime);
+ prstatus->pr_cstime.tv_usec = CT_TO_USECS(p->times.tms_cstime);
+ return;
+}
+
+static inline void fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p)
+{
+ int i;
+
+ psinfo->pr_pid = p->pid;
+ psinfo->pr_ppid = p->parent->pid;
+ psinfo->pr_pgrp = p->pgrp;
+ psinfo->pr_sid = p->session;
+
+ i = p->state ? ffz(~p->state) + 1 : 0;
+ psinfo->pr_state = i;
+ psinfo->pr_sname = (i < 0 || i > 5) ? '.' : "RSDZTD"[i];
+ psinfo->pr_zomb = psinfo->pr_sname == 'Z';
+ psinfo->pr_nice = task_nice(p);
+ psinfo->pr_flag = p->flags;
+ psinfo->pr_uid = NEW_TO_OLD_UID(p->uid);
+ psinfo->pr_gid = NEW_TO_OLD_GID(p->gid);
+ strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
+ return;
+}
+
+/* Here is the structure in which status of each thread is captured. */
+struct elf_thread_status
+{
+ struct list_head list;
+ struct elf_prstatus prstatus; /* NT_PRSTATUS */
+ elf_fpregset_t fpu; /* NT_PRFPREG */
+#ifdef ELF_CORE_COPY_XFPREGS
+ elf_fpxregset_t xfpu; /* NT_PRXFPREG */
+#endif
+ struct memelfnote notes[3];
+ int num_notes;
+};
+
+/*
+ * In order to add the specific thread information for the elf file format,
+ * we need to keep a linked list of every threads pr_status and then
+ * create a single section for them in the final core file.
+ */
+static int elf_dump_thread_status(long signr, struct task_struct * p, struct list_head * thread_list)
+{
+
+ struct elf_thread_status *t;
+ int sz = 0;
+
+ t = kmalloc(sizeof(*t), GFP_KERNEL);
+ if (!t) {
+ printk(KERN_WARNING "Cannot allocate memory for thread status.\n");
+ return 0;
+ }
+
+ INIT_LIST_HEAD(&t->list);
+ t->num_notes = 0;
+
+ fill_prstatus(&t->prstatus, p, signr);
+ elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
+
+ fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus), &(t->prstatus));
+ t->num_notes++;
+ sz += notesize(&t->notes[0]);
+
+ if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, &t->fpu))) {
+ fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu), &(t->fpu));
+ t->num_notes++;
+ sz += notesize(&t->notes[1]);
+ }
+
+#ifdef ELF_CORE_COPY_XFPREGS
+ if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
+ fill_note(&t->notes[2], "LINUX", NT_PRXFPREG, sizeof(t->xfpu), &(t->xfpu));
+ t->num_notes++;
+ sz += notesize(&t->notes[2]);
+ }
+#endif
+ list_add(&t->list, thread_list);
+ return sz;
+}
+
+
+
/*
* Actual dumper
*
@@ -1024,12 +1178,23 @@
struct elfhdr elf;
off_t offset = 0, dataoff;
unsigned long limit = current->rlim[RLIMIT_CORE].rlim_cur;
- int numnote = 4;
- struct memelfnote notes[4];
+ int numnote = 5;
+ struct memelfnote notes[5];
struct elf_prstatus prstatus; /* NT_PRSTATUS */
- elf_fpregset_t fpu; /* NT_PRFPREG */
struct elf_prpsinfo psinfo; /* NT_PRPSINFO */
+ struct task_struct *p;
+ LIST_HEAD(thread_list);
+ struct list_head *t;
+ elf_fpregset_t fpu;
+#ifdef ELF_CORE_COPY_XFPREGS
+ elf_fpxregset_t xfpu;
+#endif
+ int thread_status_size = 0;
+

+ /* First pause all related threaded processes */
+ tcore_suspend_threads();
+
/* first copy the parameters from user space */
memset(&psinfo, 0, sizeof(psinfo));
{
@@ -1047,7 +1212,6 @@

}

- memset(&prstatus, 0, sizeof(prstatus));
/*
* This transfers the registers from regs into the standard
* coredump arrangement, whatever that is.
@@ -1063,9 +1227,42 @@
else
*(struct pt_regs *)&prstatus.pr_reg = *regs;
#endif
+
+ /* capture the status of all other threads */
+ if (signr) {
+ read_lock(&tasklist_lock);
+ for_each_task(p)
+ if (current->mm == p->mm && current != p) {
+ int sz = elf_dump_thread_status(signr, p, &thread_list);
+ if (!sz) {
+ read_unlock(&tasklist_lock);
+ goto cleanup;
+ }
+ else
+ thread_status_size += sz;
+ }
+ read_unlock(&tasklist_lock);
+ }
+
+ memset(&prstatus, 0, sizeof(prstatus));
+ fill_prstatus(&prstatus, current, signr);
+ elf_core_copy_regs(&prstatus.pr_reg, regs);
+
+ /* We no longer stop all vm operations */

- /* now stop all vm operations */
- down_write(&current->mm->mmap_sem);
+ /* This because those proceses that could possibly
+ * change map_count or the mmap / vma pages are now suspended.
+ *
+ * Only ptrace can touch these memory address, but it cannot change
+ * the map_count or the pages. So no possibility of crashing exists while dumping
+ * the mm->vm_next areas to the core file.
+ *
+ * Grabbing mmap_sem in this function is risky WRT the use of suspend_threads.
+ * Although no locks ups have been induced, if one of the suspended threads was
+ * in line for the current->mmap_sem and if gets it while on the Phantom runque,
+ * then we would dead lock in this function if we continue to attempt to down_write
+ * in this function.
+ */
segs = current->mm->map_count;

#ifdef DEBUG
@@ -1073,25 +1270,7 @@
#endif

/* Set up header */
- memcpy(elf.e_ident, ELFMAG, SELFMAG);
- elf.e_ident[EI_CLASS] = ELF_CLASS;
- elf.e_ident[EI_DATA] = ELF_DATA;
- elf.e_ident[EI_VERSION] = EV_CURRENT;
- memset(elf.e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
-
- elf.e_type = ET_CORE;
- elf.e_machine = ELF_ARCH;
- elf.e_version = EV_CURRENT;
- elf.e_entry = 0;
- elf.e_phoff = sizeof(elf);
- elf.e_shoff = 0;
- elf.e_flags = 0;
- elf.e_ehsize = sizeof(elf);
- elf.e_phentsize = sizeof(struct elf_phdr);
- elf.e_phnum = segs+1; /* Include notes */
- elf.e_shentsize = 0;
- elf.e_shnum = 0;
- elf.e_shstrndx = 0;
+ fill_elf_header(&elf, segs+1); /* including notes section*/

fs = get_fs();
set_fs(KERNEL_DS);
@@ -1108,64 +1287,34 @@
* with info from their /proc.
*/

- notes[0].name = "CORE";
- notes[0].type = NT_PRSTATUS;
- notes[0].datasz = sizeof(prstatus);
- notes[0].data = &prstatus;
- prstatus.pr_info.si_signo = prstatus.pr_cursig = signr;
- prstatus.pr_sigpend = current->pending.signal.sig[0];
- prstatus.pr_sighold = current->blocked.sig[0];
- psinfo.pr_pid = prstatus.pr_pid = current->pid;
- psinfo.pr_ppid = prstatus.pr_ppid = current->parent->pid;
- psinfo.pr_pgrp = prstatus.pr_pgrp = current->pgrp;
- psinfo.pr_sid = prstatus.pr_sid = current->session;
- prstatus.pr_utime.tv_sec = CT_TO_SECS(current->times.tms_utime);
- prstatus.pr_utime.tv_usec = CT_TO_USECS(current->times.tms_utime);
- prstatus.pr_stime.tv_sec = CT_TO_SECS(current->times.tms_stime);
- prstatus.pr_stime.tv_usec = CT_TO_USECS(current->times.tms_stime);
- prstatus.pr_cutime.tv_sec = CT_TO_SECS(current->times.tms_cutime);
- prstatus.pr_cutime.tv_usec = CT_TO_USECS(current->times.tms_cutime);
- prstatus.pr_cstime.tv_sec = CT_TO_SECS(current->times.tms_cstime);
- prstatus.pr_cstime.tv_usec = CT_TO_USECS(current->times.tms_cstime);
+ fill_note(&notes[0], "CORE", NT_PRSTATUS, sizeof(prstatus), &prstatus);
+
+ fill_psinfo(&psinfo, current);
+ fill_note(&notes[1], "CORE", NT_PRPSINFO, sizeof(psinfo), &psinfo);
+
+ fill_note(&notes[2], "CORE", NT_TASKSTRUCT, sizeof(*current), current);
+
+ /* Try to dump the FPU. */
+ if ((prstatus.pr_fpvalid = elf_core_copy_task_fpregs(current, &fpu))) {
+ fill_note(&notes[3], "CORE", NT_PRFPREG, sizeof(fpu), &fpu);
+ } else {
+ --numnote;
+ }
+#ifdef ELF_CORE_COPY_XFPREGS
+ if (elf_core_copy_task_xfpregs(current, &xfpu)) {
+ fill_note(&notes[4], "LINUX", NT_PRXFPREG, sizeof(xfpu), &xfpu);
+ } else {
+ --numnote;
+ }
+#else
+ numnote --;
+#endif

#ifdef DEBUG
dump_regs("Passed in regs", (elf_greg_t *)regs);
dump_regs("prstatus regs", (elf_greg_t *)&prstatus.pr_reg);
#endif

- notes[1].name = "CORE";
- notes[1].type = NT_PRPSINFO;
- notes[1].datasz = sizeof(psinfo);
- notes[1].data = &psinfo;
- i = current->state ? ffz(~current->state) + 1 : 0;
- psinfo.pr_state = i;
- psinfo.pr_sname = (i < 0 || i > 5) ? '.' : "RSDZTD"[i];
- psinfo.pr_zomb = psinfo.pr_sname == 'Z';
- psinfo.pr_nice = task_nice(current);
- psinfo.pr_flag = current->flags;
- psinfo.pr_uid = NEW_TO_OLD_UID(current->uid);
- psinfo.pr_gid = NEW_TO_OLD_GID(current->gid);
- strncpy(psinfo.pr_fname, current->comm, sizeof(psinfo.pr_fname));
-
- notes[2].name = "CORE";
- notes[2].type = NT_TASKSTRUCT;
- notes[2].datasz = sizeof(*current);
- notes[2].data = current;
-
- /* Try to dump the FPU. */
- prstatus.pr_fpvalid = dump_fpu (regs, &fpu);
- if (!prstatus.pr_fpvalid)
- {
- numnote--;
- }
- else
- {
- notes[3].name = "CORE";
- notes[3].type = NT_PRFPREG;
- notes[3].datasz = sizeof(fpu);
- notes[3].data = &fpu;
- }
-
/* Write notes phdr entry */
{
struct elf_phdr phdr;
@@ -1173,17 +1322,11 @@

for(i = 0; i < numnote; i++)
sz += notesize(&notes[i]);
+
+ sz += thread_status_size;

- phdr.p_type = PT_NOTE;
- phdr.p_offset = offset;
- phdr.p_vaddr = 0;
- phdr.p_paddr = 0;
- phdr.p_filesz = sz;
- phdr.p_memsz = 0;
- phdr.p_flags = 0;
- phdr.p_align = 0;
-
- offset += phdr.p_filesz;
+ fill_elf_note_phdr(&phdr, sz, offset);
+ offset += sz;
DUMP_WRITE(&phdr, sizeof(phdr));
}

@@ -1212,10 +1355,19 @@
DUMP_WRITE(&phdr, sizeof(phdr));
}

+ /* write out the notes section */
for(i = 0; i < numnote; i++)
if (!writenote(&notes[i], file))
goto end_coredump;

+ /* write out the thread status notes section */
+ list_for_each(t, &thread_list) {
+ struct elf_thread_status *tmp = list_entry(t, struct elf_thread_status, list);
+ for (i = 0; i < tmp->num_notes; i++)
+ if (!writenote(&tmp->notes[i], file))
+ goto end_coredump;
+ }
+
DUMP_SEEK(dataoff);

for(vma = current->mm->mmap; vma != NULL; vma = vma->vm_next) {
@@ -1259,11 +1411,21 @@
(off_t) file->f_pos, offset);
}

- end_coredump:
+end_coredump:
set_fs(fs);
- up_write(&current->mm->mmap_sem);
+
+cleanup:
+ while(!list_empty(&thread_list)) {
+ struct list_head *tmp = thread_list.next;
+ list_del(tmp);
+ kfree(list_entry(tmp, struct elf_thread_status, list));
+ }
+
+ tcore_resume_threads();
+
return has_dumped;
}
+
#endif /* USE_ELF_CORE_DUMP */

static int __init init_elf_binfmt(void)
diff -urN -X dontdiff src/linux-2.5.18/include/asm-i386/elf.h linux2518/include/asm-i386/elf.h
--- src/linux-2.5.18/include/asm-i386/elf.h Fri May 24 21:55:29 2002
+++ linux2518/include/asm-i386/elf.h Thu Jun 6 15:56:51 2002
@@ -99,6 +99,16 @@

#ifdef __KERNEL__
#define SET_PERSONALITY(ex, ibcs2) set_personality((ibcs2)?PER_SVR4:PER_LINUX)
+
+
+extern int dump_task_regs (struct task_struct *, elf_gregset_t *);
+extern int dump_task_fpu (struct task_struct *, elf_fpregset_t *);
+extern int dump_task_extended_fpu (struct task_struct *, struct user_fxsr_struct *);
+
+#define ELF_CORE_COPY_TASK_REGS(tsk, elf_regs) dump_task_regs(tsk, elf_regs)
+#define ELF_CORE_COPY_FPREGS(tsk, elf_fpregs) dump_task_fpu(tsk, elf_fpregs)
+#define ELF_CORE_COPY_XFPREGS(tsk, elf_xfpregs) dump_task_extended_fpu(tsk, elf_xfpregs)
+
#endif

#endif
diff -urN -X dontdiff src/linux-2.5.18/include/asm-ia64/elf.h linux2518/include/asm-ia64/elf.h
--- src/linux-2.5.18/include/asm-ia64/elf.h Fri May 24 21:55:29 2002
+++ linux2518/include/asm-ia64/elf.h Thu Jun 6 15:51:09 2002
@@ -65,12 +65,16 @@
#define ELF_NGREG 128 /* we really need just 72 but let's leave some headroom... */
#define ELF_NFPREG 128 /* f0 and f1 could be omitted, but so what... */

+typedef unsigned long elf_fpxregset_t;
+
typedef unsigned long elf_greg_t;
typedef elf_greg_t elf_gregset_t[ELF_NGREG];

typedef struct ia64_fpreg elf_fpreg_t;
typedef elf_fpreg_t elf_fpregset_t[ELF_NFPREG];

+
+
struct pt_regs; /* forward declaration... */
extern void ia64_elf_core_copy_regs (struct pt_regs *src, elf_gregset_t dst);
#define ELF_CORE_COPY_REGS(_dest,_regs) ia64_elf_core_copy_regs(_regs, _dest);
@@ -88,6 +92,14 @@
struct elf64_hdr;
extern void ia64_set_personality (struct elf64_hdr *elf_ex, int ibcs2_interpreter);
#define SET_PERSONALITY(ex, ibcs2) ia64_set_personality(&(ex), ibcs2)
+
+extern int dump_task_regs(struct task_struct *, elf_gregset_t *);
+extern int dump_task_fpu (struct task_struct *, elf_fpregset_t *);
+
+#define ELF_CORE_COPY_TASK_REGS(tsk, elf_gregs) dump_task_regs(tsk, elf_gregs)
+#define ELF_CORE_COPY_FPREGS(tsk, elf_fpregs) dump_task_fpu(tsk, elf_fpregs)
+
+
#endif

#endif /* _ASM_IA64_ELF_H */
diff -urN -X dontdiff src/linux-2.5.18/include/linux/elf.h linux2518/include/linux/elf.h
--- src/linux-2.5.18/include/linux/elf.h Fri May 24 21:55:20 2002
+++ linux2518/include/linux/elf.h Thu Jun 6 15:57:37 2002
@@ -576,6 +576,9 @@
#define NT_PRPSINFO 3
#define NT_TASKSTRUCT 4
#define NT_PRFPXREG 20
+#define NT_PRXFPREG 0x46e62b7f /* note name must be "LINUX" as per GDB */
+ /* from gdb5.1/include/elf/common.h */
+

/* Note header in a PT_NOTE section */
typedef struct elf32_note {
@@ -606,6 +609,5 @@
#define elf_note elf64_note

#endif
-

#endif /* _LINUX_ELF_H */
diff -urN -X dontdiff src/linux-2.5.18/include/linux/elfcore.h linux2518/include/linux/elfcore.h
--- src/linux-2.5.18/include/linux/elfcore.h Fri May 24 21:55:26 2002
+++ linux2518/include/linux/elfcore.h Thu Jun 6 15:57:37 2002
@@ -86,4 +86,48 @@
#define PRARGSZ ELF_PRARGSZ
#endif

+#ifdef __KERNEL__
+static inline void elf_core_copy_regs(elf_gregset_t *elfregs, struct pt_regs *regs)
+{
+#ifdef ELF_CORE_COPY_REGS
+ ELF_CORE_COPY_REGS((*elfregs), regs)
+#else
+ if (sizeof(elf_gregset_t) != sizeof(struct pt_regs)) {
+ printk("sizeof(elf_gregset_t) (%ld) != sizeof(struct pt_regs) (%ld)\n",
+ (long)sizeof(elf_gregset_t), (long)sizeof(struct pt_regs));
+ } else
+ *(struct pt_regs *)elfregs = *regs;
+#endif
+}
+
+static inline int elf_core_copy_task_regs(struct task_struct *t, elf_gregset_t* elfregs)
+{
+#ifdef ELF_CORE_COPY_TASK_REGS
+
+ return ELF_CORE_COPY_TASK_REGS(t, elfregs);
+#endif
+ return 0;
+}
+
+extern int dump_fpu (struct pt_regs *, elf_fpregset_t *);
+
+static inline int elf_core_copy_task_fpregs(struct task_struct *t, elf_fpregset_t *fpu)
+{
+#ifdef ELF_CORE_COPY_FPREGS
+ return ELF_CORE_COPY_FPREGS(t, fpu);
+#else
+ return dump_fpu(NULL, fpu);
+#endif
+}
+
+#ifdef ELF_CORE_COPY_XFPREGS
+static inline int elf_core_copy_task_xfpregs(struct task_struct *t, elf_fpxregset_t *xfpu)
+{
+ return ELF_CORE_COPY_XFPREGS(t, xfpu);
+}
+#endif
+
+#endif /* __KERNEL__ */
+
+
#endif /* _LINUX_ELFCORE_H */
diff -urN -X dontdiff src/linux-2.5.18/include/linux/sched.h linux2518/include/linux/sched.h
--- src/linux-2.5.18/include/linux/sched.h Fri May 24 21:55:19 2002
+++ linux2518/include/linux/sched.h Thu Jun 6 15:55:30 2002
@@ -131,6 +131,14 @@

#include <linux/spinlock.h>

+
+/* functions for pausing and resumming functions
+ * common mm's without using signals. These are used
+ * by the multithreaded elf core dump code in binfmt_elf.c*/
+extern void tcore_suspend_threads( void );
+extern void tcore_resume_threads( void );
+
+
/*
* This serializes "schedule()" and also protects
* the run-queue from deletions/modifications (but
diff -urN -X dontdiff src/linux-2.5.18/kernel/sched.c linux2518/kernel/sched.c
--- src/linux-2.5.18/kernel/sched.c Fri May 24 21:55:22 2002
+++ linux2518/kernel/sched.c Thu Jun 6 15:51:09 2002
@@ -140,7 +140,8 @@
list_t migration_queue;
} ____cacheline_aligned;

-static struct runqueue runqueues[NR_CPUS] __cacheline_aligned;
+static struct runqueue runqueues[NR_CPUS + 1] __cacheline_aligned;
+#define PHANTOM_CPU NR_CPUS

#define cpu_rq(cpu) (runqueues + (cpu))
#define this_rq() cpu_rq(smp_processor_id())
@@ -249,6 +250,9 @@
#ifdef CONFIG_SMP
int need_resched, nrpolling;

+ if( unlikely(!p->cpus_allowed) )
+ return;
+
preempt_disable();
/* minimise the chance of sending an interrupt to poll_idle() */
nrpolling = test_tsk_thread_flag(p,TIF_POLLING_NRFLAG);
@@ -325,7 +329,7 @@
p->state = TASK_RUNNING;
if (!p->array) {
activate_task(p, rq);
- if (p->prio < rq->curr->prio)
+ if (p->cpus_allowed && (p->prio < rq->curr->prio) )
resched_task(rq->curr);
success = 1;
}
@@ -982,6 +986,133 @@

void scheduling_functions_end_here(void) { }

+/*
+ * needed for accurate core dumps of multi-threaded applications.
+ * see binfmt_elf.c for more information.
+ */
+static void reschedule_other_cpus(void)
+{
+#ifdef CONFIG_SMP
+ int i, cpu;
+ struct task_struct *p;
+
+ for(i=0; i< smp_num_cpus; i++) {
+ cpu = cpu_logical_map(i);
+ p = cpu_curr(cpu);
+ if (p->thread_info->cpu!= smp_processor_id()) {
+ set_tsk_need_resched(p);
+ smp_send_reschedule(p->thread_info->cpu);
+ }
+ }
+#endif
+ return;
+}
+
+
+/* functions for pausing and resumming functions with out using signals */
+void tcore_suspend_threads(void)
+{
+ unsigned long flags;
+ runqueue_t *phantomQ;
+ task_t *threads[NR_CPUS], *p;
+ int i, OnCPUCount = 0;
+
+//
+// grab all the rq_locks.
+// current is the process dumping core
+//
+
+ down_write(&current->mm->mmap_sem);
+ // avoid potential race on >2 way SMP if 3 or more thread procs
+ // dump core at the same time.
+
+ local_irq_save(flags);
+
+ for(i=0; i< smp_num_cpus; i++) {
+ spin_lock(&cpu_rq(i)->lock);
+ }
+
+ current->cpus_allowed = 1UL << current->thread_info->cpu;
+ // prevent migraion of dumping process making life complicated.
+
+ phantomQ = cpu_rq(PHANTOM_CPU);
+ spin_lock(&phantomQ->lock);
+
+ reschedule_other_cpus();
+ // this is an optional IPI, but it makes for the most accurate core files possible.
+
+ read_lock(&tasklist_lock);
+
+ for_each_task(p) {
+ if (current->mm == p->mm && current != p) {
+ if( p == task_rq(p)->curr ) {
+ //then remember it for later us of set_cpus_allowed
+ threads[OnCPUCount] = p;
+ p->cpus_allowed = 0;//prevent load balance from moving these guys.
+ OnCPUCount ++;
+ } else {
+ // we manualy move the process to the phantom run queue.
+
+ if (p->array) {
+ deactivate_task(p, task_rq(p));
+ activate_task(p, phantomQ);
+ }
+ p->thread_info->cpu = PHANTOM_CPU;
+ p->cpus_allowed = 0;//prevent load balance from moving these guys.
+ }
+ }
+ }
+ read_unlock(&tasklist_lock);
+
+ spin_unlock(&phantomQ->lock);
+ for(i=smp_num_cpus-1; 0<= i; i--) {
+ spin_unlock(&cpu_rq(i)->lock);
+ }
+
+ local_irq_restore(flags);
+
+ for( i = 0; i<OnCPUCount; i++) {
+ set_cpus_allowed(threads[i], 0);
+ }
+
+ up_write(&current->mm->mmap_sem);
+}
+
+void tcore_resume_threads(void)
+{
+ unsigned long flags;
+ runqueue_t *phantomQ;
+ task_t *p;
+ int i;
+
+ local_irq_save(flags);
+ phantomQ = cpu_rq(PHANTOM_CPU);
+
+ spin_lock(&task_rq(current)->lock);
+ spin_lock(&phantomQ->lock);
+
+ read_lock(&tasklist_lock);
+ for_each_task(p) {
+ if (current->mm == p->mm && current != p) {
+ p->cpus_allowed = 1UL << current->thread_info->cpu;
+ if (p->array) {
+ deactivate_task(p,phantomQ);
+ activate_task(p, task_rq(current));
+ }
+ p->thread_info->cpu = current->thread_info->cpu;
+ }
+ }
+
+ read_unlock(&tasklist_lock);
+
+ spin_unlock(&phantomQ->lock);
+ spin_unlock(&task_rq(current)->lock);
+
+ local_irq_restore(flags);
+}
+
+
+
void set_user_nice(task_t *p, long nice)
{
unsigned long flags;
@@ -1568,11 +1699,11 @@
{
runqueue_t *rq;
int i, j, k;
+ prio_array_t *array;

- for (i = 0; i < NR_CPUS; i++) {
- runqueue_t *rq = cpu_rq(i);
- prio_array_t *array;

+ for (i = 0; i < NR_CPUS; i++) {
+ rq = cpu_rq(i);
rq->active = rq->arrays;
rq->expired = rq->arrays + 1;
spin_lock_init(&rq->lock);
@@ -1589,6 +1720,28 @@
__set_bit(MAX_PRIO, array->bitmap);
}
}
+
+
+ i = PHANTOM_CPU;
+ rq = cpu_rq(i);
+ rq->active = rq->arrays;
+ rq->expired = rq->arrays + 1;
+ rq->curr = NULL;
+ spin_lock_init(&rq->lock);
+ spin_lock_init(&rq->frozen);
+ INIT_LIST_HEAD(&rq->migration_queue);
+
+ for (j = 0; j < 2; j++) {
+ array = rq->arrays + j;
+ for (k = 0; k < MAX_PRIO; k++) {
+ INIT_LIST_HEAD(array->queue + k);
+ __clear_bit(k, array->bitmap);
+ }
+ // delimiter for bitsearch
+ __set_bit(MAX_PRIO, array->bitmap);
+ }
+
+
/*
* We have to do a little magic to get the first
* process right in SMP mode.
@@ -1648,9 +1801,11 @@
migration_req_t req;
runqueue_t *rq;

- new_mask &= cpu_online_map;
- if (!new_mask)
- BUG();
+ if(new_mask){ // can be O for TCore process suspends
+ new_mask &= cpu_online_map;
+ if (!new_mask)
+ BUG();
+ }

preempt_disable();
rq = task_rq_lock(p, &flags);
@@ -1723,7 +1878,12 @@
spin_unlock_irqrestore(&rq->lock, flags);

p = req->task;
- cpu_dest = __ffs(p->cpus_allowed);
+
+ if( p->cpus_allowed)
+ cpu_dest = __ffs(p->cpus_allowed);
+ else
+ cpu_dest = PHANTOM_CPU;
+
rq_dest = cpu_rq(cpu_dest);
repeat:
cpu_src = p->thread_info->cpu;
-
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