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Subject[patch] thread-aware coredumps, 2.5.43-C3

the attached patch is the second iteration of thread-aware coredumps,
against BK-curr. I think this patch is now ready for inclusion into
mainline.

Changes:

- Ulrich Drepper has reviewed the data structures and checked actual
coredumps via readelf - everything looks fine and according to the spec.

- a serious bug has been fixed in the thread-state dumping code - it was
still based on the 2.4 assumption that the task struct points to the
kernel stack - it's task->thread_info in 2.5. This bug caused bogus
register info to be filled in for threads.

- properly wait for all threads that share the same MM to serialize with
the coredumping thread. This is CLONE_VM based, not tied to
CLONE_THREAD and/or signal semantics, ie. old-style (or different-style)
threaded apps will be properly stopped as well.

The locking might look a bit complex, but i wanted to keep the
__exit_mm() overhead as low as possible. It's not quite trivial to get
these bits right, because 'sharing the MM' is detached from signals
semantics, so we cannot rely on broadcast-kill catching all threads. So
zap_threads() iterates through every thread and zaps those which were
left out. (There's a minimal race left in where a newly forked child
might escape the attention of zap_threads() - this race is fixed by the
OOM fixes in the mmap-speedup patch.)

- fill_psinfo() is now called with the thread group leader, for the
coredump to get 'process' state.

- initialize the elf_thread_status structure with zeroes.

the IA64 ELF bits are not included, yet, to reduce complexity of the
patch. The patch has been tested on x86 UP and SMP.

Ingo

--- linux/arch/i386/kernel/i387.c.orig 2002-10-17 09:48:47.000000000 +0200
+++ linux/arch/i386/kernel/i387.c 2002-10-17 09:48:55.000000000 +0200
@@ -528,3 +528,40 @@

return fpvalid;
}
+
+int dump_task_fpu(struct task_struct *tsk, struct user_i387_struct *fpu)
+{
+ int 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 = tsk->used_math && cpu_has_fxsr;
+
+ if (fpvalid) {
+ if (tsk == current)
+ unlazy_fpu(tsk);
+ memcpy(fpu, &tsk->thread.i387.fxsave, sizeof(*fpu));
+ }
+ return fpvalid;
+}
+
+
+#ifdef CONFIG_SMP
+void dump_smp_unlazy_fpu(void)
+{
+ unlazy_fpu(current);
+ return;
+}
+#endif
+
--- linux/arch/i386/kernel/process.c.orig 2002-10-17 09:48:47.000000000 +0200
+++ linux/arch/i386/kernel/process.c 2002-10-17 10:17:22.000000000 +0200
@@ -19,6 +19,7 @@
#include <linux/fs.h>
#include <linux/kernel.h>
#include <linux/mm.h>
+#include <linux/elfcore.h>
#include <linux/smp.h>
#include <linux/smp_lock.h>
#include <linux/stddef.h>
@@ -373,6 +374,25 @@
dump->u_fpvalid = dump_fpu (regs, &dump->i387);
}

+/*
+ * Capture the user space registers if the task is not running (in user space)
+ */
+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(ptregs));
+ 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
*/
--- linux/arch/ia64/kernel/process.c.orig 2002-10-17 09:48:47.000000000 +0200
+++ linux/arch/ia64/kernel/process.c 2002-10-17 09:48:55.000000000 +0200
@@ -382,6 +382,31 @@
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;
@@ -396,12 +421,12 @@
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);

/*
@@ -450,7 +475,7 @@
}

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;
@@ -465,22 +490,41 @@
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
--- linux/fs/binfmt_elf.c.orig 2002-10-17 09:48:47.000000000 +0200
+++ linux/fs/binfmt_elf.c 2002-10-17 10:56:25.000000000 +0200
@@ -30,6 +30,7 @@
#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>
@@ -534,9 +535,6 @@
if (strcmp(elf_interpreter,"/usr/lib/libc.so.1") == 0 ||
strcmp(elf_interpreter,"/usr/lib/ld.so.1") == 0)
ibcs2_interpreter = 1;
-#if 0
- printk("Using ELF interpreter %s\n", elf_interpreter);
-#endif

SET_PERSONALITY(elf_ex, ibcs2_interpreter);

@@ -759,16 +757,6 @@

padzero(elf_bss);

-#if 0
- printk("(start_brk) %lx\n" , (long) current->mm->start_brk);
- printk("(end_code) %lx\n" , (long) current->mm->end_code);
- printk("(start_code) %lx\n" , (long) current->mm->start_code);
- printk("(start_data) %lx\n" , (long) current->mm->start_data);
- printk("(end_data) %lx\n" , (long) current->mm->end_data);
- printk("(start_stack) %lx\n" , (long) current->mm->start_stack);
- printk("(brk) %lx\n" , (long) current->mm->brk);
-#endif
-
if (current->personality & MMAP_PAGE_ZERO) {
/* Why this, you ask??? Well SVr4 maps page 0 as read-only,
and some applications "depend" upon this behavior.
@@ -967,26 +955,6 @@
return sz;
}

-/* #define DEBUG */
-
-#ifdef DEBUG
-static void dump_regs(const char *str, elf_greg_t *r)
-{
- int i;
- static const char *regs[] = { "ebx", "ecx", "edx", "esi", "edi", "ebp",
- "eax", "ds", "es", "fs", "gs",
- "orig_eax", "eip", "cs",
- "efl", "uesp", "ss"};
- printk("Registers: %s\n", str);
-
- for(i = 0; i < ELF_NGREG; i++)
- {
- unsigned long val = r[i];
- printk(" %-2d %-5s=%08lx %lu\n", i, regs[i], val, val);
- }
-}
-#endif
-
#define DUMP_WRITE(addr, nr) \
do { if (!dump_write(file, (addr), (nr))) return 0; } while(0)
#define DUMP_SEEK(off) \
@@ -1018,6 +986,164 @@
#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;
+ jiffies_to_timeval(p->utime, &prstatus->pr_utime);
+ jiffies_to_timeval(p->stime, &prstatus->pr_stime);
+ jiffies_to_timeval(p->cutime, &prstatus->pr_cutime);
+ jiffies_to_timeval(p->cstime, &prstatus->pr_cstime);
+}
+
+static inline void fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p)
+{
+ int i, len;
+
+ /* first copy the parameters from user space */
+ memset(psinfo, 0, sizeof(struct elf_prpsinfo));
+
+ len = p->mm->arg_end - p->mm->arg_start;
+ if (len >= ELF_PRARGSZ)
+ len = ELF_PRARGSZ-1;
+ copy_from_user(&psinfo->pr_psargs,
+ (const char *)p->mm->arg_start, len);
+ for(i = 0; i < len; i++)
+ if (psinfo->pr_psargs[i] == 0)
+ psinfo->pr_psargs[i] = ' ';
+ psinfo->pr_psargs[len] = 0;
+
+ 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_ATOMIC);
+ if (!t)
+ return 0;
+ memset(t, 0, sizeof(*t));
+
+ 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
*
@@ -1036,74 +1162,56 @@
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 */
-
- /* first copy the parameters from user space */
- memset(&psinfo, 0, sizeof(psinfo));
- {
- int i, len;
-
- len = current->mm->arg_end - current->mm->arg_start;
- if (len >= ELF_PRARGSZ)
- len = ELF_PRARGSZ-1;
- copy_from_user(&psinfo.pr_psargs,
- (const char *)current->mm->arg_start, len);
- for(i = 0; i < len; i++)
- if (psinfo.pr_psargs[i] == 0)
- psinfo.pr_psargs[i] = ' ';
- psinfo.pr_psargs[len] = 0;
-
- }
-
- memset(&prstatus, 0, sizeof(prstatus));
- /*
- * This transfers the registers from regs into the standard
- * coredump arrangement, whatever that is.
+ struct task_struct *g, *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;
+
+ /* We no longer stop all vm operations
+ *
+ * This because those proceses that could possibly
+ * change map_count or the mmap / vma pages are now blocked in do_exit on current finishing
+ * this core dump.
+ *
+ * Only ptrace can touch these memory addresses, but it doesn't change
+ * the map_count or the pages allocated. So no possibility of crashing exists while dumping
+ * the mm->vm_next areas to the core file.
+ *
*/
-#ifdef ELF_CORE_COPY_REGS
- ELF_CORE_COPY_REGS(prstatus.pr_reg, 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));
+
+ /* capture the status of all other threads */
+ if (signr) {
+ read_lock(&tasklist_lock);
+ do_each_thread(g,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;
+ }
+ while_each_thread(g,p);
+ read_unlock(&tasklist_lock);
}
- else
- *(struct pt_regs *)&prstatus.pr_reg = *regs;
-#endif

- /* now stop all vm operations */
- down_write(&current->mm->mmap_sem);
+ /* now collect the dump for the current */
+ memset(&prstatus, 0, sizeof(prstatus));
+ fill_prstatus(&prstatus, current, signr);
+ elf_core_copy_regs(&prstatus.pr_reg, regs);
+
segs = current->mm->map_count;

-#ifdef DEBUG
- printk("elf_core_dump: %d segs %lu limit\n", segs, limit);
-#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);
@@ -1120,60 +1228,27 @@
* 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;
- jiffies_to_timeval(current->utime, &prstatus.pr_utime);
- jiffies_to_timeval(current->stime, &prstatus.pr_stime);
- jiffies_to_timeval(current->cutime, &prstatus.pr_cutime);
- jiffies_to_timeval(current->cstime, &prstatus.pr_cstime);
-
-#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;
- }
+ fill_note(&notes[0], "CORE", NT_PRSTATUS, sizeof(prstatus), &prstatus);
+
+ fill_psinfo(&psinfo, current->group_leader);
+ 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
+
/* Write notes phdr entry */
{
struct elf_phdr phdr;
@@ -1181,17 +1256,11 @@

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));
}

@@ -1220,10 +1289,19 @@
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) {
@@ -1232,10 +1310,6 @@
if (!maydump(vma))
continue;

-#ifdef DEBUG
- printk("elf_core_dump: writing %08lx-%08lx\n", vma->vm_start, vma->vm_end);
-#endif
-
for (addr = vma->vm_start;
addr < vma->vm_end;
addr += PAGE_SIZE) {
@@ -1267,11 +1341,19 @@
(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));
+ }
+
return has_dumped;
}
+
#endif /* USE_ELF_CORE_DUMP */

static int __init init_elf_binfmt(void)
--- linux/fs/exec.c.orig 2002-10-17 09:48:47.000000000 +0200
+++ linux/fs/exec.c 2002-10-17 10:18:17.000000000 +0200
@@ -1209,6 +1209,35 @@
*out_ptr = 0;
}

+static void zap_threads (struct mm_struct *mm)
+{
+ struct task_struct *g, *p;
+
+ /* give other threads a chance to run: */
+ yield();
+
+ read_lock(&tasklist_lock);
+ do_each_thread(g,p)
+ if (mm == p->mm && !p->core_waiter)
+ force_sig_specific(SIGKILL, p);
+ while_each_thread(g,p);
+ read_unlock(&tasklist_lock);
+}
+
+static void coredump_wait(struct mm_struct *mm)
+{
+ DECLARE_WAITQUEUE(wait, current);
+
+ atomic_inc(&mm->core_waiters);
+ add_wait_queue(&mm->core_wait, &wait);
+ zap_threads(mm);
+ current->state = TASK_UNINTERRUPTIBLE;
+ if (atomic_read(&mm->core_waiters) != atomic_read(&mm->mm_users))
+ schedule();
+ else
+ current->state = TASK_RUNNING;
+}
+
int do_coredump(long signr, struct pt_regs * regs)
{
struct linux_binfmt * binfmt;
@@ -1224,13 +1253,16 @@
if (!current->mm->dumpable)
goto fail;
current->mm->dumpable = 0;
+ if (down_trylock(&current->mm->core_sem))
+ BUG();
+ coredump_wait(current->mm);
if (current->rlim[RLIMIT_CORE].rlim_cur < binfmt->min_coredump)
- goto fail;
+ goto fail_unlock;

format_corename(corename, core_pattern, signr);
file = filp_open(corename, O_CREAT | 2 | O_NOFOLLOW, 0600);
if (IS_ERR(file))
- goto fail;
+ goto fail_unlock;
inode = file->f_dentry->d_inode;
if (inode->i_nlink > 1)
goto close_fail; /* multiple links - don't dump */
@@ -1250,6 +1282,8 @@

close_fail:
filp_close(file, NULL);
+fail_unlock:
+ up(&current->mm->core_sem);
fail:
unlock_kernel();
return retval;
--- linux/include/linux/elf.h.orig 2002-10-17 09:48:47.000000000 +0200
+++ linux/include/linux/elf.h 2002-10-17 09:48:55.000000000 +0200
@@ -1,6 +1,7 @@
#ifndef _LINUX_ELF_H
#define _LINUX_ELF_H

+#include <linux/sched.h>
#include <linux/types.h>
#include <asm/elf.h>

@@ -575,7 +576,8 @@
#define NT_PRFPREG 2
#define NT_PRPSINFO 3
#define NT_TASKSTRUCT 4
-#define NT_PRFPXREG 20
+#define NT_PRXFPREG 0x46e62b7f /* copied from gdb5.1/include/elf/common.h */
+

/* Note header in a PT_NOTE section */
typedef struct elf32_note {
--- linux/include/linux/elfcore.h.orig 2002-10-17 09:48:47.000000000 +0200
+++ linux/include/linux/elfcore.h 2002-10-17 09:48:55.000000000 +0200
@@ -85,4 +85,45 @@
#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
+ BUG_ON(sizeof(*elfregs) != sizeof(*regs));
+ *(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 */
--- linux/include/linux/sched.h.orig 2002-10-17 09:48:47.000000000 +0200
+++ linux/include/linux/sched.h 2002-10-17 09:48:55.000000000 +0200
@@ -208,6 +208,11 @@
/* Architecture-specific MM context */
mm_context_t context;

+ /* coredumping support */
+ struct semaphore core_sem;
+ atomic_t core_waiters;
+ wait_queue_head_t core_wait;
+
/* aio bits */
rwlock_t ioctx_list_lock;
struct kioctx *ioctx_list;
@@ -401,6 +406,8 @@
void *journal_info;
struct dentry *proc_dentry;
struct backing_dev_info *backing_dev_info;
+/* threaded coredumping support */
+ int core_waiter;
};

extern void __put_task_struct(struct task_struct *tsk);
@@ -540,6 +547,7 @@
extern void notify_parent(struct task_struct *, int);
extern void do_notify_parent(struct task_struct *, int);
extern void force_sig(int, struct task_struct *);
+extern void force_sig_specific(int, struct task_struct *);
extern int send_sig(int, struct task_struct *, int);
extern int __broadcast_thread_group(struct task_struct *p, int sig);
extern int kill_pg(pid_t, int, int);
--- linux/include/asm-ia64/elf.h.orig 2002-10-17 09:48:47.000000000 +0200
+++ linux/include/asm-ia64/elf.h 2002-10-17 09:48:55.000000000 +0200
@@ -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 */
--- linux/include/asm-i386/elf.h.orig 2002-10-17 09:48:47.000000000 +0200
+++ linux/include/asm-i386/elf.h 2002-10-17 09:48:55.000000000 +0200
@@ -7,6 +7,7 @@

#include <asm/ptrace.h>
#include <asm/user.h>
+#include <asm/processor.h>

#include <linux/utsname.h>

@@ -59,6 +60,9 @@

/* Wow, the "main" arch needs arch dependent functions too.. :) */

+#define savesegment(seg,value) \
+ asm volatile("movl %%" #seg ",%0":"=m" (*(int *)&(value)))
+
/* regs is struct pt_regs, pr_reg is elf_gregset_t (which is
now struct_user_regs, they are different) */

@@ -72,9 +76,8 @@
pr_reg[6] = regs->eax; \
pr_reg[7] = regs->xds; \
pr_reg[8] = regs->xes; \
- /* fake once used fs and gs selectors? */ \
- pr_reg[9] = regs->xds; /* was fs and __fs */ \
- pr_reg[10] = regs->xds; /* was gs and __gs */ \
+ savesegment(fs,pr_reg[9]); \
+ savesegment(gs,pr_reg[10]); \
pr_reg[11] = regs->orig_eax; \
pr_reg[12] = regs->eip; \
pr_reg[13] = regs->xcs; \
@@ -99,6 +102,20 @@

#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)
+
+#ifdef CONFIG_SMP
+extern void dump_smp_unlazy_fpu(void);
+#define ELF_CORE_SYNC dump_smp_unlazy_fpu
+#endif
+
#endif

#endif
--- linux/kernel/exit.c.orig 2002-10-17 09:48:47.000000000 +0200
+++ linux/kernel/exit.c 2002-10-17 09:48:55.000000000 +0200
@@ -416,19 +416,31 @@
*/
static inline void __exit_mm(struct task_struct * tsk)
{
- struct mm_struct * mm = tsk->mm;
+ struct mm_struct *mm = tsk->mm;

mm_release();
- if (mm) {
- atomic_inc(&mm->mm_count);
- if (mm != tsk->active_mm) BUG();
- /* more a memory barrier than a real lock */
- task_lock(tsk);
- tsk->mm = NULL;
- enter_lazy_tlb(mm, current, smp_processor_id());
- task_unlock(tsk);
- mmput(mm);
+ if (!mm)
+ return;
+ /*
+ * Serialize with any possible pending coredump:
+ */
+ if (!mm->dumpable) {
+ current->core_waiter = 1;
+ atomic_inc(&mm->core_waiters);
+ if (atomic_read(&mm->core_waiters) ==atomic_read(&mm->mm_users))
+ wake_up(&mm->core_wait);
+ down(&mm->core_sem);
+ up(&mm->core_sem);
+ atomic_dec(&mm->core_waiters);
}
+ atomic_inc(&mm->mm_count);
+ if (mm != tsk->active_mm) BUG();
+ /* more a memory barrier than a real lock */
+ task_lock(tsk);
+ tsk->mm = NULL;
+ enter_lazy_tlb(mm, current, smp_processor_id());
+ task_unlock(tsk);
+ mmput(mm);
}

void exit_mm(struct task_struct *tsk)
--- linux/kernel/fork.c.orig 2002-10-17 09:48:47.000000000 +0200
+++ linux/kernel/fork.c 2002-10-17 09:48:55.000000000 +0200
@@ -305,6 +305,9 @@
atomic_set(&mm->mm_users, 1);
atomic_set(&mm->mm_count, 1);
init_rwsem(&mm->mmap_sem);
+ init_MUTEX(&mm->core_sem);
+ init_waitqueue_head(&mm->core_wait);
+ atomic_set(&mm->core_waiters, 0);
mm->page_table_lock = SPIN_LOCK_UNLOCKED;
mm->ioctx_list_lock = RW_LOCK_UNLOCKED;
mm->default_kioctx = (struct kioctx)INIT_KIOCTX(mm->default_kioctx, *mm);
@@ -771,6 +774,8 @@

INIT_LIST_HEAD(&p->local_pages);

+ p->core_waiter = 0;
+
retval = -ENOMEM;
if (security_ops->task_alloc_security(p))
goto bad_fork_cleanup;
--- linux/kernel/signal.c.orig 2002-10-17 09:48:47.000000000 +0200
+++ linux/kernel/signal.c 2002-10-17 09:48:55.000000000 +0200
@@ -768,7 +768,7 @@
}

static int
-specific_force_sig_info(int sig, struct task_struct *t)
+__specific_force_sig_info(int sig, struct task_struct *t)
{
if (!t->sig)
return -ESRCH;
@@ -781,6 +781,20 @@
return specific_send_sig_info(sig, (void *)2, t, 0);
}

+void
+force_sig_specific(int sig, struct task_struct *t)
+{
+ unsigned long int flags;
+
+ spin_lock_irqsave(&t->sig->siglock, flags);
+ if (t->sig->action[sig-1].sa.sa_handler == SIG_IGN)
+ t->sig->action[sig-1].sa.sa_handler = SIG_DFL;
+ sigdelset(&t->blocked, sig);
+ recalc_sigpending_tsk(t);
+ specific_send_sig_info(sig, (void *)2, t, 0);
+ spin_unlock_irqrestore(&t->sig->siglock, flags);
+}
+
#define can_take_signal(p, sig) \
(((unsigned long) p->sig->action[sig-1].sa.sa_handler > 1) && \
!sigismember(&p->blocked, sig) && (task_curr(p) || !signal_pending(p)))
@@ -846,7 +860,7 @@
int err = 0;

for_each_task_pid(p->tgid, PIDTYPE_TGID, tmp, l, pid)
- err = specific_force_sig_info(sig, tmp);
+ err = __specific_force_sig_info(sig, tmp);

return err;
}
-
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