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Subject[PATCH 6/7] [elf-fdpic] use elf_dump_thread_status() for the dumper thread as well
Date
From: Al Viro <viro@zeniv.linux.org.uk>

the only reason to have it open-coded for the first (dumper) thread is
that coredump has a couple of process-wide notes stuck right after the
first (NT_PRSTATUS) note of the first thread. But we don't need to
make the data collection side irregular for the first thread to handle
that - it's only the logics ordering the calls of writenote() that
needs to take care of that.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
fs/binfmt_elf_fdpic.c | 81 ++++++++++++++++++---------------------------------
1 file changed, 28 insertions(+), 53 deletions(-)

diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c
index ba4f264dff3a..34c45410d587 100644
--- a/fs/binfmt_elf_fdpic.c
+++ b/fs/binfmt_elf_fdpic.c
@@ -1482,7 +1482,8 @@ static struct elf_thread_status *elf_dump_thread_status(long signr, struct task_
t->num_notes++;
*sz += notesize(&t->notes[0]);

- t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu);
+ t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, task_pt_regs(p),
+ &t->fpu);
if (t->prstatus.pr_fpvalid) {
fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
&t->fpu);
@@ -1568,19 +1569,15 @@ static size_t elf_core_vma_data_size(unsigned long mm_flags)
*/
static int elf_fdpic_core_dump(struct coredump_params *cprm)
{
-#define NUM_NOTES 6
int has_dumped = 0;
int segs;
int i;
struct vm_area_struct *vma;
struct elfhdr *elf = NULL;
loff_t offset = 0, dataoff;
- int numnote;
- struct memelfnote *notes = NULL;
- struct elf_prstatus_fdpic *prstatus = NULL; /* NT_PRSTATUS */
+ struct memelfnote psinfo_note, auxv_note;
struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */
struct elf_thread_status *thread_list = NULL;
- elf_fpregset_t *fpu = NULL;
int thread_status_size = 0;
elf_addr_t *auxv;
struct elf_phdr *phdr4note = NULL;
@@ -1606,19 +1603,9 @@ static int elf_fdpic_core_dump(struct coredump_params *cprm)
elf = kmalloc(sizeof(*elf), GFP_KERNEL);
if (!elf)
goto end_coredump;
- prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL);
- if (!prstatus)
- goto end_coredump;
psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
if (!psinfo)
goto end_coredump;
- notes = kmalloc_array(NUM_NOTES, sizeof(struct memelfnote),
- GFP_KERNEL);
- if (!notes)
- goto end_coredump;
- fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
- if (!fpu)
- goto end_coredump;

for (ct = current->mm->core_state->dumper.next;
ct; ct = ct->next) {
@@ -1632,8 +1619,12 @@ static int elf_fdpic_core_dump(struct coredump_params *cprm)
}

/* now collect the dump for the current */
- fill_prstatus(prstatus, current, cprm->siginfo->si_signo);
- elf_core_copy_regs(&prstatus->pr_reg, cprm->regs);
+ tmp = elf_dump_thread_status(cprm->siginfo->si_signo,
+ current, &thread_status_size);
+ if (!tmp)
+ goto end_coredump;
+ tmp->next = thread_list;
+ thread_list = tmp;

segs = current->mm->map_count;
segs += elf_core_extra_phdrs();
@@ -1655,46 +1646,28 @@ static int elf_fdpic_core_dump(struct coredump_params *cprm)
* with info from their /proc.
*/

- fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus);
fill_psinfo(psinfo, current->group_leader, current->mm);
- fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
-
- numnote = 2;
+ fill_note(&psinfo_note, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
+ thread_status_size += notesize(&psinfo_note);

auxv = (elf_addr_t *) current->mm->saved_auxv;
-
i = 0;
do
i += 2;
while (auxv[i - 2] != AT_NULL);
- fill_note(&notes[numnote++], "CORE", NT_AUXV,
- i * sizeof(elf_addr_t), auxv);
+ fill_note(&auxv_note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv);
+ thread_status_size += notesize(&auxv_note);

- /* Try to dump the FPU. */
- if ((prstatus->pr_fpvalid =
- elf_core_copy_task_fpregs(current, cprm->regs, fpu)))
- fill_note(notes + numnote++,
- "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
-
- offset += sizeof(*elf); /* Elf header */
+ offset = sizeof(*elf); /* Elf header */
offset += segs * sizeof(struct elf_phdr); /* Program headers */

/* Write notes phdr entry */
- {
- int sz = 0;
-
- for (i = 0; i < numnote; i++)
- sz += notesize(notes + i);
-
- sz += thread_status_size;
-
- phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
- if (!phdr4note)
- goto end_coredump;
+ phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
+ if (!phdr4note)
+ goto end_coredump;

- fill_elf_note_phdr(phdr4note, sz, offset);
- offset += sz;
- }
+ fill_elf_note_phdr(phdr4note, thread_status_size, offset);
+ offset += thread_status_size;

/* Page-align dumped data */
dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
@@ -1747,12 +1720,18 @@ static int elf_fdpic_core_dump(struct coredump_params *cprm)
goto end_coredump;

/* write out the notes section */
- for (i = 0; i < numnote; i++)
- if (!writenote(notes + i, cprm))
+ if (!writenote(thread_list->notes, cprm))
+ goto end_coredump;
+ if (!writenote(&psinfo_note, cprm))
+ goto end_coredump;
+ if (!writenote(&auxv_note, cprm))
+ goto end_coredump;
+ for (i = 1; i < thread_list->num_notes; i++)
+ if (!writenote(thread_list->notes + i, cprm))
goto end_coredump;

/* write out the thread status notes section */
- for (tmp = thread_list; tmp; tmp = tmp->next) {
+ for (tmp = thread_list->next; tmp; tmp = tmp->next) {
for (i = 0; i < tmp->num_notes; i++)
if (!writenote(&tmp->notes[i], cprm))
goto end_coredump;
@@ -1787,13 +1766,9 @@ static int elf_fdpic_core_dump(struct coredump_params *cprm)
}
kfree(phdr4note);
kfree(elf);
- kfree(prstatus);
kfree(psinfo);
- kfree(notes);
- kfree(fpu);
kfree(shdr4extnum);
return has_dumped;
-#undef NUM_NOTES
}

#endif /* CONFIG_ELF_CORE */
--
2.11.0
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