From d2f581684a292ece5c10cd56ad51bf4f702b7beb Mon Sep 17 00:00:00 2001 From: Al Viro Date: Mon, 15 Jun 2020 11:03:28 -0400 Subject: [PATCH] [elf-fdpic] use elf_dump_thread_status() for the dumper thread as well 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 --- 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(¬es[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; + phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL); + if (!phdr4note) + goto end_coredump; - 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; - - 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 */