Author: cem Date: Wed Jul 20 22:03:45 2016 New Revision: 303114 URL: https://svnweb.freebsd.org/changeset/base/303114
Log: Add extended segment support to gcore A follow-up to r303099, D7255. Basically, apply the exact same change, with the exact same rationale, to gcore. gcore's elfcore.c is largely a clone of the kernel imgact_elf coredump facility. Reviewed by: emaste (earlier version, not substantially different) Requested by: jhb Sponsored by: EMC / Isilon Storage Division Differential Revision: https://reviews.freebsd.org/D7265 Modified: head/usr.bin/gcore/elfcore.c Modified: head/usr.bin/gcore/elfcore.c ============================================================================== --- head/usr.bin/gcore/elfcore.c Wed Jul 20 20:18:52 2016 (r303113) +++ head/usr.bin/gcore/elfcore.c Wed Jul 20 22:03:45 2016 (r303114) @@ -213,6 +213,8 @@ elf_coredump(int efd __unused, int fd, p */ sb = sbuf_new_auto(); hdrsize = sizeof(Elf_Ehdr) + sizeof(Elf_Phdr) * (1 + seginfo.count); + if (seginfo.count + 1 >= PN_XNUM) + hdrsize += sizeof(Elf_Shdr); /* Start header + notes section. */ sbuf_start_section(sb, NULL); /* Make empty header subsection. */ @@ -423,10 +425,10 @@ elf_puthdr(pid_t pid, vm_map_entry_t map { Elf_Ehdr *ehdr; Elf_Phdr *phdr; + Elf_Shdr *shdr; struct phdr_closure phc; ehdr = (Elf_Ehdr *)hdr; - phdr = (Elf_Phdr *)((char *)hdr + sizeof(Elf_Ehdr)); ehdr->e_ident[EI_MAG0] = ELFMAG0; ehdr->e_ident[EI_MAG1] = ELFMAG1; @@ -446,14 +448,40 @@ elf_puthdr(pid_t pid, vm_map_entry_t map ehdr->e_flags = 0; ehdr->e_ehsize = sizeof(Elf_Ehdr); ehdr->e_phentsize = sizeof(Elf_Phdr); - ehdr->e_phnum = numsegs + 1; ehdr->e_shentsize = sizeof(Elf_Shdr); - ehdr->e_shnum = 0; ehdr->e_shstrndx = SHN_UNDEF; + if (numsegs + 1 < PN_XNUM) { + ehdr->e_phnum = numsegs + 1; + ehdr->e_shnum = 0; + } else { + ehdr->e_phnum = PN_XNUM; + ehdr->e_shnum = 1; + + ehdr->e_shoff = ehdr->e_phoff + + (numsegs + 1) * ehdr->e_phentsize; + + shdr = (Elf_Shdr *)((char *)hdr + ehdr->e_shoff); + memset(shdr, 0, sizeof(*shdr)); + /* + * A special first section is used to hold large segment and + * section counts. This was proposed by Sun Microsystems in + * Solaris and has been adopted by Linux; the standard ELF + * tools are already familiar with the technique. + * + * See table 7-7 of the Solaris "Linker and Libraries Guide" + * (or 12-7 depending on the version of the document) for more + * details. + */ + shdr->sh_type = SHT_NULL; + shdr->sh_size = ehdr->e_shnum; + shdr->sh_link = ehdr->e_shstrndx; + shdr->sh_info = numsegs + 1; + } /* * Fill in the program header entries. */ + phdr = (Elf_Phdr *)((char *)hdr + ehdr->e_phoff); /* The note segement. */ phdr->p_type = PT_NOTE; _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
