[src/trunk]: src/sys/arch/i386/stand/lib Fix kernel symbols for multiboot2

[manu <manu%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/6a65209721f7
branches:  trunk
changeset: 455478:6a65209721f7
user:      manu <manu%NetBSD.org@localhost>
date:      Fri Oct 18 01:15:54 2019 +0000

description:
Fix kernel symbols for multiboot2

Previous version just provided the ELF section table, which is correct
as far as the multiboot 2 specification is concerned.

But in order to retreive kernel symboles, the NetBSD kernelneeds symbol
table and string table sections to be loaded in memory, and have an
address set in the section table.

Requires change: Add kernel symbols for multiboot1
src/sys/arch/i386/stand/lib/exec_multiboot1.c 1.2 - 1.3
src/sys/arch/i386/stand/lib/libi386.h 1.45 - 1.46

diffstat:

 sys/arch/i386/stand/lib/exec_multiboot2.c |  38 ++++++++++++------------------
 1 files changed, 15 insertions(+), 23 deletions(-)

diffs (77 lines):

diff -r 9c0bd0a577a1 -r 6a65209721f7 sys/arch/i386/stand/lib/exec_multiboot2.c
--- a/sys/arch/i386/stand/lib/exec_multiboot2.c Fri Oct 18 01:09:46 2019 +0000
+++ b/sys/arch/i386/stand/lib/exec_multiboot2.c Fri Oct 18 01:15:54 2019 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: exec_multiboot2.c,v 1.2 2019/09/15 23:55:26 manu Exp $ */
+/* $NetBSD: exec_multiboot2.c,v 1.3 2019/10/18 01:15:54 manu Exp $ */
 
 /*
  * Copyright (c) 2019 The NetBSD Foundation, Inc.
@@ -976,9 +976,10 @@
        size_t len = 0;
        struct multiboot_tag_elf_sections *mbt = buf;
        Elf_Ehdr ehdr;
+       int class;
        Elf32_Ehdr *ehdr32 = NULL;
        Elf64_Ehdr *ehdr64 = NULL;
-       uint32_t shnum, shentsize, shstrndx, shoff;
+       uint64_t shnum, shentsize, shstrndx, shoff;
        size_t shdr_len;
 
        if (mbp->mbp_marks[MARK_SYM] == 0)
@@ -992,7 +993,9 @@
        if (memcmp(&ehdr.e_ident, ELFMAG, SELFMAG) != 0)
                goto out;
 
-       switch (ehdr.e_ident[EI_CLASS]) {
+       class = ehdr.e_ident[EI_CLASS];
+
+       switch (class) {
        case ELFCLASS32:
                ehdr32 = (Elf32_Ehdr *)&ehdr;
                shnum = ehdr32->e_shnum;
@@ -1017,8 +1020,7 @@
 
        len = sizeof(*mbt) + shdr_len;
        if (mbt) {
-               int fd = -1;
-               int ret = -1;
+               char *shdr = (char *)mbp->mbp_marks[MARK_SYM] + shoff;
 
                mbt->type = MULTIBOOT_TAG_TYPE_ELF_SECTIONS;
                mbt->size = len;
@@ -1026,26 +1028,16 @@
                mbt->entsize = shentsize;
                mbt->shndx = shstrndx;
                
-               if ((fd = open(mbp->mbp_file, 0)) == -1)
-                       goto out_read;
-
-               if (lseek(fd, shoff, SEEK_SET) != shoff)
-                       goto out_read;
- 
-               if (read(fd, mbt + 1,  shdr_len) != shdr_len)
-                       goto out_read;
+               pvbcopy((void *)shdr, mbt + 1, shdr_len);
 
-               ret = 0;
-out_read:
-               if (fd != -1)
-                       close(fd);
+               /*
+                * Adjust sh_addr for symtab and strtab
+                * section that have been loaded.
+                */
+               ksyms_addr_set(&ehdr, mbt + 1,
+                   (void *)mbp->mbp_marks[MARK_SYM]);
+       }
 
-               if (ret != 0) {
-                       printf("Error reading ELF sections from %s\n",
-                           mbp->mbp_file);
-                       len = 0;
-               }
-       }
 out:
        return roundup(len, MULTIBOOT_TAG_ALIGN);
 }