Revision 0432a0a066b05361b6d4d26522233c3c76c9e5da authored by Linus Torvalds on 03 August 2019, 17:51:29 UTC, committed by Linus Torvalds on 03 August 2019, 17:51:29 UTC
Pull vdso timer fixes from Thomas Gleixner: "A series of commits to deal with the regression caused by the generic VDSO implementation. The usage of clock_gettime64() for 32bit compat fallback syscalls caused seccomp filters to kill innocent processes because they only allow clock_gettime(). Handle the compat syscalls with clock_gettime() as before, which is not a functional problem for the VDSO as the legacy compat application interface is not y2038 safe anyway. It's just extra fallback code which needs to be implemented on every architecture. It's opt in for now so that it does not break the compile of already converted architectures in linux-next. Once these are fixed, the #ifdeffery goes away. So much for trying to be smart and reuse code..." * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: arm64: compat: vdso: Use legacy syscalls as fallback x86/vdso/32: Use 32bit syscall fallback lib/vdso/32: Provide legacy syscall fallbacks lib/vdso: Move fallback invocation to the callers lib/vdso/32: Remove inconsistent NULL pointer checks
sortextable.h
/* SPDX-License-Identifier: GPL-2.0-only */
/*
* sortextable.h
*
* Copyright 2011 - 2012 Cavium, Inc.
*
* Some of this code was taken out of recordmcount.h written by:
*
* Copyright 2009 John F. Reiser <jreiser@BitWagon.com>. All rights reserved.
* Copyright 2010 Steven Rostedt <srostedt@redhat.com>, Red Hat Inc.
*/
#undef extable_ent_size
#undef compare_extable
#undef do_func
#undef Elf_Addr
#undef Elf_Ehdr
#undef Elf_Shdr
#undef Elf_Rel
#undef Elf_Rela
#undef Elf_Sym
#undef ELF_R_SYM
#undef Elf_r_sym
#undef ELF_R_INFO
#undef Elf_r_info
#undef ELF_ST_BIND
#undef ELF_ST_TYPE
#undef fn_ELF_R_SYM
#undef fn_ELF_R_INFO
#undef uint_t
#undef _r
#undef _w
#ifdef SORTEXTABLE_64
# define extable_ent_size 16
# define compare_extable compare_extable_64
# define do_func do64
# define Elf_Addr Elf64_Addr
# define Elf_Ehdr Elf64_Ehdr
# define Elf_Shdr Elf64_Shdr
# define Elf_Rel Elf64_Rel
# define Elf_Rela Elf64_Rela
# define Elf_Sym Elf64_Sym
# define ELF_R_SYM ELF64_R_SYM
# define Elf_r_sym Elf64_r_sym
# define ELF_R_INFO ELF64_R_INFO
# define Elf_r_info Elf64_r_info
# define ELF_ST_BIND ELF64_ST_BIND
# define ELF_ST_TYPE ELF64_ST_TYPE
# define fn_ELF_R_SYM fn_ELF64_R_SYM
# define fn_ELF_R_INFO fn_ELF64_R_INFO
# define uint_t uint64_t
# define _r r8
# define _w w8
#else
# define extable_ent_size 8
# define compare_extable compare_extable_32
# define do_func do32
# define Elf_Addr Elf32_Addr
# define Elf_Ehdr Elf32_Ehdr
# define Elf_Shdr Elf32_Shdr
# define Elf_Rel Elf32_Rel
# define Elf_Rela Elf32_Rela
# define Elf_Sym Elf32_Sym
# define ELF_R_SYM ELF32_R_SYM
# define Elf_r_sym Elf32_r_sym
# define ELF_R_INFO ELF32_R_INFO
# define Elf_r_info Elf32_r_info
# define ELF_ST_BIND ELF32_ST_BIND
# define ELF_ST_TYPE ELF32_ST_TYPE
# define fn_ELF_R_SYM fn_ELF32_R_SYM
# define fn_ELF_R_INFO fn_ELF32_R_INFO
# define uint_t uint32_t
# define _r r
# define _w w
#endif
static int compare_extable(const void *a, const void *b)
{
Elf_Addr av = _r(a);
Elf_Addr bv = _r(b);
if (av < bv)
return -1;
if (av > bv)
return 1;
return 0;
}
static void
do_func(Elf_Ehdr *ehdr, char const *const fname, table_sort_t custom_sort)
{
Elf_Shdr *shdr;
Elf_Shdr *shstrtab_sec;
Elf_Shdr *strtab_sec = NULL;
Elf_Shdr *symtab_sec = NULL;
Elf_Shdr *extab_sec = NULL;
Elf_Sym *sym;
const Elf_Sym *symtab;
Elf32_Word *symtab_shndx_start = NULL;
Elf_Sym *sort_needed_sym;
Elf_Shdr *sort_needed_sec;
Elf_Rel *relocs = NULL;
int relocs_size = 0;
uint32_t *sort_done_location;
const char *secstrtab;
const char *strtab;
char *extab_image;
int extab_index = 0;
int i;
int idx;
unsigned int num_sections;
unsigned int secindex_strings;
shdr = (Elf_Shdr *)((char *)ehdr + _r(&ehdr->e_shoff));
num_sections = r2(&ehdr->e_shnum);
if (num_sections == SHN_UNDEF)
num_sections = _r(&shdr[0].sh_size);
secindex_strings = r2(&ehdr->e_shstrndx);
if (secindex_strings == SHN_XINDEX)
secindex_strings = r(&shdr[0].sh_link);
shstrtab_sec = shdr + secindex_strings;
secstrtab = (const char *)ehdr + _r(&shstrtab_sec->sh_offset);
for (i = 0; i < num_sections; i++) {
idx = r(&shdr[i].sh_name);
if (strcmp(secstrtab + idx, "__ex_table") == 0) {
extab_sec = shdr + i;
extab_index = i;
}
if ((r(&shdr[i].sh_type) == SHT_REL ||
r(&shdr[i].sh_type) == SHT_RELA) &&
r(&shdr[i].sh_info) == extab_index) {
relocs = (void *)ehdr + _r(&shdr[i].sh_offset);
relocs_size = _r(&shdr[i].sh_size);
}
if (strcmp(secstrtab + idx, ".symtab") == 0)
symtab_sec = shdr + i;
if (strcmp(secstrtab + idx, ".strtab") == 0)
strtab_sec = shdr + i;
if (r(&shdr[i].sh_type) == SHT_SYMTAB_SHNDX)
symtab_shndx_start = (Elf32_Word *)(
(const char *)ehdr + _r(&shdr[i].sh_offset));
}
if (strtab_sec == NULL) {
fprintf(stderr, "no .strtab in file: %s\n", fname);
fail_file();
}
if (symtab_sec == NULL) {
fprintf(stderr, "no .symtab in file: %s\n", fname);
fail_file();
}
symtab = (const Elf_Sym *)((const char *)ehdr +
_r(&symtab_sec->sh_offset));
if (extab_sec == NULL) {
fprintf(stderr, "no __ex_table in file: %s\n", fname);
fail_file();
}
strtab = (const char *)ehdr + _r(&strtab_sec->sh_offset);
extab_image = (void *)ehdr + _r(&extab_sec->sh_offset);
if (custom_sort) {
custom_sort(extab_image, _r(&extab_sec->sh_size));
} else {
int num_entries = _r(&extab_sec->sh_size) / extable_ent_size;
qsort(extab_image, num_entries,
extable_ent_size, compare_extable);
}
/* If there were relocations, we no longer need them. */
if (relocs)
memset(relocs, 0, relocs_size);
/* find main_extable_sort_needed */
sort_needed_sym = NULL;
for (i = 0; i < _r(&symtab_sec->sh_size) / sizeof(Elf_Sym); i++) {
sym = (void *)ehdr + _r(&symtab_sec->sh_offset);
sym += i;
if (ELF_ST_TYPE(sym->st_info) != STT_OBJECT)
continue;
idx = r(&sym->st_name);
if (strcmp(strtab + idx, "main_extable_sort_needed") == 0) {
sort_needed_sym = sym;
break;
}
}
if (sort_needed_sym == NULL) {
fprintf(stderr,
"no main_extable_sort_needed symbol in file: %s\n",
fname);
fail_file();
}
sort_needed_sec = &shdr[get_secindex(r2(&sym->st_shndx),
sort_needed_sym - symtab,
symtab_shndx_start)];
sort_done_location = (void *)ehdr +
_r(&sort_needed_sec->sh_offset) +
_r(&sort_needed_sym->st_value) -
_r(&sort_needed_sec->sh_addr);
#if 0
printf("sort done marker at %lx\n",
(unsigned long)((char *)sort_done_location - (char *)ehdr));
#endif
/* We sorted it, clear the flag. */
w(0, sort_done_location);
}
![swh spinner](/static/img/swh-spinner.gif)
Computing file changes ...