diff options
Diffstat (limited to 'libexec/ld.so/resolve.c')
| -rw-r--r-- | libexec/ld.so/resolve.c | 84 |
1 files changed, 83 insertions, 1 deletions
diff --git a/libexec/ld.so/resolve.c b/libexec/ld.so/resolve.c index 1916341158c..b6e21f9d005 100644 --- a/libexec/ld.so/resolve.c +++ b/libexec/ld.so/resolve.c @@ -1,4 +1,4 @@ -/* $OpenBSD: resolve.c,v 1.100 2023/07/08 14:09:43 jasper Exp $ */ +/* $OpenBSD: resolve.c,v 1.101 2024/01/16 19:07:31 deraadt Exp $ */ /* * Copyright (c) 1998 Per Fogelstrom, Opsycon AB @@ -29,6 +29,8 @@ #define _DYN_LOADER #include <sys/types.h> +#include <sys/mman.h> +#include <sys/syscall.h> #include <limits.h> #include <link.h> @@ -36,6 +38,7 @@ #include "util.h" #include "path.h" #include "resolve.h" +#include "syscall.h" /* substitution types */ typedef enum { @@ -745,3 +748,82 @@ _dl_debug_state(void) { /* Debugger stub */ } + +/* + * Search for DT_SONAME, and check if this is libc + */ +int +_dl_islibc(Elf_Dyn *_dynp, Elf_Addr loff) +{ + Elf_Dyn *d, *dynp = (Elf_Dyn *)((unsigned long)_dynp + loff); + long base = 0; + + for (d = dynp; d->d_tag != DT_NULL; d++) + if (d->d_tag == DT_STRTAB) { + base = d->d_un.d_ptr + loff; + break; + } + if (base == 0) + return 0; + for (d = dynp; d->d_tag != DT_NULL; d++) + if (d->d_tag == DT_SONAME) { + if (_dl_strncmp((char *)(base + d->d_un.d_ptr), + "libc.so.", 8) == 0) + return 1; + break; + } + return 0; +} + +void +_dl_pin(int file, Elf_Phdr *phdp, void *base, size_t len, + void *exec_base, size_t exec_size) +{ + struct pinsyscalls { + u_int offset; + u_int sysno; + } *syscalls; + int npins = 0, nsyscalls, i; + u_int *pins = NULL; + vaddr_t offset; + + if (phdp->p_filesz > SYS_MAXSYSCALL * 2 * sizeof(*syscalls) || + phdp->p_filesz % sizeof(*syscalls) != 0 || + phdp->p_offset & 0x3) + return; + syscalls = _dl_mmap(NULL, phdp->p_filesz, PROT_READ, + MAP_PRIVATE|MAP_FILE, file, phdp->p_offset); + if (syscalls == MAP_FAILED) + return; + + /* Validate, and calculate pintable size */ + nsyscalls = phdp->p_filesz / sizeof(*syscalls); + for (i = 0; i < nsyscalls; i++) { + if (syscalls[i].sysno < 0 || + syscalls[i].sysno >= SYS_MAXSYSCALL || + syscalls[i].offset >= len) + goto bad; + npins = MAXIMUM(npins, syscalls[i].sysno); + } + npins++; + + /* + * Fill pintable: 0 = invalid, -1 = accept, else offset + * from base, rebase to text_start while at it + */ + pins = _dl_calloc(npins, sizeof(u_int)); + offset = exec_base - base; + for (i = 0; i < nsyscalls; i++) { + if (pins[syscalls[i].sysno]) + pins[syscalls[i].sysno] = (u_int)-1; /* duplicated */ + else + pins[syscalls[i].sysno] = syscalls[i].offset - offset; + } + base += offset; + len = len - offset; +bad: + _dl_munmap(syscalls, phdp->p_filesz); + if (pins) + _dl_pinsyscalls(base, len, pins, npins); + _dl_free(pins); +} |