diff options
Diffstat (limited to 'linux-user/elfload.c')
| -rw-r--r-- | linux-user/elfload.c | 82 |
1 files changed, 77 insertions, 5 deletions
diff --git a/linux-user/elfload.c b/linux-user/elfload.c index ce902dbd56..ba5c4c02e5 100644 --- a/linux-user/elfload.c +++ b/linux-user/elfload.c @@ -195,6 +195,27 @@ static void elf_core_copy_regs(target_elf_gregset_t *regs, const CPUX86State *en (*regs)[26] = tswapreg(env->segs[R_GS].selector & 0xffff); } +#if ULONG_MAX > UINT32_MAX +#define INIT_GUEST_COMMPAGE +static bool init_guest_commpage(void) +{ + /* + * The vsyscall page is at a high negative address aka kernel space, + * which means that we cannot actually allocate it with target_mmap. + * We still should be able to use page_set_flags, unless the user + * has specified -R reserved_va, which would trigger an assert(). + */ + if (reserved_va != 0 && + TARGET_VSYSCALL_PAGE + TARGET_PAGE_SIZE >= reserved_va) { + error_report("Cannot allocate vsyscall page"); + exit(EXIT_FAILURE); + } + page_set_flags(TARGET_VSYSCALL_PAGE, + TARGET_VSYSCALL_PAGE + TARGET_PAGE_SIZE, + PAGE_EXEC | PAGE_VALID); + return true; +} +#endif #else #define ELF_START_MMAP 0x80000000 @@ -211,6 +232,7 @@ static void elf_core_copy_regs(target_elf_gregset_t *regs, const CPUX86State *en #define ELF_ARCH EM_386 #define ELF_PLATFORM get_elf_platform() +#define EXSTACK_DEFAULT true static const char *get_elf_platform(void) { @@ -287,6 +309,7 @@ static void elf_core_copy_regs(target_elf_gregset_t *regs, const CPUX86State *en #define ELF_ARCH EM_ARM #define ELF_CLASS ELFCLASS32 +#define EXSTACK_DEFAULT true static inline void init_thread(struct target_pt_regs *regs, struct image_info *infop) @@ -398,7 +421,8 @@ enum { static bool init_guest_commpage(void) { - void *want = g2h_untagged(HI_COMMPAGE & -qemu_host_page_size); + abi_ptr commpage = HI_COMMPAGE & -qemu_host_page_size; + void *want = g2h_untagged(commpage); void *addr = mmap(want, qemu_host_page_size, PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE | MAP_FIXED, -1, 0); @@ -417,6 +441,9 @@ static bool init_guest_commpage(void) perror("Protecting guest commpage"); exit(EXIT_FAILURE); } + + page_set_flags(commpage, commpage + qemu_host_page_size, + PAGE_READ | PAGE_EXEC | PAGE_VALID); return true; } @@ -751,6 +778,7 @@ static inline void init_thread(struct target_pt_regs *regs, #else #define ELF_CLASS ELFCLASS32 +#define EXSTACK_DEFAULT true #endif @@ -948,6 +976,7 @@ static void elf_core_copy_regs(target_elf_gregset_t *regs, const CPUPPCState *en #define ELF_CLASS ELFCLASS64 #define ELF_ARCH EM_LOONGARCH +#define EXSTACK_DEFAULT true #define elf_check_arch(x) ((x) == EM_LOONGARCH) @@ -1043,6 +1072,7 @@ static uint32_t get_elf_hwcap(void) #define ELF_CLASS ELFCLASS32 #endif #define ELF_ARCH EM_MIPS +#define EXSTACK_DEFAULT true #ifdef TARGET_ABI_MIPSN32 #define elf_check_abi(x) ((x) & EF_MIPS_ABI2) @@ -1642,6 +1672,34 @@ static inline void init_thread(struct target_pt_regs *regs, regs->gr[31] = infop->entry; } +#define LO_COMMPAGE 0 + +static bool init_guest_commpage(void) +{ + void *want = g2h_untagged(LO_COMMPAGE); + void *addr = mmap(want, qemu_host_page_size, PROT_NONE, + MAP_ANONYMOUS | MAP_PRIVATE | MAP_FIXED, -1, 0); + + if (addr == MAP_FAILED) { + perror("Allocating guest commpage"); + exit(EXIT_FAILURE); + } + if (addr != want) { + return false; + } + + /* + * On Linux, page zero is normally marked execute only + gateway. + * Normal read or write is supposed to fail (thus PROT_NONE above), + * but specific offsets have kernel code mapped to raise permissions + * and implement syscalls. Here, simply mark the page executable. + * Special case the entry points during translation (see do_page_zero). + */ + page_set_flags(LO_COMMPAGE, LO_COMMPAGE + TARGET_PAGE_SIZE, + PAGE_EXEC | PAGE_VALID); + return true; +} + #endif /* TARGET_HPPA */ #ifdef TARGET_XTENSA @@ -1753,6 +1811,10 @@ static inline void init_thread(struct target_pt_regs *regs, #define bswaptls(ptr) bswap32s(ptr) #endif +#ifndef EXSTACK_DEFAULT +#define EXSTACK_DEFAULT false +#endif + #include "elf.h" /* We must delay the following stanzas until after "elf.h". */ @@ -2028,6 +2090,7 @@ static abi_ulong setup_arg_pages(struct linux_binprm *bprm, struct image_info *info) { abi_ulong size, error, guard; + int prot; size = guest_stack_size; if (size < STACK_LOWER_LIMIT) { @@ -2038,7 +2101,11 @@ static abi_ulong setup_arg_pages(struct linux_binprm *bprm, guard = qemu_real_host_page_size(); } - error = target_mmap(0, size + guard, PROT_READ | PROT_WRITE, + prot = PROT_READ | PROT_WRITE; + if (info->exec_stack) { + prot |= PROT_EXEC; + } + error = target_mmap(0, size + guard, prot, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); if (error == -1) { perror("mmap stack"); @@ -2322,14 +2389,16 @@ static abi_ulong create_elf_tables(abi_ulong p, int argc, int envc, } #if defined(HI_COMMPAGE) -#define LO_COMMPAGE 0 +#define LO_COMMPAGE -1 #elif defined(LO_COMMPAGE) #define HI_COMMPAGE 0 #else #define HI_COMMPAGE 0 -#define LO_COMMPAGE 0 +#define LO_COMMPAGE -1 +#ifndef INIT_GUEST_COMMPAGE #define init_guest_commpage() true #endif +#endif static void pgb_fail_in_use(const char *image_name) { @@ -2551,7 +2620,7 @@ static void pgb_static(const char *image_name, abi_ulong orig_loaddr, } else { offset = -(HI_COMMPAGE & -align); } - } else if (LO_COMMPAGE != 0) { + } else if (LO_COMMPAGE != -1) { loaddr = MIN(loaddr, LO_COMMPAGE & -align); } @@ -2866,6 +2935,7 @@ static void load_elf_image(const char *image_name, int image_fd, */ loaddr = -1, hiaddr = 0; info->alignment = 0; + info->exec_stack = EXSTACK_DEFAULT; for (i = 0; i < ehdr->e_phnum; ++i) { struct elf_phdr *eppnt = phdr + i; if (eppnt->p_type == PT_LOAD) { @@ -2908,6 +2978,8 @@ static void load_elf_image(const char *image_name, int image_fd, if (!parse_elf_properties(image_fd, info, eppnt, bprm_buf, &err)) { goto exit_errmsg; } + } else if (eppnt->p_type == PT_GNU_STACK) { + info->exec_stack = eppnt->p_flags & PF_X; } } |