diff options
Diffstat (limited to 'linux-user/elfload.c')
| -rw-r--r-- | linux-user/elfload.c | 50 |
1 files changed, 49 insertions, 1 deletions
diff --git a/linux-user/elfload.c b/linux-user/elfload.c index d34cd4fe43..329b2375ef 100644 --- a/linux-user/elfload.c +++ b/linux-user/elfload.c @@ -1099,6 +1099,47 @@ static void init_thread(struct target_pt_regs *regs, struct image_info *infop) regs->estatus = 0x3; } +#define LO_COMMPAGE TARGET_PAGE_SIZE + +static bool init_guest_commpage(void) +{ + static const uint8_t kuser_page[4 + 2 * 64] = { + /* __kuser_helper_version */ + [0x00] = 0x02, 0x00, 0x00, 0x00, + + /* __kuser_cmpxchg */ + [0x04] = 0x3a, 0x6c, 0x3b, 0x00, /* trap 16 */ + 0x3a, 0x28, 0x00, 0xf8, /* ret */ + + /* __kuser_sigtramp */ + [0x44] = 0xc4, 0x22, 0x80, 0x00, /* movi r2, __NR_rt_sigreturn */ + 0x3a, 0x68, 0x3b, 0x00, /* trap 0 */ + }; + + void *want = g2h_untagged(LO_COMMPAGE & -qemu_host_page_size); + void *addr = mmap(want, qemu_host_page_size, PROT_READ | PROT_WRITE, + MAP_ANONYMOUS | MAP_PRIVATE | MAP_FIXED, -1, 0); + + if (addr == MAP_FAILED) { + perror("Allocating guest commpage"); + exit(EXIT_FAILURE); + } + if (addr != want) { + return false; + } + + memcpy(addr, kuser_page, sizeof(kuser_page)); + + if (mprotect(addr, qemu_host_page_size, PROT_READ)) { + perror("Protecting guest commpage"); + exit(EXIT_FAILURE); + } + + page_set_flags(LO_COMMPAGE, LO_COMMPAGE + TARGET_PAGE_SIZE, + PAGE_READ | PAGE_EXEC | PAGE_VALID); + return true; +} + #define ELF_EXEC_PAGESIZE 4096 #define USE_ELF_CORE_DUMP @@ -2160,8 +2201,13 @@ static abi_ulong create_elf_tables(abi_ulong p, int argc, int envc, return sp; } -#ifndef HI_COMMPAGE +#if defined(HI_COMMPAGE) +#define LO_COMMPAGE 0 +#elif defined(LO_COMMPAGE) +#define HI_COMMPAGE 0 +#else #define HI_COMMPAGE 0 +#define LO_COMMPAGE 0 #define init_guest_commpage() true #endif @@ -2374,6 +2420,8 @@ static void pgb_static(const char *image_name, abi_ulong orig_loaddr, } else { offset = -(HI_COMMPAGE & -align); } + } else if (LO_COMMPAGE) { + loaddr = MIN(loaddr, LO_COMMPAGE & -align); } addr = pgb_find_hole(loaddr, hiaddr - loaddr, align, offset); |