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| author | Richard Henderson | 2022-08-11 20:18:29 +0200 |
|---|---|---|
| committer | Richard Henderson | 2022-09-06 09:04:25 +0200 |
| commit | d461b73ec007ccbe861db91bbcd792c92e46fcad (patch) | |
| tree | f1720424c45baa92c6830faf05faf409e837d72b /linux-user | |
| parent | linux-user/hppa: Allocate page zero as a commpage (diff) | |
| download | qemu-d461b73ec007ccbe861db91bbcd792c92e46fcad.tar.gz qemu-d461b73ec007ccbe861db91bbcd792c92e46fcad.tar.xz qemu-d461b73ec007ccbe861db91bbcd792c92e46fcad.zip | |
linux-user/x86_64: Allocate vsyscall page as a commpage
We're about to start validating PAGE_EXEC, which means that we've
got to mark the vsyscall page executable. We had been special
casing this entirely within translate.
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Tested-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Diffstat (limited to 'linux-user')
| -rw-r--r-- | linux-user/elfload.c | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/linux-user/elfload.c b/linux-user/elfload.c index 29d910c4cc..82fecf9e5a 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 @@ -2360,8 +2381,10 @@ static abi_ulong create_elf_tables(abi_ulong p, int argc, int envc, #else #define HI_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) { |