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| author |   Gabriel Krisman Bertazi <krisman@collabora.com> | 2020-10-03 23:25:35 -0400 |
|---|---|---|
| committer |   Thomas Gleixner <tglx@linutronix.de> | 2020-10-26 13:46:47 +0100 |
| commit | ff170cd0595398a7b66cb40f249eb2f10c29b66d (patch) | |
| tree | aaea8a15b4b7675f326d2cf8936e67fce26fd5f3 /arch/x86/entry/vsyscall/vsyscall_64.c | |
| parent | x86/elf: Use e_machine to check for x32/ia32 in setup_additional_pages() (diff) | |
| download | linux-dev-ff170cd0595398a7b66cb40f249eb2f10c29b66d.tar.xz linux-dev-ff170cd0595398a7b66cb40f249eb2f10c29b66d.zip | |
x86/mm: Convert mmu context ia32_compat into a proper flags field
The ia32_compat attribute is a weird thing. It mirrors TIF_IA32 and
TIF_X32 and is used only in two very unrelated places: (1) to decide if
the vsyscall page is accessible (2) for uprobes to find whether the
patched instruction is 32 or 64 bit.
In preparation to remove the TIF flags, a new mechanism is required for
ia32_compat, but given its odd semantics, adding a real flags field which
configures these specific behaviours is the best option.
So, set_personality_x64() can ask for the vsyscall page, which is not
available in x32/ia32 and set_personality_ia32() can configure the uprobe
code as needed.
uprobe cannot rely on other methods like user_64bit_mode() to decide how
to patch, so it needs some specific flag like this.
Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Andy Lutomirski<luto@kernel.org>
Link: https://lore.kernel.org/r/20201004032536.1229030-10-krisman@collabora.com
Diffstat (limited to 'arch/x86/entry/vsyscall/vsyscall_64.c')
| -rw-r--r-- | arch/x86/entry/vsyscall/vsyscall_64.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/entry/vsyscall/vsyscall_64.c b/arch/x86/entry/vsyscall/vsyscall_64.c index 44c33103a955..1b40b9297083 100644 --- a/arch/x86/entry/vsyscall/vsyscall_64.c +++ b/arch/x86/entry/vsyscall/vsyscall_64.c @@ -316,7 +316,7 @@ static struct vm_area_struct gate_vma __ro_after_init = { struct vm_area_struct *get_gate_vma(struct mm_struct *mm) { #ifdef CONFIG_COMPAT - if (!mm || mm->context.ia32_compat) + if (!mm || !(mm->context.flags & MM_CONTEXT_HAS_VSYSCALL)) return NULL; #endif if (vsyscall_mode == NONE) |