Messages in this thread Patch in this message | | | From | Dmitry Safonov <> | Subject | [PATCH v3 20/23] arm64/vdso: Migrate native signals to generic vdso_base | Date | Fri, 11 Jun 2021 19:02:39 +0100 |
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Generic way to track the land vma area. As a bonus, after unmapping vdso, kernel won't try to land on its previous position (due to UNMAPPED_VDSO_BASE check instead of context.vdso ?= 0 check).
Signed-off-by: Dmitry Safonov <dima@arista.com> --- arch/arm64/include/asm/mmu.h | 1 - arch/arm64/kernel/signal.c | 10 +++++++--- arch/arm64/kernel/vdso.c | 15 ++++++--------- 3 files changed, 13 insertions(+), 13 deletions(-)
diff --git a/arch/arm64/include/asm/mmu.h b/arch/arm64/include/asm/mmu.h index 434acd49dbc3..4432a2809e0d 100644 --- a/arch/arm64/include/asm/mmu.h +++ b/arch/arm64/include/asm/mmu.h @@ -19,7 +19,6 @@ typedef struct { atomic64_t id; refcount_t pinned; - void *vdso; unsigned long flags; } mm_context_t; diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c index 6237486ff6bb..5f6a8c0abc4c 100644 --- a/arch/arm64/kernel/signal.c +++ b/arch/arm64/kernel/signal.c @@ -723,9 +723,10 @@ static int get_sigframe(struct rt_sigframe_user_layout *user, return 0; } -static void setup_return(struct pt_regs *regs, struct k_sigaction *ka, +static int setup_return(struct pt_regs *regs, struct k_sigaction *ka, struct rt_sigframe_user_layout *user, int usig) { + unsigned long land = (unsigned long)current->mm->vdso_base; __sigrestore_t sigtramp; regs->regs[0] = usig; @@ -754,10 +755,13 @@ static void setup_return(struct pt_regs *regs, struct k_sigaction *ka, if (ka->sa.sa_flags & SA_RESTORER) sigtramp = ka->sa.sa_restorer; + else if (land != UNMAPPED_VDSO_BASE) + sigtramp = VDSO_SYMBOL(land, sigtramp); else - sigtramp = VDSO_SYMBOL(current->mm->context.vdso, sigtramp); + return 1; regs->regs[30] = (unsigned long)sigtramp; + return 0; } static int setup_rt_frame(int usig, struct ksignal *ksig, sigset_t *set, @@ -780,7 +784,7 @@ static int setup_rt_frame(int usig, struct ksignal *ksig, sigset_t *set, err |= __save_altstack(&frame->uc.uc_stack, regs->sp); err |= setup_sigframe(&user, regs, set); if (err == 0) { - setup_return(regs, &ksig->ka, &user, usig); + err = setup_return(regs, &ksig->ka, &user, usig); if (ksig->ka.sa.sa_flags & SA_SIGINFO) { err |= copy_siginfo_to_user(&frame->info, &ksig->info); regs->regs[1] = (unsigned long)&frame->info; diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c index 3e9dd41abee0..4af29f89be37 100644 --- a/arch/arm64/kernel/vdso.c +++ b/arch/arm64/kernel/vdso.c @@ -78,12 +78,6 @@ static union { } vdso_data_store __page_aligned_data; struct vdso_data *vdso_data = vdso_data_store.data; -static void vdso_mremap(const struct vm_special_mapping *sm, - struct vm_area_struct *new_vma) -{ - current->mm->context.vdso = (void *)new_vma->vm_start; -} - static int __init __vdso_init(enum vdso_abi abi) { int i; @@ -244,7 +238,12 @@ static int __setup_additional_pages(enum vdso_abi abi, if (IS_ERR(ret)) return PTR_ERR(ret); - mm->context.vdso = (void *)vdso_base; + /* + * 32-bit ABI is to land on sigpage (see aarch32_sigreturn_setup()), + * 64-bit on vDSO. + */ + if (abi == VDSO_ABI_AA64) + mm->vdso_base = (void __user *)vdso_base; *sysinfo_ehdr = vdso_base; return 0; @@ -279,7 +278,6 @@ static struct vm_special_mapping aarch32_vdso_maps[] = { }, [AA32_MAP_VDSO] = { .name = "[vdso]", - .mremap = vdso_mremap, }, }; @@ -426,7 +424,6 @@ static struct vm_special_mapping aarch64_vdso_maps[] __ro_after_init = { }, [AA64_MAP_VDSO] = { .name = "[vdso]", - .mremap = vdso_mremap, }, }; -- 2.31.1
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