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authorWill Deacon <will@kernel.org>2020-06-22 12:35:41 +0100
committerWill Deacon <will@kernel.org>2020-06-23 14:47:03 +0100
commita39060b009ca0b5b5fe0c0dab85ed437531aab52 (patch)
tree735f34e4e687056048ef3da0e75d98a9dbe12ba9 /arch
parent87676cfca14171fc4c99d96ae2f3e87780488ac4 (diff)
arm64: compat: Allow 32-bit vdso and sigpage to co-exist
In preparation for removing the signal trampoline from the compat vDSO, allow the sigpage and the compat vDSO to co-exist. For the moment the vDSO signal trampoline will still be used when built. Subsequent patches will move to the sigpage consistently. Acked-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/arm64/include/asm/mmu.h3
-rw-r--r--arch/arm64/kernel/Makefile2
-rw-r--r--arch/arm64/kernel/signal32.c2
-rw-r--r--arch/arm64/kernel/vdso.c61
4 files changed, 32 insertions, 36 deletions
diff --git a/arch/arm64/include/asm/mmu.h b/arch/arm64/include/asm/mmu.h
index 68140fdd89d6..8444df000181 100644
--- a/arch/arm64/include/asm/mmu.h
+++ b/arch/arm64/include/asm/mmu.h
@@ -19,6 +19,9 @@
typedef struct {
atomic64_t id;
+#ifdef CONFIG_COMPAT
+ void *sigpage;
+#endif
void *vdso;
unsigned long flags;
} mm_context_t;
diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
index 151f28521f1e..a561cbb91d4d 100644
--- a/arch/arm64/kernel/Makefile
+++ b/arch/arm64/kernel/Makefile
@@ -29,9 +29,7 @@ $(obj)/%.stub.o: $(obj)/%.o FORCE
obj-$(CONFIG_COMPAT) += sys32.o signal32.o \
sys_compat.o
-ifneq ($(CONFIG_COMPAT_VDSO), y)
obj-$(CONFIG_COMPAT) += sigreturn32.o
-endif
obj-$(CONFIG_KUSER_HELPERS) += kuser32.o
obj-$(CONFIG_FUNCTION_TRACER) += ftrace.o entry-ftrace.o
obj-$(CONFIG_MODULES) += module.o
diff --git a/arch/arm64/kernel/signal32.c b/arch/arm64/kernel/signal32.c
index 82feca6f7052..0aa0b33744de 100644
--- a/arch/arm64/kernel/signal32.c
+++ b/arch/arm64/kernel/signal32.c
@@ -371,7 +371,7 @@ static void compat_setup_return(struct pt_regs *regs, struct k_sigaction *ka,
if (ka->sa.sa_flags & SA_SIGINFO)
idx += 3;
- retcode = (unsigned long)current->mm->context.vdso +
+ retcode = (unsigned long)current->mm->context.sigpage +
(idx << 2) + thumb;
#endif
}
diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c
index 4e016574bd91..e546df0efefb 100644
--- a/arch/arm64/kernel/vdso.c
+++ b/arch/arm64/kernel/vdso.c
@@ -191,15 +191,12 @@ enum aarch32_map {
#ifdef CONFIG_COMPAT_VDSO
AA32_MAP_VVAR,
AA32_MAP_VDSO,
-#else
- AA32_MAP_SIGPAGE
#endif
+ AA32_MAP_SIGPAGE
};
static struct page *aarch32_vectors_page __ro_after_init;
-#ifndef CONFIG_COMPAT_VDSO
static struct page *aarch32_sig_page __ro_after_init;
-#endif
static struct vm_special_mapping aarch32_vdso_maps[] = {
[AA32_MAP_VECTORS] = {
@@ -214,12 +211,11 @@ static struct vm_special_mapping aarch32_vdso_maps[] = {
.name = "[vdso]",
.mremap = aarch32_vdso_mremap,
},
-#else
+#endif /* CONFIG_COMPAT_VDSO */
[AA32_MAP_SIGPAGE] = {
.name = "[sigpage]", /* ABI */
.pages = &aarch32_sig_page,
},
-#endif /* CONFIG_COMPAT_VDSO */
};
static int aarch32_alloc_kuser_vdso_page(void)
@@ -242,27 +238,11 @@ static int aarch32_alloc_kuser_vdso_page(void)
return 0;
}
-#ifdef CONFIG_COMPAT_VDSO
-static int __aarch32_alloc_vdso_pages(void)
-{
- int ret;
-
- vdso_info[VDSO_ABI_AA32].dm = &aarch32_vdso_maps[AA32_MAP_VVAR];
- vdso_info[VDSO_ABI_AA32].cm = &aarch32_vdso_maps[AA32_MAP_VDSO];
-
- ret = __vdso_init(VDSO_ABI_AA32);
- if (ret)
- return ret;
-
- return aarch32_alloc_kuser_vdso_page();
-}
-#else
-static int __aarch32_alloc_vdso_pages(void)
+static int aarch32_alloc_sigpage(void)
{
extern char __aarch32_sigret_code_start[], __aarch32_sigret_code_end[];
int sigret_sz = __aarch32_sigret_code_end - __aarch32_sigret_code_start;
unsigned long sigpage;
- int ret;
sigpage = get_zeroed_page(GFP_ATOMIC);
if (!sigpage)
@@ -271,18 +251,34 @@ static int __aarch32_alloc_vdso_pages(void)
memcpy((void *)sigpage, __aarch32_sigret_code_start, sigret_sz);
aarch32_sig_page = virt_to_page(sigpage);
flush_dcache_page(aarch32_sig_page);
+ return 0;
+}
- ret = aarch32_alloc_kuser_vdso_page();
- if (ret)
- free_page(sigpage);
+#ifdef CONFIG_COMPAT_VDSO
+static int __aarch32_alloc_vdso_pages(void)
+{
+ vdso_info[VDSO_ABI_AA32].dm = &aarch32_vdso_maps[AA32_MAP_VVAR];
+ vdso_info[VDSO_ABI_AA32].cm = &aarch32_vdso_maps[AA32_MAP_VDSO];
- return ret;
+ return __vdso_init(VDSO_ABI_AA32);
}
#endif /* CONFIG_COMPAT_VDSO */
static int __init aarch32_alloc_vdso_pages(void)
{
- return __aarch32_alloc_vdso_pages();
+ int ret;
+
+#ifdef CONFIG_COMPAT_VDSO
+ ret = __aarch32_alloc_vdso_pages();
+ if (ret)
+ return ret;
+#endif
+
+ ret = aarch32_alloc_sigpage();
+ if (ret)
+ return ret;
+
+ return aarch32_alloc_kuser_vdso_page();
}
arch_initcall(aarch32_alloc_vdso_pages);
@@ -305,7 +301,6 @@ static int aarch32_kuser_helpers_setup(struct mm_struct *mm)
return PTR_ERR_OR_ZERO(ret);
}
-#ifndef CONFIG_COMPAT_VDSO
static int aarch32_sigreturn_setup(struct mm_struct *mm)
{
unsigned long addr;
@@ -328,12 +323,11 @@ static int aarch32_sigreturn_setup(struct mm_struct *mm)
if (IS_ERR(ret))
goto out;
- mm->context.vdso = (void *)addr;
+ mm->context.sigpage = (void *)addr;
out:
return PTR_ERR_OR_ZERO(ret);
}
-#endif /* !CONFIG_COMPAT_VDSO */
int aarch32_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
{
@@ -352,10 +346,11 @@ int aarch32_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
mm,
bprm,
uses_interp);
-#else
- ret = aarch32_sigreturn_setup(mm);
+ if (ret)
+ goto out;
#endif /* CONFIG_COMPAT_VDSO */
+ ret = aarch32_sigreturn_setup(mm);
out:
mmap_write_unlock(mm);
return ret;