diff mbox series

[v2,09/17] linux-user/aarch64: Implement PR_TAGGED_ADDR_ENABLE

Message ID 20200605041733.415188-10-richard.henderson@linaro.org (mailing list archive)
State New, archived
Headers show
Series target-arm: Implement ARMv8.5-MemTag, user mode | expand

Commit Message

Richard Henderson June 5, 2020, 4:17 a.m. UTC
This is the prctl bit that controls whether syscalls accept tagged
addresses.  See Documentation/arm64/tagged-address-abi.rst in the
linux kernel.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 linux-user/aarch64/target_syscall.h |  4 ++++
 linux-user/syscall.c                | 23 +++++++++++++++++++++++
 2 files changed, 27 insertions(+)

Comments

Peter Maydell June 25, 2020, 4:46 p.m. UTC | #1
On Fri, 5 Jun 2020 at 05:17, Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> This is the prctl bit that controls whether syscalls accept tagged
> addresses.  See Documentation/arm64/tagged-address-abi.rst in the
> linux kernel.
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>  linux-user/aarch64/target_syscall.h |  4 ++++
>  linux-user/syscall.c                | 23 +++++++++++++++++++++++
>  2 files changed, 27 insertions(+)
>

> +        case TARGET_PR_SET_TAGGED_ADDR_CTRL:
> +            {
> +                abi_ulong valid_mask = TARGET_PR_TAGGED_ADDR_ENABLE;
> +
> +                if ((arg2 & ~valid_mask) || arg3 || arg4 || arg5) {
> +                    return -TARGET_EINVAL;
> +                }
> +                untagged_addr_mask = (arg2 & TARGET_PR_TAGGED_ADDR_ENABLE
> +                                      ? MAKE_64BIT_MASK(0, 56) : -1);
> +                return 0;
> +            }

The spec says the tagged-address control is thread-scoped, not process-wide.

thanks
-- PMM
diff mbox series

Patch

diff --git a/linux-user/aarch64/target_syscall.h b/linux-user/aarch64/target_syscall.h
index 995e475c73..5fb0bf4a5d 100644
--- a/linux-user/aarch64/target_syscall.h
+++ b/linux-user/aarch64/target_syscall.h
@@ -29,4 +29,8 @@  struct target_pt_regs {
 # define TARGET_PR_PAC_APDBKEY   (1 << 3)
 # define TARGET_PR_PAC_APGAKEY   (1 << 4)
 
+#define TARGET_PR_SET_TAGGED_ADDR_CTRL 55
+#define TARGET_PR_GET_TAGGED_ADDR_CTRL 56
+# define TARGET_PR_TAGGED_ADDR_ENABLE  (1UL << 0)
+
 #endif /* AARCH64_TARGET_SYSCALL_H */
diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index d190fb1122..e4da53c5b3 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -10460,6 +10460,29 @@  static abi_long do_syscall1(void *cpu_env, int num, abi_long arg1,
                 }
             }
             return -TARGET_EINVAL;
+        case TARGET_PR_SET_TAGGED_ADDR_CTRL:
+            {
+                abi_ulong valid_mask = TARGET_PR_TAGGED_ADDR_ENABLE;
+
+                if ((arg2 & ~valid_mask) || arg3 || arg4 || arg5) {
+                    return -TARGET_EINVAL;
+                }
+                untagged_addr_mask = (arg2 & TARGET_PR_TAGGED_ADDR_ENABLE
+                                      ? MAKE_64BIT_MASK(0, 56) : -1);
+                return 0;
+            }
+        case TARGET_PR_GET_TAGGED_ADDR_CTRL:
+            {
+                abi_long ret = 0;
+
+                if (arg2 || arg3 || arg4 || arg5) {
+                    return -TARGET_EINVAL;
+                }
+                if (~untagged_addr_mask != 0) {
+                    ret |= TARGET_PR_TAGGED_ADDR_ENABLE;
+                }
+                return ret;
+            }
 #endif /* AARCH64 */
         case PR_GET_SECCOMP:
         case PR_SET_SECCOMP: