@@ -152,6 +152,14 @@ struct tpidr2_context {
__u64 tpidr2;
};
+/* FPMR context */
+#define FPMR_MAGIC 0x46504d52
+
+struct fpmr_context {
+ struct _aarch64_ctx head;
+ __u64 fpmr;
+};
+
#define ZA_MAGIC 0x54366345
struct za_context {
@@ -60,6 +60,7 @@ struct rt_sigframe_user_layout {
unsigned long tpidr2_offset;
unsigned long za_offset;
unsigned long zt_offset;
+ unsigned long fpmr_offset;
unsigned long extra_offset;
unsigned long end_offset;
};
@@ -182,6 +183,8 @@ struct user_ctxs {
u32 za_size;
struct zt_context __user *zt;
u32 zt_size;
+ struct fpmr_context __user *fpmr;
+ u32 fpmr_size;
};
static int preserve_fpsimd_context(struct fpsimd_context __user *ctx)
@@ -227,6 +230,33 @@ static int restore_fpsimd_context(struct user_ctxs *user)
return err ? -EFAULT : 0;
}
+static int preserve_fpmr_context(struct fpmr_context __user *ctx)
+{
+ int err = 0;
+
+ current->thread.fpmr = read_sysreg_s(SYS_FPMR);
+
+ __put_user_error(FPMR_MAGIC, &ctx->head.magic, err);
+ __put_user_error(sizeof(*ctx), &ctx->head.size, err);
+ __put_user_error(current->thread.fpmr, &ctx->fpmr, err);
+
+ return err;
+}
+
+static int restore_fpmr_context(struct user_ctxs *user)
+{
+ u64 fpmr;
+ int err = 0;
+
+ if (user->fpmr_size != sizeof(*user->fpmr))
+ return -EINVAL;
+
+ __get_user_error(fpmr, &user->fpmr->fpmr, err);
+ if (!err)
+ write_sysreg_s(fpmr, SYS_FPMR);
+
+ return err;
+}
#ifdef CONFIG_ARM64_SVE
@@ -590,6 +620,7 @@ static int parse_user_sigframe(struct user_ctxs *user,
user->tpidr2 = NULL;
user->za = NULL;
user->zt = NULL;
+ user->fpmr = NULL;
if (!IS_ALIGNED((unsigned long)base, 16))
goto invalid;
@@ -684,6 +715,17 @@ static int parse_user_sigframe(struct user_ctxs *user,
user->zt_size = size;
break;
+ case FPMR_MAGIC:
+ if (!system_supports_fpmr())
+ goto invalid;
+
+ if (user->fpmr)
+ goto invalid;
+
+ user->fpmr = (struct fpmr_context __user *)head;
+ user->fpmr_size = size;
+ break;
+
case EXTRA_MAGIC:
if (have_extra_context)
goto invalid;
@@ -806,6 +848,9 @@ static int restore_sigframe(struct pt_regs *regs,
if (err == 0 && system_supports_tpidr2() && user.tpidr2)
err = restore_tpidr2_context(&user);
+ if (err == 0 && system_supports_fpmr() && user.fpmr)
+ err = restore_fpmr_context(&user);
+
if (err == 0 && system_supports_sme() && user.za)
err = restore_za_context(&user);
@@ -928,6 +973,13 @@ static int setup_sigframe_layout(struct rt_sigframe_user_layout *user,
}
}
+ if (system_supports_fpmr()) {
+ err = sigframe_alloc(user, &user->fpmr_offset,
+ sizeof(struct fpmr_context));
+ if (err)
+ return err;
+ }
+
return sigframe_alloc_end(user);
}
@@ -983,6 +1035,13 @@ static int setup_sigframe(struct rt_sigframe_user_layout *user,
err |= preserve_tpidr2_context(tpidr2_ctx);
}
+ /* FPMR if supported */
+ if (system_supports_fpmr() && err == 0) {
+ struct fpmr_context __user *fpmr_ctx =
+ apply_user_offset(user, user->fpmr_offset);
+ err |= preserve_fpmr_context(fpmr_ctx);
+ }
+
/* ZA state if present */
if (system_supports_sme() && err == 0 && user->za_offset) {
struct za_context __user *za_ctx =
Expose FPMR in the signal context on systems where it is supported. The kernel validates the exact size of the FPSIMD registers so we can't readily add it to fpsimd_context without disruption. Signed-off-by: Mark Brown <broonie@kernel.org> --- arch/arm64/include/uapi/asm/sigcontext.h | 8 +++++ arch/arm64/kernel/signal.c | 59 ++++++++++++++++++++++++++++++++ 2 files changed, 67 insertions(+)