mainline inclusion from mainline-v6.9-rc1 commit 8c46def44409fc914278630b7ba5ac142ab7c4f4 category: feature bugzilla: https://atomgit.com/openeuler/kernel/issues/8904 CVE: NA Reference: https://web.git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commi... ---------------------------------------------------------------------- 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: Qinxin Xia <xiaqinxin@huawei.com> Signed-off-by: Hongye Lin <linhongye@h-partners.com> --- arch/arm64/include/asm/signal_common.h | 16 +++++++++ arch/arm64/include/uapi/asm/sigcontext.h | 8 +++++ arch/arm64/kernel/signal.c | 46 ++++++++++++++++++++++++ 3 files changed, 70 insertions(+) diff --git a/arch/arm64/include/asm/signal_common.h b/arch/arm64/include/asm/signal_common.h index 3a00144c6952..f6f8d6aa6765 100644 --- a/arch/arm64/include/asm/signal_common.h +++ b/arch/arm64/include/asm/signal_common.h @@ -40,6 +40,7 @@ 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; }; @@ -55,6 +56,8 @@ struct user_ctxs { u32 za_size; struct zt_context __user *zt; u32 zt_size; + struct fpmr_context __user *fpmr; + u32 fpmr_size; }; struct frame_record { @@ -77,6 +80,9 @@ int __parse_user_sigcontext(struct user_ctxs *user, int preserve_fpsimd_context(struct fpsimd_context __user *ctx); int restore_fpsimd_context(struct user_ctxs *user); +int preserve_fpmr_context(struct fpmr_context __user *ctx); +int restore_fpmr_context(struct user_ctxs *user); + #ifdef CONFIG_ARM64_SVE int preserve_sve_context(struct sve_context __user *ctx); int restore_sve_fpsimd_context(struct user_ctxs *user); @@ -203,6 +209,9 @@ 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); @@ -264,6 +273,13 @@ 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 = diff --git a/arch/arm64/include/uapi/asm/sigcontext.h b/arch/arm64/include/uapi/asm/sigcontext.h index 8f003db7a696..57f76d82077e 100644 --- a/arch/arm64/include/uapi/asm/sigcontext.h +++ b/arch/arm64/include/uapi/asm/sigcontext.h @@ -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 { diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c index e83c9d9d56f8..2425828f6213 100644 --- a/arch/arm64/kernel/signal.c +++ b/arch/arm64/kernel/signal.c @@ -180,6 +180,33 @@ int restore_fpsimd_context(struct user_ctxs *user) return 0; } +int preserve_fpmr_context(struct fpmr_context __user *ctx) +{ + int err = 0; + + current->thread.uw.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.uw.fpmr, &ctx->fpmr, err); + + return err; +} + +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 @@ -556,6 +583,7 @@ int __parse_user_sigcontext(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; @@ -650,6 +678,17 @@ int __parse_user_sigcontext(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; @@ -817,6 +856,13 @@ int setup_sigframe_layout(struct rt_sigframe_user_layout *user, bool add_all) } } + if (system_supports_fpmr()) { + err = sigframe_alloc(user, &user->fpmr_offset, + sizeof(struct fpmr_context)); + if (err) + return err; + } + return sigframe_alloc_end(user); } -- 2.33.0