diff options
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/include/asm/fpu/internal.h | 43 | ||||
| -rw-r--r-- | arch/x86/kernel/fpu/signal.c | 62 |
2 files changed, 92 insertions, 13 deletions
diff --git a/arch/x86/include/asm/fpu/internal.h b/arch/x86/include/asm/fpu/internal.h index da75d7b3e37d..2cf04fbcba5d 100644 --- a/arch/x86/include/asm/fpu/internal.h +++ b/arch/x86/include/asm/fpu/internal.h @@ -121,6 +121,21 @@ extern void fpstate_sanitize_xstate(struct fpu *fpu); err; \ }) +#define kernel_insn_err(insn, output, input...) \ +({ \ + int err; \ + asm volatile("1:" #insn "\n\t" \ + "2:\n" \ + ".section .fixup,\"ax\"\n" \ + "3: movl $-1,%[err]\n" \ + " jmp 2b\n" \ + ".previous\n" \ + _ASM_EXTABLE(1b, 3b) \ + : [err] "=r" (err), output \ + : "0"(0), input); \ + err; \ +}) + #define kernel_insn(insn, output, input...) \ asm volatile("1:" #insn "\n\t" \ "2:\n" \ @@ -149,6 +164,14 @@ static inline void copy_kernel_to_fxregs(struct fxregs_state *fx) kernel_insn(fxrstorq %[fx], "=m" (*fx), [fx] "m" (*fx)); } +static inline int copy_kernel_to_fxregs_err(struct fxregs_state *fx) +{ + if (IS_ENABLED(CONFIG_X86_32)) + return kernel_insn_err(fxrstor %[fx], "=m" (*fx), [fx] "m" (*fx)); + else + return kernel_insn_err(fxrstorq %[fx], "=m" (*fx), [fx] "m" (*fx)); +} + static inline int copy_user_to_fxregs(struct fxregs_state __user *fx) { if (IS_ENABLED(CONFIG_X86_32)) @@ -162,6 +185,11 @@ static inline void copy_kernel_to_fregs(struct fregs_state *fx) kernel_insn(frstor %[fx], "=m" (*fx), [fx] "m" (*fx)); } +static inline int copy_kernel_to_fregs_err(struct fregs_state *fx) +{ + return kernel_insn_err(frstor %[fx], "=m" (*fx), [fx] "m" (*fx)); +} + static inline int copy_user_to_fregs(struct fregs_state __user *fx) { return user_insn(frstor %[fx], "=m" (*fx), [fx] "m" (*fx)); @@ -362,6 +390,21 @@ static inline int copy_user_to_xregs(struct xregs_state __user *buf, u64 mask) } /* + * Restore xstate from kernel space xsave area, return an error code instead of + * an exception. + */ +static inline int copy_kernel_to_xregs_err(struct xregs_state *xstate, u64 mask) +{ + u32 lmask = mask; + u32 hmask = mask >> 32; + int err; + + XSTATE_OP(XRSTOR, xstate, lmask, hmask, err); + + return err; +} + +/* * These must be called with preempt disabled. Returns * 'true' if the FPU state is still intact and we can * keep registers active. diff --git a/arch/x86/kernel/fpu/signal.c b/arch/x86/kernel/fpu/signal.c index c2ff43fbbd07..9ea1eaa4c9b1 100644 --- a/arch/x86/kernel/fpu/signal.c +++ b/arch/x86/kernel/fpu/signal.c @@ -234,7 +234,8 @@ sanitize_restored_xstate(union fpregs_state *state, */ xsave->i387.mxcsr &= mxcsr_feature_mask; - convert_to_fxsr(&state->fxsave, ia32_env); + if (ia32_env) + convert_to_fxsr(&state->fxsave, ia32_env); } } @@ -337,28 +338,63 @@ static int __fpu__restore_sig(void __user *buf, void __user *buf_fx, int size) kfree(tmp); return err; } else { + union fpregs_state *state; + void *tmp; int ret; + tmp = kzalloc(sizeof(*state) + fpu_kernel_xstate_size + 64, GFP_KERNEL); + if (!tmp) + return -ENOMEM; + state = PTR_ALIGN(tmp, 64); + /* * For 64-bit frames and 32-bit fsave frames, restore the user * state to the registers directly (with exceptions handled). */ - if (use_xsave()) { - if ((unsigned long)buf_fx % 64 || fx_only) { - u64 init_bv = xfeatures_mask & ~XFEATURE_MASK_FPSSE; - copy_kernel_to_xregs(&init_fpstate.xsave, init_bv); - ret = copy_user_to_fxregs(buf_fx); + if ((unsigned long)buf_fx % 64) + fx_only = 1; + + if (use_xsave() && !fx_only) { + u64 init_bv = xfeatures_mask & ~xfeatures; + + if (using_compacted_format()) { + ret = copy_user_to_xstate(&state->xsave, buf_fx); } else { - u64 init_bv = xfeatures_mask & ~xfeatures; - if (unlikely(init_bv)) - copy_kernel_to_xregs(&init_fpstate.xsave, init_bv); - ret = copy_user_to_xregs(buf_fx, xfeatures); + ret = __copy_from_user(&state->xsave, buf_fx, state_size); + + if (!ret && state_size > offsetof(struct xregs_state, header)) + ret = validate_xstate_header(&state->xsave.header); } + if (ret) + goto err_out; + + sanitize_restored_xstate(state, NULL, xfeatures, fx_only); + + if (unlikely(init_bv)) + copy_kernel_to_xregs(&init_fpstate.xsave, init_bv); + ret = copy_kernel_to_xregs_err(&state->xsave, xfeatures); + } else if (use_fxsr()) { - ret = copy_user_to_fxregs(buf_fx); - } else - ret = copy_user_to_fregs(buf_fx); + ret = __copy_from_user(&state->fxsave, buf_fx, state_size); + if (ret) + goto err_out; + if (use_xsave()) { + u64 init_bv = xfeatures_mask & ~XFEATURE_MASK_FPSSE; + copy_kernel_to_xregs(&init_fpstate.xsave, init_bv); + } + state->fxsave.mxcsr &= mxcsr_feature_mask; + + ret = copy_kernel_to_fxregs_err(&state->fxsave); + } else { + ret = __copy_from_user(&state->fsave, buf_fx, state_size); + if (ret) + goto err_out; + ret = copy_kernel_to_fregs_err(&state->fsave); + } + +err_out: + kfree(tmp); if (ret) { fpu__clear(fpu); return -1; |