diff options
| -rw-r--r-- | arch/x86/kernel/fpu/xstate.c | 86 |
1 files changed, 41 insertions, 45 deletions
diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index 5a069c2a3675..c55f72eb5466 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -81,8 +81,6 @@ static unsigned int xstate_offsets[XFEATURE_MAX] __ro_after_init = { [ 0 ... XFEATURE_MAX - 1] = -1}; static unsigned int xstate_sizes[XFEATURE_MAX] __ro_after_init = { [ 0 ... XFEATURE_MAX - 1] = -1}; -static unsigned int xstate_comp_offsets[XFEATURE_MAX] __ro_after_init = - { [ 0 ... XFEATURE_MAX - 1] = -1}; static unsigned int xstate_flags[XFEATURE_MAX] __ro_after_init; #define XSTATE_FLAG_SUPERVISOR BIT(0) @@ -136,6 +134,33 @@ static bool xfeature_is_supervisor(int xfeature_nr) return xstate_flags[xfeature_nr] & XSTATE_FLAG_SUPERVISOR; } +static unsigned int xfeature_get_offset(u64 xcomp_bv, int xfeature) +{ + unsigned int offs, i; + + /* + * Non-compacted format and legacy features use the cached fixed + * offsets. + */ + if (!cpu_feature_enabled(X86_FEATURE_XSAVES) || xfeature <= XFEATURE_SSE) + return xstate_offsets[xfeature]; + + /* + * Compacted format offsets depend on the actual content of the + * compacted xsave area which is determined by the xcomp_bv header + * field. + */ + offs = FXSAVE_SIZE + XSAVE_HDR_SIZE; + for_each_extended_xfeature(i, xcomp_bv) { + if (xfeature_is_aligned64(i)) + offs = ALIGN(offs, 64); + if (i == xfeature) + break; + offs += xstate_sizes[i]; + } + return offs; +} + /* * Enable the extended processor state save/restore feature. * Called once per CPU onlining. @@ -264,42 +289,6 @@ static void __init print_xstate_features(void) } while (0) /* - * This function sets up offsets and sizes of all extended states in - * xsave area. This supports both standard format and compacted format - * of the xsave area. - */ -static void __init setup_xstate_comp_offsets(void) -{ - unsigned int next_offset; - int i; - - /* - * The FP xstates and SSE xstates are legacy states. They are always - * in the fixed offsets in the xsave area in either compacted form - * or standard form. - */ - xstate_comp_offsets[XFEATURE_FP] = 0; - xstate_comp_offsets[XFEATURE_SSE] = offsetof(struct fxregs_state, - xmm_space); - - if (!cpu_feature_enabled(X86_FEATURE_XSAVES)) { - for_each_extended_xfeature(i, fpu_kernel_cfg.max_features) - xstate_comp_offsets[i] = xstate_offsets[i]; - return; - } - - next_offset = FXSAVE_SIZE + XSAVE_HDR_SIZE; - - for_each_extended_xfeature(i, fpu_kernel_cfg.max_features) { - if (xfeature_is_aligned64(i)) - next_offset = ALIGN(next_offset, 64); - - xstate_comp_offsets[i] = next_offset; - next_offset += xstate_sizes[i]; - } -} - -/* * Print out xstate component offsets and sizes */ static void __init print_xstate_offset_size(void) @@ -308,7 +297,8 @@ static void __init print_xstate_offset_size(void) for_each_extended_xfeature(i, fpu_kernel_cfg.max_features) { pr_info("x86/fpu: xstate_offset[%d]: %4d, xstate_sizes[%d]: %4d\n", - i, xstate_comp_offsets[i], i, xstate_sizes[i]); + i, xfeature_get_offset(fpu_kernel_cfg.max_features, i), + i, xstate_sizes[i]); } } @@ -901,7 +891,6 @@ void __init fpu__init_system_xstate(unsigned int legacy_size) fpu_user_cfg.max_features); setup_init_fpu_buf(); - setup_xstate_comp_offsets(); /* * Paranoia check whether something in the setup modified the @@ -956,13 +945,19 @@ void fpu__resume_cpu(void) */ static void *__raw_xsave_addr(struct xregs_state *xsave, int xfeature_nr) { - if (!xfeature_enabled(xfeature_nr)) { - WARN_ON_FPU(1); + u64 xcomp_bv = xsave->header.xcomp_bv; + + if (WARN_ON_ONCE(!xfeature_enabled(xfeature_nr))) return NULL; + + if (cpu_feature_enabled(X86_FEATURE_XSAVES)) { + if (WARN_ON_ONCE(!(xcomp_bv & BIT_ULL(xfeature_nr)))) + return NULL; } - return (void *)xsave + xstate_comp_offsets[xfeature_nr]; + return (void *)xsave + xfeature_get_offset(xcomp_bv, xfeature_nr); } + /* * Given the xsave area and a state inside, this function returns the * address of the state. @@ -993,8 +988,9 @@ void *get_xsave_addr(struct xregs_state *xsave, int xfeature_nr) * We should not ever be requesting features that we * have not enabled. */ - WARN_ONCE(!(fpu_kernel_cfg.max_features & BIT_ULL(xfeature_nr)), - "get of unsupported state"); + if (WARN_ON_ONCE(!xfeature_enabled(xfeature_nr))) + return NULL; + /* * This assumes the last 'xsave*' instruction to * have requested that 'xfeature_nr' be saved. |