diff options
Diffstat (limited to 'arch/x86/kernel/fpu/xstate.c')
| -rw-r--r-- | arch/x86/kernel/fpu/xstate.c | 110 |
1 files changed, 108 insertions, 2 deletions
diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index 33a214b1a4ce..22abb5ee0cf2 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -13,6 +13,7 @@ #include <linux/seq_file.h> #include <linux/proc_fs.h> #include <linux/vmalloc.h> +#include <linux/coredump.h> #include <asm/fpu/api.h> #include <asm/fpu/regset.h> @@ -23,6 +24,8 @@ #include <asm/prctl.h> #include <asm/elf.h> +#include <uapi/asm/elf.h> + #include "context.h" #include "internal.h" #include "legacy.h" @@ -788,6 +791,9 @@ void __init fpu__init_system_xstate(unsigned int legacy_size) goto out_disable; } + fpu_kernel_cfg.independent_features = fpu_kernel_cfg.max_features & + XFEATURE_MASK_INDEPENDENT; + /* * Clear XSAVE features that are disabled in the normal CPUID. */ @@ -991,6 +997,20 @@ void *get_xsave_addr(struct xregs_state *xsave, int xfeature_nr) return __raw_xsave_addr(xsave, xfeature_nr); } +EXPORT_SYMBOL_GPL(get_xsave_addr); + +/* + * Given an xstate feature nr, calculate where in the xsave buffer the state is. + * The xsave buffer should be in standard format, not compacted (e.g. user mode + * signal frames). + */ +void __user *get_xsave_addr_user(struct xregs_state __user *xsave, int xfeature_nr) +{ + if (WARN_ON_ONCE(!xfeature_enabled(xfeature_nr))) + return NULL; + + return (void __user *)xsave + xstate_offsets[xfeature_nr]; +} #ifdef CONFIG_ARCH_HAS_PKEYS @@ -1434,8 +1454,8 @@ static bool xstate_op_valid(struct fpstate *fpstate, u64 mask, bool rstor) return rstor; /* - * XSAVE(S): clone(), fpu_swap_kvm_fpu() - * XRSTORS(S): fpu_swap_kvm_fpu() + * XSAVE(S): clone(), fpu_swap_kvm_fpstate() + * XRSTORS(S): fpu_swap_kvm_fpstate() */ /* @@ -1837,3 +1857,89 @@ int proc_pid_arch_status(struct seq_file *m, struct pid_namespace *ns, return 0; } #endif /* CONFIG_PROC_PID_ARCH_STATUS */ + +#ifdef CONFIG_COREDUMP +static const char owner_name[] = "LINUX"; + +/* + * Dump type, size, offset and flag values for every xfeature that is present. + */ +static int dump_xsave_layout_desc(struct coredump_params *cprm) +{ + int num_records = 0; + int i; + + for_each_extended_xfeature(i, fpu_user_cfg.max_features) { + struct x86_xfeat_component xc = { + .type = i, + .size = xstate_sizes[i], + .offset = xstate_offsets[i], + /* reserved for future use */ + .flags = 0, + }; + + if (!dump_emit(cprm, &xc, sizeof(xc))) + return 0; + + num_records++; + } + return num_records; +} + +static u32 get_xsave_desc_size(void) +{ + u32 cnt = 0; + u32 i; + + for_each_extended_xfeature(i, fpu_user_cfg.max_features) + cnt++; + + return cnt * (sizeof(struct x86_xfeat_component)); +} + +int elf_coredump_extra_notes_write(struct coredump_params *cprm) +{ + int num_records = 0; + struct elf_note en; + + if (!fpu_user_cfg.max_features) + return 0; + + en.n_namesz = sizeof(owner_name); + en.n_descsz = get_xsave_desc_size(); + en.n_type = NT_X86_XSAVE_LAYOUT; + + if (!dump_emit(cprm, &en, sizeof(en))) + return 1; + if (!dump_emit(cprm, owner_name, en.n_namesz)) + return 1; + if (!dump_align(cprm, 4)) + return 1; + + num_records = dump_xsave_layout_desc(cprm); + if (!num_records) + return 1; + + /* Total size should be equal to the number of records */ + if ((sizeof(struct x86_xfeat_component) * num_records) != en.n_descsz) + return 1; + + return 0; +} + +int elf_coredump_extra_notes_size(void) +{ + int size; + + if (!fpu_user_cfg.max_features) + return 0; + + /* .note header */ + size = sizeof(struct elf_note); + /* Name plus alignment to 4 bytes */ + size += roundup(sizeof(owner_name), 4); + size += get_xsave_desc_size(); + + return size; +} +#endif /* CONFIG_COREDUMP */ |