From 5b3efd500854d45d305b53c54c97db5970959980 Mon Sep 17 00:00:00 2001 From: Suresh Siddha Date: Thu, 11 Feb 2010 11:50:59 -0800 Subject: x86, ptrace: regset extensions to support xstate Add the xstate regset support which helps extend the kernel ptrace and the core-dump interfaces to support AVX state etc. This regset interface is designed to support all the future state that gets supported using xsave/xrstor infrastructure. Looking at the memory layout saved by "xsave", one can't say which state is represented in the memory layout. This is because if a particular state is in init state, in the xsave hdr it can be represented by bit '0'. And hence we can't really say by the xsave header wether a state is in init state or the state is not saved in the memory layout. And hence the xsave memory layout available through this regset interface uses SW usable bytes [464..511] to convey what state is represented in the memory layout. First 8 bytes of the sw_usable_bytes[464..467] will be set to OS enabled xstate mask(which is same as the 64bit mask returned by the xgetbv's xCR0). The note NT_X86_XSTATE represents the extended state information in the core file, using the above mentioned memory layout. Signed-off-by: Suresh Siddha LKML-Reference: <20100211195614.802495327@sbs-t61.sc.intel.com> Signed-off-by: Hongjiu Lu Cc: Roland McGrath Signed-off-by: H. Peter Anvin --- arch/x86/include/asm/i387.h | 12 +++++-- arch/x86/include/asm/user.h | 58 +++++++++++++++++++++++++++++++ arch/x86/include/asm/xsave.h | 2 ++ arch/x86/kernel/i387.c | 83 ++++++++++++++++++++++++++++++++++++++++++++ arch/x86/kernel/ptrace.c | 34 ++++++++++++++++-- arch/x86/kernel/xsave.c | 1 + include/linux/elf.h | 1 + 7 files changed, 187 insertions(+), 4 deletions(-) diff --git a/arch/x86/include/asm/i387.h b/arch/x86/include/asm/i387.h index ebfb8a9e11f7..da2930924501 100644 --- a/arch/x86/include/asm/i387.h +++ b/arch/x86/include/asm/i387.h @@ -33,8 +33,16 @@ extern void init_thread_xstate(void); extern int dump_fpu(struct pt_regs *, struct user_i387_struct *); extern user_regset_active_fn fpregs_active, xfpregs_active; -extern user_regset_get_fn fpregs_get, xfpregs_get, fpregs_soft_get; -extern user_regset_set_fn fpregs_set, xfpregs_set, fpregs_soft_set; +extern user_regset_get_fn fpregs_get, xfpregs_get, fpregs_soft_get, + xstateregs_get; +extern user_regset_set_fn fpregs_set, xfpregs_set, fpregs_soft_set, + xstateregs_set; + +/* + * xstateregs_active == fpregs_active. Please refer to the comment + * at the definition of fpregs_active. + */ +#define xstateregs_active fpregs_active extern struct _fpx_sw_bytes fx_sw_reserved; #ifdef CONFIG_IA32_EMULATION diff --git a/arch/x86/include/asm/user.h b/arch/x86/include/asm/user.h index 999873b22e7f..24532c7da3d6 100644 --- a/arch/x86/include/asm/user.h +++ b/arch/x86/include/asm/user.h @@ -1,5 +1,63 @@ +#ifndef _ASM_X86_USER_H +#define _ASM_X86_USER_H + #ifdef CONFIG_X86_32 # include "user_32.h" #else # include "user_64.h" #endif + +#include + +struct user_ymmh_regs { + /* 16 * 16 bytes for each YMMH-reg */ + __u32 ymmh_space[64]; +}; + +struct user_xsave_hdr { + __u64 xstate_bv; + __u64 reserved1[2]; + __u64 reserved2[5]; +}; + +/* + * The structure layout of user_xstateregs, used for exporting the + * extended register state through ptrace and core-dump (NT_X86_XSTATE note) + * interfaces will be same as the memory layout of xsave used by the processor + * (except for the bytes 464..511, which can be used by the software) and hence + * the size of this structure varies depending on the features supported by the + * processor and OS. The size of the structure that users need to use can be + * obtained by doing: + * cpuid_count(0xd, 0, &eax, &ptrace_xstateregs_struct_size, &ecx, &edx); + * i.e., cpuid.(eax=0xd,ecx=0).ebx will be the size that user (debuggers, etc.) + * need to use. + * + * For now, only the first 8 bytes of the software usable bytes[464..471] will + * be used and will be set to OS enabled xstate mask (which is same as the + * 64bit mask returned by the xgetbv's xCR0). Users (analyzing core dump + * remotely, etc.) can use this mask as well as the mask saved in the + * xstate_hdr bytes and interpret what states the processor/OS supports + * and what states are in modified/initialized conditions for the + * particular process/thread. + * + * Also when the user modifies certain state FP/SSE/etc through the + * ptrace interface, they must ensure that the xsave_hdr.xstate_bv + * bytes[512..519] of the memory layout are updated correspondingly. + * i.e., for example when FP state is modified to a non-init state, + * xsave_hdr.xstate_bv's bit 0 must be set to '1', when SSE is modified to + * non-init state, xsave_hdr.xstate_bv's bit 1 must to be set to '1', etc. + */ +#define USER_XSTATE_FX_SW_WORDS 6 +#define USER_XSTATE_XCR0_WORD 0 + +struct user_xstateregs { + struct { + __u64 fpx_space[58]; + __u64 xstate_fx_sw[USER_XSTATE_FX_SW_WORDS]; + } i387; + struct user_xsave_hdr xsave_hdr; + struct user_ymmh_regs ymmh; + /* further processor state extensions go here */ +}; + +#endif /* _ASM_X86_USER_H */ diff --git a/arch/x86/include/asm/xsave.h b/arch/x86/include/asm/xsave.h index 727acc152344..ddc04ccad03b 100644 --- a/arch/x86/include/asm/xsave.h +++ b/arch/x86/include/asm/xsave.h @@ -27,9 +27,11 @@ extern unsigned int xstate_size; extern u64 pcntxt_mask; extern struct xsave_struct *init_xstate_buf; +extern u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS]; extern void xsave_cntxt_init(void); extern void xsave_init(void); +extern void update_regset_xstate_info(unsigned int size, u64 xstate_mask); extern int init_fpu(struct task_struct *child); extern int check_for_xstate(struct i387_fxsave_struct __user *buf, void __user *fpstate, diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c index f2f8540a7f3d..7a8a193b5144 100644 --- a/arch/x86/kernel/i387.c +++ b/arch/x86/kernel/i387.c @@ -164,6 +164,11 @@ int init_fpu(struct task_struct *tsk) return 0; } +/* + * The xstateregs_active() routine is the same as the fpregs_active() routine, + * as the "regset->n" for the xstate regset will be updated based on the feature + * capabilites supported by the xsave. + */ int fpregs_active(struct task_struct *target, const struct user_regset *regset) { return tsk_used_math(target) ? regset->n : 0; @@ -224,6 +229,84 @@ int xfpregs_set(struct task_struct *target, const struct user_regset *regset, return ret; } +int xstateregs_get(struct task_struct *target, const struct user_regset *regset, + unsigned int pos, unsigned int count, + void *kbuf, void __user *ubuf) +{ + int ret; + + if (!cpu_has_xsave) + return -ENODEV; + + ret = init_fpu(target); + if (ret) + return ret; + + /* + * First copy the fxsave bytes 0..463. + */ + ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, + &target->thread.xstate->xsave, 0, + offsetof(struct user_xstateregs, + i387.xstate_fx_sw)); + if (ret) + return ret; + + /* + * Copy the 48bytes defined by software. + */ + ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, + xstate_fx_sw_bytes, + offsetof(struct user_xstateregs, + i387.xstate_fx_sw), + offsetof(struct user_xstateregs, + xsave_hdr)); + if (ret) + return ret; + + /* + * Copy the rest of xstate memory layout. + */ + ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, + &target->thread.xstate->xsave.xsave_hdr, + offsetof(struct user_xstateregs, + xsave_hdr), -1); + return ret; +} + +int xstateregs_set(struct task_struct *target, const struct user_regset *regset, + unsigned int pos, unsigned int count, + const void *kbuf, const void __user *ubuf) +{ + int ret; + struct xsave_hdr_struct *xsave_hdr; + + if (!cpu_has_xsave) + return -ENODEV; + + ret = init_fpu(target); + if (ret) + return ret; + + ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, + &target->thread.xstate->xsave, 0, -1); + + /* + * mxcsr reserved bits must be masked to zero for security reasons. + */ + target->thread.xstate->fxsave.mxcsr &= mxcsr_feature_mask; + + xsave_hdr = &target->thread.xstate->xsave.xsave_hdr; + + xsave_hdr->xstate_bv &= pcntxt_mask; + /* + * These bits must be zero. + */ + xsave_hdr->reserved1[0] = xsave_hdr->reserved1[1] = 0; + + return ret; +} + #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION /* diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c index 017d937639fe..16433a59b396 100644 --- a/arch/x86/kernel/ptrace.c +++ b/arch/x86/kernel/ptrace.c @@ -48,6 +48,7 @@ enum x86_regset { REGSET_FP, REGSET_XFP, REGSET_IOPERM64 = REGSET_XFP, + REGSET_XSTATE, REGSET_TLS, REGSET_IOPERM32, }; @@ -1584,7 +1585,7 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request, #ifdef CONFIG_X86_64 -static const struct user_regset x86_64_regsets[] = { +static struct user_regset x86_64_regsets[] __read_mostly = { [REGSET_GENERAL] = { .core_note_type = NT_PRSTATUS, .n = sizeof(struct user_regs_struct) / sizeof(long), @@ -1597,6 +1598,12 @@ static const struct user_regset x86_64_regsets[] = { .size = sizeof(long), .align = sizeof(long), .active = xfpregs_active, .get = xfpregs_get, .set = xfpregs_set }, + [REGSET_XSTATE] = { + .core_note_type = NT_X86_XSTATE, + .size = sizeof(u64), .align = sizeof(u64), + .active = xstateregs_active, .get = xstateregs_get, + .set = xstateregs_set + }, [REGSET_IOPERM64] = { .core_note_type = NT_386_IOPERM, .n = IO_BITMAP_LONGS, @@ -1622,7 +1629,7 @@ static const struct user_regset_view user_x86_64_view = { #endif /* CONFIG_X86_64 */ #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION -static const struct user_regset x86_32_regsets[] = { +static struct user_regset x86_32_regsets[] __read_mostly = { [REGSET_GENERAL] = { .core_note_type = NT_PRSTATUS, .n = sizeof(struct user_regs_struct32) / sizeof(u32), @@ -1641,6 +1648,12 @@ static const struct user_regset x86_32_regsets[] = { .size = sizeof(u32), .align = sizeof(u32), .active = xfpregs_active, .get = xfpregs_get, .set = xfpregs_set }, + [REGSET_XSTATE] = { + .core_note_type = NT_X86_XSTATE, + .size = sizeof(u64), .align = sizeof(u64), + .active = xstateregs_active, .get = xstateregs_get, + .set = xstateregs_set + }, [REGSET_TLS] = { .core_note_type = NT_386_TLS, .n = GDT_ENTRY_TLS_ENTRIES, .bias = GDT_ENTRY_TLS_MIN, @@ -1663,6 +1676,23 @@ static const struct user_regset_view user_x86_32_view = { }; #endif +/* + * This represents bytes 464..511 in the memory layout exported through + * the REGSET_XSTATE interface. + */ +u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS]; + +void update_regset_xstate_info(unsigned int size, u64 xstate_mask) +{ +#ifdef CONFIG_X86_64 + x86_64_regsets[REGSET_XSTATE].n = size / sizeof(u64); +#endif +#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION + x86_32_regsets[REGSET_XSTATE].n = size / sizeof(u64); +#endif + xstate_fx_sw_bytes[USER_XSTATE_XCR0_WORD] = xstate_mask; +} + const struct user_regset_view *task_user_regset_view(struct task_struct *task) { #ifdef CONFIG_IA32_EMULATION diff --git a/arch/x86/kernel/xsave.c b/arch/x86/kernel/xsave.c index c5ee17e8c6d9..782c3a362ec6 100644 --- a/arch/x86/kernel/xsave.c +++ b/arch/x86/kernel/xsave.c @@ -337,6 +337,7 @@ void __ref xsave_cntxt_init(void) cpuid_count(0xd, 0, &eax, &ebx, &ecx, &edx); xstate_size = ebx; + update_regset_xstate_info(xstate_size, pcntxt_mask); prepare_fx_sw_frame(); setup_xstate_init(); diff --git a/include/linux/elf.h b/include/linux/elf.h index 0cc4d55151b7..a8c4af073ce9 100644 --- a/include/linux/elf.h +++ b/include/linux/elf.h @@ -361,6 +361,7 @@ typedef struct elf64_shdr { #define NT_PPC_VSX 0x102 /* PowerPC VSX registers */ #define NT_386_TLS 0x200 /* i386 TLS slots (struct user_desc) */ #define NT_386_IOPERM 0x201 /* x86 io permission bitmap (1=deny) */ +#define NT_X86_XSTATE 0x202 /* x86 extended state using xsave */ #define NT_S390_HIGH_GPRS 0x300 /* s390 upper register halves */ -- cgit v1.2.3 From 2225a122ae26d542bdce523d9d87a4a7ba10e07b Mon Sep 17 00:00:00 2001 From: Suresh Siddha Date: Thu, 11 Feb 2010 11:51:00 -0800 Subject: ptrace: Add support for generic PTRACE_GETREGSET/PTRACE_SETREGSET Generic support for PTRACE_GETREGSET/PTRACE_SETREGSET commands which export the regsets supported by each architecture using the correponding NT_* types. These NT_* types are already part of the userland ABI, used in representing the architecture specific register sets as different NOTES in an ELF core file. 'addr' parameter for the ptrace system call encode the REGSET type (using the corresppnding NT_* type) and the 'data' parameter points to the struct iovec having the user buffer and the length of that buffer. struct iovec iov = { buf, len}; ret = ptrace(PTRACE_GETREGSET/PTRACE_SETREGSET, pid, NT_XXX_TYPE, &iov); On successful completion, iov.len will be updated by the kernel specifying how much the kernel has written/read to/from the user's iov.buf. x86 extended state registers are primarily exported using this interface. Signed-off-by: Suresh Siddha LKML-Reference: <20100211195614.886724710@sbs-t61.sc.intel.com> Acked-by: Hongjiu Lu Cc: Roland McGrath Signed-off-by: H. Peter Anvin --- include/linux/elf.h | 6 +++- include/linux/ptrace.h | 15 +++++++++ kernel/ptrace.c | 88 ++++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 108 insertions(+), 1 deletion(-) diff --git a/include/linux/elf.h b/include/linux/elf.h index a8c4af073ce9..d8e6e61ad9ff 100644 --- a/include/linux/elf.h +++ b/include/linux/elf.h @@ -349,7 +349,11 @@ typedef struct elf64_shdr { #define ELF_OSABI ELFOSABI_NONE #endif -/* Notes used in ET_CORE */ +/* + * Notes used in ET_CORE. Architectures export some of the arch register sets + * using the corresponding note types via the PTRACE_GETREGSET and + * PTRACE_SETREGSET requests. + */ #define NT_PRSTATUS 1 #define NT_PRFPREG 2 #define NT_PRPSINFO 3 diff --git a/include/linux/ptrace.h b/include/linux/ptrace.h index 56f2d63a5cbb..dbfa821d5a6e 100644 --- a/include/linux/ptrace.h +++ b/include/linux/ptrace.h @@ -27,6 +27,21 @@ #define PTRACE_GETSIGINFO 0x4202 #define PTRACE_SETSIGINFO 0x4203 +/* + * Generic ptrace interface that exports the architecture specific regsets + * using the corresponding NT_* types (which are also used in the core dump). + * + * This interface usage is as follows: + * struct iovec iov = { buf, len}; + * + * ret = ptrace(PTRACE_GETREGSET/PTRACE_SETREGSET, pid, NT_XXX_TYPE, &iov); + * + * On the successful completion, iov.len will be updated by the kernel, + * specifying how much the kernel has written/read to/from the user's iov.buf. + */ +#define PTRACE_GETREGSET 0x4204 +#define PTRACE_SETREGSET 0x4205 + /* options set using PTRACE_SETOPTIONS */ #define PTRACE_O_TRACESYSGOOD 0x00000001 #define PTRACE_O_TRACEFORK 0x00000002 diff --git a/kernel/ptrace.c b/kernel/ptrace.c index 23bd09cd042e..13b4554d8fbb 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -22,6 +22,7 @@ #include #include #include +#include /* @@ -511,6 +512,47 @@ static int ptrace_resume(struct task_struct *child, long request, long data) return 0; } +#ifdef CONFIG_HAVE_ARCH_TRACEHOOK + +static const struct user_regset * +find_regset(const struct user_regset_view *view, unsigned int type) +{ + const struct user_regset *regset; + int n; + + for (n = 0; n < view->n; ++n) { + regset = view->regsets + n; + if (regset->core_note_type == type) + return regset; + } + + return NULL; +} + +static int ptrace_regset(struct task_struct *task, int req, unsigned int type, + struct iovec *kiov) +{ + const struct user_regset_view *view = task_user_regset_view(task); + const struct user_regset *regset = find_regset(view, type); + int regset_no; + + if (!regset || (kiov->iov_len % regset->size) != 0) + return -EIO; + + regset_no = regset - view->regsets; + kiov->iov_len = min(kiov->iov_len, + (__kernel_size_t) (regset->n * regset->size)); + + if (req == PTRACE_GETREGSET) + return copy_regset_to_user(task, view, regset_no, 0, + kiov->iov_len, kiov->iov_base); + else + return copy_regset_from_user(task, view, regset_no, 0, + kiov->iov_len, kiov->iov_base); +} + +#endif + int ptrace_request(struct task_struct *child, long request, long addr, long data) { @@ -573,6 +615,26 @@ int ptrace_request(struct task_struct *child, long request, return 0; return ptrace_resume(child, request, SIGKILL); +#ifdef CONFIG_HAVE_ARCH_TRACEHOOK + case PTRACE_GETREGSET: + case PTRACE_SETREGSET: + { + struct iovec kiov; + struct iovec __user *uiov = (struct iovec __user *) data; + + if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) + return -EFAULT; + + if (__get_user(kiov.iov_base, &uiov->iov_base) || + __get_user(kiov.iov_len, &uiov->iov_len)) + return -EFAULT; + + ret = ptrace_regset(child, request, addr, &kiov); + if (!ret) + ret = __put_user(kiov.iov_len, &uiov->iov_len); + break; + } +#endif default: break; } @@ -711,6 +773,32 @@ int compat_ptrace_request(struct task_struct *child, compat_long_t request, else ret = ptrace_setsiginfo(child, &siginfo); break; +#ifdef CONFIG_HAVE_ARCH_TRACEHOOK + case PTRACE_GETREGSET: + case PTRACE_SETREGSET: + { + struct iovec kiov; + struct compat_iovec __user *uiov = + (struct compat_iovec __user *) datap; + compat_uptr_t ptr; + compat_size_t len; + + if (!access_ok(VERIFY_WRITE, uiov, sizeof(*uiov))) + return -EFAULT; + + if (__get_user(ptr, &uiov->iov_base) || + __get_user(len, &uiov->iov_len)) + return -EFAULT; + + kiov.iov_base = compat_ptr(ptr); + kiov.iov_len = len; + + ret = ptrace_regset(child, request, addr, &kiov); + if (!ret) + ret = __put_user(kiov.iov_len, &uiov->iov_len); + break; + } +#endif default: ret = ptrace_request(child, request, addr, data); -- cgit v1.2.3 From 5e6dbc260704ce4d22fc9664f517f0bb6748feaa Mon Sep 17 00:00:00 2001 From: Roland McGrath Date: Mon, 22 Feb 2010 10:37:07 -0800 Subject: parisc: Disable CONFIG_HAVE_ARCH_TRACEHOOK > FYI, this commit broke tip:master on PARISC (other architectures are fine): > > kernel/built-in.o: In function `ptrace_request': > (.text.ptrace_request+0x2cc): undefined reference to `task_user_regset_view' This means that parisc failed to meet the documented requirements for setting CONFIG_HAVE_ARCH_TRACEHOOK, but set it anyway. If arch folks don't follow the specs, it defeats the whole purpose of having clear statements of requirements for arch code. Until parisc finishes up its requirements, disable CONFIG_HAVE_ARCH_TRACEHOOK. Signed-off-by: H. Peter Anvin LKML-Reference: <20100222183707.8749D64C@magilla.sf.frob.com> Cc: Cc: Kyle McMartin Cc: Helge Deller Cc: James E.J. Bottomley --- arch/parisc/Kconfig | 1 - 1 file changed, 1 deletion(-) diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig index 524d9352f17e..f388dc68f605 100644 --- a/arch/parisc/Kconfig +++ b/arch/parisc/Kconfig @@ -18,7 +18,6 @@ config PARISC select BUG select HAVE_PERF_EVENTS select GENERIC_ATOMIC64 if !64BIT - select HAVE_ARCH_TRACEHOOK help The PA-RISC microprocessor is designed by Hewlett-Packard and used in many of their workstations & servers (HP9000 700 and 800 series, -- cgit v1.2.3 From c6a0dd7ec6fb2d4927979ed4dc562fc5c122d826 Mon Sep 17 00:00:00 2001 From: Suresh Siddha Date: Mon, 22 Feb 2010 14:51:32 -0800 Subject: ptrace: Fix ptrace_regset() comments and diagnose errors specifically Return -EINVAL for the bad size and for unrecognized NT_* type in ptrace_regset() instead of -EIO. Also update the comments for this ptrace interface with more clarifications. Requested-by: Roland McGrath Requested-by: Oleg Nesterov Signed-off-by: Suresh Siddha LKML-Reference: <20100222225240.397523600@sbs-t61.sc.intel.com> Acked-by: Roland McGrath Signed-off-by: H. Peter Anvin --- include/linux/ptrace.h | 5 +++++ kernel/ptrace.c | 2 +- 2 files changed, 6 insertions(+), 1 deletion(-) diff --git a/include/linux/ptrace.h b/include/linux/ptrace.h index dbfa821d5a6e..c5eab89da51e 100644 --- a/include/linux/ptrace.h +++ b/include/linux/ptrace.h @@ -30,6 +30,11 @@ /* * Generic ptrace interface that exports the architecture specific regsets * using the corresponding NT_* types (which are also used in the core dump). + * Please note that the NT_PRSTATUS note type in a core dump contains a full + * 'struct elf_prstatus'. But the user_regset for NT_PRSTATUS contains just the + * elf_gregset_t that is the pr_reg field of 'struct elf_prstatus'. For all the + * other user_regset flavors, the user_regset layout and the ELF core dump note + * payload are exactly the same layout. * * This interface usage is as follows: * struct iovec iov = { buf, len}; diff --git a/kernel/ptrace.c b/kernel/ptrace.c index 13b4554d8fbb..42ad8ae729a0 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -537,7 +537,7 @@ static int ptrace_regset(struct task_struct *task, int req, unsigned int type, int regset_no; if (!regset || (kiov->iov_len % regset->size) != 0) - return -EIO; + return -EINVAL; regset_no = regset - view->regsets; kiov->iov_len = min(kiov->iov_len, -- cgit v1.2.3 From ff7fbc72e0c3ef7e94a27a3a918fd09ec9a30204 Mon Sep 17 00:00:00 2001 From: Suresh Siddha Date: Mon, 22 Feb 2010 14:51:33 -0800 Subject: x86, ptrace: Simplify xstateregs_get() 48 bytes (bytes 464..511) of the xstateregs payload come from the kernel defined structure (xstate_fx_sw_bytes). Rest comes from the xstate regs structure in the thread struct. Instead of having multiple user_regset_copyout()'s, simplify the xstateregs_get() by first copying the SW bytes into the xstate regs structure in the thread structure and then using one user_regset_copyout() to copyout the xstateregs. Requested-by: Roland McGrath Signed-off-by: Suresh Siddha LKML-Reference: <20100222225240.494688491@sbs-t61.sc.intel.com> Acked-by: Roland McGrath Signed-off-by: H. Peter Anvin Cc: Oleg Nesterov --- arch/x86/kernel/i387.c | 30 +++++++----------------------- 1 file changed, 7 insertions(+), 23 deletions(-) diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c index 7a8a193b5144..81e23bf12c12 100644 --- a/arch/x86/kernel/i387.c +++ b/arch/x86/kernel/i387.c @@ -243,34 +243,18 @@ int xstateregs_get(struct task_struct *target, const struct user_regset *regset, return ret; /* - * First copy the fxsave bytes 0..463. + * Copy the 48bytes defined by the software first into the xstate + * memory layout in the thread struct, so that we can copy the entire + * xstateregs to the user using one user_regset_copyout(). */ - ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, - &target->thread.xstate->xsave, 0, - offsetof(struct user_xstateregs, - i387.xstate_fx_sw)); - if (ret) - return ret; - - /* - * Copy the 48bytes defined by software. - */ - ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, - xstate_fx_sw_bytes, - offsetof(struct user_xstateregs, - i387.xstate_fx_sw), - offsetof(struct user_xstateregs, - xsave_hdr)); - if (ret) - return ret; + memcpy(&target->thread.xstate->fxsave.sw_reserved, + xstate_fx_sw_bytes, sizeof(xstate_fx_sw_bytes)); /* - * Copy the rest of xstate memory layout. + * Copy the xstate memory layout. */ ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, - &target->thread.xstate->xsave.xsave_hdr, - offsetof(struct user_xstateregs, - xsave_hdr), -1); + &target->thread.xstate->xsave, 0, -1); return ret; } -- cgit v1.2.3 From 6dbbe14f21368a45aedba7eab0221857b8ad8d16 Mon Sep 17 00:00:00 2001 From: Suresh Siddha Date: Mon, 22 Feb 2010 14:51:34 -0800 Subject: x86, ptrace: Remove set_stopped_child_used_math() in [x]fpregs_set init_fpu() already ensures that the used_math() is set for the stopped child. Remove the redundant set_stopped_child_used_math() in [x]fpregs_set() Reported-by: Oleg Nesterov Signed-off-by: Suresh Siddha LKML-Reference: <20100222225240.642169080@sbs-t61.sc.intel.com> Acked-by: Rolan McGrath Signed-off-by: H. Peter Anvin --- arch/x86/kernel/i387.c | 4 ---- 1 file changed, 4 deletions(-) diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c index 81e23bf12c12..c01a2b846d47 100644 --- a/arch/x86/kernel/i387.c +++ b/arch/x86/kernel/i387.c @@ -209,8 +209,6 @@ int xfpregs_set(struct task_struct *target, const struct user_regset *regset, if (ret) return ret; - set_stopped_child_used_math(target); - ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &target->thread.xstate->fxsave, 0, -1); @@ -471,8 +469,6 @@ int fpregs_set(struct task_struct *target, const struct user_regset *regset, if (ret) return ret; - set_stopped_child_used_math(target); - if (!HAVE_HWFP) return fpregs_soft_set(target, regset, pos, count, kbuf, ubuf); -- cgit v1.2.3