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 --- include/linux/elf.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include') 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 v1.2.2 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 +++++++++++++++ 2 files changed, 20 insertions(+), 1 deletion(-) (limited to 'include') 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 -- cgit v1.2.2 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 +++++ 1 file changed, 5 insertions(+) (limited to 'include') 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}; -- cgit v1.2.2