diff options
Diffstat (limited to 'gdb/nat')
| -rw-r--r-- | gdb/nat/aarch64-hw-point.c | 6 | ||||
| -rw-r--r-- | gdb/nat/linux-namespaces.c | 167 | ||||
| -rw-r--r-- | gdb/nat/linux-namespaces.h | 11 | ||||
| -rw-r--r-- | gdb/nat/linux-procfs.c | 30 | ||||
| -rw-r--r-- | gdb/nat/linux-procfs.h | 14 | ||||
| -rw-r--r-- | gdb/nat/linux-ptrace.c | 4 | ||||
| -rw-r--r-- | gdb/nat/x86-gcc-cpuid.h | 153 | ||||
| -rw-r--r-- | gdb/nat/x86-linux-tdesc.c | 20 | ||||
| -rw-r--r-- | gdb/nat/x86-linux-tdesc.h | 7 | ||||
| -rw-r--r-- | gdb/nat/x86-linux.c | 59 | ||||
| -rw-r--r-- | gdb/nat/x86-linux.h | 4 |
11 files changed, 383 insertions, 92 deletions
diff --git a/gdb/nat/aarch64-hw-point.c b/gdb/nat/aarch64-hw-point.c index 6d8dce8..8c0854b 100644 --- a/gdb/nat/aarch64-hw-point.c +++ b/gdb/nat/aarch64-hw-point.c @@ -710,10 +710,8 @@ aarch64_stopped_data_address (const struct aarch64_debug_reg_state *state, itself. For instance, the access size of an stp instruction is 16. So, if we use stp to store to address p, and set a watchpoint on address p + 8, the reported ADDR_TRAP can be p + 8 (observed on - RK3399 SOC). But it also can be p (observed on M1 SOC). Checking - for this situation introduces the possibility of false positives, - so we only do this for hw_write watchpoints. */ - const CORE_ADDR max_access_size = type == hw_write ? 16 : 8; + RK3399 SOC). But it also can be p (observed on M1 SOC). */ + const CORE_ADDR max_access_size = 16; const CORE_ADDR addr_watch_base = addr_watch_aligned - (max_access_size - AARCH64_HWP_MAX_LEN_PER_REG); if (!(addr_trap >= addr_watch_base diff --git a/gdb/nat/linux-namespaces.c b/gdb/nat/linux-namespaces.c index ea94fdd..2a65fb0 100644 --- a/gdb/nat/linux-namespaces.c +++ b/gdb/nat/linux-namespaces.c @@ -233,6 +233,12 @@ enum mnsh_msg_type MNSH_RET_INT. */ MNSH_REQ_SETNS, + /* A request that the helper call lstat. The single + argument (the filename) should be passed in BUF, and + should include a terminating NUL character. The helper + should respond with a MNSH_RET_INTSTR. */ + MNSH_REQ_LSTAT, + /* A request that the helper call open. Arguments should be passed in BUF, INT1 and INT2. The filename (in BUF) should include a terminating NUL character. The helper @@ -265,62 +271,69 @@ enum mnsh_msg_type MNSH_RET_INTSTR, }; -/* Print a string representation of a message using debug_printf. - This function is not async-signal-safe so should never be - called from the helper. */ +/* Return a string representation of a message. This function is not + async-signal-safe so should never be called from the helper. */ -static void +static std::string mnsh_debug_print_message (enum mnsh_msg_type type, int fd, int int1, int int2, const void *buf, int bufsiz) { + std::string res; + gdb_byte *c = (gdb_byte *) buf; gdb_byte *cl = c + bufsiz; switch (type) { case MNSH_MSG_ERROR: - debug_printf ("ERROR"); + res += "ERROR"; + break; + + case MNSH_REQ_LSTAT: + res += "LSTAT"; break; case MNSH_REQ_SETNS: - debug_printf ("SETNS"); + res += "SETNS"; break; case MNSH_REQ_OPEN: - debug_printf ("OPEN"); + res += "OPEN"; break; case MNSH_REQ_UNLINK: - debug_printf ("UNLINK"); + res += "UNLINK"; break; case MNSH_REQ_READLINK: - debug_printf ("READLINK"); + res += "READLINK"; break; case MNSH_RET_INT: - debug_printf ("INT"); + res += "INT"; break; case MNSH_RET_FD: - debug_printf ("FD"); + res += "FD"; break; case MNSH_RET_INTSTR: - debug_printf ("INTSTR"); + res += "INTSTR"; break; default: - debug_printf ("unknown-packet-%d", type); + res += string_printf ("unknown-packet-%d", type); } - debug_printf (" %d %d %d \"", fd, int1, int2); + res += string_printf (" %d %d %d \"", fd, int1, int2); for (; c < cl; c++) - debug_printf (*c >= ' ' && *c <= '~' ? "%c" : "\\%o", *c); + res += string_printf (*c >= ' ' && *c <= '~' ? "%c" : "\\%o", *c); - debug_printf ("\""); + res += "\""; + + return res; } /* Forward declaration. */ @@ -390,12 +403,10 @@ mnsh_send_message (int sock, enum mnsh_msg_type type, if (size < 0) mnsh_maybe_mourn_peer (); - if (debug_linux_namespaces) - { - debug_printf ("mnsh: send: "); - mnsh_debug_print_message (type, fd, int1, int2, buf, bufsiz); - debug_printf (" -> %s\n", pulongest (size)); - } + linux_namespaces_debug_printf + ("send: %s -> %s", + mnsh_debug_print_message (type, fd, int1, int2, buf, bufsiz).c_str (), + pulongest (size)); return size; } @@ -445,9 +456,8 @@ mnsh_recv_message (int sock, enum mnsh_msg_type *type, size = recvmsg (sock, &msg, MSG_CMSG_CLOEXEC); if (size < 0) { - if (debug_linux_namespaces) - debug_printf ("namespace-helper: recv failed (%s)\n", - pulongest (size)); + linux_namespaces_debug_printf + ("namespace-helper: recv failed (%s)", pulongest (size)); mnsh_maybe_mourn_peer (); @@ -457,9 +467,9 @@ mnsh_recv_message (int sock, enum mnsh_msg_type *type, /* Check for truncation. */ if (size < fixed_size || (msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC))) { - if (debug_linux_namespaces) - debug_printf ("namespace-helper: recv truncated (%s 0x%x)\n", - pulongest (size), msg.msg_flags); + linux_namespaces_debug_printf + ("namespace-helper: recv truncated (%s 0x%x)", + pulongest (size), msg.msg_flags); mnsh_maybe_mourn_peer (); @@ -477,13 +487,10 @@ mnsh_recv_message (int sock, enum mnsh_msg_type *type, else *fd = -1; - if (debug_linux_namespaces) - { - debug_printf ("mnsh: recv: "); - mnsh_debug_print_message (*type, *fd, *int1, *int2, buf, - size - fixed_size); - debug_printf ("\n"); - } + linux_namespaces_debug_printf + ("recv: %s", + mnsh_debug_print_message (*type, *fd, *int1, *int2, buf, + size - fixed_size).c_str ()); /* Return the number of bytes of data in BUF. */ return size - fixed_size; @@ -514,6 +521,20 @@ mnsh_handle_setns (int sock, int fd, int nstype) return mnsh_return_int (sock, result, errno); } + +/* Handle a MNSH_REQ_LSTAT message. Must be async-signal-safe. */ + +static ssize_t +mnsh_handle_lstat (int sock, const char *filename) +{ + struct stat sb; + int stat_ok = lstat (filename, &sb); + + return mnsh_return_intstr (sock, stat_ok, &sb, + stat_ok == -1 ? 0 : sizeof (sb), + errno); +} + /* Handle a MNSH_REQ_OPEN message. Must be async-signal-safe. */ static ssize_t @@ -574,6 +595,11 @@ mnsh_main (int sock) response = mnsh_handle_setns (sock, fd, int1); break; + case MNSH_REQ_LSTAT: + if (size > 0 && buf[size - 1] == '\0') + response = mnsh_handle_lstat (sock, buf); + break; + case MNSH_REQ_OPEN: if (size > 0 && buf[size - 1] == '\0') response = mnsh_handle_open (sock, buf, int1, int2); @@ -673,7 +699,7 @@ linux_mntns_get_helper (void) mnsh_creator_pid = helper_creator; /* Debug printing isn't async-signal-safe. */ - debug_linux_namespaces = 0; + debug_linux_namespaces = false; mnsh_main (sv[1]); } @@ -685,9 +711,8 @@ linux_mntns_get_helper (void) helper->sock = sv[0]; helper->nsid = ns->id; - if (debug_linux_namespaces) - debug_printf ("Started mount namespace helper process %d\n", - helper->pid); + linux_namespaces_debug_printf + ("Started mount namespace helper process %d", helper->pid); } return helper; @@ -765,6 +790,10 @@ mnsh_maybe_mourn_peer (void) mnsh_send_message (helper->sock, MNSH_REQ_OPEN, -1, flags, mode, \ filename, strlen (filename) + 1) +#define mnsh_send_lstat(helper, filename) \ + mnsh_send_message (helper->sock, MNSH_REQ_LSTAT, -1, 0, 0, \ + filename, strlen (filename) + 1) + #define mnsh_send_unlink(helper, filename) \ mnsh_send_message (helper->sock, MNSH_REQ_UNLINK, -1, 0, 0, \ filename, strlen (filename) + 1) @@ -884,7 +913,7 @@ linux_mntns_access_fs (pid_t pid) struct stat sb; struct linux_mnsh *helper; ssize_t size; - int fd; + int fd, fd_user = -1; if (pid == getpid ()) return MNSH_FS_DIRECT; @@ -901,6 +930,8 @@ linux_mntns_access_fs (pid_t pid) { int save_errno = errno; close (fd); + if (fd_user >= 0) + close (fd_user); errno = save_errno; }; @@ -910,6 +941,13 @@ linux_mntns_access_fs (pid_t pid) if (sb.st_ino == ns->id) return MNSH_FS_DIRECT; + struct linux_ns *ns_user = linux_ns_get_namespace (LINUX_NS_USER); + if (ns_user != nullptr) + { + const char *ns_filename = linux_ns_filename (ns_user, pid); + fd_user = gdb_open_cloexec (ns_filename, O_RDONLY, 0).release (); + } + helper = linux_mntns_get_helper (); if (helper == NULL) return MNSH_FS_ERROR; @@ -918,6 +956,19 @@ linux_mntns_access_fs (pid_t pid) { int result, error; + /* Try to enter the user namespace first. The current user might + have elevated privileges within the user namespace, which would + then allow the attempt to enter the mount namespace to succeed. */ + if (fd_user >= 0) + { + size = mnsh_send_setns (helper, fd_user, 0); + if (size < 0) + return MNSH_FS_ERROR; + + if (mnsh_recv_int (helper, &result, &error) != 0) + return MNSH_FS_ERROR; + } + size = mnsh_send_setns (helper, fd, 0); if (size < 0) return MNSH_FS_ERROR; @@ -948,6 +999,42 @@ linux_mntns_access_fs (pid_t pid) /* See nat/linux-namespaces.h. */ int +linux_mntns_lstat (pid_t pid, const char *filename, + struct stat *sb) +{ + enum mnsh_fs_code access = linux_mntns_access_fs (pid); + + if (access == MNSH_FS_ERROR) + return -1; + + if (access == MNSH_FS_DIRECT) + return lstat (filename, sb); + + gdb_assert (access == MNSH_FS_HELPER); + + struct linux_mnsh *helper = linux_mntns_get_helper (); + + ssize_t size = mnsh_send_lstat (helper, filename); + if (size < 0) + return -1; + + int stat_ok, error; + size = mnsh_recv_intstr (helper, &stat_ok, &error, sb, sizeof (*sb)); + + if (size < 0) + { + stat_ok = -1; + errno = error; + } + else + gdb_assert (stat_ok == -1 || size == sizeof (*sb)); + + return stat_ok; +} + +/* See nat/linux-namespaces.h. */ + +int linux_mntns_open_cloexec (pid_t pid, const char *filename, int flags, mode_t mode) { diff --git a/gdb/nat/linux-namespaces.h b/gdb/nat/linux-namespaces.h index a548d83..a9a99f1 100644 --- a/gdb/nat/linux-namespaces.h +++ b/gdb/nat/linux-namespaces.h @@ -24,6 +24,12 @@ extern bool debug_linux_namespaces; +/* Print a "linux-namespaces" debug statement. */ + +#define linux_namespaces_debug_printf(fmt, ...) \ + debug_prefixed_printf_cond (debug_linux_namespaces, "linux-namespaces", \ + fmt, ##__VA_ARGS__) + /* Enumeration of Linux namespace types. */ enum linux_ns_type @@ -58,6 +64,11 @@ enum linux_ns_type extern int linux_ns_same (pid_t pid, enum linux_ns_type type); +/* Like lstat(2), but in the mount namespace of process PID. */ + +extern int linux_mntns_lstat (pid_t pid, const char *filename, + struct stat *sb); + /* Like gdb_open_cloexec, but in the mount namespace of process PID. */ diff --git a/gdb/nat/linux-procfs.c b/gdb/nat/linux-procfs.c index a72df2a..d4f9af3 100644 --- a/gdb/nat/linux-procfs.c +++ b/gdb/nat/linux-procfs.c @@ -424,7 +424,7 @@ linux_proc_task_list_dir_exists (pid_t pid) /* See linux-procfs.h. */ const char * -linux_proc_pid_to_exec_file (int pid) +linux_proc_pid_to_exec_file (int pid, bool is_local_fs) { static char buf[PATH_MAX]; char name[PATH_MAX]; @@ -437,9 +437,31 @@ linux_proc_pid_to_exec_file (int pid) else buf[len] = '\0'; - /* Use /proc/PID/exe if the actual file can't be read, but /proc/PID/exe - can be. */ - if (access (buf, R_OK) != 0 && access (name, R_OK) == 0) + /* If the inferior and GDB can see the same filesystem, and NAME + cannot be read, maybe the file has been deleted, then we can + potentially use /proc/PID/exe instead. + + GDB always interprets the results of this function within the + current sysroot (which is 'target:' by default). This means + that, if we return /proc/PID/exe, GDB will try to find this file + within the sysroot. + + This doesn't make sense if GDB is using a sysroot like: + '/some/random/directory/', not only is it possible that NAME + could be found within the sysroot, it is unlikely that + /proc/PID/exe will exist within the sysroot. + + Similarly, if the sysroot is 'target:', but the inferior is + running within a separate MNT namespace, then it is more than + likely that the inferior will also be running in a separate PID + namespace, in this case PID is the pid on the host system, + /proc/PID/exe will not be correct within the inferiors MNT/PID + namespace. + + So, we can fallback to use /proc/PID/exe only if IS_LOCAL_FS is + true, this indicates that GDB and the inferior are using the same + MNT namespace, and GDB's sysroot is either empty, or 'target:'. */ + if (is_local_fs && access (buf, R_OK) != 0 && access (name, R_OK) == 0) strcpy (buf, name); return buf; diff --git a/gdb/nat/linux-procfs.h b/gdb/nat/linux-procfs.h index 0c80622..4b02d31 100644 --- a/gdb/nat/linux-procfs.h +++ b/gdb/nat/linux-procfs.h @@ -87,9 +87,19 @@ extern int linux_proc_task_list_dir_exists (pid_t pid); /* Return the full absolute name of the executable file that was run to create the process PID. The returned value persists until this - function is next called. */ + function is next called. -extern const char *linux_proc_pid_to_exec_file (int pid); + LOCAL_FS should be true if the file returned from the function will + be searched for in the same filesystem as GDB itself is running. + In practice, this means LOCAL_FS should be true if PID and GDB are + running in the same MNT namespace and GDB's sysroot is either the + empty string, or is 'target:'. + + When used from gdbserver, where there is no sysroot, the only check + that matters is that PID and gdbserver are running in the same MNT + namespace. */ + +extern const char *linux_proc_pid_to_exec_file (int pid, bool local_fs); /* Display possible problems on this system. Display them only once per GDB execution. */ diff --git a/gdb/nat/linux-ptrace.c b/gdb/nat/linux-ptrace.c index 0510b39..f73058b 100644 --- a/gdb/nat/linux-ptrace.c +++ b/gdb/nat/linux-ptrace.c @@ -23,6 +23,7 @@ #include <sys/procfs.h> #endif #include "gdbsupport/eintr.h" +#include "gdbsupport/signals-state-save-restore.h" /* Stores the ptrace options supported by the running kernel. A value of -1 means we did not check for features yet. A value @@ -148,6 +149,9 @@ linux_ptrace_test_ret_to_nx (void) return; case 0: + /* Set signal handlers to their default because it doesn't make sense + to call GDB-specific handlers any more in the child process. */ + restore_original_signals_state (); l = ptrace (PTRACE_TRACEME, 0, (PTRACE_TYPE_ARG3) NULL, (PTRACE_TYPE_ARG4) NULL); if (l != 0) diff --git a/gdb/nat/x86-gcc-cpuid.h b/gdb/nat/x86-gcc-cpuid.h index 1498100..9e27fd8 100644 --- a/gdb/nat/x86-gcc-cpuid.h +++ b/gdb/nat/x86-gcc-cpuid.h @@ -1,5 +1,5 @@ /* - * Helper cpuid.h file copied from gcc-6.0.0. Code in gdb should not + * Helper cpuid.h file copied from gcc-14.2.0. Code in gdb should not * include this directly, but pull in x86-cpuid.h and use that func. */ @@ -55,7 +55,7 @@ #define bit_SSE (1 << 25) #define bit_SSE2 (1 << 26) -/* Extended Features */ +/* Extended Features (%eax == 0x80000001) */ /* %ecx */ #define bit_LAHF_LM (1 << 0) #define bit_ABM (1 << 5) @@ -68,29 +68,28 @@ #define bit_MWAITX (1 << 29) /* %edx */ -#define bit_AVX5124VNNIW (1 << 2) -#define bit_AVX5124FMAPS (1 << 3) #define bit_MMXEXT (1 << 22) #define bit_LM (1 << 29) #define bit_3DNOWP (1 << 30) -#define bit_3DNOW (1 << 31) +#define bit_3DNOW (1u << 31) -/* %ebx. */ +/* %ebx */ #define bit_CLZERO (1 << 0) +#define bit_WBNOINVD (1 << 9) -/* Extended Features (%eax == 7) */ +/* Extended Features Leaf (%eax == 7, %ecx == 0) */ /* %ebx */ #define bit_FSGSBASE (1 << 0) -#define bit_BMI (1 << 3) -#define bit_HLE (1 << 4) +#define bit_SGX (1 << 2) +#define bit_BMI (1 << 3) +#define bit_HLE (1 << 4) #define bit_AVX2 (1 << 5) #define bit_BMI2 (1 << 8) -#define bit_RTM (1 << 11) -#define bit_MPX (1 << 14) +#define bit_RTM (1 << 11) #define bit_AVX512F (1 << 16) #define bit_AVX512DQ (1 << 17) #define bit_RDSEED (1 << 18) -#define bit_ADX (1 << 19) +#define bit_ADX (1 << 19) #define bit_AVX512IFMA (1 << 21) #define bit_CLFLUSHOPT (1 << 23) #define bit_CLWB (1 << 24) @@ -99,23 +98,85 @@ #define bit_AVX512CD (1 << 28) #define bit_SHA (1 << 29) #define bit_AVX512BW (1 << 30) -#define bit_AVX512VL (1 << 31) +#define bit_AVX512VL (1u << 31) /* %ecx */ -#define bit_PREFETCHWT1 (1 << 0) +#define bit_PREFETCHWT1 (1 << 0) #define bit_AVX512VBMI (1 << 1) -#define bit_PKU (1 << 3) +#define bit_PKU (1 << 3) #define bit_OSPKE (1 << 4) +#define bit_WAITPKG (1 << 5) +#define bit_AVX512VBMI2 (1 << 6) +#define bit_SHSTK (1 << 7) +#define bit_GFNI (1 << 8) +#define bit_VAES (1 << 9) +#define bit_VPCLMULQDQ (1 << 10) +#define bit_AVX512VNNI (1 << 11) +#define bit_AVX512BITALG (1 << 12) +#define bit_AVX512VPOPCNTDQ (1 << 14) +#define bit_RDPID (1 << 22) +#define bit_KL (1 << 23) +#define bit_CLDEMOTE (1 << 25) +#define bit_MOVDIRI (1 << 27) +#define bit_MOVDIR64B (1 << 28) +#define bit_ENQCMD (1 << 29) -/* XFEATURE_ENABLED_MASK register bits (%eax == 13, %ecx == 0) */ -#define bit_BNDREGS (1 << 3) -#define bit_BNDCSR (1 << 4) +/* %edx */ +#define bit_AVX5124VNNIW (1 << 2) +#define bit_AVX5124FMAPS (1 << 3) +#define bit_UINTR (1 << 5) +#define bit_AVX512VP2INTERSECT (1 << 8) +#define bit_SERIALIZE (1 << 14) +#define bit_TSXLDTRK (1 << 16) +#define bit_PCONFIG (1 << 18) +#define bit_IBT (1 << 20) +#define bit_AMX_BF16 (1 << 22) +#define bit_AVX512FP16 (1 << 23) +#define bit_AMX_TILE (1 << 24) +#define bit_AMX_INT8 (1 << 25) + +/* Extended Features Sub-leaf (%eax == 7, %ecx == 1) */ +/* %eax */ +#define bit_SHA512 (1 << 0) +#define bit_SM3 (1 << 1) +#define bit_SM4 (1 << 2) +#define bit_RAOINT (1 << 3) +#define bit_AVXVNNI (1 << 4) +#define bit_AVX512BF16 (1 << 5) +#define bit_CMPCCXADD (1 << 7) +#define bit_AMX_COMPLEX (1 << 8) +#define bit_AMX_FP16 (1 << 21) +#define bit_HRESET (1 << 22) +#define bit_AVXIFMA (1 << 23) -/* Extended State Enumeration Sub-leaf (%eax == 13, %ecx == 1) */ +/* %edx */ +#define bit_AVXVNNIINT8 (1 << 4) +#define bit_AVXNECONVERT (1 << 5) +#define bit_AVXVNNIINT16 (1 << 10) +#define bit_PREFETCHI (1 << 14) +#define bit_USER_MSR (1 << 15) +#define bit_AVX10 (1 << 19) +#define bit_APX_F (1 << 21) + +/* Extended State Enumeration Sub-leaf (%eax == 0xd, %ecx == 1) */ #define bit_XSAVEOPT (1 << 0) #define bit_XSAVEC (1 << 1) #define bit_XSAVES (1 << 3) +/* PT sub leaf (%eax == 0x14, %ecx == 0) */ +/* %ebx */ +#define bit_PTWRITE (1 << 4) + +/* Keylocker leaf (%eax == 0x19) */ +/* %ebx */ +#define bit_AESKLE ( 1<<0 ) +#define bit_WIDEKL ( 1<<2 ) + +/* AVX10 sub leaf (%eax == 0x24) */ +/* %ebx */ +#define bit_AVX10_256 (1 << 17) +#define bit_AVX10_512 (1 << 18) + /* Signatures for different CPU implementations as returned in uses of cpuid with level 0. */ #define signature_AMD_ebx 0x68747541 @@ -170,19 +231,40 @@ #define signature_VORTEX_ecx 0x436f5320 #define signature_VORTEX_edx 0x36387865 -#define __cpuid(level, a, b, c, d) \ - __asm__ ("cpuid\n\t" \ - : "=a" (a), "=b" (b), "=c" (c), "=d" (d) \ - : "0" (level)) +#define signature_SHANGHAI_ebx 0x68532020 +#define signature_SHANGHAI_ecx 0x20206961 +#define signature_SHANGHAI_edx 0x68676e61 -#define __cpuid_count(level, count, a, b, c, d) \ - __asm__ ("cpuid\n\t" \ - : "=a" (a), "=b" (b), "=c" (c), "=d" (d) \ - : "0" (level), "2" (count)) +#ifndef __x86_64__ +/* At least one cpu (Winchip 2) does not set %ebx and %ecx + for cpuid leaf 1. Forcibly zero the two registers before + calling cpuid as a precaution. */ +#define __cpuid(level, a, b, c, d) \ + do { \ + if (__builtin_constant_p (level) && (level) != 1) \ + __asm__ __volatile__ ("cpuid\n\t" \ + : "=a" (a), "=b" (b), "=c" (c), "=d" (d) \ + : "0" (level)); \ + else \ + __asm__ __volatile__ ("cpuid\n\t" \ + : "=a" (a), "=b" (b), "=c" (c), "=d" (d) \ + : "0" (level), "1" (0), "2" (0)); \ + } while (0) +#else +#define __cpuid(level, a, b, c, d) \ + __asm__ __volatile__ ("cpuid\n\t" \ + : "=a" (a), "=b" (b), "=c" (c), "=d" (d) \ + : "0" (level)) +#endif + +#define __cpuid_count(level, count, a, b, c, d) \ + __asm__ __volatile__ ("cpuid\n\t" \ + : "=a" (a), "=b" (b), "=c" (c), "=d" (d) \ + : "0" (level), "2" (count)) /* Return highest supported input value for cpuid instruction. ext can - be either 0x0 or 0x8000000 to return highest supported value for + be either 0x0 or 0x80000000 to return highest supported value for basic or extended cpuid information. Function returns 0 if cpuid is not supported or whatever cpuid returns in eax register. If sig pointer is non-null, then first four bytes of the signature @@ -225,7 +307,7 @@ __get_cpuid_max (unsigned int __ext, unsigned int *__sig) : "i" (0x00200000)); #endif - if (!((__eax ^ __ebx) & 0x00200000)) + if (__builtin_expect (!((__eax ^ __ebx) & 0x00200000), 0)) return 0; #endif @@ -249,8 +331,9 @@ __get_cpuid (unsigned int __leaf, unsigned int *__ecx, unsigned int *__edx) { unsigned int __ext = __leaf & 0x80000000; + unsigned int __maxlevel = __get_cpuid_max (__ext, 0); - if (__get_cpuid_max (__ext, 0) < __leaf) + if (__maxlevel == 0 || __maxlevel < __leaf) return 0; __cpuid (__leaf, *__eax, *__ebx, *__ecx, *__edx); @@ -265,12 +348,20 @@ __get_cpuid_count (unsigned int __leaf, unsigned int __subleaf, unsigned int *__ecx, unsigned int *__edx) { unsigned int __ext = __leaf & 0x80000000; + unsigned int __maxlevel = __get_cpuid_max (__ext, 0); - if (__get_cpuid_max (__ext, 0) < __leaf) + if (__builtin_expect (__maxlevel == 0, 0) || __maxlevel < __leaf) return 0; __cpuid_count (__leaf, __subleaf, *__eax, *__ebx, *__ecx, *__edx); return 1; } +static __inline void +__cpuidex (int __cpuid_info[4], int __leaf, int __subleaf) +{ + __cpuid_count (__leaf, __subleaf, __cpuid_info[0], __cpuid_info[1], + __cpuid_info[2], __cpuid_info[3]); +} + #endif /* GDB_NAT_X86_GCC_CPUID_H */ diff --git a/gdb/nat/x86-linux-tdesc.c b/gdb/nat/x86-linux-tdesc.c index 80e4337..5bc36b6 100644 --- a/gdb/nat/x86-linux-tdesc.c +++ b/gdb/nat/x86-linux-tdesc.c @@ -43,7 +43,7 @@ /* See nat/x86-linux-tdesc.h. */ const target_desc * -x86_linux_tdesc_for_tid (int tid, uint64_t *xcr0_storage, +x86_linux_tdesc_for_tid (int tid, uint64_t *xstate_bv_storage, x86_xsave_layout *xsave_layout_storage) { #ifdef __x86_64__ @@ -96,30 +96,34 @@ x86_linux_tdesc_for_tid (int tid, uint64_t *xcr0_storage, these bits being set we generate a completely empty tdesc for i386 which will be rejected by GDB. */ have_ptrace_getregset = TRIBOOL_FALSE; - *xcr0_storage = X86_XSTATE_SSE_MASK; + *xstate_bv_storage = X86_XSTATE_SSE_MASK; } else { have_ptrace_getregset = TRIBOOL_TRUE; /* Get XCR0 from XSAVE extended state. */ - *xcr0_storage = xstateregs[(I386_LINUX_XSAVE_XCR0_OFFSET + uint64_t xcr0 = xstateregs[(I386_LINUX_XSAVE_XCR0_OFFSET / sizeof (uint64_t))]; *xsave_layout_storage - = x86_fetch_xsave_layout (*xcr0_storage, x86_xsave_length ()); + = x86_fetch_xsave_layout (xcr0, x86_xsave_length ()); + + *xstate_bv_storage = xcr0; + if (x86_check_ssp_support (tid)) + *xstate_bv_storage |= X86_XSTATE_CET_U; } } - /* Use cached xcr0 value. */ - uint64_t xcr0_features_bits = *xcr0_storage & X86_XSTATE_ALL_MASK; + /* Use cached XSTATE_BV_STORAGE value. */ + uint64_t xstate_bv_features_bits = *xstate_bv_storage & X86_XSTATE_ALL_MASK; #ifdef __x86_64__ if (is_64bit) - return amd64_linux_read_description (xcr0_features_bits, is_x32); + return amd64_linux_read_description (xstate_bv_features_bits, is_x32); else #endif - return i386_linux_read_description (xcr0_features_bits); + return i386_linux_read_description (xstate_bv_features_bits); } #endif /* !IN_PROCESS_AGENT */ diff --git a/gdb/nat/x86-linux-tdesc.h b/gdb/nat/x86-linux-tdesc.h index 38c71f1..19aa84f 100644 --- a/gdb/nat/x86-linux-tdesc.h +++ b/gdb/nat/x86-linux-tdesc.h @@ -27,9 +27,9 @@ struct x86_xsave_layout; /* Return the target description for Linux thread TID. - The storage pointed to by XCR0_STORAGE and XSAVE_LAYOUT_STORAGE must + The storage pointed to by XSTATE_BV_STORAGE and XSAVE_LAYOUT_STORAGE must exist until the program (GDB or gdbserver) terminates, this storage is - used to cache the xcr0 and xsave layout values. The values pointed to + used to cache the xstate_bv and xsave layout values. The values pointed to by these arguments are only updated at most once, the first time this function is called if the have_ptrace_getregset global is set to TRIBOOL_UNKNOWN. @@ -45,6 +45,7 @@ struct x86_xsave_layout; returned. */ extern const target_desc *x86_linux_tdesc_for_tid - (int tid, uint64_t *xcr0_storage, x86_xsave_layout *xsave_layout_storage); + (int tid, uint64_t *xstate_bv_storage, + x86_xsave_layout *xsave_layout_storage); #endif /* GDB_NAT_X86_LINUX_TDESC_H */ diff --git a/gdb/nat/x86-linux.c b/gdb/nat/x86-linux.c index 0bdff73..5515826 100644 --- a/gdb/nat/x86-linux.c +++ b/gdb/nat/x86-linux.c @@ -17,6 +17,12 @@ You should have received a copy of the GNU General Public License along with this program. If not, see <http://www.gnu.org/licenses/>. */ +#include "elf/common.h" +#include "gdbsupport/common-defs.h" +#include "nat/gdb_ptrace.h" +#include "nat/linux-ptrace.h" +#include "nat/x86-cpuid.h" +#include <sys/uio.h> #include "x86-linux.h" #include "x86-linux-dregs.h" #include "nat/gdb_ptrace.h" @@ -126,3 +132,56 @@ x86_linux_ptrace_get_arch_size (int tid) return x86_linux_arch_size (false, false); #endif } + +/* See nat/x86-linux.h. */ + +bool +x86_check_ssp_support (const int tid) +{ + /* It's not enough to check shadow stack support with the ptrace call + below only, as we cannot distinguish between shadow stack not enabled + for the current thread and shadow stack is not supported by HW. In + both scenarios the ptrace call fails with ENODEV. In case shadow + stack is not enabled for the current thread, we still want to return + true. */ + unsigned int eax, ebx, ecx, edx; + eax = ebx = ecx = edx = 0; + + if (!__get_cpuid_count (7, 0, &eax, &ebx, &ecx, &edx)) + return false; + + if ((ecx & bit_SHSTK) == 0) + return false; + + /* Further check for NT_X86_SHSTK kernel support. */ + uint64_t ssp; + iovec iov {&ssp, sizeof (ssp) }; + + errno = 0; + int res = ptrace (PTRACE_GETREGSET, tid, NT_X86_SHSTK, &iov); + if (res < 0) + { + if (errno == EINVAL) + { + /* The errno EINVAL for a PTRACE_GETREGSET call indicates that + kernel support is not available. */ + return false; + } + else if (errno == ENODEV) + { + /* At this point, since we already checked CPUID, the errno + ENODEV for a PTRACE_GETREGSET call indicates that shadow + stack is not enabled for the current thread. As it could be + enabled later, we still want to return true here. */ + return true; + } + else + { + warning (_("Unknown ptrace error for NT_X86_SHSTK: %s"), + safe_strerror (errno)); + return false; + } + } + + return true; +} diff --git a/gdb/nat/x86-linux.h b/gdb/nat/x86-linux.h index dbdef08..1783aae 100644 --- a/gdb/nat/x86-linux.h +++ b/gdb/nat/x86-linux.h @@ -75,4 +75,8 @@ private: extern x86_linux_arch_size x86_linux_ptrace_get_arch_size (int tid); +/* Check shadow stack hardware and kernel support. */ + +extern bool x86_check_ssp_support (const int tid); + #endif /* GDB_NAT_X86_LINUX_H */ |