From 4fc3cdde40f977ee8deecf988eea7acfa373117a Mon Sep 17 00:00:00 2001 From: Filip Bozuta Date: Fri, 19 Jun 2020 14:33:28 +0200 Subject: [PATCH] linux-user: Add strace support for printing argument of syscalls used for extended attributes This patch implements strace argument printing functionality for following syscalls: *getxattr, lgetxattr, fgetxattr - retrieve an extended attribute value ssize_t getxattr(const char *path, const char *name, void *value, size_t size) ssize_t lgetxattr(const char *path, const char *name, void *value, size_t size) ssize_t fgetxattr(int fd, const char *name, void *value, size_t size) man page: https://www.man7.org/linux/man-pages/man2/getxattr.2.html *listxattr, llistxattr, flistxattr - list extended attribute names ssize_t listxattr(const char *path, char *list, size_t size) ssize_t llistxattr(const char *path, char *list, size_t size) ssize_t flistxattr(int fd, char *list, size_t size) man page: https://www.man7.org/linux/man-pages/man2/listxattr.2.html *removexattr, lremovexattr, fremovexattr - remove an extended attribute int removexattr(const char *path, const char *name) int lremovexattr(const char *path, const char *name) int fremovexattr(int fd, const char *name) man page: https://www.man7.org/linux/man-pages/man2/removexattr.2.html Implementation notes: All of the syscalls have strings as argument types and thus a separate printing function was stated in file "strace.list" for every one of them. All of these printing functions were defined in "strace.c" using existing printing functions for appropriate argument types: "print_string()" - for (const char*) type "print_pointer()" - for (char*) and (void *) type "print_raw_param()" for (int) and (size_t) type Syscalls "getxattr()" and "lgetxattr()" have the same number and type of arguments and thus their print functions ("print_getxattr", "print_lgetxattr") share a same definition. The same statement applies to syscalls "listxattr()" and "llistxattr()". Function "print_syscall_ret_listxattr()" was added to print the returned list of extended attributes for syscalls "print_listxattr(), print_llistxattr() and print_flistxattr()". Signed-off-by: Filip Bozuta Reviewed-by: Laurent Vivier Message-Id: <20200619123331.17387-4-filip.bozuta@syrmia.com> Signed-off-by: Laurent Vivier --- linux-user/strace.c | 121 +++++++++++++++++++++++++++++++++++++++++ linux-user/strace.list | 21 ++++--- 2 files changed, 133 insertions(+), 9 deletions(-) diff --git a/linux-user/strace.c b/linux-user/strace.c index 123e022c35..760020132b 100644 --- a/linux-user/strace.c +++ b/linux-user/strace.c @@ -826,6 +826,40 @@ print_syscall_ret_adjtimex(const struct syscallname *name, abi_long ret, } #endif +#if defined(TARGET_NR_listxattr) || defined(TARGET_NR_llistxattr) \ + || defined(TARGGET_NR_flistxattr) +static void +print_syscall_ret_listxattr(const struct syscallname *name, abi_long ret, + abi_long arg0, abi_long arg1, abi_long arg2, + abi_long arg3, abi_long arg4, abi_long arg5) +{ + print_syscall_err(ret); + + if (ret >= 0) { + qemu_log(TARGET_ABI_FMT_ld, ret); + qemu_log(" (list = "); + if (arg1 != 0) { + abi_long attr = arg1; + while (ret) { + if (attr != arg1) { + qemu_log(","); + } + print_string(attr, 1); + ret -= target_strlen(attr) + 1; + attr += target_strlen(attr) + 1; + } + } else { + qemu_log("NULL"); + } + qemu_log(")"); + } + + qemu_log("\n"); +} +#define print_syscall_ret_llistxattr print_syscall_ret_listxattr +#define print_syscall_ret_flistxattr print_syscall_ret_listxattr +#endif + UNUSED static struct flags access_flags[] = { FLAG_GENERIC(F_OK), FLAG_GENERIC(R_OK), @@ -1633,6 +1667,93 @@ print_fcntl(const struct syscallname *name, #define print_fcntl64 print_fcntl #endif +#ifdef TARGET_NR_fgetxattr +static void +print_fgetxattr(const struct syscallname *name, + abi_long arg0, abi_long arg1, abi_long arg2, + abi_long arg3, abi_long arg4, abi_long arg5) +{ + print_syscall_prologue(name); + print_raw_param("%d", arg0, 0); + print_string(arg1, 0); + print_pointer(arg2, 0); + print_raw_param(TARGET_FMT_lu, arg3, 1); + print_syscall_epilogue(name); +} +#endif + +#ifdef TARGET_NR_flistxattr +static void +print_flistxattr(const struct syscallname *name, + abi_long arg0, abi_long arg1, abi_long arg2, + abi_long arg3, abi_long arg4, abi_long arg5) +{ + print_syscall_prologue(name); + print_raw_param("%d", arg0, 0); + print_pointer(arg1, 0); + print_raw_param(TARGET_FMT_lu, arg2, 1); + print_syscall_epilogue(name); +} +#endif + +#if defined(TARGET_NR_getxattr) || defined(TARGET_NR_lgetxattr) +static void +print_getxattr(const struct syscallname *name, + abi_long arg0, abi_long arg1, abi_long arg2, + abi_long arg3, abi_long arg4, abi_long arg5) +{ + print_syscall_prologue(name); + print_string(arg0, 0); + print_string(arg1, 0); + print_pointer(arg2, 0); + print_raw_param(TARGET_FMT_lu, arg3, 1); + print_syscall_epilogue(name); +} +#define print_lgetxattr print_getxattr +#endif + +#if defined(TARGET_NR_listxattr) || defined(TARGET_NR_llistxattr) +static void +print_listxattr(const struct syscallname *name, + abi_long arg0, abi_long arg1, abi_long arg2, + abi_long arg3, abi_long arg4, abi_long arg5) +{ + print_syscall_prologue(name); + print_string(arg0, 0); + print_pointer(arg1, 0); + print_raw_param(TARGET_FMT_lu, arg2, 1); + print_syscall_epilogue(name); +} +#define print_llistxattr print_listxattr +#endif + +#if defined(TARGET_NR_fremovexattr) +static void +print_fremovexattr(const struct syscallname *name, + abi_long arg0, abi_long arg1, abi_long arg2, + abi_long arg3, abi_long arg4, abi_long arg5) +{ + print_syscall_prologue(name); + print_raw_param("%d", arg0, 0); + print_string(arg1, 1); + print_syscall_epilogue(name); +} +#endif + +#if defined(TARGET_NR_removexattr) || defined(TARGET_NR_lremovexattr) +static void +print_removexattr(const struct syscallname *name, + abi_long arg0, abi_long arg1, abi_long arg2, + abi_long arg3, abi_long arg4, abi_long arg5) +{ + print_syscall_prologue(name); + print_string(arg0, 0); + print_string(arg1, 1); + print_syscall_epilogue(name); +} +#define print_lremovexattr print_removexattr +#endif + #ifdef TARGET_NR_futimesat static void print_futimesat(const struct syscallname *name, diff --git a/linux-user/strace.list b/linux-user/strace.list index 8a887fc16d..d04ad507b0 100644 --- a/linux-user/strace.list +++ b/linux-user/strace.list @@ -218,13 +218,14 @@ { TARGET_NR_fdatasync, "fdatasync" , "%s(%d)", NULL, NULL }, #endif #ifdef TARGET_NR_fgetxattr -{ TARGET_NR_fgetxattr, "fgetxattr" , NULL, NULL, NULL }, +{ TARGET_NR_fgetxattr, "fgetxattr" , NULL, print_fgetxattr, NULL }, #endif #ifdef TARGET_NR_finit_module { TARGET_NR_finit_module, "finit_module" , NULL, NULL, NULL }, #endif #ifdef TARGET_NR_flistxattr -{ TARGET_NR_flistxattr, "flistxattr" , NULL, NULL, NULL }, +{ TARGET_NR_flistxattr, "flistxattr" , NULL, print_flistxattr, + print_syscall_ret_flistxattr}, #endif #ifdef TARGET_NR_flock { TARGET_NR_flock, "flock" , NULL, NULL, NULL }, @@ -233,7 +234,7 @@ { TARGET_NR_fork, "fork" , "%s()", NULL, NULL }, #endif #ifdef TARGET_NR_fremovexattr -{ TARGET_NR_fremovexattr, "fremovexattr" , NULL, NULL, NULL }, +{ TARGET_NR_fremovexattr, "fremovexattr" , NULL, print_fremovexattr, NULL }, #endif #ifdef TARGET_NR_fsetxattr { TARGET_NR_fsetxattr, "fsetxattr" , NULL, NULL, NULL }, @@ -396,7 +397,7 @@ { TARGET_NR_getuid32, "getuid32" , NULL, NULL, NULL }, #endif #ifdef TARGET_NR_getxattr -{ TARGET_NR_getxattr, "getxattr" , NULL, NULL, NULL }, +{ TARGET_NR_getxattr, "getxattr" , NULL, print_getxattr, NULL }, #endif #ifdef TARGET_NR_getxgid { TARGET_NR_getxgid, "getxgid" , NULL, NULL, NULL }, @@ -480,7 +481,7 @@ { TARGET_NR_lchown32, "lchown32" , NULL, NULL, NULL }, #endif #ifdef TARGET_NR_lgetxattr -{ TARGET_NR_lgetxattr, "lgetxattr" , NULL, NULL, NULL }, +{ TARGET_NR_lgetxattr, "lgetxattr" , NULL, print_lgetxattr, NULL }, #endif #ifdef TARGET_NR_link { TARGET_NR_link, "link" , NULL, print_link, NULL }, @@ -495,10 +496,12 @@ { TARGET_NR_listen, "listen" , "%s(%d,%d)", NULL, NULL }, #endif #ifdef TARGET_NR_listxattr -{ TARGET_NR_listxattr, "listxattr" , NULL, NULL, NULL }, +{ TARGET_NR_listxattr, "listxattr" , NULL, print_listxattr, + print_syscall_ret_listxattr}, #endif #ifdef TARGET_NR_llistxattr -{ TARGET_NR_llistxattr, "llistxattr" , NULL, NULL, NULL }, +{ TARGET_NR_llistxattr, "llistxattr" , NULL, print_llistxattr, + print_syscall_ret_llistxattr}, #endif #ifdef TARGET_NR__llseek { TARGET_NR__llseek, "_llseek" , NULL, print__llseek, NULL }, @@ -510,7 +513,7 @@ { TARGET_NR_lookup_dcookie, "lookup_dcookie" , NULL, NULL, NULL }, #endif #ifdef TARGET_NR_lremovexattr -{ TARGET_NR_lremovexattr, "lremovexattr" , NULL, NULL, NULL }, +{ TARGET_NR_lremovexattr, "lremovexattr" , NULL, print_lremovexattr, NULL }, #endif #ifdef TARGET_NR_lseek { TARGET_NR_lseek, "lseek" , NULL, NULL, NULL }, @@ -1116,7 +1119,7 @@ { TARGET_NR_remap_file_pages, "remap_file_pages" , NULL, NULL, NULL }, #endif #ifdef TARGET_NR_removexattr -{ TARGET_NR_removexattr, "removexattr" , NULL, NULL, NULL }, +{ TARGET_NR_removexattr, "removexattr" , NULL, print_removexattr, NULL }, #endif #ifdef TARGET_NR_rename { TARGET_NR_rename, "rename" , NULL, print_rename, NULL },