X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=src%2Fcommon%2Frunas.c;fp=src%2Fcommon%2Frunas.c;h=e0c317c4e40347fb7001b74fb9900e9bcfafe32f;hb=e71aad1fa4b06a5f91ddceace42366f3d79bd77e;hp=60e02a2bf85a4e22ff363d2a6ede3cfc1a0fd277;hpb=4c462e790c62ed5f6c5d61b3a182762fe02f7e9a;p=lttng-tools.git diff --git a/src/common/runas.c b/src/common/runas.c index 60e02a2bf..e0c317c4e 100644 --- a/src/common/runas.c +++ b/src/common/runas.c @@ -28,16 +28,29 @@ #include #include #include -#include +#include #include +#include +#include #include "runas.h" #define RUNAS_CHILD_STACK_SIZE 10485760 -#ifndef MAP_STACK -#define MAP_STACK 0 +#ifdef __FreeBSD__ +/* FreeBSD MAP_STACK always return -ENOMEM */ +#define LTTNG_MAP_STACK 0 +#else +#define LTTNG_MAP_STACK MAP_STACK +#endif + +#ifndef MAP_GROWSDOWN +#define MAP_GROWSDOWN 0 +#endif + +#ifndef MAP_ANONYMOUS +#define MAP_ANONYMOUS MAP_ANON #endif struct run_as_data { @@ -187,7 +200,7 @@ int child_run_as(void *_data) } static -int run_as(int (*cmd)(void *data), void *data, uid_t uid, gid_t gid) +int run_as_clone(int (*cmd)(void *data), void *data, uid_t uid, gid_t gid) { struct run_as_data run_as_data; int ret = 0; @@ -225,7 +238,7 @@ int run_as(int (*cmd)(void *data), void *data, uid_t uid, gid_t gid) run_as_data.retval_pipe = retval_pipe[1]; /* write end */ child_stack = mmap(NULL, RUNAS_CHILD_STACK_SIZE, PROT_WRITE | PROT_READ, - MAP_PRIVATE | MAP_GROWSDOWN | MAP_ANONYMOUS | MAP_STACK, + MAP_PRIVATE | MAP_GROWSDOWN | MAP_ANONYMOUS | LTTNG_MAP_STACK, -1, 0); if (child_stack == MAP_FAILED) { PERROR("mmap"); @@ -236,9 +249,8 @@ int run_as(int (*cmd)(void *data), void *data, uid_t uid, gid_t gid) * Pointing to the middle of the stack to support architectures * where the stack grows up (HPPA). */ - pid = clone(child_run_as, child_stack + (RUNAS_CHILD_STACK_SIZE / 2), - CLONE_FILES | SIGCHLD, - &run_as_data, NULL); + pid = lttng_clone_files(child_run_as, child_stack + (RUNAS_CHILD_STACK_SIZE / 2), + &run_as_data); if (pid < 0) { PERROR("clone"); retval.i = pid; @@ -286,6 +298,29 @@ end: return retval.i; } +/* + * To be used on setups where gdb has issues debugging programs using + * clone/rfork. Note that this is for debuging ONLY, and should not be + * considered secure. + */ +static +int run_as_noclone(int (*cmd)(void *data), void *data, uid_t uid, gid_t gid) +{ + return cmd(data); +} + +static +int run_as(int (*cmd)(void *data), void *data, uid_t uid, gid_t gid) +{ + if (!getenv("LTTNG_DEBUG_NOCLONE")) { + DBG("Using run_as_clone"); + return run_as_clone(cmd, data, uid, gid); + } else { + DBG("Using run_as_noclone"); + return run_as_noclone(cmd, data, uid, gid); + } +} + int run_as_mkdir_recursive(const char *path, mode_t mode, uid_t uid, gid_t gid) { struct run_as_mkdir_data data;