diff options
author | Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> | 2006-04-11 01:53:37 -0400 |
---|---|---|
committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-04-11 09:18:36 -0400 |
commit | b1c332c9e813cbee6ca77c3a66ee4d312eb96770 (patch) | |
tree | 8ce0329e77d6c293b0c15ef1d163a81cb1e1a950 /arch/um | |
parent | e6fb54abb8a36703f54b7e27a756a3df6667c37b (diff) |
[PATCH] uml: fix hang on run_helper() failure on uml_net
Fix an hang on a pipe when run_helper() fails when called by change_tramp()
(i.e. when calling uml_net) - reproduced the bug and verified this fixes it.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/um')
-rw-r--r-- | arch/um/drivers/net_user.c | 4 | ||||
-rw-r--r-- | arch/um/os-Linux/helper.c | 10 |
2 files changed, 8 insertions, 6 deletions
diff --git a/arch/um/drivers/net_user.c b/arch/um/drivers/net_user.c index 0e2f06187ea7..0a7786e00cfb 100644 --- a/arch/um/drivers/net_user.c +++ b/arch/um/drivers/net_user.c | |||
@@ -182,7 +182,9 @@ static int change_tramp(char **argv, char *output, int output_len) | |||
182 | pe_data.stdout = fds[1]; | 182 | pe_data.stdout = fds[1]; |
183 | pid = run_helper(change_pre_exec, &pe_data, argv, NULL); | 183 | pid = run_helper(change_pre_exec, &pe_data, argv, NULL); |
184 | 184 | ||
185 | read_output(fds[0], output, output_len); | 185 | if (pid > 0) /* Avoid hang as we won't get data in failure case. */ |
186 | read_output(fds[0], output, output_len); | ||
187 | |||
186 | os_close_file(fds[0]); | 188 | os_close_file(fds[0]); |
187 | os_close_file(fds[1]); | 189 | os_close_file(fds[1]); |
188 | 190 | ||
diff --git a/arch/um/os-Linux/helper.c b/arch/um/os-Linux/helper.c index 6490a4ff40ac..6987d1d247a2 100644 --- a/arch/um/os-Linux/helper.c +++ b/arch/um/os-Linux/helper.c | |||
@@ -43,7 +43,7 @@ static int helper_child(void *arg) | |||
43 | (*data->pre_exec)(data->pre_data); | 43 | (*data->pre_exec)(data->pre_data); |
44 | execvp(argv[0], argv); | 44 | execvp(argv[0], argv); |
45 | errval = errno; | 45 | errval = errno; |
46 | printk("execvp of '%s' failed - errno = %d\n", argv[0], errno); | 46 | printk("helper_child - execve of '%s' failed - errno = %d\n", argv[0], errno); |
47 | os_write_file(data->fd, &errval, sizeof(errval)); | 47 | os_write_file(data->fd, &errval, sizeof(errval)); |
48 | kill(os_getpid(), SIGKILL); | 48 | kill(os_getpid(), SIGKILL); |
49 | return(0); | 49 | return(0); |
@@ -92,15 +92,15 @@ int run_helper(void (*pre_exec)(void *), void *pre_data, char **argv, | |||
92 | close(fds[1]); | 92 | close(fds[1]); |
93 | fds[1] = -1; | 93 | fds[1] = -1; |
94 | 94 | ||
95 | /*Read the errno value from the child.*/ | 95 | /* Read the errno value from the child, if the exec failed, or get 0 if |
96 | * the exec succeeded because the pipe fd was set as close-on-exec. */ | ||
96 | n = os_read_file(fds[0], &ret, sizeof(ret)); | 97 | n = os_read_file(fds[0], &ret, sizeof(ret)); |
97 | if(n < 0){ | 98 | if (n < 0) { |
98 | printk("run_helper : read on pipe failed, ret = %d\n", -n); | 99 | printk("run_helper : read on pipe failed, ret = %d\n", -n); |
99 | ret = n; | 100 | ret = n; |
100 | kill(pid, SIGKILL); | 101 | kill(pid, SIGKILL); |
101 | CATCH_EINTR(waitpid(pid, NULL, 0)); | 102 | CATCH_EINTR(waitpid(pid, NULL, 0)); |
102 | } | 103 | } else if(n != 0){ |
103 | else if(n != 0){ | ||
104 | CATCH_EINTR(n = waitpid(pid, NULL, 0)); | 104 | CATCH_EINTR(n = waitpid(pid, NULL, 0)); |
105 | ret = -errno; | 105 | ret = -errno; |
106 | } else { | 106 | } else { |