glebfm/strace
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

ia64: do not bail out in get_syscall_args if umove fails with EPERM

Browse Source 
If the kernel contains commit 84d77d3f06e7e8dea057d10e8ec77ad71f721be3,
both PTRACE_PEEKDATA and process_vm_readv become unavailable when the
process dumpable flag is cleared, on ia64 this results to all syscall
arguments being unavailable.

Recognize this situation and do not treat it as get_syscall_args error
because the latter leaves the tracee in a ptrace stop.

This condition used to be triggered by prctl-dumpable test that caused
strace to hang indefinitely.

* linux/ia64/get_syscall_args.c (get_syscall_args): Do not bail out
if umove fails.
* tests/prctl-dumpable.c [__ia64__]: Skip the test.
This commit is contained in:
Дмитрий Левин 2018-01-24 01:56:15 +00:00
parent 5fcdae5359
commit c7e8fc0e63
2 changed files with 10 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
linux/ia64/get_syscall_args.c
View File

@ -15,8 +15,12 @@ get_syscall_args(struct tcb *tcp)
for (i = 0; i < tcp->s_ent->nargs; ++i) {
if (umove(tcp,
(unsigned long) ia64_rse_skip_regs(out0, i),
&tcp->u_arg[i]) < 0)
return -1;
&tcp->u_arg[i]) < 0) {
if (errno == EPERM)
tcp->u_arg[i] = 0;
else
return -1;
}
}
} else {
/* truncate away IVE sign-extension */

6
tests/prctl-dumpable.c
View File

@ -32,7 +32,8 @@
#include <asm/unistd.h>
#include <linux/prctl.h>
#if defined __NR_prctl && defined PR_GET_DUMPABLE && defined PR_SET_DUMPABLE
#if defined __NR_prctl && defined PR_GET_DUMPABLE && defined PR_SET_DUMPABLE \
&& !defined __ia64__
# include <stdio.h>
# include <unistd.h>
@ -101,6 +102,7 @@ main(void)
#else
SKIP_MAIN_UNDEFINED("__NR_prctl && PR_GET_DUMPABLE && PR_SET_DUMPABLE")
SKIP_MAIN_UNDEFINED("__NR_prctl && PR_GET_DUMPABLE && PR_SET_DUMPABLE"
" && !__ia64__")
#endif