diff options
| author | Jeff Dike <jdike@addtoit.com> | 2007-06-05 16:57:50 -0400 |
|---|---|---|
| committer | Chris Wright <chrisw@sous-sol.org> | 2007-06-11 11:36:49 -0700 |
| commit | 5eba323639c5964dab344eba4f8613c1e724be6a (patch) | |
| tree | 6bb0a977ad490d1bfd344a0a1992b4c51aa71d49 | |
| parent | ce6ea86f71e02e0ae421475d3b03eda9fb7088cd (diff) | |
[PATCH] UML - Improve host PTRACE_SYSEMU check
Make the PTRACE_SYSEMU checking more robust. It will make sure that
system call numbers are reported correctly. If there is a problem, it
will disable PTRACE_SYSEMU use and use PTRACE_SYSCALL instead.
This fixes a hang on boot on FC6 hosts with a broken PTRACE_SYSEMU.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
--
arch/um/os-Linux/start_up.c | 24 ++++++++++++++++--------
1 file changed, 16 insertions(+), 8 deletions(-)
| -rw-r--r-- | arch/um/os-Linux/start_up.c | 24 |
1 files changed, 16 insertions, 8 deletions
diff --git a/arch/um/os-Linux/start_up.c b/arch/um/os-Linux/start_up.c index 5178eba9afa..c2502fe6175 100644 --- a/arch/um/os-Linux/start_up.c +++ b/arch/um/os-Linux/start_up.c @@ -144,9 +144,7 @@ static int stop_ptraced_child(int pid, void *stack, int exitcode, int exit_with = WEXITSTATUS(status); if (exit_with == 2) non_fatal("check_ptrace : child exited with status 2. " - "Serious trouble happening! Try updating " - "your host skas patch!\nDisabling SYSEMU " - "support."); + "\nDisabling SYSEMU support.\n"); non_fatal("check_ptrace : child exited with exitcode %d, while " "expecting %d; status 0x%x\n", exit_with, exitcode, status); @@ -209,6 +207,7 @@ __uml_setup("nosysemu", nosysemu_cmd_param, static void __init check_sysemu(void) { void *stack; + unsigned long regs[MAX_REG_NR]; int pid, n, status, count=0; non_fatal("Checking syscall emulation patch for ptrace..."); @@ -225,11 +224,20 @@ static void __init check_sysemu(void) fatal("check_sysemu : expected SIGTRAP, got status = %d", status); - n = ptrace(PTRACE_POKEUSR, pid, PT_SYSCALL_RET_OFFSET, - os_getpid()); - if(n < 0) - fatal_perror("check_sysemu : failed to modify system call " - "return"); + if(ptrace(PTRACE_GETREGS, pid, 0, regs) < 0) + fatal_perror("check_sysemu : PTRACE_GETREGS failed"); + if(PT_SYSCALL_NR(regs) != __NR_getpid){ + non_fatal("check_sysemu got system call number %d, " + "expected %d...", PT_SYSCALL_NR(regs), __NR_getpid); + goto fail; + } + + n = ptrace(PTRACE_POKEUSR, pid, PT_SYSCALL_RET_OFFSET, os_getpid()); + if(n < 0){ + non_fatal("check_sysemu : failed to modify system call " + "return"); + goto fail; + } if (stop_ptraced_child(pid, stack, 0, 0) < 0) goto fail_stopped; |