From: benjamin@sipsolutions.net
To: linux-um@lists.infradead.org
Cc: Benjamin Berg <benjamin@sipsolutions.net>
Subject: [PATCH v2 05/28] um: Make errors to stop ptraced child fatal during startup
Date: Tue, 22 Nov 2022 11:07:36 +0100 [thread overview]
Message-ID: <20221122100759.208290-6-benjamin@sipsolutions.net> (raw)
In-Reply-To: <20221122100759.208290-1-benjamin@sipsolutions.net>
From: Benjamin Berg <benjamin@sipsolutions.net>
For the detection code to check whether SYSEMU_SINGLESTEP works
correctly we needed some error cases while stopping to be non-fatal.
However, at this point stop_ptraced_child must always succeed, and we
can therefore simplify it slightly to exit immediately on error.
Signed-off-by: Benjamin Berg <benjamin@sipsolutions.net>
---
arch/um/os-Linux/start_up.c | 41 +++++++++++--------------------------
1 file changed, 12 insertions(+), 29 deletions(-)
diff --git a/arch/um/os-Linux/start_up.c b/arch/um/os-Linux/start_up.c
index 561c08e0cc9c..8b0e98ab842c 100644
--- a/arch/um/os-Linux/start_up.c
+++ b/arch/um/os-Linux/start_up.c
@@ -112,35 +112,20 @@ static int start_ptraced_child(void)
return pid;
}
-/* When testing for SYSEMU support, if it is one of the broken versions, we
- * must just avoid using sysemu, not panic, but only if SYSEMU features are
- * broken.
- * So only for SYSEMU features we test mustpanic, while normal host features
- * must work anyway!
- */
-static int stop_ptraced_child(int pid, int exitcode, int mustexit)
+static void stop_ptraced_child(int pid, int exitcode)
{
- int status, n, ret = 0;
+ int status, n;
+
+ if (ptrace(PTRACE_CONT, pid, 0, 0) < 0)
+ fatal_perror("stop_ptraced_child : ptrace failed");
- if (ptrace(PTRACE_CONT, pid, 0, 0) < 0) {
- perror("stop_ptraced_child : ptrace failed");
- return -1;
- }
CATCH_EINTR(n = waitpid(pid, &status, 0));
if (!WIFEXITED(status) || (WEXITSTATUS(status) != exitcode)) {
int exit_with = WEXITSTATUS(status);
- if (exit_with == 2)
- non_fatal("check_ptrace : child exited with status 2. "
- "\nDisabling SYSEMU support.\n");
- non_fatal("check_ptrace : child exited with exitcode %d, while "
- "expecting %d; status 0x%x\n", exit_with,
- exitcode, status);
- if (mustexit)
- exit(1);
- ret = -1;
+ fatal("stop_ptraced_child : child exited with exitcode %d, "
+ "while expecting %d; status 0x%x\n", exit_with,
+ exitcode, status);
}
-
- return ret;
}
static void __init check_sysemu(void)
@@ -185,16 +170,14 @@ static void __init check_sysemu(void)
goto fail;
}
}
- if (stop_ptraced_child(pid, 0, 0) < 0)
- goto fail_stopped;
+ stop_ptraced_child(pid, 0);
os_info("OK\n");
return;
fail:
- stop_ptraced_child(pid, 1, 0);
-fail_stopped:
+ stop_ptraced_child(pid, 1);
fatal("missing\n");
}
@@ -233,7 +216,7 @@ static void __init check_ptrace(void)
break;
}
}
- stop_ptraced_child(pid, 0, 1);
+ stop_ptraced_child(pid, 0);
os_info("OK\n");
check_sysemu();
}
@@ -312,7 +295,7 @@ void __init os_early_checks(void)
pid = start_ptraced_child();
if (init_pid_registers(pid))
fatal("Failed to initialize default registers");
- stop_ptraced_child(pid, 1, 1);
+ stop_ptraced_child(pid, 1);
}
int __init parse_iomem(char *str, int *add)
--
2.38.1
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next prev parent reply other threads:[~2022-11-22 10:11 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-22 10:07 [PATCH v2 00/28] Implement SECCOMP based userland benjamin
2022-11-22 10:07 ` [PATCH v2 01/28] um: Switch printk calls to adhere to correct coding style benjamin
2022-11-22 10:07 ` [PATCH v2 02/28] um: Declare fix_range_common as a static function benjamin
2022-11-22 10:07 ` [PATCH v2 03/28] um: Drop support for hosts without SYSEMU_SINGLESTEP support benjamin
2022-11-22 10:07 ` [PATCH v2 04/28] um: Drop NULL check from start_userspace benjamin
2022-11-22 10:07 ` benjamin [this message]
2022-11-22 10:07 ` [PATCH v2 06/28] um: Don't use vfprintf() for os_info() benjamin
2022-11-22 10:07 ` [PATCH v2 07/28] um: Do not use printk in SIGWINCH helper thread benjamin
2022-11-22 10:07 ` [PATCH v2 08/28] um: Reap winch thread if it fails benjamin
2022-11-22 10:07 ` [PATCH v2 09/28] um: Do not use printk in userspace trampoline benjamin
2022-11-22 10:07 ` [PATCH v2 10/28] um: Always inline stub functions benjamin
2022-11-22 10:07 ` [PATCH v2 11/28] um: Rely on PTRACE_SETREGSET to set FS/GS base registers benjamin
2022-11-22 10:07 ` [PATCH v2 12/28] um: Remove unused register save/restore functions benjamin
2022-11-22 10:07 ` [PATCH v2 13/28] um: Mark 32bit syscall helpers as clobbering memory benjamin
2022-11-22 10:07 ` [PATCH v2 14/28] um: Remove stub-data.h include from common-offsets.h benjamin
2022-11-22 10:07 ` [PATCH v2 15/28] um: Create signal stack memory assignment in stub_data benjamin
2022-11-22 10:07 ` [PATCH v2 16/28] um: Add generic stub_syscall6 function benjamin
2022-11-22 10:07 ` [PATCH v2 17/28] um: Rework syscall handling benjamin
2022-11-22 10:07 ` [PATCH v2 18/28] um: Store full CSGSFS and SS register from mcontext benjamin
2022-11-22 10:07 ` [PATCH v2 19/28] um: Pass full mm_id to functions creating helper processes benjamin
2022-11-22 10:07 ` [PATCH v2 20/28] um: Move faultinfo extraction into userspace routine benjamin
2022-11-22 10:07 ` [PATCH v2 21/28] um: Use struct uml_pt_regs for copy_context_skas0 benjamin
2022-11-22 10:07 ` [PATCH v2 22/28] um: Add UML_SECCOMP configuration option benjamin
2022-11-22 10:07 ` [PATCH v2 23/28] um: Add stub side of SECCOMP/futex based process handling benjamin
2022-11-22 10:07 ` [PATCH v2 24/28] um: Add helper functions to get/set state for SECCOMP benjamin
2022-11-22 10:07 ` [PATCH v2 25/28] um: Add SECCOMP support detection and initialization benjamin
2022-11-22 10:07 ` [PATCH v2 26/28] um: Die if a child dies unexpectedly in seccomp mode benjamin
2022-11-22 10:07 ` [PATCH v2 27/28] um: Implement kernel side of SECCOMP based process handling benjamin
2022-11-22 10:07 ` [PATCH v2 28/28] um: Delay flushing syscalls until the thread is restarted benjamin
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