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From: Benjamin Berg <benjamin@sipsolutions.net>
To: linux-um@lists.infradead.org
Cc: Benjamin Berg <benjamin@sipsolutions.net>
Subject: [PATCH 09/27] um: Do not use printk in userspace trampoline
Date: Wed,  3 Mar 2021 16:55:05 +0100	[thread overview]
Message-ID: <20210303155523.124277-10-benjamin@sipsolutions.net> (raw)
In-Reply-To: <20210303155523.124277-1-benjamin@sipsolutions.net>

The trampoline is running in a cloned process. It is not safe to use
printk for error printing there.

Signed-off-by: Benjamin Berg <benjamin@sipsolutions.net>
---
 arch/um/os-Linux/skas/process.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/arch/um/os-Linux/skas/process.c b/arch/um/os-Linux/skas/process.c
index 1c31f833a7ed..15818009731d 100644
--- a/arch/um/os-Linux/skas/process.c
+++ b/arch/um/os-Linux/skas/process.c
@@ -220,8 +220,8 @@ static int userspace_tramp(void *stack)
 	addr = mmap64((void *) STUB_CODE, UM_KERN_PAGE_SIZE,
 		      PROT_EXEC, MAP_FIXED | MAP_PRIVATE, fd, offset);
 	if (addr == MAP_FAILED) {
-		printk(UM_KERN_ERR "mapping mmap stub at 0x%lx failed, errno = %d\n",
-		       STUB_CODE, errno);
+		os_info("mapping mmap stub at 0x%lx failed, errno = %d\n",
+			STUB_CODE, errno);
 		exit(1);
 	}
 
@@ -230,8 +230,8 @@ static int userspace_tramp(void *stack)
 		    UM_KERN_PAGE_SIZE, PROT_READ | PROT_WRITE,
 		    MAP_FIXED | MAP_SHARED, fd, offset);
 	if (addr == MAP_FAILED) {
-		printk(UM_KERN_ERR "mapping segfault stack at 0x%lx failed, errno = %d\n",
-		       STUB_DATA, errno);
+		os_info("mapping segfault stack at 0x%lx failed, errno = %d\n",
+			STUB_DATA, errno);
 		exit(1);
 	}
 
@@ -241,8 +241,8 @@ static int userspace_tramp(void *stack)
 	sa.sa_sigaction = (void *) segv_handler;
 	sa.sa_restorer = NULL;
 	if (sigaction(SIGSEGV, &sa, NULL) < 0) {
-		printk(UM_KERN_ERR "%s - setting SIGSEGV handler failed - errno = %d\n",
-		       __func__, errno);
+		os_info("%s - setting SIGSEGV handler failed - errno = %d\n",
+			__func__, errno);
 		exit(1);
 	}
 
-- 
2.29.2


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  parent reply	other threads:[~2021-03-03 15:56 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-03 15:54 [PATCH 00/27] Implement SECCOMP based userland Benjamin Berg
2021-03-03 15:54 ` [PATCH 01/27] um: Switch printk calls to adhere to correct coding style Benjamin Berg
2021-03-03 15:54 ` [PATCH 02/27] um: Declare fix_range_common as a static function Benjamin Berg
2021-03-03 15:54 ` [PATCH 03/27] um: Drop support for hosts without SYSEMU_SINGLESTEP support Benjamin Berg
2021-06-19 20:17   ` Richard Weinberger
2021-06-20 12:05     ` Benjamin Berg
2021-03-03 15:55 ` [PATCH 04/27] um: Drop NULL check from start_userspace Benjamin Berg
2021-03-03 15:55 ` [PATCH 05/27] um: Make errors to stop ptraced child fatal during startup Benjamin Berg
2021-03-03 15:55 ` [PATCH 06/27] um: Don't use vfprintf() for os_info() Benjamin Berg
2021-03-03 15:55 ` [PATCH 07/27] um: Do not use printk in SIGWINCH helper thread Benjamin Berg
2021-03-03 15:55 ` [PATCH 08/27] um: Reap winch thread if it fails Benjamin Berg
2021-03-03 15:55 ` Benjamin Berg [this message]
2021-03-03 15:55 ` [PATCH 10/27] um: Always inline stub functions Benjamin Berg
2021-03-03 15:55 ` [PATCH 11/27] um: Rely on PTRACE_SETREGSET to set FS/GS base registers Benjamin Berg
2021-03-03 15:55 ` [PATCH 12/27] um: Remove unused register save/restore functions Benjamin Berg
2021-03-03 15:55 ` [PATCH 13/27] um: Mark 32bit syscall helpers as clobbering memory Benjamin Berg
2021-03-03 15:55 ` [PATCH 14/27] um: Create signal stack memory assignment in stub_data Benjamin Berg
2021-03-03 15:55 ` [PATCH 15/27] um: Add generic stub_syscall6 function Benjamin Berg
2021-03-03 15:55 ` [PATCH 16/27] um: Rework syscall handling Benjamin Berg
2021-03-03 15:55 ` [PATCH 17/27] um: Store full CSGSFS and SS register from mcontext Benjamin Berg
2021-03-03 15:55 ` [PATCH 18/27] um: Pass full mm_id to functions creating helper processes Benjamin Berg
2021-03-03 15:55 ` [PATCH 19/27] um: Move faultinfo extraction into userspace routine Benjamin Berg
2021-03-03 15:55 ` [PATCH 20/27] um: Use struct uml_pt_regs for copy_context_skas0 Benjamin Berg
2021-03-03 15:55 ` [PATCH 21/27] um: Add UML_SECCOMP configuration option Benjamin Berg
2021-03-03 15:55 ` [PATCH 22/27] um: Add stub side of SECCOMP/futex based process handling Benjamin Berg
2021-03-03 15:55 ` [PATCH 23/27] um: Add helper functions to get/set state for SECCOMP Benjamin Berg
2021-03-03 15:55 ` [PATCH 24/27] um: Add SECCOMP support detection and initialization Benjamin Berg
2021-03-03 15:55 ` [PATCH 25/27] um: Die if a child dies unexpectedly in seccomp mode Benjamin Berg
2021-03-03 15:55 ` [PATCH 26/27] um: Implement kernel side of SECCOMP based process handling Benjamin Berg
2021-03-03 15:55 ` [PATCH 27/27] um: Delay flushing syscalls until the thread is restarted Benjamin Berg

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