On 11/23/25 06:51, Aleksei Oladko wrote:
> This patch fixes an issue where a segfault occurring inside a CT caused
> the kernel segfault message to be logged to the CT dmesg, while the
> opcode dump was printed to the host dmesg. It also fixes a bug where the
> segfault message recorded in the CT dmesg used the host PID instead of
> the PID inside the container.
>
> https://virtuozzo.atlassian.net/browse/VSTOR-119875
> Fixes c3d2bd4b6946f ("ve: Use ve_printk() for often kernel messages about
> user actions")
>
> Signed-off-by: Aleksei Oladko <[email protected]>
> ---
> arch/x86/include/asm/stacktrace.h | 1 +
> arch/x86/kernel/dumpstack.c | 11 ++++++++---
> arch/x86/mm/fault.c | 7 ++++---
> 3 files changed, 13 insertions(+), 6 deletions(-)
>
> diff --git a/arch/x86/include/asm/stacktrace.h
> b/arch/x86/include/asm/stacktrace.h
> index 3881b5333eb8..09e08f36d02e 100644
> --- a/arch/x86/include/asm/stacktrace.h
> +++ b/arch/x86/include/asm/stacktrace.h
> @@ -109,6 +109,7 @@ struct stack_frame_ia32 {
> u32 return_address;
> };
>
> +void ve_show_opcodes(struct pt_regs *regs, const char *loglvl, int dst);
> void show_opcodes(struct pt_regs *regs, const char *loglvl);
> void show_ip(struct pt_regs *regs, const char *loglvl);
> #endif /* _ASM_X86_STACKTRACE_H */
> diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c
> index a7d562697e50..b8cd4ae49e9e 100644
> --- a/arch/x86/kernel/dumpstack.c
> +++ b/arch/x86/kernel/dumpstack.c
> @@ -110,7 +110,7 @@ static int copy_code(struct pt_regs *regs, u8 *buf,
> unsigned long src,
> * Thus, the 2/3rds prologue and 64 byte OPCODE_BUFSIZE is just a random
> * guesstimate in attempt to achieve all of the above.
> */
> -void show_opcodes(struct pt_regs *regs, const char *loglvl)
> +void ve_show_opcodes(struct pt_regs *regs, const char *loglvl, int dst)
> {
> #define PROLOGUE_SIZE 42
> #define EPILOGUE_SIZE 21
> @@ -120,7 +120,7 @@ void show_opcodes(struct pt_regs *regs, const char
> *loglvl)
>
> switch (copy_code(regs, opcodes, prologue, sizeof(opcodes))) {
> case 0:
> - printk("%sCode: %" __stringify(PROLOGUE_SIZE) "ph <%02x> %"
> + ve_printk(dst, "%sCode: %" __stringify(PROLOGUE_SIZE) "ph
> <%02x> %"
> __stringify(EPILOGUE_SIZE) "ph\n", loglvl, opcodes,
> opcodes[PROLOGUE_SIZE], opcodes + PROLOGUE_SIZE + 1);
> break;
> @@ -128,12 +128,17 @@ void show_opcodes(struct pt_regs *regs, const char
> *loglvl)
> /* No access to the user space stack of other tasks. Ignore. */
> break;
> default:
> - printk("%sCode: Unable to access opcode bytes at 0x%lx.\n",
> + ve_printk(dst, "%sCode: Unable to access opcode bytes at
> 0x%lx.\n",
> loglvl, prologue);
> break;
> }
> }
>
> +void show_opcodes(struct pt_regs *regs, const char *loglvl)
> +{
> + return ve_show_opcodes(regs, loglvl, VE0_LOG);
> +}
> +
> void show_ip(struct pt_regs *regs, const char *loglvl)
> {
> #ifdef CONFIG_X86_32
> diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
> index 2beac0d7924d..ca65e80dacab 100644
> --- a/arch/x86/mm/fault.c
> +++ b/arch/x86/mm/fault.c
> @@ -757,8 +757,9 @@ show_signal_msg(struct pt_regs *regs, unsigned long
> error_code,
> return;
>
> ve_printk(VE_LOG, "%s%s[%d]: segfault at %lx ip %px sp %px error %lx",
> - loglvl, tsk->comm, task_pid_nr(tsk), address,
> - (void *)regs->ip, (void *)regs->sp, error_code);
> + loglvl, tsk->comm,
> + ve_is_super(get_exec_env()) ? task_pid_nr(tsk) :
> task_pid_vnr(tsk),
The task_pid_nr() shows pid in root pidns on host, if we want to virtualize it
in VE we should show pid in root pidns of VE. You are instead showing pid in
tasks's own pidns which can be different to root pidns of VE.
E.g.: tsk->task_ve->ve_ns->pid_ns_for_children is a root pidns of VE.
Can you please add a task_pid_ve_nr() helper for that?
> + address, (void *)regs->ip, (void *)regs->sp, error_code);
>
> ve_print_vma_addr(VE_LOG, KERN_CONT " in ", regs->ip);
>
> @@ -773,7 +774,7 @@ show_signal_msg(struct pt_regs *regs, unsigned long
> error_code,
>
> ve_printk(VE_LOG, KERN_CONT "\n");
>
> - show_opcodes(regs, loglvl);
> + ve_show_opcodes(regs, loglvl, VE_LOG);
> }
>
> static void
--
Best regards, Pavel Tikhomirov
Senior Software Developer, Virtuozzo.
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