[PATCH v16 08/42] x86_64, dept: add support CONFIG_ARCH_HAS_DEPT_SUPPORT to x86_64
From: Byungchul Park <byungchul@sk.com>
Date: 2025-05-19 09:18:44
Also in:
dri-devel, linux-block, linux-ext4, linux-fsdevel, linux-ide, linux-mm, lkml
Subsystem:
the rest, x86 architecture (32-bit and 64-bit), x86 entry code, x86 mm · Maintainers:
Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen, Andy Lutomirski, Peter Zijlstra
dept needs to notice every entrance from user to kernel mode to treat every kernel context independently when tracking wait-event dependencies. Roughly, system call and user oriented fault are the cases. Make dept aware of the entrances of x86_64 and add support CONFIG_ARCH_HAS_DEPT_SUPPORT to x86_64. Signed-off-by: Byungchul Park <byungchul@sk.com> --- arch/x86/Kconfig | 1 + arch/x86/entry/syscall_64.c | 7 +++++++ arch/x86/mm/fault.c | 7 +++++++ 3 files changed, 15 insertions(+)
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 5873c9e39919..4b6d9e59d96c 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig@@ -38,6 +38,7 @@ config X86_64 select ARCH_HAS_ELFCORE_COMPAT select ZONE_DMA32 select EXECMEM if DYNAMIC_FTRACE + select ARCH_HAS_DEPT_SUPPORT config FORCE_DYNAMIC_FTRACE def_bool y
diff --git a/arch/x86/entry/syscall_64.c b/arch/x86/entry/syscall_64.c
index b6e68ea98b83..66bd5af5aff1 100644
--- a/arch/x86/entry/syscall_64.c
+++ b/arch/x86/entry/syscall_64.c@@ -8,6 +8,7 @@ #include <linux/entry-common.h> #include <linux/nospec.h> #include <asm/syscall.h> +#include <linux/dept.h> #define __SYSCALL(nr, sym) extern long __x64_##sym(const struct pt_regs *); #define __SYSCALL_NORETURN(nr, sym) extern long __noreturn __x64_##sym(const struct pt_regs *);
@@ -86,6 +87,12 @@ static __always_inline bool do_syscall_x32(struct pt_regs *regs, int nr) /* Returns true to return using SYSRET, or false to use IRET */ __visible noinstr bool do_syscall_64(struct pt_regs *regs, int nr) { + /* + * This is a system call from user mode. Make dept work with a + * new kernel mode context. + */ + dept_update_cxt(); + add_random_kstack_offset(); nr = syscall_enter_from_user_mode(regs, nr);
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 296d294142c8..241537ce47fe 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c@@ -20,6 +20,7 @@ #include <linux/mm_types.h> #include <linux/mm.h> /* find_and_lock_vma() */ #include <linux/vmalloc.h> +#include <linux/dept.h> #include <asm/cpufeature.h> /* boot_cpu_has, ... */ #include <asm/traps.h> /* dotraplinkage, ... */
@@ -1220,6 +1221,12 @@ void do_user_addr_fault(struct pt_regs *regs, tsk = current; mm = tsk->mm; + /* + * This fault comes from user mode. Make dept work with a new + * kernel mode context. + */ + dept_update_cxt(); + if (unlikely((error_code & (X86_PF_USER | X86_PF_INSTR)) == X86_PF_INSTR)) { /* * Whoops, this is kernel mode code trying to execute from
--
2.17.1