* [PATCH 1/6] Revert "arch: remove unused function syscall_set_arguments()"
2025-01-07 23:01 [PATCH 0/6] ptrace: introduce PTRACE_SET_SYSCALL_INFO API Dmitry V. Levin
@ 2025-01-07 23:04 ` Dmitry V. Levin
2025-01-07 23:04 ` [PATCH 3/6] syscall.h: introduce syscall_set_nr() Dmitry V. Levin
2025-01-10 3:15 ` [PATCH 0/6] ptrace: introduce PTRACE_SET_SYSCALL_INFO API H. Peter Anvin
2 siblings, 0 replies; 6+ messages in thread
From: Dmitry V. Levin @ 2025-01-07 23:04 UTC (permalink / raw)
To: Oleg Nesterov
Cc: Eugene Syromyatnikov, Mike Frysinger, Renzo Davoli,
Davide Berardi, strace-devel, Dinh Nguyen, Jonas Bonn,
Stefan Kristiansson, Stafford Horne, Michael Ellerman,
Nicholas Piggin, Christophe Leroy, Naveen N Rao,
Madhavan Srinivasan, Paul Walmsley, Palmer Dabbelt, Albert Ou,
Heiko Carstens, Vasily Gorbik, Alexander Gordeev,
Christian Borntraeger, Sven Schnelle, Yoshinori Sato, Rich Felker,
John Paul Adrian Glaubitz, David S. Miller, Andreas Larsson,
Richard Weinberger, Anton Ivanov, Johannes Berg, Thomas Gleixner,
Ingo Molnar, Borislav Petkov, Dave Hansen, x86, H. Peter Anvin,
Chris Zankel, Max Filippov, Arnd Bergmann, linux-kernel,
linux-openrisc, linuxppc-dev, linux-riscv, linux-s390, linux-sh,
sparclinux, linux-um, linux-arch
syscall_set_arguments() is going to be needed to implement
PTRACE_SET_SYSCALL_INFO API.
This is a partial revert: on a few architectures syscall_set_arguments()
implementations were buggy, so instead of adding them here and applying
fixes on top, cleaner implementations are coming in follow-up commits.
This reverts commit 7962c2eddbfe7cce879acb06f9b4f205789e57b7.
Signed-off-by: Dmitry V. Levin <ldv@strace.io>
---
arch/nios2/include/asm/syscall.h | 11 ++++++++
arch/openrisc/include/asm/syscall.h | 7 ++++++
arch/powerpc/include/asm/syscall.h | 10 ++++++++
arch/riscv/include/asm/syscall.h | 9 +++++++
arch/s390/include/asm/syscall.h | 12 +++++++++
arch/sh/include/asm/syscall_32.h | 12 +++++++++
arch/sparc/include/asm/syscall.h | 10 ++++++++
arch/um/include/asm/syscall-generic.h | 14 +++++++++++
arch/x86/include/asm/syscall.h | 36 +++++++++++++++++++++++++++
arch/xtensa/include/asm/syscall.h | 11 ++++++++
include/asm-generic/syscall.h | 16 ++++++++++++
11 files changed, 148 insertions(+)
diff --git a/arch/nios2/include/asm/syscall.h b/arch/nios2/include/asm/syscall.h
index fff52205fb65..526449edd768 100644
--- a/arch/nios2/include/asm/syscall.h
+++ b/arch/nios2/include/asm/syscall.h
@@ -58,6 +58,17 @@ static inline void syscall_get_arguments(struct task_struct *task,
*args = regs->r9;
}
+static inline void syscall_set_arguments(struct task_struct *task,
+ struct pt_regs *regs, const unsigned long *args)
+{
+ regs->r4 = *args++;
+ regs->r5 = *args++;
+ regs->r6 = *args++;
+ regs->r7 = *args++;
+ regs->r8 = *args++;
+ regs->r9 = *args;
+}
+
static inline int syscall_get_arch(struct task_struct *task)
{
return AUDIT_ARCH_NIOS2;
diff --git a/arch/openrisc/include/asm/syscall.h b/arch/openrisc/include/asm/syscall.h
index 903ed882bdec..e6383be2a195 100644
--- a/arch/openrisc/include/asm/syscall.h
+++ b/arch/openrisc/include/asm/syscall.h
@@ -57,6 +57,13 @@ syscall_get_arguments(struct task_struct *task, struct pt_regs *regs,
memcpy(args, ®s->gpr[3], 6 * sizeof(args[0]));
}
+static inline void
+syscall_set_arguments(struct task_struct *task, struct pt_regs *regs,
+ const unsigned long *args)
+{
+ memcpy(®s->gpr[3], args, 6 * sizeof(args[0]));
+}
+
static inline int syscall_get_arch(struct task_struct *task)
{
return AUDIT_ARCH_OPENRISC;
diff --git a/arch/powerpc/include/asm/syscall.h b/arch/powerpc/include/asm/syscall.h
index 3dd36c5e334a..b2715448a660 100644
--- a/arch/powerpc/include/asm/syscall.h
+++ b/arch/powerpc/include/asm/syscall.h
@@ -110,6 +110,16 @@ static inline void syscall_get_arguments(struct task_struct *task,
}
}
+static inline void syscall_set_arguments(struct task_struct *task,
+ struct pt_regs *regs,
+ const unsigned long *args)
+{
+ memcpy(®s->gpr[3], args, 6 * sizeof(args[0]));
+
+ /* Also copy the first argument into orig_gpr3 */
+ regs->orig_gpr3 = args[0];
+}
+
static inline int syscall_get_arch(struct task_struct *task)
{
if (is_tsk_32bit_task(task))
diff --git a/arch/riscv/include/asm/syscall.h b/arch/riscv/include/asm/syscall.h
index 121fff429dce..8d389ba995c8 100644
--- a/arch/riscv/include/asm/syscall.h
+++ b/arch/riscv/include/asm/syscall.h
@@ -66,6 +66,15 @@ static inline void syscall_get_arguments(struct task_struct *task,
memcpy(args, ®s->a1, 5 * sizeof(args[0]));
}
+static inline void syscall_set_arguments(struct task_struct *task,
+ struct pt_regs *regs,
+ const unsigned long *args)
+{
+ regs->orig_a0 = args[0];
+ args++;
+ memcpy(®s->a1, args, 5 * sizeof(regs->a1));
+}
+
static inline int syscall_get_arch(struct task_struct *task)
{
#ifdef CONFIG_64BIT
diff --git a/arch/s390/include/asm/syscall.h b/arch/s390/include/asm/syscall.h
index 27e3d804b311..b3dd883699e7 100644
--- a/arch/s390/include/asm/syscall.h
+++ b/arch/s390/include/asm/syscall.h
@@ -78,6 +78,18 @@ static inline void syscall_get_arguments(struct task_struct *task,
args[0] = regs->orig_gpr2 & mask;
}
+static inline void syscall_set_arguments(struct task_struct *task,
+ struct pt_regs *regs,
+ const unsigned long *args)
+{
+ unsigned int n = 6;
+
+ while (n-- > 0)
+ if (n > 0)
+ regs->gprs[2 + n] = args[n];
+ regs->orig_gpr2 = args[0];
+}
+
static inline int syscall_get_arch(struct task_struct *task)
{
#ifdef CONFIG_COMPAT
diff --git a/arch/sh/include/asm/syscall_32.h b/arch/sh/include/asm/syscall_32.h
index d87738eebe30..cb51a7528384 100644
--- a/arch/sh/include/asm/syscall_32.h
+++ b/arch/sh/include/asm/syscall_32.h
@@ -57,6 +57,18 @@ static inline void syscall_get_arguments(struct task_struct *task,
args[0] = regs->regs[4];
}
+static inline void syscall_set_arguments(struct task_struct *task,
+ struct pt_regs *regs,
+ const unsigned long *args)
+{
+ regs->regs[1] = args[5];
+ regs->regs[0] = args[4];
+ regs->regs[7] = args[3];
+ regs->regs[6] = args[2];
+ regs->regs[5] = args[1];
+ regs->regs[4] = args[0];
+}
+
static inline int syscall_get_arch(struct task_struct *task)
{
int arch = AUDIT_ARCH_SH;
diff --git a/arch/sparc/include/asm/syscall.h b/arch/sparc/include/asm/syscall.h
index 20c109ac8cc9..62a5a78804c4 100644
--- a/arch/sparc/include/asm/syscall.h
+++ b/arch/sparc/include/asm/syscall.h
@@ -117,6 +117,16 @@ static inline void syscall_get_arguments(struct task_struct *task,
}
}
+static inline void syscall_set_arguments(struct task_struct *task,
+ struct pt_regs *regs,
+ const unsigned long *args)
+{
+ unsigned int i;
+
+ for (i = 0; i < 6; i++)
+ regs->u_regs[UREG_I0 + i] = args[i];
+}
+
static inline int syscall_get_arch(struct task_struct *task)
{
#if defined(CONFIG_SPARC64) && defined(CONFIG_COMPAT)
diff --git a/arch/um/include/asm/syscall-generic.h b/arch/um/include/asm/syscall-generic.h
index 172b74143c4b..2984feb9d576 100644
--- a/arch/um/include/asm/syscall-generic.h
+++ b/arch/um/include/asm/syscall-generic.h
@@ -62,6 +62,20 @@ static inline void syscall_get_arguments(struct task_struct *task,
*args = UPT_SYSCALL_ARG6(r);
}
+static inline void syscall_set_arguments(struct task_struct *task,
+ struct pt_regs *regs,
+ const unsigned long *args)
+{
+ struct uml_pt_regs *r = ®s->regs;
+
+ UPT_SYSCALL_ARG1(r) = *args++;
+ UPT_SYSCALL_ARG2(r) = *args++;
+ UPT_SYSCALL_ARG3(r) = *args++;
+ UPT_SYSCALL_ARG4(r) = *args++;
+ UPT_SYSCALL_ARG5(r) = *args++;
+ UPT_SYSCALL_ARG6(r) = *args;
+}
+
/* See arch/x86/um/asm/syscall.h for syscall_get_arch() definition. */
#endif /* __UM_SYSCALL_GENERIC_H */
diff --git a/arch/x86/include/asm/syscall.h b/arch/x86/include/asm/syscall.h
index 7c488ff0c764..b9c249dd9e3d 100644
--- a/arch/x86/include/asm/syscall.h
+++ b/arch/x86/include/asm/syscall.h
@@ -90,6 +90,18 @@ static inline void syscall_get_arguments(struct task_struct *task,
args[5] = regs->bp;
}
+static inline void syscall_set_arguments(struct task_struct *task,
+ struct pt_regs *regs,
+ const unsigned long *args)
+{
+ regs->bx = args[0];
+ regs->cx = args[1];
+ regs->dx = args[2];
+ regs->si = args[3];
+ regs->di = args[4];
+ regs->bp = args[5];
+}
+
static inline int syscall_get_arch(struct task_struct *task)
{
return AUDIT_ARCH_I386;
@@ -121,6 +133,30 @@ static inline void syscall_get_arguments(struct task_struct *task,
}
}
+static inline void syscall_set_arguments(struct task_struct *task,
+ struct pt_regs *regs,
+ const unsigned long *args)
+{
+# ifdef CONFIG_IA32_EMULATION
+ if (task->thread_info.status & TS_COMPAT) {
+ regs->bx = *args++;
+ regs->cx = *args++;
+ regs->dx = *args++;
+ regs->si = *args++;
+ regs->di = *args++;
+ regs->bp = *args;
+ } else
+# endif
+ {
+ regs->di = *args++;
+ regs->si = *args++;
+ regs->dx = *args++;
+ regs->r10 = *args++;
+ regs->r8 = *args++;
+ regs->r9 = *args;
+ }
+}
+
static inline int syscall_get_arch(struct task_struct *task)
{
/* x32 tasks should be considered AUDIT_ARCH_X86_64. */
diff --git a/arch/xtensa/include/asm/syscall.h b/arch/xtensa/include/asm/syscall.h
index 5ee974bf8330..f9a671cbf933 100644
--- a/arch/xtensa/include/asm/syscall.h
+++ b/arch/xtensa/include/asm/syscall.h
@@ -68,6 +68,17 @@ static inline void syscall_get_arguments(struct task_struct *task,
args[i] = regs->areg[reg[i]];
}
+static inline void syscall_set_arguments(struct task_struct *task,
+ struct pt_regs *regs,
+ const unsigned long *args)
+{
+ static const unsigned int reg[] = XTENSA_SYSCALL_ARGUMENT_REGS;
+ unsigned int i;
+
+ for (i = 0; i < 6; ++i)
+ regs->areg[reg[i]] = args[i];
+}
+
asmlinkage long xtensa_rt_sigreturn(void);
asmlinkage long xtensa_shmat(int, char __user *, int);
asmlinkage long xtensa_fadvise64_64(int, int,
diff --git a/include/asm-generic/syscall.h b/include/asm-generic/syscall.h
index 5a80fe728dc8..0f7b9a493de7 100644
--- a/include/asm-generic/syscall.h
+++ b/include/asm-generic/syscall.h
@@ -117,6 +117,22 @@ void syscall_set_return_value(struct task_struct *task, struct pt_regs *regs,
void syscall_get_arguments(struct task_struct *task, struct pt_regs *regs,
unsigned long *args);
+/**
+ * syscall_set_arguments - change system call parameter value
+ * @task: task of interest, must be in system call entry tracing
+ * @regs: task_pt_regs() of @task
+ * @args: array of argument values to store
+ *
+ * Changes 6 arguments to the system call.
+ * The first argument gets value @args[0], and so on.
+ *
+ * It's only valid to call this when @task is stopped for tracing on
+ * entry to a system call, due to %SYSCALL_WORK_SYSCALL_TRACE or
+ * %SYSCALL_WORK_SYSCALL_AUDIT.
+ */
+void syscall_set_arguments(struct task_struct *task, struct pt_regs *regs,
+ const unsigned long *args);
+
/**
* syscall_get_arch - return the AUDIT_ARCH for the current system call
* @task: task of interest, must be blocked
--
ldv
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH 3/6] syscall.h: introduce syscall_set_nr()
2025-01-07 23:01 [PATCH 0/6] ptrace: introduce PTRACE_SET_SYSCALL_INFO API Dmitry V. Levin
2025-01-07 23:04 ` [PATCH 1/6] Revert "arch: remove unused function syscall_set_arguments()" Dmitry V. Levin
@ 2025-01-07 23:04 ` Dmitry V. Levin
2025-01-10 7:37 ` Sven Schnelle
2025-01-10 3:15 ` [PATCH 0/6] ptrace: introduce PTRACE_SET_SYSCALL_INFO API H. Peter Anvin
2 siblings, 1 reply; 6+ messages in thread
From: Dmitry V. Levin @ 2025-01-07 23:04 UTC (permalink / raw)
To: Oleg Nesterov
Cc: Eugene Syromyatnikov, Mike Frysinger, Renzo Davoli,
Davide Berardi, strace-devel, Vineet Gupta, Russell King,
Catalin Marinas, Will Deacon, Brian Cain, Huacai Chen,
WANG Xuerui, Geert Uytterhoeven, Michal Simek,
Thomas Bogendoerfer, Dinh Nguyen, Jonas Bonn, Stefan Kristiansson,
Stafford Horne, James E.J. Bottomley, Helge Deller,
Michael Ellerman, Nicholas Piggin, Christophe Leroy, Naveen N Rao,
Madhavan Srinivasan, Paul Walmsley, Palmer Dabbelt, Albert Ou,
Heiko Carstens, Vasily Gorbik, Alexander Gordeev,
Christian Borntraeger, Sven Schnelle, Yoshinori Sato, Rich Felker,
John Paul Adrian Glaubitz, David S. Miller, Andreas Larsson,
Richard Weinberger, Anton Ivanov, Johannes Berg, Thomas Gleixner,
Ingo Molnar, Borislav Petkov, Dave Hansen, x86, H. Peter Anvin,
Chris Zankel, Max Filippov, Arnd Bergmann, linux-snps-arc,
linux-kernel, linux-arm-kernel, linux-hexagon, loongarch,
linux-m68k, linux-mips, linux-openrisc, linux-parisc,
linuxppc-dev, linux-riscv, linux-s390, linux-sh, sparclinux,
linux-um, linux-arch
Similar to syscall_set_arguments() that complements
syscall_get_arguments(), introduce syscall_set_nr()
that complements syscall_get_nr().
syscall_set_nr() is going to be needed along with
syscall_set_arguments() on all HAVE_ARCH_TRACEHOOK
architectures to implement PTRACE_SET_SYSCALL_INFO API.
Signed-off-by: Dmitry V. Levin <ldv@strace.io>
---
arch/arc/include/asm/syscall.h | 6 ++++++
arch/arm/include/asm/syscall.h | 12 ++++++++++++
arch/arm64/include/asm/syscall.h | 7 +++++++
arch/hexagon/include/asm/syscall.h | 7 +++++++
arch/loongarch/include/asm/syscall.h | 7 +++++++
arch/m68k/include/asm/syscall.h | 7 +++++++
arch/microblaze/include/asm/syscall.h | 7 +++++++
arch/mips/include/asm/syscall.h | 7 +++++++
arch/nios2/include/asm/syscall.h | 5 +++++
arch/openrisc/include/asm/syscall.h | 6 ++++++
arch/parisc/include/asm/syscall.h | 7 +++++++
arch/powerpc/include/asm/syscall.h | 5 +++++
arch/riscv/include/asm/syscall.h | 7 +++++++
arch/s390/include/asm/syscall.h | 7 +++++++
arch/sh/include/asm/syscall_32.h | 7 +++++++
arch/sparc/include/asm/syscall.h | 7 +++++++
arch/um/include/asm/syscall-generic.h | 5 +++++
arch/x86/include/asm/syscall.h | 7 +++++++
arch/xtensa/include/asm/syscall.h | 7 +++++++
include/asm-generic/syscall.h | 14 ++++++++++++++
20 files changed, 144 insertions(+)
diff --git a/arch/arc/include/asm/syscall.h b/arch/arc/include/asm/syscall.h
index 89c1e1736356..6095fbfa74ab 100644
--- a/arch/arc/include/asm/syscall.h
+++ b/arch/arc/include/asm/syscall.h
@@ -23,6 +23,12 @@ syscall_get_nr(struct task_struct *task, struct pt_regs *regs)
return -1;
}
+static inline void
+syscall_set_nr(struct task_struct *task, struct pt_regs *regs, int nr)
+{
+ regs->r8 = nr;
+}
+
static inline void
syscall_rollback(struct task_struct *task, struct pt_regs *regs)
{
diff --git a/arch/arm/include/asm/syscall.h b/arch/arm/include/asm/syscall.h
index 21927fa0ae2b..cfa61f355675 100644
--- a/arch/arm/include/asm/syscall.h
+++ b/arch/arm/include/asm/syscall.h
@@ -31,6 +31,18 @@ static inline int syscall_get_nr(struct task_struct *task,
return task_thread_info(task)->abi_syscall & __NR_SYSCALL_MASK;
}
+static inline void syscall_set_nr(struct task_struct *task,
+ struct pt_regs *regs,
+ int nr)
+{
+ if (!IS_ENABLED(CONFIG_AEABI) || IS_ENABLED(CONFIG_OABI_COMPAT)) {
+ if (nr != -1)
+ nr &= __NR_SYSCALL_MASK;
+ }
+
+ task_thread_info(task)->abi_syscall = nr;
+}
+
static inline bool __in_oabi_syscall(struct task_struct *task)
{
return IS_ENABLED(CONFIG_OABI_COMPAT) &&
diff --git a/arch/arm64/include/asm/syscall.h b/arch/arm64/include/asm/syscall.h
index 76020b66286b..0e6807618bed 100644
--- a/arch/arm64/include/asm/syscall.h
+++ b/arch/arm64/include/asm/syscall.h
@@ -23,6 +23,13 @@ static inline int syscall_get_nr(struct task_struct *task,
return regs->syscallno;
}
+static inline void syscall_set_nr(struct task_struct *task,
+ struct pt_regs *regs,
+ int nr)
+{
+ regs->syscallno = nr;
+}
+
static inline void syscall_rollback(struct task_struct *task,
struct pt_regs *regs)
{
diff --git a/arch/hexagon/include/asm/syscall.h b/arch/hexagon/include/asm/syscall.h
index 12d2df6aaa03..72befa719434 100644
--- a/arch/hexagon/include/asm/syscall.h
+++ b/arch/hexagon/include/asm/syscall.h
@@ -26,6 +26,13 @@ static inline long syscall_get_nr(struct task_struct *task,
return regs->r06;
}
+static inline void syscall_set_nr(struct task_struct *task,
+ struct pt_regs *regs,
+ int nr)
+{
+ regs->r06 = nr;
+}
+
static inline void syscall_get_arguments(struct task_struct *task,
struct pt_regs *regs,
unsigned long *args)
diff --git a/arch/loongarch/include/asm/syscall.h b/arch/loongarch/include/asm/syscall.h
index ff415b3c0a8e..81d2733f7b94 100644
--- a/arch/loongarch/include/asm/syscall.h
+++ b/arch/loongarch/include/asm/syscall.h
@@ -26,6 +26,13 @@ static inline long syscall_get_nr(struct task_struct *task,
return regs->regs[11];
}
+static inline void syscall_set_nr(struct task_struct *task,
+ struct pt_regs *regs,
+ int nr)
+{
+ regs->regs[11] = nr;
+}
+
static inline void syscall_rollback(struct task_struct *task,
struct pt_regs *regs)
{
diff --git a/arch/m68k/include/asm/syscall.h b/arch/m68k/include/asm/syscall.h
index d1453e850cdd..bf84b160c2eb 100644
--- a/arch/m68k/include/asm/syscall.h
+++ b/arch/m68k/include/asm/syscall.h
@@ -14,6 +14,13 @@ static inline int syscall_get_nr(struct task_struct *task,
return regs->orig_d0;
}
+static inline void syscall_set_nr(struct task_struct *task,
+ struct pt_regs *regs,
+ int nr)
+{
+ regs->orig_d0 = nr;
+}
+
static inline void syscall_rollback(struct task_struct *task,
struct pt_regs *regs)
{
diff --git a/arch/microblaze/include/asm/syscall.h b/arch/microblaze/include/asm/syscall.h
index 5eb3f624cc59..b5b6b91fae3e 100644
--- a/arch/microblaze/include/asm/syscall.h
+++ b/arch/microblaze/include/asm/syscall.h
@@ -14,6 +14,13 @@ static inline long syscall_get_nr(struct task_struct *task,
return regs->r12;
}
+static inline void syscall_set_nr(struct task_struct *task,
+ struct pt_regs *regs,
+ int nr)
+{
+ regs->r12 = nr;
+}
+
static inline void syscall_rollback(struct task_struct *task,
struct pt_regs *regs)
{
diff --git a/arch/mips/include/asm/syscall.h b/arch/mips/include/asm/syscall.h
index b8a19e465bf4..793026c4c7f0 100644
--- a/arch/mips/include/asm/syscall.h
+++ b/arch/mips/include/asm/syscall.h
@@ -41,6 +41,13 @@ static inline long syscall_get_nr(struct task_struct *task,
return task_thread_info(task)->syscall;
}
+static inline void syscall_set_nr(struct task_struct *task,
+ struct pt_regs *regs,
+ int nr)
+{
+ task_thread_info(task)->syscall = nr;
+}
+
static inline void mips_syscall_update_nr(struct task_struct *task,
struct pt_regs *regs)
{
diff --git a/arch/nios2/include/asm/syscall.h b/arch/nios2/include/asm/syscall.h
index 526449edd768..8e3eb1d689bb 100644
--- a/arch/nios2/include/asm/syscall.h
+++ b/arch/nios2/include/asm/syscall.h
@@ -15,6 +15,11 @@ static inline int syscall_get_nr(struct task_struct *task, struct pt_regs *regs)
return regs->r2;
}
+static inline void syscall_set_nr(struct task_struct *task, struct pt_regs *regs, int nr)
+{
+ regs->r2 = nr;
+}
+
static inline void syscall_rollback(struct task_struct *task,
struct pt_regs *regs)
{
diff --git a/arch/openrisc/include/asm/syscall.h b/arch/openrisc/include/asm/syscall.h
index e6383be2a195..5e037d9659c5 100644
--- a/arch/openrisc/include/asm/syscall.h
+++ b/arch/openrisc/include/asm/syscall.h
@@ -25,6 +25,12 @@ syscall_get_nr(struct task_struct *task, struct pt_regs *regs)
return regs->orig_gpr11;
}
+static inline void
+syscall_set_nr(struct task_struct *task, struct pt_regs *regs, int nr)
+{
+ regs->orig_gpr11 = nr;
+}
+
static inline void
syscall_rollback(struct task_struct *task, struct pt_regs *regs)
{
diff --git a/arch/parisc/include/asm/syscall.h b/arch/parisc/include/asm/syscall.h
index b146d0ae4c77..c11222798ab2 100644
--- a/arch/parisc/include/asm/syscall.h
+++ b/arch/parisc/include/asm/syscall.h
@@ -17,6 +17,13 @@ static inline long syscall_get_nr(struct task_struct *tsk,
return regs->gr[20];
}
+static inline void syscall_set_nr(struct task_struct *tsk,
+ struct pt_regs *regs,
+ int nr)
+{
+ regs->gr[20] = nr;
+}
+
static inline void syscall_get_arguments(struct task_struct *tsk,
struct pt_regs *regs,
unsigned long *args)
diff --git a/arch/powerpc/include/asm/syscall.h b/arch/powerpc/include/asm/syscall.h
index b2715448a660..09e34d19c961 100644
--- a/arch/powerpc/include/asm/syscall.h
+++ b/arch/powerpc/include/asm/syscall.h
@@ -39,6 +39,11 @@ static inline int syscall_get_nr(struct task_struct *task, struct pt_regs *regs)
return -1;
}
+static inline void syscall_set_nr(struct task_struct *task, struct pt_regs *regs, int nr)
+{
+ regs->gpr[0] = nr;
+}
+
static inline void syscall_rollback(struct task_struct *task,
struct pt_regs *regs)
{
diff --git a/arch/riscv/include/asm/syscall.h b/arch/riscv/include/asm/syscall.h
index 8d389ba995c8..a5281cdf2b10 100644
--- a/arch/riscv/include/asm/syscall.h
+++ b/arch/riscv/include/asm/syscall.h
@@ -30,6 +30,13 @@ static inline int syscall_get_nr(struct task_struct *task,
return regs->a7;
}
+static inline void syscall_set_nr(struct task_struct *task,
+ struct pt_regs *regs,
+ int nr)
+{
+ regs->a7 = nr;
+}
+
static inline void syscall_rollback(struct task_struct *task,
struct pt_regs *regs)
{
diff --git a/arch/s390/include/asm/syscall.h b/arch/s390/include/asm/syscall.h
index b3dd883699e7..1c0e349fd5c9 100644
--- a/arch/s390/include/asm/syscall.h
+++ b/arch/s390/include/asm/syscall.h
@@ -24,6 +24,13 @@ static inline long syscall_get_nr(struct task_struct *task,
(regs->int_code & 0xffff) : -1;
}
+static inline void syscall_set_nr(struct task_struct *task,
+ struct pt_regs *regs,
+ int nr)
+{
+ regs->int_code = (regs->int_code & ~0xffff) | (nr & 0xffff);
+}
+
static inline void syscall_rollback(struct task_struct *task,
struct pt_regs *regs)
{
diff --git a/arch/sh/include/asm/syscall_32.h b/arch/sh/include/asm/syscall_32.h
index cb51a7528384..0e1e7b029457 100644
--- a/arch/sh/include/asm/syscall_32.h
+++ b/arch/sh/include/asm/syscall_32.h
@@ -15,6 +15,13 @@ static inline long syscall_get_nr(struct task_struct *task,
return (regs->tra >= 0) ? regs->regs[3] : -1L;
}
+static inline void syscall_set_nr(struct task_struct *task,
+ struct pt_regs *regs,
+ int nr)
+{
+ regs->regs[3] = nr;
+}
+
static inline void syscall_rollback(struct task_struct *task,
struct pt_regs *regs)
{
diff --git a/arch/sparc/include/asm/syscall.h b/arch/sparc/include/asm/syscall.h
index 62a5a78804c4..36830a37fda4 100644
--- a/arch/sparc/include/asm/syscall.h
+++ b/arch/sparc/include/asm/syscall.h
@@ -25,6 +25,13 @@ static inline long syscall_get_nr(struct task_struct *task,
return (syscall_p ? regs->u_regs[UREG_G1] : -1L);
}
+static inline void syscall_set_nr(struct task_struct *task,
+ struct pt_regs *regs,
+ int nr)
+{
+ regs->u_regs[UREG_G1] = nr;
+}
+
static inline void syscall_rollback(struct task_struct *task,
struct pt_regs *regs)
{
diff --git a/arch/um/include/asm/syscall-generic.h b/arch/um/include/asm/syscall-generic.h
index 2984feb9d576..bcd73bcfe577 100644
--- a/arch/um/include/asm/syscall-generic.h
+++ b/arch/um/include/asm/syscall-generic.h
@@ -21,6 +21,11 @@ static inline int syscall_get_nr(struct task_struct *task, struct pt_regs *regs)
return PT_REGS_SYSCALL_NR(regs);
}
+static inline void syscall_set_nr(struct task_struct *task, struct pt_regs *regs, int nr)
+{
+ PT_REGS_SYSCALL_NR(regs) = nr;
+}
+
static inline void syscall_rollback(struct task_struct *task,
struct pt_regs *regs)
{
diff --git a/arch/x86/include/asm/syscall.h b/arch/x86/include/asm/syscall.h
index b9c249dd9e3d..c10dbb74cd00 100644
--- a/arch/x86/include/asm/syscall.h
+++ b/arch/x86/include/asm/syscall.h
@@ -38,6 +38,13 @@ static inline int syscall_get_nr(struct task_struct *task, struct pt_regs *regs)
return regs->orig_ax;
}
+static inline void syscall_set_nr(struct task_struct *task,
+ struct pt_regs *regs,
+ int nr)
+{
+ regs->orig_ax = nr;
+}
+
static inline void syscall_rollback(struct task_struct *task,
struct pt_regs *regs)
{
diff --git a/arch/xtensa/include/asm/syscall.h b/arch/xtensa/include/asm/syscall.h
index f9a671cbf933..7db3b489c8ad 100644
--- a/arch/xtensa/include/asm/syscall.h
+++ b/arch/xtensa/include/asm/syscall.h
@@ -28,6 +28,13 @@ static inline long syscall_get_nr(struct task_struct *task,
return regs->syscall;
}
+static inline void syscall_set_nr(struct task_struct *task,
+ struct pt_regs *regs,
+ int nr)
+{
+ regs->syscall = nr;
+}
+
static inline void syscall_rollback(struct task_struct *task,
struct pt_regs *regs)
{
diff --git a/include/asm-generic/syscall.h b/include/asm-generic/syscall.h
index 0f7b9a493de7..e33fd4e783c1 100644
--- a/include/asm-generic/syscall.h
+++ b/include/asm-generic/syscall.h
@@ -37,6 +37,20 @@ struct pt_regs;
*/
int syscall_get_nr(struct task_struct *task, struct pt_regs *regs);
+/**
+ * syscall_set_nr - change the system call a task is executing
+ * @task: task of interest, must be blocked
+ * @regs: task_pt_regs() of @task
+ * @nr: system call number
+ *
+ * Changes the system call number @task is about to execute.
+ *
+ * It's only valid to call this when @task is stopped for tracing on
+ * entry to a system call, due to %SYSCALL_WORK_SYSCALL_TRACE or
+ * %SYSCALL_WORK_SYSCALL_AUDIT.
+ */
+void syscall_set_nr(struct task_struct *task, struct pt_regs *regs, int nr);
+
/**
* syscall_rollback - roll back registers after an aborted system call
* @task: task of interest, must be in system call exit tracing
--
ldv
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH 3/6] syscall.h: introduce syscall_set_nr()
2025-01-07 23:04 ` [PATCH 3/6] syscall.h: introduce syscall_set_nr() Dmitry V. Levin
@ 2025-01-10 7:37 ` Sven Schnelle
2025-01-11 1:16 ` Dmitry V. Levin
0 siblings, 1 reply; 6+ messages in thread
From: Sven Schnelle @ 2025-01-10 7:37 UTC (permalink / raw)
To: Dmitry V. Levin
Cc: Oleg Nesterov, Eugene Syromyatnikov, Mike Frysinger, Renzo Davoli,
Davide Berardi, strace-devel, Vineet Gupta, Russell King,
Catalin Marinas, Will Deacon, Brian Cain, Huacai Chen,
WANG Xuerui, Geert Uytterhoeven, Michal Simek,
Thomas Bogendoerfer, Dinh Nguyen, Jonas Bonn, Stefan Kristiansson,
Stafford Horne, James E.J. Bottomley, Helge Deller,
Michael Ellerman, Nicholas Piggin, Christophe Leroy, Naveen N Rao,
Madhavan Srinivasan, Paul Walmsley, Palmer Dabbelt, Albert Ou,
Heiko Carstens, Vasily Gorbik, Alexander Gordeev,
Christian Borntraeger, Yoshinori Sato, Rich Felker,
John Paul Adrian Glaubitz, David S. Miller, Andreas Larsson,
Richard Weinberger, Anton Ivanov, Johannes Berg, Thomas Gleixner,
Ingo Molnar, Borislav Petkov, Dave Hansen, x86, H. Peter Anvin,
Chris Zankel, Max Filippov, Arnd Bergmann, linux-snps-arc,
linux-kernel, linux-arm-kernel, linux-hexagon, loongarch,
linux-m68k, linux-mips, linux-openrisc, linux-parisc,
linuxppc-dev, linux-riscv, linux-s390, linux-sh, sparclinux,
linux-um, linux-arch
"Dmitry V. Levin" <ldv@strace.io> writes:
> Similar to syscall_set_arguments() that complements
> syscall_get_arguments(), introduce syscall_set_nr()
> that complements syscall_get_nr().
>
> syscall_set_nr() is going to be needed along with
> syscall_set_arguments() on all HAVE_ARCH_TRACEHOOK
> architectures to implement PTRACE_SET_SYSCALL_INFO API.
>
> Signed-off-by: Dmitry V. Levin <ldv@strace.io>
> ---
> arch/arc/include/asm/syscall.h | 6 ++++++
> arch/arm/include/asm/syscall.h | 12 ++++++++++++
> arch/arm64/include/asm/syscall.h | 7 +++++++
> arch/hexagon/include/asm/syscall.h | 7 +++++++
> arch/loongarch/include/asm/syscall.h | 7 +++++++
> arch/m68k/include/asm/syscall.h | 7 +++++++
> arch/microblaze/include/asm/syscall.h | 7 +++++++
> arch/mips/include/asm/syscall.h | 7 +++++++
> arch/nios2/include/asm/syscall.h | 5 +++++
> arch/openrisc/include/asm/syscall.h | 6 ++++++
> arch/parisc/include/asm/syscall.h | 7 +++++++
> arch/powerpc/include/asm/syscall.h | 5 +++++
> arch/riscv/include/asm/syscall.h | 7 +++++++
> arch/s390/include/asm/syscall.h | 7 +++++++
> arch/sh/include/asm/syscall_32.h | 7 +++++++
> arch/sparc/include/asm/syscall.h | 7 +++++++
> arch/um/include/asm/syscall-generic.h | 5 +++++
> arch/x86/include/asm/syscall.h | 7 +++++++
> arch/xtensa/include/asm/syscall.h | 7 +++++++
> include/asm-generic/syscall.h | 14 ++++++++++++++
> 20 files changed, 144 insertions(+)
>
> diff --git a/arch/s390/include/asm/syscall.h b/arch/s390/include/asm/syscall.h
> index b3dd883699e7..1c0e349fd5c9 100644
> --- a/arch/s390/include/asm/syscall.h
> +++ b/arch/s390/include/asm/syscall.h
> @@ -24,6 +24,13 @@ static inline long syscall_get_nr(struct task_struct *task,
> (regs->int_code & 0xffff) : -1;
> }
>
> +static inline void syscall_set_nr(struct task_struct *task,
> + struct pt_regs *regs,
> + int nr)
> +{
I think there should be a
if (!test_pt_regs_flags(regs, PIF_SYSCALL))
return;
before the modification so a user can't accidentally change int_code
when ptrace stopped in a non-syscall path.
> + regs->int_code = (regs->int_code & ~0xffff) | (nr & 0xffff);
> +}
> +
> static inline void syscall_rollback(struct task_struct *task,
> struct pt_regs *regs)
> {
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH 3/6] syscall.h: introduce syscall_set_nr()
2025-01-10 7:37 ` Sven Schnelle
@ 2025-01-11 1:16 ` Dmitry V. Levin
0 siblings, 0 replies; 6+ messages in thread
From: Dmitry V. Levin @ 2025-01-11 1:16 UTC (permalink / raw)
To: Sven Schnelle
Cc: Oleg Nesterov, Eugene Syromyatnikov, Mike Frysinger, Renzo Davoli,
Davide Berardi, strace-devel, Vineet Gupta, Russell King,
Catalin Marinas, Will Deacon, Brian Cain, Huacai Chen,
WANG Xuerui, Geert Uytterhoeven, Michal Simek,
Thomas Bogendoerfer, Dinh Nguyen, Jonas Bonn, Stefan Kristiansson,
Stafford Horne, James E.J. Bottomley, Helge Deller,
Michael Ellerman, Nicholas Piggin, Christophe Leroy, Naveen N Rao,
Madhavan Srinivasan, Paul Walmsley, Palmer Dabbelt, Albert Ou,
Heiko Carstens, Vasily Gorbik, Alexander Gordeev,
Christian Borntraeger, Yoshinori Sato, Rich Felker,
John Paul Adrian Glaubitz, David S. Miller, Andreas Larsson,
Richard Weinberger, Anton Ivanov, Johannes Berg, Thomas Gleixner,
Ingo Molnar, Borislav Petkov, Dave Hansen, x86, H. Peter Anvin,
Chris Zankel, Max Filippov, Arnd Bergmann, linux-snps-arc,
linux-kernel, linux-arm-kernel, linux-hexagon, loongarch,
linux-m68k, linux-mips, linux-openrisc, linux-parisc,
linuxppc-dev, linux-riscv, linux-s390, linux-sh, sparclinux,
linux-um, linux-arch
On Fri, Jan 10, 2025 at 08:37:46AM +0100, Sven Schnelle wrote:
> "Dmitry V. Levin" <ldv@strace.io> writes:
>
> > Similar to syscall_set_arguments() that complements
> > syscall_get_arguments(), introduce syscall_set_nr()
> > that complements syscall_get_nr().
> >
> > syscall_set_nr() is going to be needed along with
> > syscall_set_arguments() on all HAVE_ARCH_TRACEHOOK
> > architectures to implement PTRACE_SET_SYSCALL_INFO API.
[...]
> > diff --git a/arch/s390/include/asm/syscall.h b/arch/s390/include/asm/syscall.h
> > index b3dd883699e7..1c0e349fd5c9 100644
> > --- a/arch/s390/include/asm/syscall.h
> > +++ b/arch/s390/include/asm/syscall.h
> > @@ -24,6 +24,13 @@ static inline long syscall_get_nr(struct task_struct *task,
> > (regs->int_code & 0xffff) : -1;
> > }
> >
> > +static inline void syscall_set_nr(struct task_struct *task,
> > + struct pt_regs *regs,
> > + int nr)
> > +{
>
> I think there should be a
>
> if (!test_pt_regs_flags(regs, PIF_SYSCALL))
> return;
>
> before the modification so a user can't accidentally change int_code
> when ptrace stopped in a non-syscall path.
The reason why syscall_get_nr() has this check on s390 (and similar checks
on arc, powerpc, and sparc) is that syscall_get_nr() can be called while
the target task is not in syscall.
Unlike syscall_get_nr(), syscall_set_nr() can be called only when the
target task is stopped for tracing on entering syscall: the description in
include/asm-generic/syscall.h explicitly states that, and the follow-up
patch that introduces PTRACE_SET_SYSCALL_INFO adds a syscall_set_nr() call
when the tracee is stopped on entering syscall in either
PTRACE_SYSCALL_INFO_ENTRY or PTRACE_SYSCALL_INFO_SECCOMP state.
I don't mind adding a check, but syscall_set_nr() invocation while the
target task is not in syscall wouldn't be a result of user actions but
a kernel programing error, and in that case WARN_ON_ONCE() would be more
appropriate.
If calling syscall_set_nr() while the target task is not in syscall was
legal, then syscall_set_nr() would have been designed to return a value
indicating the status of operation.
Anyway, I'll add an explanatory comment to syscall_set_nr() on all
architectures where syscall_get_nr() has a check.
--
ldv
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 0/6] ptrace: introduce PTRACE_SET_SYSCALL_INFO API
2025-01-07 23:01 [PATCH 0/6] ptrace: introduce PTRACE_SET_SYSCALL_INFO API Dmitry V. Levin
2025-01-07 23:04 ` [PATCH 1/6] Revert "arch: remove unused function syscall_set_arguments()" Dmitry V. Levin
2025-01-07 23:04 ` [PATCH 3/6] syscall.h: introduce syscall_set_nr() Dmitry V. Levin
@ 2025-01-10 3:15 ` H. Peter Anvin
2 siblings, 0 replies; 6+ messages in thread
From: H. Peter Anvin @ 2025-01-10 3:15 UTC (permalink / raw)
To: Dmitry V. Levin, Oleg Nesterov
Cc: Eugene Syromyatnikov, Mike Frysinger, Renzo Davoli,
Davide Berardi, strace-devel, Vineet Gupta, Russell King,
Catalin Marinas, Will Deacon, Guo Ren, Brian Cain, Huacai Chen,
WANG Xuerui, Geert Uytterhoeven, Michal Simek,
Thomas Bogendoerfer, Dinh Nguyen, Jonas Bonn, Stefan Kristiansson,
Stafford Horne, James E.J. Bottomley, Helge Deller,
Michael Ellerman, Nicholas Piggin, Christophe Leroy, Naveen N Rao,
Madhavan Srinivasan, Paul Walmsley, Palmer Dabbelt, Albert Ou,
Heiko Carstens, Vasily Gorbik, Alexander Gordeev,
Christian Borntraeger, Sven Schnelle, Yoshinori Sato, Rich Felker,
John Paul Adrian Glaubitz, David S. Miller, Andreas Larsson,
Richard Weinberger, Anton Ivanov, Johannes Berg, Thomas Gleixner,
Ingo Molnar, Borislav Petkov, Dave Hansen, x86, Chris Zankel,
Max Filippov, Arnd Bergmann, Shuah Khan, linux-snps-arc,
linux-kernel, linux-arm-kernel, linux-csky, linux-hexagon,
loongarch, linux-m68k, linux-mips, linux-openrisc, linux-parisc,
linuxppc-dev, linux-riscv, linux-s390, linux-sh, sparclinux,
linux-um, linux-arch, linux-kselftest
This would seem like a very good idea. However, it is perhaps important
to realize that it doesn't fully eliminate the problems with 64-bit
arguments on 32-bit ABIs being handled differently (never mind
inconsistencies in system call ABIs etc.) There isn't all that much that
can be done about that directly, though.
-hpa
On 1/7/25 15:01, Dmitry V. Levin wrote:
> PTRACE_SET_SYSCALL_INFO is a generic ptrace API that complements
> PTRACE_GET_SYSCALL_INFO by letting the ptracer modify details of
> system calls the tracee is blocked in.
>
> This API allows ptracers to obtain and modify system call details
> in a straightforward and architecture-agnostic way.
>
> Current implementation supports changing only those bits of system call
> information that are used by strace, namely, syscall number, syscall
> arguments, and syscall return value.
>
> Support of changing additional details returned by PTRACE_GET_SYSCALL_INFO,
> such as instruction pointer and stack pointer, could be added later
> if needed, by re-using struct ptrace_syscall_info.reserved to specify
> the additional details that should be set. Currently, the reserved
> field of struct ptrace_syscall_info must be initialized with zeroes;
> arch, instruction_pointer, and stack_pointer fields are ignored.
>
> PTRACE_SET_SYSCALL_INFO currently supports only PTRACE_SYSCALL_INFO_ENTRY,
> PTRACE_SYSCALL_INFO_EXIT, and PTRACE_SYSCALL_INFO_SECCOMP operations.
> Other operations could be added later if needed.
>
> Ideally, PTRACE_SET_SYSCALL_INFO should have been introduced along with
> PTRACE_GET_SYSCALL_INFO, but it didn't happen. The last straw that
> convinced me to implement PTRACE_SET_SYSCALL_INFO was apparent failure
> to provide an API of changing the first system call argument on riscv
> architecture [1].
>
> ptrace(2) man page:
>
> long ptrace(enum __ptrace_request request, pid_t pid, void *addr, void *data);
> ...
> PTRACE_SET_SYSCALL_INFO
> Modify information about the system call that caused the stop.
> The "data" argument is a pointer to struct ptrace_syscall_info
> that specifies the system call information to be set.
> The "addr" argument should be set to sizeof(struct ptrace_syscall_info)).
>
> [1] https://lore.kernel.org/all/59505464-c84a-403d-972f-d4b2055eeaac@gmail.com/
>
> Dmitry V. Levin (6):
> Revert "arch: remove unused function syscall_set_arguments()"
> syscall.h: add syscall_set_arguments() on remaining
> HAVE_ARCH_TRACEHOOK arches
> syscall.h: introduce syscall_set_nr()
> ptrace_get_syscall_info: factor out ptrace_get_syscall_info_op
> ptrace: introduce PTRACE_SET_SYSCALL_INFO request
> selftests/ptrace: add a test case for PTRACE_SET_SYSCALL_INFO
>
> arch/arc/include/asm/syscall.h | 20 +
> arch/arm/include/asm/syscall.h | 25 +
> arch/arm64/include/asm/syscall.h | 20 +
> arch/csky/include/asm/syscall.h | 13 +
> arch/hexagon/include/asm/syscall.h | 14 +
> arch/loongarch/include/asm/syscall.h | 15 +
> arch/m68k/include/asm/syscall.h | 7 +
> arch/microblaze/include/asm/syscall.h | 7 +
> arch/mips/include/asm/syscall.h | 53 +++
> arch/nios2/include/asm/syscall.h | 16 +
> arch/openrisc/include/asm/syscall.h | 13 +
> arch/parisc/include/asm/syscall.h | 19 +
> arch/powerpc/include/asm/syscall.h | 15 +
> arch/riscv/include/asm/syscall.h | 16 +
> arch/s390/include/asm/syscall.h | 19 +
> arch/sh/include/asm/syscall_32.h | 19 +
> arch/sparc/include/asm/syscall.h | 17 +
> arch/um/include/asm/syscall-generic.h | 19 +
> arch/x86/include/asm/syscall.h | 43 ++
> arch/xtensa/include/asm/syscall.h | 18 +
> include/asm-generic/syscall.h | 30 ++
> include/linux/ptrace.h | 3 +
> include/uapi/linux/ptrace.h | 3 +-
> kernel/ptrace.c | 154 ++++++-
> tools/testing/selftests/ptrace/Makefile | 2 +-
> .../selftests/ptrace/set_syscall_info.c | 436 ++++++++++++++++++
> 26 files changed, 994 insertions(+), 22 deletions(-)
> create mode 100644 tools/testing/selftests/ptrace/set_syscall_info.c
>
^ permalink raw reply [flat|nested] 6+ messages in thread