From: Richard Henderson <richard.henderson@linaro.org>
To: qemu-devel@nongnu.org
Cc: Ilya Leoshkevich <iii@linux.ibm.com>
Subject: [PULL 03/27] linux-user/i386: Emulate orig_ax
Date: Sun, 13 Oct 2024 15:12:11 -0700 [thread overview]
Message-ID: <20241013221235.1585193-4-richard.henderson@linaro.org> (raw)
In-Reply-To: <20241013221235.1585193-1-richard.henderson@linaro.org>
From: Ilya Leoshkevich <iii@linux.ibm.com>
The kernel uses orig_rax/orig_eax to store the syscall number before
a syscall. One can see this value in core dumps and ptrace.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Message-ID: <20240912093012.402366-3-iii@linux.ibm.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
linux-user/qemu.h | 4 ++++
linux-user/elfload.c | 4 ++--
linux-user/i386/cpu_loop.c | 3 +++
3 files changed, 9 insertions(+), 2 deletions(-)
diff --git a/linux-user/qemu.h b/linux-user/qemu.h
index 98ad848ab2..895bdd722a 100644
--- a/linux-user/qemu.h
+++ b/linux-user/qemu.h
@@ -113,6 +113,10 @@ struct TaskState {
struct target_vm86plus_struct vm86plus;
uint32_t v86flags;
uint32_t v86mask;
+#endif
+#if defined(TARGET_I386)
+ /* Last syscall number. */
+ target_ulong orig_ax;
#endif
abi_ulong child_tidptr;
#ifdef TARGET_M68K
diff --git a/linux-user/elfload.c b/linux-user/elfload.c
index 352960b771..6cef8db3b5 100644
--- a/linux-user/elfload.c
+++ b/linux-user/elfload.c
@@ -203,7 +203,7 @@ static void elf_core_copy_regs(target_elf_gregset_t *regs, const CPUX86State *en
(*regs)[12] = tswapreg(env->regs[R_EDX]);
(*regs)[13] = tswapreg(env->regs[R_ESI]);
(*regs)[14] = tswapreg(env->regs[R_EDI]);
- (*regs)[15] = tswapreg(env->regs[R_EAX]); /* XXX */
+ (*regs)[15] = tswapreg(get_task_state(env_cpu_const(env))->orig_ax);
(*regs)[16] = tswapreg(env->eip);
(*regs)[17] = tswapreg(env->segs[R_CS].selector & 0xffff);
(*regs)[18] = tswapreg(env->eflags);
@@ -306,7 +306,7 @@ static void elf_core_copy_regs(target_elf_gregset_t *regs, const CPUX86State *en
(*regs)[8] = tswapreg(env->segs[R_ES].selector & 0xffff);
(*regs)[9] = tswapreg(env->segs[R_FS].selector & 0xffff);
(*regs)[10] = tswapreg(env->segs[R_GS].selector & 0xffff);
- (*regs)[11] = tswapreg(env->regs[R_EAX]); /* XXX */
+ (*regs)[11] = tswapreg(get_task_state(env_cpu_const(env))->orig_ax);
(*regs)[12] = tswapreg(env->eip);
(*regs)[13] = tswapreg(env->segs[R_CS].selector & 0xffff);
(*regs)[14] = tswapreg(env->eflags);
diff --git a/linux-user/i386/cpu_loop.c b/linux-user/i386/cpu_loop.c
index 92beb6830c..7a35215278 100644
--- a/linux-user/i386/cpu_loop.c
+++ b/linux-user/i386/cpu_loop.c
@@ -172,6 +172,7 @@ static void emulate_vsyscall(CPUX86State *env)
/*
* Perform the syscall. None of the vsyscalls should need restarting.
*/
+ get_task_state(env_cpu(env))->orig_ax = syscall;
ret = do_syscall(env, syscall, env->regs[R_EDI], env->regs[R_ESI],
env->regs[R_EDX], env->regs[10], env->regs[8],
env->regs[9], 0, 0);
@@ -221,6 +222,7 @@ void cpu_loop(CPUX86State *env)
case EXCP_SYSCALL:
#endif
/* linux syscall from int $0x80 */
+ get_task_state(cs)->orig_ax = env->regs[R_EAX];
ret = do_syscall(env,
env->regs[R_EAX],
env->regs[R_EBX],
@@ -239,6 +241,7 @@ void cpu_loop(CPUX86State *env)
#ifdef TARGET_X86_64
case EXCP_SYSCALL:
/* linux syscall from syscall instruction. */
+ get_task_state(cs)->orig_ax = env->regs[R_EAX];
ret = do_syscall(env,
env->regs[R_EAX],
env->regs[R_EDI],
--
2.43.0
next prev parent reply other threads:[~2024-10-13 22:13 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-10-13 22:12 [PULL 00/27] tcg + linux patch queue Richard Henderson
2024-10-13 22:12 ` [PULL 01/27] tcg: remove singlestep_enabled from DisasContextBase Richard Henderson
2024-10-13 22:12 ` [PULL 02/27] include/exec: Introduce env_cpu_const() Richard Henderson
2024-10-13 22:12 ` Richard Henderson [this message]
2024-10-13 22:12 ` [PULL 04/27] target/i386/gdbstub: Factor out gdb_get_reg() and gdb_write_reg() Richard Henderson
2024-10-13 22:12 ` [PULL 05/27] target/i386/gdbstub: Expose orig_ax Richard Henderson
2024-10-13 22:12 ` [PULL 06/27] tests/tcg: Run test-proc-mappings.py on i386 Richard Henderson
2024-10-13 22:12 ` [PULL 07/27] linux-user/vm86: Fix compilation with Clang Richard Henderson
2024-10-13 22:12 ` [PULL 08/27] accel/tcg: Assert noreturn from write-only page for atomics Richard Henderson
2024-10-13 22:12 ` [PULL 09/27] include/exec/memop: Move get_alignment_bits from tcg.h Richard Henderson
2024-10-13 22:12 ` [PULL 10/27] include/exec/memop: Rename get_alignment_bits Richard Henderson
2024-10-13 22:12 ` [PULL 11/27] include/exec/memop: Introduce memop_atomicity_bits Richard Henderson
2024-10-13 22:12 ` [PULL 12/27] accel/tcg: Add TCGCPUOps.tlb_fill_align Richard Henderson
2024-10-13 22:12 ` [PULL 13/27] accel/tcg: Use the alignment test in tlb_fill_align Richard Henderson
2024-10-13 22:12 ` [PULL 14/27] target/hppa: Add MemOp argument to hppa_get_physical_address Richard Henderson
2024-10-13 22:12 ` [PULL 15/27] target/hppa: Perform access rights before protection id check Richard Henderson
2024-10-13 22:12 ` [PULL 16/27] target/hppa: Fix priority of T, D, and B page faults Richard Henderson
2024-10-13 22:12 ` [PULL 17/27] target/hppa: Handle alignment faults in hppa_get_physical_address Richard Henderson
2024-10-13 22:12 ` [PULL 18/27] target/hppa: Implement TCGCPUOps.tlb_fill_align Richard Henderson
2024-10-13 22:12 ` [PULL 19/27] target/arm: Pass MemOp to get_phys_addr Richard Henderson
2024-10-13 22:12 ` [PULL 20/27] target/arm: Pass MemOp to get_phys_addr_with_space_nogpc Richard Henderson
2024-10-13 22:12 ` [PULL 21/27] target/arm: Pass MemOp to get_phys_addr_gpc Richard Henderson
2024-10-13 22:12 ` [PULL 22/27] target/arm: Pass MemOp to get_phys_addr_nogpc Richard Henderson
2024-10-13 22:12 ` [PULL 23/27] target/arm: Pass MemOp through get_phys_addr_twostage Richard Henderson
2024-10-13 22:12 ` [PULL 24/27] target/arm: Pass MemOp to get_phys_addr_lpae Richard Henderson
2024-10-13 22:12 ` [PULL 25/27] target/arm: Move device detection earlier in get_phys_addr_lpae Richard Henderson
2024-10-13 22:12 ` [PULL 26/27] target/arm: Implement TCGCPUOps.tlb_fill_align Richard Henderson
2024-10-13 22:12 ` [PULL 27/27] target/arm: Fix alignment fault priority in get_phys_addr_lpae Richard Henderson
2024-10-14 12:03 ` [PULL 00/27] tcg + linux patch queue Peter Maydell
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