diff mbox series

[3/5] accel/tcg: Take mmap lock in the whole cpu_memory_rw_debug() function

Message ID 20250217130610.18313-4-philmd@linaro.org
State New
Headers show
Series accel/tcg: Clean cpu_memory_rw_debug() up | expand

Commit Message

Philippe Mathieu-Daudé Feb. 17, 2025, 1:06 p.m. UTC 
Simplify user implementation of cpu_memory_rw_debug() by
taking the mmap lock globally. See commit 87ab2704296
("linux-user: Allow gdbstub to ignore page protection")
for why this lock is necessary.

Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
 cpu-target.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

Comments

Richard Henderson Feb. 17, 2025, 7:37 p.m. UTC | #1 
On 2/17/25 05:06, Philippe Mathieu-Daudé wrote:
> Simplify user implementation of cpu_memory_rw_debug() by
> taking the mmap lock globally. See commit 87ab2704296
> ("linux-user: Allow gdbstub to ignore page protection")
> for why this lock is necessary.
> 
> Suggested-by: Richard Henderson <richard.henderson@linaro.org>
> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> ---
>   cpu-target.c | 6 ++++--
>   1 file changed, 4 insertions(+), 2 deletions(-)

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

r~
diff mbox series

Patch

diff --git a/cpu-target.c b/cpu-target.c
index 20933bde7d4..b5230ce1837 100644
--- a/cpu-target.c
+++ b/cpu-target.c
@@ -380,6 +380,8 @@  int cpu_memory_rw_debug(CPUState *cpu, vaddr addr,
     int ret = -1;
     int fd = -1;
 
+    mmap_lock();
+
     while (len > 0) {
         page = addr & TARGET_PAGE_MASK;
         l = (page + TARGET_PAGE_SIZE) - addr;
@@ -414,11 +416,9 @@  int cpu_memory_rw_debug(CPUState *cpu, vaddr addr,
                  * be under mmap_lock() in order to prevent the creation of
                  * another TranslationBlock in between.
                  */
-                mmap_lock();
                 tb_invalidate_phys_range(addr, addr + l - 1);
                 written = pwrite(fd, buf, l,
                                  (off_t)(uintptr_t)g2h_untagged(addr));
-                mmap_unlock();
                 if (written != l) {
                     goto out_close;
                 }
@@ -454,6 +454,8 @@  out_close:
         close(fd);
     }
 out:
+    mmap_unlock();
+
     return ret;
 }
 #endif