From: "Philippe Mathieu-Daudé" <philmd@linaro.org>
To: qemu-devel@nongnu.org
Cc: "Riku Voipio" <riku.voipio@iki.fi>,
"Richard Henderson" <richard.henderson@linaro.org>,
"Pierrick Bouvier" <pierrick.bouvier@linaro.org>,
"Paolo Bonzini" <pbonzini@redhat.com>,
"Anton Johansson" <anjo@rev.ng>,
"Ilya Leoshkevich" <iii@linux.ibm.com>,
"Philippe Mathieu-Daudé" <philmd@linaro.org>
Subject: [PATCH 4/5] accel/tcg: Avoid using lock_user() in cpu_memory_rw_debug()
Date: Mon, 17 Feb 2025 14:06:09 +0100 [thread overview]
Message-ID: <20250217130610.18313-5-philmd@linaro.org> (raw)
In-Reply-To: <20250217130610.18313-1-philmd@linaro.org>
We checked the page flags with page_get_flags(), so
locking the page is superfluous. Remove the lock_user()
calls and directly use g2h() in place.
Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
cpu-target.c | 17 ++---------------
1 file changed, 2 insertions(+), 15 deletions(-)
diff --git a/cpu-target.c b/cpu-target.c
index b5230ce1837..3892ce12229 100644
--- a/cpu-target.c
+++ b/cpu-target.c
@@ -374,7 +374,6 @@ int cpu_memory_rw_debug(CPUState *cpu, vaddr addr,
{
int flags;
vaddr l, page;
- void * p;
uint8_t *buf = ptr;
ssize_t written;
int ret = -1;
@@ -393,13 +392,7 @@ int cpu_memory_rw_debug(CPUState *cpu, vaddr addr,
}
if (is_write) {
if (flags & PAGE_WRITE) {
- /* XXX: this code should not depend on lock_user */
- p = lock_user(VERIFY_WRITE, addr, l, 0);
- if (!p) {
- goto out_close;
- }
- memcpy(p, buf, l);
- unlock_user(p, addr, l);
+ memcpy(g2h(cpu, addr), buf, l);
} else {
/* Bypass the host page protection using ptrace. */
if (fd == -1) {
@@ -424,13 +417,7 @@ int cpu_memory_rw_debug(CPUState *cpu, vaddr addr,
}
}
} else if (flags & PAGE_READ) {
- /* XXX: this code should not depend on lock_user */
- p = lock_user(VERIFY_READ, addr, l, 1);
- if (!p) {
- goto out_close;
- }
- memcpy(buf, p, l);
- unlock_user(p, addr, 0);
+ memcpy(buf, g2h(cpu, addr), l);
} else {
/* Bypass the host page protection using ptrace. */
if (fd == -1) {
--
2.47.1
next prev parent reply other threads:[~2025-02-17 13:07 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-02-17 13:06 [PATCH 0/5] accel/tcg: Clean cpu_memory_rw_debug() up Philippe Mathieu-Daudé
2025-02-17 13:06 ` [PATCH 1/5] accel/accel-cpu-target.h: Include missing 'cpu.h' header Philippe Mathieu-Daudé
2025-02-17 13:06 ` [PATCH 2/5] accel/tcg: Include missing bswap headers in user-exec.c Philippe Mathieu-Daudé
2025-02-17 19:36 ` Richard Henderson
2025-02-17 13:06 ` [PATCH 3/5] accel/tcg: Take mmap lock in the whole cpu_memory_rw_debug() function Philippe Mathieu-Daudé
2025-02-17 19:37 ` Richard Henderson
2025-02-17 13:06 ` Philippe Mathieu-Daudé [this message]
2025-02-17 19:39 ` [PATCH 4/5] accel/tcg: Avoid using lock_user() in cpu_memory_rw_debug() Richard Henderson
2025-02-17 13:06 ` [PATCH 5/5] accel/tcg: Move cpu_memory_rw_debug() user implementation to user-exec.c Philippe Mathieu-Daudé
2025-02-17 19:40 ` Richard Henderson
2025-02-20 15:28 ` [PATCH 0/5] accel/tcg: Clean cpu_memory_rw_debug() up Philippe Mathieu-Daudé
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