From: Richard Henderson <richard.henderson@linaro.org>
To: qemu-devel@nongnu.org
Cc: laurent@vivier.eu, imp@bsdimp.com, kariem.taha2.7@gmail.com
Subject: [PATCH 2/4] linux-user: Use WITH_MMAP_LOCK_GUARD in target_{shmat, shmdt}
Date: Sun, 20 Aug 2023 13:44:06 -0700 [thread overview]
Message-ID: <20230820204408.327348-3-richard.henderson@linaro.org> (raw)
In-Reply-To: <20230820204408.327348-1-richard.henderson@linaro.org>
Move the CF_PARALLEL setting outside of the mmap lock.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
linux-user/mmap.c | 98 ++++++++++++++++++++++-------------------------
1 file changed, 46 insertions(+), 52 deletions(-)
diff --git a/linux-user/mmap.c b/linux-user/mmap.c
index 3aeacd1ecd..f45b2d307c 100644
--- a/linux-user/mmap.c
+++ b/linux-user/mmap.c
@@ -1017,9 +1017,8 @@ abi_ulong target_shmat(CPUArchState *cpu_env, int shmid,
{
CPUState *cpu = env_cpu(cpu_env);
abi_ulong raddr;
- void *host_raddr;
struct shmid_ds shm_info;
- int i, ret;
+ int ret;
abi_ulong shmlba;
/* shmat pointers are always untagged */
@@ -1044,7 +1043,43 @@ abi_ulong target_shmat(CPUArchState *cpu_env, int shmid,
return -TARGET_EINVAL;
}
- mmap_lock();
+ WITH_MMAP_LOCK_GUARD() {
+ void *host_raddr;
+
+ if (shmaddr) {
+ host_raddr = shmat(shmid, (void *)g2h_untagged(shmaddr), shmflg);
+ } else {
+ abi_ulong mmap_start;
+
+ /* In order to use the host shmat, we need to honor host SHMLBA. */
+ mmap_start = mmap_find_vma(0, shm_info.shm_segsz,
+ MAX(SHMLBA, shmlba));
+
+ if (mmap_start == -1) {
+ return -TARGET_ENOMEM;
+ }
+ host_raddr = shmat(shmid, g2h_untagged(mmap_start),
+ shmflg | SHM_REMAP);
+ }
+
+ if (host_raddr == (void *)-1) {
+ return get_errno(-1);
+ }
+ raddr = h2g(host_raddr);
+
+ page_set_flags(raddr, raddr + shm_info.shm_segsz - 1,
+ PAGE_VALID | PAGE_RESET | PAGE_READ |
+ (shmflg & SHM_RDONLY ? 0 : PAGE_WRITE));
+
+ for (int i = 0; i < N_SHM_REGIONS; i++) {
+ if (!shm_regions[i].in_use) {
+ shm_regions[i].in_use = true;
+ shm_regions[i].start = raddr;
+ shm_regions[i].size = shm_info.shm_segsz;
+ break;
+ }
+ }
+ }
/*
* We're mapping shared memory, so ensure we generate code for parallel
@@ -1057,65 +1092,24 @@ abi_ulong target_shmat(CPUArchState *cpu_env, int shmid,
tb_flush(cpu);
}
- if (shmaddr) {
- host_raddr = shmat(shmid, (void *)g2h_untagged(shmaddr), shmflg);
- } else {
- abi_ulong mmap_start;
-
- /* In order to use the host shmat, we need to honor host SHMLBA. */
- mmap_start = mmap_find_vma(0, shm_info.shm_segsz, MAX(SHMLBA, shmlba));
-
- if (mmap_start == -1) {
- errno = ENOMEM;
- host_raddr = (void *)-1;
- } else {
- host_raddr = shmat(shmid, g2h_untagged(mmap_start),
- shmflg | SHM_REMAP);
- }
- }
-
- if (host_raddr == (void *)-1) {
- mmap_unlock();
- return get_errno((intptr_t)host_raddr);
- }
- raddr = h2g((uintptr_t)host_raddr);
-
- page_set_flags(raddr, raddr + shm_info.shm_segsz - 1,
- PAGE_VALID | PAGE_RESET | PAGE_READ |
- (shmflg & SHM_RDONLY ? 0 : PAGE_WRITE));
-
- for (i = 0; i < N_SHM_REGIONS; i++) {
- if (!shm_regions[i].in_use) {
- shm_regions[i].in_use = true;
- shm_regions[i].start = raddr;
- shm_regions[i].size = shm_info.shm_segsz;
- break;
- }
- }
-
- mmap_unlock();
return raddr;
}
abi_long target_shmdt(abi_ulong shmaddr)
{
- int i;
abi_long rv;
/* shmdt pointers are always untagged */
- mmap_lock();
-
- for (i = 0; i < N_SHM_REGIONS; ++i) {
- if (shm_regions[i].in_use && shm_regions[i].start == shmaddr) {
- shm_regions[i].in_use = false;
- page_set_flags(shmaddr, shmaddr + shm_regions[i].size - 1, 0);
- break;
+ WITH_MMAP_LOCK_GUARD() {
+ for (int i = 0; i < N_SHM_REGIONS; ++i) {
+ if (shm_regions[i].in_use && shm_regions[i].start == shmaddr) {
+ shm_regions[i].in_use = false;
+ page_set_flags(shmaddr, shmaddr + shm_regions[i].size - 1, 0);
+ break;
+ }
}
+ rv = get_errno(shmdt(g2h_untagged(shmaddr)));
}
- rv = get_errno(shmdt(g2h_untagged(shmaddr)));
-
- mmap_unlock();
-
return rv;
}
--
2.34.1
next prev parent reply other threads:[~2023-08-20 20:44 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-08-20 20:44 [PATCH 0/4] linux-user: shmat/shmdt improvements Richard Henderson
2023-08-20 20:44 ` [PATCH 1/4] linux-user: Move shmat and shmdt implementations to mmap.c Richard Henderson
2023-08-21 6:25 ` Philippe Mathieu-Daudé
2023-08-22 16:55 ` Warner Losh
2023-08-20 20:44 ` Richard Henderson [this message]
2023-08-20 20:44 ` [PATCH 3/4] linux-user: Fix shmdt Richard Henderson
2023-08-20 20:44 ` [PATCH 4/4] linux-user: Track shm regions with an interval tree Richard Henderson
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20230820204408.327348-3-richard.henderson@linaro.org \
--to=richard.henderson@linaro.org \
--cc=imp@bsdimp.com \
--cc=kariem.taha2.7@gmail.com \
--cc=laurent@vivier.eu \
--cc=qemu-devel@nongnu.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).