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From: Richard Henderson <richard.henderson@linaro.org>
To: qemu-devel@nongnu.org
Cc: Pierrick Bouvier <pierrick.bouvier@linaro.org>,
	Helge Deller <deller@gmx.de>
Subject: [PULL 26/39] linux-user: Split out mmap_h_eq_g
Date: Thu, 22 Feb 2024 10:43:10 -1000	[thread overview]
Message-ID: <20240222204323.268539-27-richard.henderson@linaro.org> (raw)
In-Reply-To: <20240222204323.268539-1-richard.henderson@linaro.org>

Move the MAX_FIXED_NOREPLACE check for reserved_va earlier.
Move the computation of host_prot earlier.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Acked-by: Helge Deller <deller@gmx.de>
Message-Id: <20240102015808.132373-22-richard.henderson@linaro.org>
---
 linux-user/mmap.c | 68 ++++++++++++++++++++++++++++++++++++++---------
 1 file changed, 55 insertions(+), 13 deletions(-)

diff --git a/linux-user/mmap.c b/linux-user/mmap.c
index cbcd31e941..d3556bcc14 100644
--- a/linux-user/mmap.c
+++ b/linux-user/mmap.c
@@ -542,6 +542,33 @@ static abi_long mmap_end(abi_ulong start, abi_ulong last,
     return start;
 }
 
+/*
+ * Special case host page size == target page size,
+ * where there are no edge conditions.
+ */
+static abi_long mmap_h_eq_g(abi_ulong start, abi_ulong len,
+                            int host_prot, int flags, int page_flags,
+                            int fd, off_t offset)
+{
+    void *p, *want_p = g2h_untagged(start);
+    abi_ulong last;
+
+    p = mmap(want_p, len, host_prot, flags, fd, offset);
+    if (p == MAP_FAILED) {
+        return -1;
+    }
+    /* If the host kernel does not support MAP_FIXED_NOREPLACE, emulate. */
+    if ((flags & MAP_FIXED_NOREPLACE) && p != want_p) {
+        do_munmap(p, len);
+        errno = EEXIST;
+        return -1;
+    }
+
+    start = h2g(p);
+    last = start + len - 1;
+    return mmap_end(start, last, start, last, flags, page_flags);
+}
+
 static abi_long target_mmap__locked(abi_ulong start, abi_ulong len,
                                     int target_prot, int flags, int page_flags,
                                     int fd, off_t offset)
@@ -550,6 +577,7 @@ static abi_long target_mmap__locked(abi_ulong start, abi_ulong len,
     abi_ulong ret, last, real_start, real_last, retaddr, host_len;
     abi_ulong passthrough_start = -1, passthrough_last = 0;
     off_t host_offset;
+    int host_prot;
 
     real_start = start & -host_page_size;
     host_offset = offset & -host_page_size;
@@ -558,16 +586,33 @@ static abi_long target_mmap__locked(abi_ulong start, abi_ulong len,
      * For reserved_va, we are in full control of the allocation.
      * Find a suitable hole and convert to MAP_FIXED.
      */
-    if (reserved_va && !(flags & (MAP_FIXED | MAP_FIXED_NOREPLACE))) {
-        host_len = len + offset - host_offset;
-        start = mmap_find_vma(real_start, host_len,
-                              MAX(host_page_size, TARGET_PAGE_SIZE));
-        if (start == (abi_ulong)-1) {
-            errno = ENOMEM;
-            return -1;
+    if (reserved_va) {
+        if (flags & MAP_FIXED_NOREPLACE) {
+            /* Validate that the chosen range is empty. */
+            if (!page_check_range_empty(start, start + len - 1)) {
+                errno = EEXIST;
+                return -1;
+            }
+            flags = (flags & ~MAP_FIXED_NOREPLACE) | MAP_FIXED;
+        } else if (!(flags & MAP_FIXED)) {
+            size_t real_len = len + offset - host_offset;
+            abi_ulong align = MAX(host_page_size, TARGET_PAGE_SIZE);
+
+            start = mmap_find_vma(real_start, real_len, align);
+            if (start == (abi_ulong)-1) {
+                errno = ENOMEM;
+                return -1;
+            }
+            start += offset - host_offset;
+            flags |= MAP_FIXED;
         }
-        start += offset - host_offset;
-        flags |= MAP_FIXED;
+    }
+
+    host_prot = target_to_host_prot(target_prot);
+
+    if (host_page_size == TARGET_PAGE_SIZE) {
+        return mmap_h_eq_g(start, len, host_prot, flags,
+                           page_flags, fd, offset);
     }
 
     /*
@@ -603,12 +648,10 @@ static abi_long target_mmap__locked(abi_ulong start, abi_ulong len,
 
     if (!(flags & (MAP_FIXED | MAP_FIXED_NOREPLACE))) {
         uintptr_t host_start;
-        int host_prot;
         void *p;
 
         host_len = len + offset - host_offset;
         host_len = ROUND_UP(host_len, host_page_size);
-        host_prot = target_to_host_prot(target_prot);
 
         /* Note: we prefer to control the mapping address. */
         p = mmap(g2h_untagged(start), host_len, host_prot,
@@ -731,8 +774,7 @@ static abi_long target_mmap__locked(abi_ulong start, abi_ulong len,
             len1 = real_last - real_start + 1;
             want_p = g2h_untagged(real_start);
 
-            p = mmap(want_p, len1, target_to_host_prot(target_prot),
-                     flags, fd, offset1);
+            p = mmap(want_p, len1, host_prot, flags, fd, offset1);
             if (p != want_p) {
                 if (p != MAP_FAILED) {
                     do_munmap(p, len1);
-- 
2.34.1



  parent reply	other threads:[~2024-02-22 20:46 UTC|newest]

Thread overview: 42+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-02-22 20:42 [PULL 00/39] tcg and linux-user patch queue Richard Henderson
2024-02-22 20:42 ` [PULL 01/39] tcg/aarch64: Apple does not align __int128_t in even registers Richard Henderson
2024-02-22 20:42 ` [PULL 02/39] accel/tcg: Set can_do_io at at start of lookup_tb_ptr helper Richard Henderson
2024-02-22 20:42 ` [PULL 03/39] tcg: Avoid double lock if page tables happen to be in mmio memory Richard Henderson
2024-02-22 20:42 ` [PULL 04/39] accel/tcg: Remove qemu_host_page_size from page_protect/page_unprotect Richard Henderson
2024-02-22 20:42 ` [PULL 05/39] linux-user: Adjust SVr4 NULL page mapping Richard Henderson
2024-02-22 20:42 ` [PULL 06/39] linux-user: Remove qemu_host_page_{size, mask} in probe_guest_base Richard Henderson
2024-02-22 20:42 ` [PULL 07/39] linux-user: Remove qemu_host_page_size from create_elf_tables Richard Henderson
2024-02-22 20:42 ` [PULL 08/39] linux-user/hppa: Simplify init_guest_commpage Richard Henderson
2024-02-22 20:42 ` [PULL 09/39] linux-user/nios2: Remove qemu_host_page_size from init_guest_commpage Richard Henderson
2024-02-22 20:42 ` [PULL 10/39] linux-user/arm: " Richard Henderson
2024-02-22 20:42 ` [PULL 11/39] linux-user: Remove qemu_host_page_{size, mask} from mmap.c Richard Henderson
2024-02-22 20:42 ` [PULL 12/39] linux-user: Remove REAL_HOST_PAGE_ALIGN " Richard Henderson
2024-02-22 20:42 ` [PULL 13/39] linux-user: Remove HOST_PAGE_ALIGN " Richard Henderson
2024-02-22 20:42 ` [PULL 14/39] migration: Remove qemu_host_page_size Richard Henderson
2024-02-22 20:42 ` [PULL 15/39] hw/tpm: Remove HOST_PAGE_ALIGN from tpm_ppi_init Richard Henderson
2024-02-22 20:43 ` [PULL 16/39] softmmu/physmem: Remove qemu_host_page_size Richard Henderson
2024-02-22 20:43 ` [PULL 17/39] softmmu/physmem: Remove HOST_PAGE_ALIGN Richard Henderson
2024-02-22 20:43 ` [PULL 18/39] linux-user: Remove qemu_host_page_size from main Richard Henderson
2024-02-22 20:43 ` [PULL 19/39] linux-user: Split out target_mmap__locked Richard Henderson
2024-02-22 20:43 ` [PULL 20/39] linux-user: Move some mmap checks outside the lock Richard Henderson
2024-02-22 20:43 ` [PULL 21/39] linux-user: Fix sub-host-page mmap Richard Henderson
2024-02-22 20:43 ` [PULL 22/39] linux-user: Split out mmap_end Richard Henderson
2024-02-22 20:43 ` [PULL 23/39] linux-user: Do early mmap placement only for reserved_va Richard Henderson
2024-02-22 20:43 ` [PULL 24/39] linux-user: Split out do_munmap Richard Henderson
2024-02-22 20:43 ` [PULL 25/39] linux-user: Use do_munmap for target_mmap failure Richard Henderson
2024-02-22 20:43 ` Richard Henderson [this message]
2024-02-22 20:43 ` [PULL 27/39] linux-user: Split out mmap_h_lt_g Richard Henderson
2024-02-22 20:43 ` [PULL 28/39] linux-user: Split out mmap_h_gt_g Richard Henderson
2024-02-22 20:43 ` [PULL 29/39] tests/tcg: Remove run-test-mmap-* Richard Henderson
2024-02-22 20:43 ` [PULL 30/39] tests/tcg: Extend file in linux-madvise.c Richard Henderson
2024-02-22 20:43 ` [PULL 31/39] *-user: Deprecate and disable -p pagesize Richard Henderson
2024-02-22 20:43 ` [PULL 32/39] cpu: Remove page_size_init Richard Henderson
2024-02-22 20:43 ` [PULL 33/39] accel/tcg: Disconnect TargetPageDataNode from page size Richard Henderson
2024-02-22 20:43 ` [PULL 34/39] linux-user: Allow TARGET_PAGE_BITS_VARY Richard Henderson
2024-02-22 20:43 ` [PULL 35/39] target/arm: Enable TARGET_PAGE_BITS_VARY for AArch64 user-only Richard Henderson
2024-02-22 20:43 ` [PULL 36/39] linux-user: Bound mmap_min_addr by host page size Richard Henderson
2024-02-22 20:43 ` [PULL 37/39] target/ppc: Enable TARGET_PAGE_BITS_VARY for user-only Richard Henderson
2024-02-22 20:43 ` [PULL 38/39] target/alpha: " Richard Henderson
2024-02-22 20:43 ` [PULL 39/39] linux-user: Remove pgb_dynamic alignment assertion Richard Henderson
2024-02-23 13:45 ` [PULL 00/39] tcg and linux-user patch queue Peter Maydell
2024-02-23 22:26   ` Richard Henderson

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