[Valgrind-developers] [valgrind] Darwin syscall: clean up posix_spawn and add to scalar

[Paul F. <pa...@so...>]

https://sourceware.org/cgit/valgrind/commit/?id=ab1cf750c53cc1ec2ecb3d885764caa81b8fdd14

commit ab1cf750c53cc1ec2ecb3d885764caa81b8fdd14
Author: Paul Floyd <pj...@wa...>
Date:   Sat Feb 28 16:43:38 2026 +0100

    Darwin syscall: clean up posix_spawn and add to scalar

Diff:
---
 coregrind/m_syswrap/syswrap-darwin.c    |  4 +++-
 memcheck/tests/darwin/scalar.c          |  6 ++++-
 memcheck/tests/darwin/scalar.stderr.exp | 39 ++++++++++++++++++++++++++++++++-
 3 files changed, 46 insertions(+), 3 deletions(-)

diff --git a/coregrind/m_syswrap/syswrap-darwin.c b/coregrind/m_syswrap/syswrap-darwin.c
index ff0eaa27b0..44357b0afb 100644
--- a/coregrind/m_syswrap/syswrap-darwin.c
+++ b/coregrind/m_syswrap/syswrap-darwin.c
@@ -3801,6 +3801,8 @@ static void pre_argv_envp(Addr a, ThreadId tid, const HChar* s1, const HChar* s2
       Addr a_deref;
       Addr* a_p = (Addr*)a;
       PRE_MEM_READ( s1, (Addr)a_p, sizeof(Addr) );
+      if (!ML_(safe_to_deref)(a_p, sizeof(char*)))
+         return;
       a_deref = *a_p;
       if (0 == a_deref)
          break;
@@ -4009,7 +4011,7 @@ PRE(posix_spawn)
    // are omitted.
    //
    if (!trace_this_child) {
-      argv = (HChar**)ARG6;
+      argv = (HChar**)ARG5;
    } else {
       vg_assert( VG_(args_for_valgrind) );
       vg_assert( VG_(args_for_valgrind_noexecpass) >= 0 );
diff --git a/memcheck/tests/darwin/scalar.c b/memcheck/tests/darwin/scalar.c
index dd53145d2c..c4e93814ba 100644
--- a/memcheck/tests/darwin/scalar.c
+++ b/memcheck/tests/darwin/scalar.c
@@ -421,7 +421,11 @@ int main(void)
    // __NR_flistxattr 241
    // __NR_fsctl 242
    // __NR_initgroups 243
-   // __NR_posix_spawn 244
+
+   // two of the pointers, file_actions and attr, are opaque void* pointers
+   // currently we do not check what they point to, so "4m" for the moment
+   GO(__NR_posix_spawn, 244, "6s 4m");
+   SY(__NR_posix_spawn, x0+1, x0+1, x0+1, x0+1, x0+1, x0+1);
 
    GO_UNIMP(245-246, "unused");
 
diff --git a/memcheck/tests/darwin/scalar.stderr.exp b/memcheck/tests/darwin/scalar.stderr.exp
index b0fd9e4a34..da616dcb79 100644
--- a/memcheck/tests/darwin/scalar.stderr.exp
+++ b/memcheck/tests/darwin/scalar.stderr.exp
@@ -544,6 +544,43 @@ Syscall param exchangedata(path2) points to unaddressable byte(s)
 -----------------------------------------------------
 (228-229):       unused
 -----------------------------------------------------
+-----------------------------------------------------
+x20000f4(244):    __NR_posix_spawn 6s 4m
+-----------------------------------------------------
+Syscall param posix_spawn(pid) contains uninitialised byte(s)
+   ...
+
+Syscall param posix_spawn(path) contains uninitialised byte(s)
+   ...
+
+Syscall param posix_spawn(file_actions) contains uninitialised byte(s)
+   ...
+
+Syscall param posix_spawn(attrp) contains uninitialised byte(s)
+   ...
+
+Syscall param posix_spawn(argv) contains uninitialised byte(s)
+   ...
+
+Syscall param posix_spawn(envp) contains uninitialised byte(s)
+   ...
+
+Syscall param posix_spawn(pid) points to unaddressable byte(s)
+   ...
+ Address 0x........ is not stack'd, malloc'd or (recently) free'd
+
+Syscall param posix_spawn(path) points to unaddressable byte(s)
+   ...
+ Address 0x........ is not stack'd, malloc'd or (recently) free'd
+
+Syscall param posix_spawn(argv) points to unaddressable byte(s)
+   ...
+ Address 0x........ is not stack'd, malloc'd or (recently) free'd
+
+Syscall param posix_spawn(envp) points to unaddressable byte(s)
+   ...
+ Address 0x........ is not stack'd, malloc'd or (recently) free'd
+
 -----------------------------------------------------
 (245-246):       unused
 -----------------------------------------------------
@@ -584,6 +621,7 @@ Syscall param shmctl(IPC_STAT, buf) points to unaddressable byte(s)
 -----------------------------------------------------
 x2000108(264):          __NR_shmdt 1s 0m
 -----------------------------------------------------
+
 Syscall param shmdt(shmaddr) contains uninitialised byte(s)
    ...
 
@@ -630,7 +668,6 @@ Syscall param sem_close(sem) contains uninitialised byte(s)
 -----------------------------------------------------
 x200010e(270):     __NR_sem_unlink 1s 1m
 -----------------------------------------------------
-
 Syscall param sem_unlink(name) contains uninitialised byte(s)
    ...