[LTP] [PATCH v1] shmctl03: Fix 32-bit compat mode failure by forcing limits

[LTP] [PATCH v1] shmctl03: Fix 32-bit compat mode failure by forcing limits

[Wei Gao via ltp]

On 64-bit kernels, the default shmmax and shmall values often exceed
the range of a 32-bit unsigned long or are clipped differently by the
kernel's compat syscall layer than they appear in /proc.

Signed-off-by: Wei Gao <wegao@suse.com>
---
 testcases/kernel/syscalls/ipc/shmctl/shmctl03.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/testcases/kernel/syscalls/ipc/shmctl/shmctl03.c b/testcases/kernel/syscalls/ipc/shmctl/shmctl03.c
index a3291c37f..335a60980 100644
--- a/testcases/kernel/syscalls/ipc/shmctl/shmctl03.c
+++ b/testcases/kernel/syscalls/ipc/shmctl/shmctl03.c
@@ -13,6 +13,13 @@
 #include "tst_safe_sysv_ipc.h"
 #include "libnewipc.h"
 
+/* Force 32-bit limits to avoid overflow/mismatch on 64-bit kernels */
+#if __WORDSIZE == 32
+# define SET_SHM_LIMIT "2147483647"
+#else
+# define SET_SHM_LIMIT NULL
+#endif
+
 static void verify_ipcinfo(void)
 {
 	struct shminfo info;
@@ -37,4 +44,9 @@ static void verify_ipcinfo(void)
 
 static struct tst_test test = {
 	.test_all = verify_ipcinfo,
+	.save_restore = (const struct tst_path_val[]) {
+		{"/proc/sys/kernel/shmmax", SET_SHM_LIMIT, TST_SR_TCONF_MISSING},
+		{"/proc/sys/kernel/shmall", SET_SHM_LIMIT, TST_SR_TCONF_MISSING},
+		{}
+	},
 };
-- 
2.52.0


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Re: [LTP] [PATCH v1] shmctl03: Fix 32-bit compat mode failure by forcing limits

[Andrea Cervesato via ltp]

Hi!

We already have a discussion on this test, so we should take a look at
there " [LTP] shmctl03.c is broken for 32bit compat mode ".
Apparently, from 08 August 2025...

-- 
Andrea Cervesato
SUSE QE Automation Engineer Linux
andrea.cervesato@suse.com


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[LTP] [PATCH v1] shmctl03: Fix 32-bit compat mode failure by forcing limits

[Wei Gao via ltp]

On 64-bit kernels, the default shmmax and shmall values often exceed
the range of a 32-bit unsigned long or are clipped differently by the
kernel's compat syscall layer than they appear in /proc.

Link: https://lore.kernel.org/ltp/aJm5SBOaRoe1e0PB@yuki.lan/
Signed-off-by: Wei Gao <wegao@suse.com>
Suggested-by: Cyril Hrubis <chrubis@suse.cz>
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
---
 include/tst_assert.h                          | 10 +++++---
 lib/tst_assert.c                              | 25 ++++++++++++++-----
 .../kernel/syscalls/ipc/shmctl/shmctl03.c     | 12 ++++++---
 3 files changed, 35 insertions(+), 12 deletions(-)

diff --git a/include/tst_assert.h b/include/tst_assert.h
index dcb62dfea..5b3bd0e12 100644
--- a/include/tst_assert.h
+++ b/include/tst_assert.h
@@ -21,14 +21,18 @@ void tst_assert_int(const char *file, const int lineno,
 #define TST_ASSERT_FILE_INT(path, prefix, val) \
 	tst_assert_file_int(__FILE__, __LINE__, path, prefix, val)
 
+#define TST_ASSERT_SATURATED_INT   0x01
+#define TST_ASSERT_SATURATED_ULONG 0x02
+#define TST_ASSERT_BITWISE         0x04
+
 /*
  * Same as tst_assert_int() but for unsigned long.
  */
 void tst_assert_ulong(const char *file, const int lineno,
-                      const char *path, unsigned long val);
+                      const char *path, unsigned long val, int flags);
 
-#define TST_ASSERT_ULONG(path, val) \
-	tst_assert_ulong(__FILE__, __LINE__, path, val)
+#define TST_ASSERT_ULONG(path, val, ...) \
+	tst_assert_ulong(__FILE__, __LINE__, path, val, (0, ##__VA_ARGS__))
 
 /*
  * Asserts that integer value stored in the prefix field of file pointed by path
diff --git a/lib/tst_assert.c b/lib/tst_assert.c
index b68bd5d39..09d7d8a6f 100644
--- a/lib/tst_assert.c
+++ b/lib/tst_assert.c
@@ -23,18 +23,31 @@ void tst_assert_int(const char *file, const int lineno, const char *path, int va
 	tst_res_(file, lineno, TFAIL, "%s != %d got %d", path, val, sys_val);
 }
 
-void tst_assert_ulong(const char *file, const int lineno, const char *path, unsigned long val)
+void tst_assert_ulong(const char *file, const int lineno, const char *path,
+			unsigned long val, int flags)
 {
-	unsigned long sys_val;
-
-	safe_file_scanf(file, lineno, NULL, path, "%lu", &sys_val);
+	unsigned long long sys_val_64;
+	unsigned long expected_val;
+
+	safe_file_scanf(file, lineno, NULL, path, "%llu", &sys_val_64);
+
+	if (flags & TST_ASSERT_SATURATED_INT) {
+		expected_val = (sys_val_64 > 2147483647ULL) ? 2147483647UL : (unsigned long)sys_val_64;
+	} else if (flags & TST_ASSERT_SATURATED_ULONG) {
+		expected_val = (sys_val_64 > 4294967295ULL) ? 4294967295UL : (unsigned long)sys_val_64;
+	} else if (flags & TST_ASSERT_BITWISE) {
+		expected_val = (unsigned long)(sys_val_64 & 0xFFFFFFFFULL);
+	} else {
+		expected_val = (unsigned long)sys_val_64;
+	}
 
-	if (val == sys_val) {
+	if (val == expected_val) {
 		tst_res_(file, lineno, TPASS, "%s = %lu", path, val);
 		return;
 	}
 
-	tst_res_(file, lineno, TFAIL, "%s != %lu got %lu", path, val, sys_val);
+	tst_res_(file, lineno, TFAIL, "%s != %lu got %lu (raw: %llu)",
+		path, val, expected_val, sys_val_64);
 }
 
 void tst_assert_file_int(const char *file, const int lineno, const char *path, const char *prefix, int val)
diff --git a/testcases/kernel/syscalls/ipc/shmctl/shmctl03.c b/testcases/kernel/syscalls/ipc/shmctl/shmctl03.c
index a1f53e7c1..6d073789c 100644
--- a/testcases/kernel/syscalls/ipc/shmctl/shmctl03.c
+++ b/testcases/kernel/syscalls/ipc/shmctl/shmctl03.c
@@ -30,9 +30,15 @@ static void verify_ipcinfo(void)
 	else
 		tst_res(TPASS, "shmmin = 1");
 
-	TST_ASSERT_ULONG("/proc/sys/kernel/shmmax", info.shmmax);
-	TST_ASSERT_ULONG("/proc/sys/kernel/shmmni", info.shmmni);
-	TST_ASSERT_ULONG("/proc/sys/kernel/shmall", info.shmall);
+	if (tst_is_compat_mode()) {
+		TST_ASSERT_ULONG("/proc/sys/kernel/shmmax", info.shmmax, TST_ASSERT_SATURATED_INT);
+		TST_ASSERT_ULONG("/proc/sys/kernel/shmmni", info.shmmni, TST_ASSERT_BITWISE);
+		TST_ASSERT_ULONG("/proc/sys/kernel/shmall", info.shmall, TST_ASSERT_BITWISE);
+	} else {
+		TST_ASSERT_ULONG("/proc/sys/kernel/shmmax", info.shmmax);
+		TST_ASSERT_ULONG("/proc/sys/kernel/shmmni", info.shmmni);
+		TST_ASSERT_ULONG("/proc/sys/kernel/shmall", info.shmall);
+	}
 }
 
 static struct tst_test test = {
-- 
2.52.0


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Re: [LTP] [PATCH v1] shmctl03: Fix 32-bit compat mode failure by forcing limits

[Andrea Cervesato via ltp]

Hi Wei,

this review is pretty accurate. Please follow the suggestions here first:
https://github.com/acerv/ltp-agent/actions/runs/24074831444

King regards,
--
Andrea Cervesato
SUSE QE Automation Engineer Linux
andrea.cervesato@suse.com

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Re: [LTP] [PATCH v1] shmctl03: Fix 32-bit compat mode failure by forcing limits

[Wei Gao via ltp]

On Fri, Apr 10, 2026 at 01:14:41PM +0000, Andrea Cervesato via ltp wrote:
> Hi Wei,
> 
> this review is pretty accurate. Please follow the suggestions here first:
> https://github.com/acerv/ltp-agent/actions/runs/24074831444

I will update the subject line and use INT_MAX/UINT_MAX as AI suggested.
But I'd prefer to keep TST_ASSERT_SATURATED_ULONG even without a current caller,
as it completes the logic for the helper function. The logic is clear enough
that an extra comment isn't needed also, if you are agree then i will sent next patch.

Thanks.

> 
> King regards,
> --
> Andrea Cervesato
> SUSE QE Automation Engineer Linux
> andrea.cervesato@suse.com
> 
> -- 
> Mailing list info: https://lists.linux.it/listinfo/ltp

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Re: [LTP] [PATCH v1] shmctl03: Fix 32-bit compat mode failure by forcing limits

[Andrea Cervesato via ltp]

Hi Wei,

> I will update the subject line and use INT_MAX/UINT_MAX as AI suggested.
> But I'd prefer to keep TST_ASSERT_SATURATED_ULONG even without a current caller,
> as it completes the logic for the helper function. The logic is clear enough
> that an extra comment isn't needed also, if you are agree then i will sent next patch.

Fair enough, feel free to ignore that part and to send a new patch.

Regards,
--
Andrea Cervesato
SUSE QE Automation Engineer Linux
andrea.cervesato@suse.com

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