From: =?utf-8?q?Thomas_Wei=C3=9Fschuh?= Date: Tue, 2 Apr 2024 18:55:29 +0200 Subject: libblkid: topology/ioctl: correctly handle kernel types MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Commit 5d71d711d07a ("libblkid: topolicy/ioctl: use union for multiple data types") incorrectly assumed that set_ulong and set_int refer to the type returned by the kernel. Instead the different function pointer names refer to the types of the function pointers. However all ioctls, except for the later added BLKGETDISKSEQ, return 32bit integers. This made libblkid also interpret the upper 32bits too, leading to garbage values. Introduce a new member 'kernel_size' to also handle the 64bit BLKGETDISKSEQ. Drop data.ul as it is no actually used. Closes #2904 Signed-off-by: Thomas Weißschuh (cherry picked from commit a10081a52c48a5232db30d8e0a7a7570cc8163ae) --- libblkid/src/topology/ioctl.c | 29 +++++++++++++++++++---------- 1 file changed, 19 insertions(+), 10 deletions(-) diff --git a/libblkid/src/topology/ioctl.c b/libblkid/src/topology/ioctl.c index 3560a2f..4be20e8 100644 --- a/libblkid/src/topology/ioctl.c +++ b/libblkid/src/topology/ioctl.c @@ -24,6 +24,7 @@ static const struct topology_val { long ioc; + size_t kernel_size; /* functions to set probing result */ int (*set_ulong)(blkid_probe, unsigned long); @@ -31,11 +32,16 @@ static const struct topology_val { int (*set_u64)(blkid_probe, uint64_t); } topology_vals[] = { - { BLKALIGNOFF, NULL, blkid_topology_set_alignment_offset }, - { BLKIOMIN, blkid_topology_set_minimum_io_size }, - { BLKIOOPT, blkid_topology_set_optimal_io_size }, - { BLKPBSZGET, blkid_topology_set_physical_sector_size }, - { BLKGETDISKSEQ, .set_u64 = blkid_topology_set_diskseq }, + { BLKALIGNOFF, sizeof(int), + .set_int = blkid_topology_set_alignment_offset }, + { BLKIOMIN, sizeof(int), + .set_ulong = blkid_topology_set_minimum_io_size }, + { BLKIOOPT, sizeof(int), + .set_ulong = blkid_topology_set_optimal_io_size }, + { BLKPBSZGET, sizeof(int), + .set_ulong = blkid_topology_set_physical_sector_size }, + { BLKGETDISKSEQ, sizeof(uint64_t), + .set_u64 = blkid_topology_set_diskseq }, /* we read BLKSSZGET in topology.c */ }; @@ -48,18 +54,21 @@ static int probe_ioctl_tp(blkid_probe pr, const struct topology_val *val = &topology_vals[i]; int rc = 1; union { - unsigned long ul; - int i; + int s32; uint64_t u64; - } data; + } data = { 0 }; if (ioctl(pr->fd, val->ioc, &data) == -1) goto nothing; + /* Convert from kernel to libblkid type */ + if (val->kernel_size == 4) + data.u64 = data.s32; + if (val->set_int) - rc = val->set_int(pr, data.i); + rc = val->set_int(pr, data.u64); else if (val->set_ulong) - rc = val->set_ulong(pr, data.ul); + rc = val->set_ulong(pr, data.u64); else rc = val->set_u64(pr, data.u64);