devices: generic: generic_poll: Fix unitialized pollfd struct fields.GNUtoo/history/04-02-2022-after-pollfd-fix

Before that fix, ipc-modem would sometimes hang in generic_poll.

Sometimes it would hang a lot and stop hanging after a reboot of the
Galaxy SIII (GT-I9300), and sometimes that bug was really hard to
reproduce.

Here is the log of when it happens. It hangs at the end:
    # ipc-modem start --pin=1234 --debug --call=06xxxxxxxx
    [I] Got SIM PIN!
    [I] Got call number!
    [I] Debug enabled
    [0] Starting modem on FMT client
    [D] ENTER generic_data_create
    [D] generic_data_create DONE
    [D] ENTER generic_boot
    [D] Starting generic modem boot
    Bus 001 Device 002: ID 1519:0020 Comneon HSIC Device
    Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
    [D] open_android_modem_partition_by_name: Trying to open /dev/disk/by-partlabel/RADIO
    [D] generic_boot: Opened the RADIO partition
    [D] Mapped modem image data to memory
    [D] ENTER xmm626_kernel_linux_modem_hci_power
    [D] xmm626_kernel_linux_modem_hci_power: DONE
    [D] Turned the modem off
    [D] generic_boot: xmm626_kernel_linux_modem_power(NULL, 1) = 0
    [D] ENTER xmm626_kernel_linux_modem_hci_power
    [D] xmm626_kernel_linux_modem_hci_power: DONE
    [D] generic_boot: xmm626_kernel_linux_modem_hci_power(client, 1) = 0
    [D] Turned the modem on
    Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
    [D] Opened modem boot device
    [D] Wrote ATAT in ASCII
    [D] Read chip id (0x16)
    [D] Wrote PSI header
    [D] Wrote PSI, CRC is 0xc8
    [D] Wrote PSI CRC (0xc8)
    [D] Read PSI CRC ACK
    [D] Read PSI ACK
    [D] Sent XMM626 HSIC PSI
    [D] Wrote EBL size
    [D] Wrote EBL, CRC is 0xb5
    [D] Wrote EBL CRC (0xb5)
    [D] Sent XMM626 HSIC EBL
    [D] Read port config
    [D] Sent XMM626 HSIC port config
    [D] Sent XMM626 HSIC SEC start
    [D] Sent XMM626 HSIC firmware
    [D] Checked nv_data path
    [D] Checked nv_data md5 path
    [D] Calculated nv_data md5: 7f6d593d706cf196f16c4ea9efdcf49f
    [D] Read nv_data md5: 7f6d593d706cf196f16c4ea9efdcf49f
    [D] Checked nv_data backup path
    [D] Loaded nv_data
    [D] Sent XMM626 HSIC nv_data
    [D] Sent XMM626 HSIC SEC end
    [D] Sent XMM626 HSIC HW reset
    [D] Waited for host wake
    [D] ENTER xmm626_kernel_linux_modem_hci_power
    [D] xmm626_kernel_linux_modem_hci_power: DONE
    [D] Turned off the modem
    [D] Waited for host wake
    [D] ENTER xmm626_kernel_linux_modem_hci_power
    [D] xmm626_kernel_linux_modem_hci_power: DONE
    [D] Turned the modem on
    Bus 001 Device 002: ID 1519:0020 Comneon HSIC Device
    Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
    [D] Wait for the modem to come up again
    Bus 001 Device 002: ID 1519:0020 Comneon HSIC Device
    Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
    [D] generic_boot complete
    [D] generic_boot DONE
    [D] ENTER generic_open
    [D] ENTER xmm626_kernel_linux_modem_open
    [D] xmm626_kernel_linux_modem_open: client type: FMT
    [D] EXIT xmm626_kernel_linux_modem_open
    [D] generic_open DONE
    [D] ENTER generic_power_on: dummy function
    [1] Starting modem_read_loop on FMT client
    [D] ENTER generic_poll
    [D] generic_poll: poll: 1
    [D] ENTER generic_read
    [D] generic_read DONE
    [D] xmm626_kernel_smdk4412_fmt_recv: Received FMT message
    [D] xmm626_kernel_smdk4412_fmt_recv: Message: aseq=0xff, command=IPC_DISP_RSSI_INFO, type=IPC_TYPE_NOTI, size=1
    [D] ================================= IPC FMT data =================================
    [D] [0000]   45                                                 E
    [D] ================================================================================
    [D] ENTER generic_poll

With the current code, only the 'fd' field of the pollfd 'fd' variable
is set, so events and revents are unitialized.

And since it blocks at generic_poll, this commit can hopefuly fix that
issue.

Signed-off-by: Belgin Stirbu <belginstirbu@hotmail.com>
GNUtoo: commit message
Signed-off-by: Denis 'GNUtoo' Carikli <GNUtoo@cyberdimension.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/samsung-ipc/devices/generic/generic.c b/samsung-ipc/devices/generic/generic.c
index 31fbbea..0cf25d9 100644
--- a/samsung-ipc/devices/generic/generic.c
+++ b/samsung-ipc/devices/generic/generic.c
@@ -692,6 +692,8 @@ int generic_poll(__attribute__((unused)) struct ipc_client *client,
 	int rc;
 	struct pollfd fd;
 
+	memset(&fd, 0, sizeof(fd));
+
 #if GENERIC_DEBUG
 	ipc_client_log(client, "ENTER %s", __func__);
 #endif