From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 From: Khem Raj Date: Tue, 4 Aug 2026 00:00:00 -0700 Subject: [PATCH] lib\/diag: do not use a variable length array in a struct switchtec_osa_capture_data() declares the MRPC reply buffer as a struct whose last member is a VLA: uint32_t entry_dwords[osa_data_entries_out.entries_remaining * 6]; A variably-modified type as a struct member is a GCC extension that clang has never implemented, so the build fails with: lib\/diag.c:2454:12: error: fields must have a constant size: 'variable length array in structure' extension will never be supported v4.3 expressed the same buffer as a flexible array member sized at run time with alloca(), which is portable; that idiom was lost when this function was reworked to fill in a switchtec_osa_capture_data structure. Restore it: declare entry_dwords[] as a flexible array member, allocate the struct with alloca(), and pass the computed size to switchtec_cmd() instead of sizeof() so the reply length is unchanged. Upstream-Status: Pending Signed-off-by: Khem Raj --- diff --git a\/lib\/diag.c b\/lib\/diag.c index 62b2b7d..63769ee 100644 --- a\/lib\/diag.c +++ b\/lib\/diag.c @@ -36,6 +36,7 @@ #include "switchtec\/switchtec.h" #include "switchtec\/utils.h" +#include #include #include #include @@ -2442,7 +2443,7 @@ int switchtec_osa_capture_data(struct switchtec_dev *dev, int stack_id, return ret; } - struct { + struct osa_data_read_out { uint8_t entries_read; uint8_t stack_id; uint8_t lane; @@ -2451,11 +2452,17 @@ int switchtec_osa_capture_data(struct switchtec_dev *dev, int stack_id, uint16_t entries_remaining; uint16_t wrap; uint16_t reserved; - uint32_t entry_dwords[osa_data_entries_out.entries_remaining * 6]; - } osa_data_read_out; + uint32_t entry_dwords[]; + } *osa_data_read_out; + size_t osa_data_read_out_size; + + osa_data_read_out_size = sizeof(*osa_data_read_out) + + osa_data_entries_out.entries_remaining * 6 * + sizeof(uint32_t); + osa_data_read_out = alloca(osa_data_read_out_size); - osa_data_read_out.entries_remaining = osa_data_entries_out.entries_remaining; - osa_data_read_out.next_entry = osa_data_entries_out.next_entry; + osa_data_read_out->entries_remaining = osa_data_entries_out.entries_remaining; + osa_data_read_out->next_entry = osa_data_entries_out.next_entry; if (data) { data->stack_id = stack_id; @@ -2475,31 +2482,31 @@ int switchtec_osa_capture_data(struct switchtec_dev *dev, int stack_id, uint32_t osa_data_dwords[4]; int osa_data_idx = 0; - while (osa_data_read_out.entries_remaining != 0) { + while (osa_data_read_out->entries_remaining != 0) { if (data && total_entries >= SWITCHTEC_OSA_MAX_ENTRIES) break; - osa_data_read_in.num_entries = osa_data_read_out.entries_remaining; - osa_data_read_in.start_entry = osa_data_read_out.next_entry; + osa_data_read_in.num_entries = osa_data_read_out->entries_remaining; + osa_data_read_in.start_entry = osa_data_read_out->next_entry; ret = switchtec_cmd(dev, MRPC_ORDERED_SET_ANALYZER, &osa_data_read_in, sizeof(osa_data_read_in), - &osa_data_read_out, sizeof(osa_data_read_out)); + osa_data_read_out, osa_data_read_out_size); if (ret) return -1; - for (int i = total_dword; i < total_dword + (osa_data_read_out.entries_read * 6); i++) { + for (int i = total_dword; i < total_dword + (osa_data_read_out->entries_read * 6); i++) { if (curr_entry_dword < 4) { - osa_data_dwords[osa_data_idx++] = osa_data_read_out.entry_dwords[i]; + osa_data_dwords[osa_data_idx++] = osa_data_read_out->entry_dwords[i]; } else if (curr_entry_dword == 4) { - timestamp_lower = (osa_data_read_out.entry_dwords[i] >> 22) & 0x3FF; - timestamp_upper = (osa_data_read_out.entry_dwords[i+1] & 0x1A); + timestamp_lower = (osa_data_read_out->entry_dwords[i] >> 22) & 0x3FF; + timestamp_upper = (osa_data_read_out->entry_dwords[i+1] & 0x1A); timestamp = timestamp_upper | timestamp_lower; - link_rate = osa_data_read_out.entry_dwords[i] & 0x3; - counter = (osa_data_read_out.entry_dwords[i] >> 3) & 0x12; - trigger = (osa_data_read_out.entry_dwords[i+1] >> 28) & 0x1; - os_droppped = (osa_data_read_out.entry_dwords[i+1] >> 29) & 0x1; + link_rate = osa_data_read_out->entry_dwords[i] & 0x3; + counter = (osa_data_read_out->entry_dwords[i] >> 3) & 0x12; + trigger = (osa_data_read_out->entry_dwords[i+1] >> 28) & 0x1; + os_droppped = (osa_data_read_out->entry_dwords[i+1] >> 29) & 0x1; if (data && total_entries < SWITCHTEC_OSA_MAX_ENTRIES) { data->entries[total_entries].timestamp = timestamp; @@ -2522,7 +2529,7 @@ int switchtec_osa_capture_data(struct switchtec_dev *dev, int stack_id, curr_entry_dword = 0; } } - total_dword += osa_data_read_out.entries_read; + total_dword += osa_data_read_out->entries_read; } return ret;

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