[PATCH v2 2/2] powerpc/pseries/ras: Use struct_size() to simplify fwnmi_get_errinfo()
From: Thorsten Blum <thorsten.blum@linux.dev>
Date: 2026-06-27 10:48:26
Also in:
lkml
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
Now that struct rtas_error_log uses a flexible array member for the extended log buffer, use struct_size() to calculate the total RTAS error log size and avoid using the hard-coded header size of 8 bytes. Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev> --- Changes in v2: - memcpy_and_pad() cannot be used in real mode; use memset() + memcpy() - v1: https://lore.kernel.org/r/20260626184750.166642-4-thorsten.blum@linux.dev/ (local) --- arch/powerpc/platforms/pseries/ras.c | 16 +++++++--------- 1 file changed, 7 insertions(+), 9 deletions(-)
diff --git a/arch/powerpc/platforms/pseries/ras.c b/arch/powerpc/platforms/pseries/ras.c
index adafd593d9d3..7b8713bdd978 100644
--- a/arch/powerpc/platforms/pseries/ras.c
+++ b/arch/powerpc/platforms/pseries/ras.c@@ -7,6 +7,7 @@ #include <linux/interrupt.h> #include <linux/irq.h> #include <linux/of.h> +#include <linux/overflow.h> #include <linux/fs.h> #include <linux/reboot.h> #include <linux/irq_work.h>
@@ -440,6 +441,8 @@ static __be64 *fwnmi_get_savep(struct pt_regs *regs) static struct rtas_error_log *fwnmi_get_errinfo(struct pt_regs *regs) { struct rtas_error_log *h; + u32 extended_log_length; + size_t len; __be64 *savep; savep = fwnmi_get_savep(regs);
@@ -449,17 +452,12 @@ static struct rtas_error_log *fwnmi_get_errinfo(struct pt_regs *regs) regs->gpr[3] = be64_to_cpu(savep[0]); /* restore original r3 */ h = (struct rtas_error_log *)&savep[1]; + extended_log_length = rtas_error_extended(h) ? rtas_error_extended_log_length(h) : 0; + len = struct_size(h, buffer, extended_log_length); + len = min(len, RTAS_ERROR_LOG_MAX); /* Use the per cpu buffer from paca to store rtas error log */ memset(local_paca->mce_data_buf, 0, RTAS_ERROR_LOG_MAX); - if (!rtas_error_extended(h)) { - memcpy(local_paca->mce_data_buf, h, sizeof(__u64)); - } else { - int len, error_log_length; - - error_log_length = 8 + rtas_error_extended_log_length(h); - len = min_t(int, error_log_length, RTAS_ERROR_LOG_MAX); - memcpy(local_paca->mce_data_buf, h, len); - } + memcpy(local_paca->mce_data_buf, h, len); return (struct rtas_error_log *)local_paca->mce_data_buf; }