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tools/javaobjnew: Use MIN macro instead of min function #5406

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merged 1 commit into from
Nov 12, 2025
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tools/javaobjnew: Use MIN macro instead of min function #5406

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5 changes: 4 additions & 1 deletion tools/lib/uobjnew.py
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Original file line number Diff line number Diff line change
Expand Up @@ -92,6 +92,9 @@
#
elif language == "java":
program += """
#ifndef MIN
#define MIN(x, y) ((x) < (y) ? (x) : (y))
#endif
int alloc_entry(struct pt_regs *ctx) {
struct key_t key = {};
struct val_t *valp, zero = {};
Expand All @@ -100,7 +103,7 @@
bpf_usdt_readarg(2, ctx, &classptr);
bpf_usdt_readarg(3, ctx, &length);
bpf_usdt_readarg(4, ctx, &size);
bpf_probe_read_user(&key.name, min(sizeof(key.name), (size_t)length), (void *)classptr);
bpf_probe_read_user(&key.name, MIN(sizeof(key.name), (size_t)length), (void *)classptr);
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@ekyooo ekyooo Oct 13, 2025

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If the content stored in key.name is confirmed to be a NUL-terminated string, would it be possible to replace bpf_probe_read_user with bpf_probe_read_user_str (without the MIN macro)?

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@jeromemarchand jeromemarchand Oct 15, 2025

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I don't know about this one: searching for the object__alloc usdt probe returns surprisingly few results.

Using bpf_probe_read_user_str() seems to work.

valp = allocs.lookup_or_try_init(&key, &zero);
if (valp) {
valp->total_size += size;
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