Patch "bpftool: JIT limited misreported as negative value on aarch64" has been added to the 5.15-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    bpftool: JIT limited misreported as negative value on aarch64

to the 5.15-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     bpftool-jit-limited-misreported-as-negative-value-on.patch
and it can be found in the queue-5.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit e30ffc7f4944f15844f3fa36e7ee237fb16ea4e6
Author: Alan Maguire <alan.maguire@xxxxxxxxxx>
Date:   Fri May 12 12:31:34 2023 +0100

    bpftool: JIT limited misreported as negative value on aarch64
    
    [ Upstream commit 04cb8453a91c7c22f60ddadb6cef0d19abb33bb5 ]
    
    On aarch64, "bpftool feature" reports an incorrect BPF JIT limit:
    
    $ sudo /sbin/bpftool feature
    Scanning system configuration...
    bpf() syscall restricted to privileged users
    JIT compiler is enabled
    JIT compiler hardening is disabled
    JIT compiler kallsyms exports are enabled for root
    skipping kernel config, can't open file: No such file or directory
    Global memory limit for JIT compiler for unprivileged users is -201326592 bytes
    
    This is because /proc/sys/net/core/bpf_jit_limit reports
    
    $ sudo cat /proc/sys/net/core/bpf_jit_limit
    68169519595520
    
    ...and an int is assumed in read_procfs().  Change read_procfs()
    to return a long to avoid negative value reporting.
    
    Fixes: 7a4522bbef0c ("tools: bpftool: add probes for /proc/ eBPF parameters")
    Reported-by: Nicky Veitch <nicky.veitch@xxxxxxxxxx>
    Signed-off-by: Alan Maguire <alan.maguire@xxxxxxxxxx>
    Signed-off-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
    Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx>
    Acked-by: Quentin Monnet <quentin@xxxxxxxxxxxxx>
    Link: https://lore.kernel.org/bpf/20230512113134.58996-1-alan.maguire@xxxxxxxxxx
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/tools/bpf/bpftool/feature.c b/tools/bpf/bpftool/feature.c
index 7f36385aa9e2e..0c9544c6d3020 100644
--- a/tools/bpf/bpftool/feature.c
+++ b/tools/bpf/bpftool/feature.c
@@ -135,12 +135,12 @@ static void print_end_section(void)
 
 /* Probing functions */
 
-static int read_procfs(const char *path)
+static long read_procfs(const char *path)
 {
 	char *endptr, *line = NULL;
 	size_t len = 0;
 	FILE *fd;
-	int res;
+	long res;
 
 	fd = fopen(path, "r");
 	if (!fd)
@@ -162,7 +162,7 @@ static int read_procfs(const char *path)
 
 static void probe_unprivileged_disabled(void)
 {
-	int res;
+	long res;
 
 	/* No support for C-style ouptut */
 
@@ -181,14 +181,14 @@ static void probe_unprivileged_disabled(void)
 			printf("Unable to retrieve required privileges for bpf() syscall\n");
 			break;
 		default:
-			printf("bpf() syscall restriction has unknown value %d\n", res);
+			printf("bpf() syscall restriction has unknown value %ld\n", res);
 		}
 	}
 }
 
 static void probe_jit_enable(void)
 {
-	int res;
+	long res;
 
 	/* No support for C-style ouptut */
 
@@ -210,7 +210,7 @@ static void probe_jit_enable(void)
 			printf("Unable to retrieve JIT-compiler status\n");
 			break;
 		default:
-			printf("JIT-compiler status has unknown value %d\n",
+			printf("JIT-compiler status has unknown value %ld\n",
 			       res);
 		}
 	}
@@ -218,7 +218,7 @@ static void probe_jit_enable(void)
 
 static void probe_jit_harden(void)
 {
-	int res;
+	long res;
 
 	/* No support for C-style ouptut */
 
@@ -240,7 +240,7 @@ static void probe_jit_harden(void)
 			printf("Unable to retrieve JIT hardening status\n");
 			break;
 		default:
-			printf("JIT hardening status has unknown value %d\n",
+			printf("JIT hardening status has unknown value %ld\n",
 			       res);
 		}
 	}
@@ -248,7 +248,7 @@ static void probe_jit_harden(void)
 
 static void probe_jit_kallsyms(void)
 {
-	int res;
+	long res;
 
 	/* No support for C-style ouptut */
 
@@ -267,14 +267,14 @@ static void probe_jit_kallsyms(void)
 			printf("Unable to retrieve JIT kallsyms export status\n");
 			break;
 		default:
-			printf("JIT kallsyms exports status has unknown value %d\n", res);
+			printf("JIT kallsyms exports status has unknown value %ld\n", res);
 		}
 	}
 }
 
 static void probe_jit_limit(void)
 {
-	int res;
+	long res;
 
 	/* No support for C-style ouptut */
 
@@ -287,7 +287,7 @@ static void probe_jit_limit(void)
 			printf("Unable to retrieve global memory limit for JIT compiler for unprivileged users\n");
 			break;
 		default:
-			printf("Global memory limit for JIT compiler for unprivileged users is %d bytes\n", res);
+			printf("Global memory limit for JIT compiler for unprivileged users is %ld bytes\n", res);
 		}
 	}
 }